Glossary extracted starting with manual seeds, with PTM for the domain gel and language EN
| savanna | the biome found in tropical areas either side of the equatorial zone between 10˚ and 20˚. |
| subtropical high pressure zone | Surface zone of atmospheric high pressure located at about 30° North and South latitude |
| t1 | A contract service provided by a telecommunications company. This will be used in place of MLOS. |
| piezometer | An instrument used to measure pressure head in a conduit, tank, soil, etc |
| synergism | The combined action of several chemicals, which produces a total effect greater than the effects of the chemicals separately. |
| perennial | lit |
| continental margin | The area between a continent's shoreline and the beginning of the ocean floor |
| average annual yield | The average annual supply of water produced by a given stream or water development over a period of 12 months. |
| deindustrialization | fall in the percentage contribution of secondary industry to an economy in terms such as value of input to GDP and importance as an employment sector. |
| hic | The Hydrometeorological Information Center of the Office of Hydrology (OH). |
| unsaturated zone | The area above the water table where soil pores are not fully saturated with water. |
| aqueduct | a pipe, conduit, channel or canal used to transport water, generally by gravity. |
| emergency action plan | A predetermined plan of action to be taken to reduce the potential for property damage and loss of life in an area affected by a dam break or excessive spillway. |
| pollen analysis | the study of preserved pollen particles used to reconstruct past climatic conditions based on the types of plants prevalent at the time. |
| streambank stabilization | Natural geological tendency for a stream to mold its banks to conform with the channel of least resistance to flow |
| dilution ratio | the critical low flow of the receiving water at the point of recycled water discharge divided by the flow of the discharge. Is used in the biomonitoring test to simulate in-stream conditions that organisms will be exposed to during critical low-flow times. |
| subspecies | A population of a species occupying a particular geographic area, or less commonly, a distinct habitat, capable of interbreeding with other populations of the same species. |
| stream segment | refers to the surface waters of an approved planning area exhibiting common biological, chemical, hydrological, natural, and physical characteristics and processes |
| backbar channel | A channel formed behind a bar connected to the main channel but usually at a higher bed elevation than the main channel |
| effective porosity | the portion of pore space in saturated permeable material where the movement of water takes place. |
| phase | A state of matter |
| helical flow | the spiraling flow of water in meandering channels caused by the deflection of flow as water hits the bending banks. |
| recession hydrograph | A Hydrograph which shows the decreasing rate of runoff following a period of rain or snowmelt |
| weir | Usually a barrier constructed to catch upstream migrating adult fish. |
| autogenic recharge | recharge that occurs by falling directly on an aquifer's outcrop at the surface |
| dynamic equilibrium | lack of change in a system as inputs and outputs remain in balance |
| jet stream | A narrow band of strong winds in the atmosphere that controls the movement of high and low pressure systems and associated fronts |
| mid-latitude cyclone | Cyclonic storm that forms primarily in the middle latitudes |
| coefficient of determination | The percentage of variation of the independent variable (y) that is attributed to its linear regression in the dependent variable (x). |
| arid | A term used for an extremely dry climate |
| dissolved load | Portion of the stream load that is in solution in the flowing water. |
| back-building thunderstorm | A thunderstorm in which new development takes place on the upwind side (usually the west or southwest side), such that the storm seems to remain stationary or propagate in a backward direction. |
| solar year | The time it takes the Earth to make one orbit around the Sun |
| homichlophobia | The fear of fog. |
| depth filtration | Treatment process in which the entire filter bed is used to trap insoluble and suspended particles in its voids as water flows through it. |
| mean annual runoff | The average value of all annual runoff amounts usually estimated from the period of record or during a specified base period from a specified area. |
| once-through cooling water | Water (fresh or saline) that is withdrawn from a river, stream or other water body (man-made or natural), or a well, that is passed through a steam condenser one time, and then returned to the stream or water body some distance from the intake |
| cation exchange capacity | The capacity of a soil to exchange cations with the soil solution |
| two-tailed statistical test | Is an inferential statistical test where the values for which one can reject the null hypothesis are located either side of the center of the probability distribution. |
| oregon production index | An annual index to the measurable number of 3-year-old adult coho salmon south of Illwaco, Washington. |
| shingle | the mixture of gravels, pebbles and shell fragments that accumulate on some beaches. |
| drainage area | of a stream at a specified location is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from precipitation normally drains by gravity into the stream above the specified location. |
| vertical-velocity curve | A curve showing how the down-gradient velocity varies with depth along a vertical depth-observation line in a surface stream. |
| hi-tech industry | those industries that have developed since the late 20th century in areas such as electronics, IT, pharmaceuticals etc |
| creek | A small stream of water which serves as the natural drainage course for a drainage basin of nominal, or small size |
| municipal sewage | sewage from a community which may be composed of domestic sewage, industrial wastes or both. |
| first flush | The first portion of a rain event washed out approximately 90% of the pollutants in the first part of a rain event. |
| tail water | the runoff of irrigation water from the lower end of an irrigated field. |
| transect | a line drawn between points and then used to investigate changes in surface features along that line. |
| chlorine-contact chamber | The part of a water treatment plant where effluent is disinfected by chlorine. |
| hygroscopic nuclei | piece of dust or other particle around which water condenses in the atmophere |
| irrigation water management | The use and management of irrigation water where the quantity of water used for each irrigation is determined by the water-holding capacity of the soil and the need for the crop, and where the water is applied at a rate and in such a manner that the crop can use it efficiently and significant erosion does not occur. |
| subbasin planning | See system planning. |
| bank and channel stabilization | Implementation of structural features along a streambank to prevent or reduce bank erosion and channel degradation. |
| management indicator species | (Environmental) A species selected because its welfare is presumed to be an indicator of the welfare of other species in the habitat |
| consumer | two types: |
| ground water barrier | Rock, clay, or other natural or artificial materials with a relatively low permeability that occurs (or is placed) below ground surface, where it impedes the movement of ground water and thus causes a pronounced difference in the heads on opposite sides of the barrier. |
| advisory | Statements that are issued by the National Weather Service for probable weather situations of inconvenience that do not carry the danger of warning criteria, but, if not observed, could lead to hazardous situations |
| scale | A specific relative or proportional size or extent of a phenomena as measured through space and/or time. |
| monsoon | A wind which blow from opposite directions between winter and summer |
| intrusive landform | one produced by the cooling of magma into solid igneous rock within the crust. |
| porous | A condition which allows liquids to pass through. |
| graben fault | This fault is produced when tensional stresses result in the subsidence of a block of rock |
| laterization | Soil forming process that creates a laterite layer. |
| lithosphere | The solid, outer portion of the earth's crust coupled to the rigid upper mantle |
| trap and haul program | A program to collect fish at a given point, transport them to a different point, and release them. |
| joints | natural crack in a rock running vertically between bedding planes. |
| seepage lakes | Lakes whose ecology is determined primarily by ground water rather than surface water. |
| sustainable development | Describes those efforts to guide economic growth, especially in less-developed countries, in an environmentally sound manner, with an emphasis on natural resource conservation. |
| waste treatment plant | A facility containing a series of tanks, screens, filters and other processes by which pollutants are removed from water |
| community water system | In Texas, a public water system which has a potential to serve at least 15 residential service connections on a year-round basis or serves at least 25 residents on a year-round basis. |
| standard deviation | A statistical measure of the dispersion of observation values in a data set |
| injection well | a well constructed for injecting treated wastewater directly into the ground for storage to increase ground water supplies |
| fracture | Any break or rupture formed in an ice cover or floe due to deformation. |
| net pen | A fish rearing enclosure used in lakes and marine areas. |
| natural selection | Environment's influence on the reproductive success of individuals in a population |
| pressure | Force per unit area |
| forebay guidance net | A large net placed in the forebay of a dam to guide juvenile fish away from the powerhouse. |
| dry slot | A zone of dry (and relatively cloud-free) air which wraps east- or northeastward into the southern and eastern parts of a synoptic scale or |
| tidal period | Time it takes for one tidal cycle. |
| prisere | the stages that make up a primary succession. |
| reverse osmosis | A water treatment technique that forces water through a dense membrane to remove impurities. |
| global ocean model | Another global model used by NCEP is the Global Ocean Model |
| dissolved oxygen | The amount of oxygen freely available in water and necessary for aquatic life and the oxidation of organic materials. |
| headwater | the source of a stream or river. |
| binder | Chemicals that hold short fibres together in a cartridge filter. |
| science park | an industrial estate near a university or other research establishment where it is hoped cooperation between business and research can lead to the commercialization of technological advances. |
| monitoring well | (1) A well used to obtain water quality samples or measure groundwater levels |
| combined sewer | A sewer system that carries both sewage and rain water runoff. |
| snow pellets | Precipitation of white, opaque grains of ice |
| duration curve | A cumulative frequency curve that shows the percent of time during which specified units of items (e.g |
| turbidity | "The term ""turbid"" is applied to waters containing suspended matter that interferes with the passage of light through the water or in which visual depth is restricted." |
| filtrate | Liquid that has been passed through a filter. |
| backwater pool | A pool that formed from an eddy along a channel margin as a result of an upstream obstruction like a large tree, rootwad, or boulder. |
| drainage basin | land area where precipitation from surrounding high points runs off into streams, rivers, lakes. Also known as a "watershed". |
| advection | The horizontal transfer of any property in the atmosphere by the movement of air (wind) |
| bailer | An instrument such as a long pipe with a valve at the lower end used to extract a water sample from a groundwater well |
| onshore | a movement from sea to land |
| echo sounder | A device for measuring the depth of water or the depth of an object below the surface by sending pressure waves down from the surface and recording the time until the echo returns from the bottom. |
| shield area | ancient, stable area of crust away from plate margins and therefore unaffected by volcanic or earthquake activity. |
| monsoon | a seasonal prevailing wind |
| coral reef | Ridge of limestone found generally below the ocean surface |
| isohel | A line drawn through geographic points having equal duration of sunshine or another form of solar radiation during a specified time period. |
| zone of saturation | The locus of points below the water table where soil pores are filled with water |
| tailrace | The canal or channel that carries water away from the dam. |
| river channels | Large natural or artificial open streams that continuously or periodically contain moving water, or which form a connection between two bodies of water. |
| newtonian fluid | A fluid which yields to increasing force (stress) at a uniformly increasing rate. |
| filtration | (1) The process in which suspended matter is removed from a liquid through a medium which is permeable to the liquid but not to the suspended material |
| ecology | The study of the factors that influence the distribution and abundance of species. |
| denitrification | the conversion of nitrates to nitrogen in soils by bacteria which thus leaves the soil low in nitrate and therefore less fertile. |
| toxic waste | poisonous by-products of industrial processes which use metals |
| thermoelectric power | Electrical power generated using fossil-fuel (coal, oil, or natural gas), geothermal, or nuclear energy. |
| soil-heat flux | The rate of flow of heat energy into, from, or through the soil. |
| subsurface | Of, relating to, or situated in an area beneath a surface, especially the surface of the earth or of a body of water. |
| zone of aeration | The locus of points just above the water table where soil pores may either contain air or water |
| aquatic ecosystem | Any body of water, such as a stream, lake or estuary, and all organisms and nonliving components within it, functioning as a natural system. |
| secondary treatment | The removal or reduction of contaminants and BOD of effluent from primary wastewater treatment. |
| contour ditch | An irrigation ditch laid out approximately on the contour, or elevation of the land. |
| glacial lake | Proglacial lakes form the angle of the land and the angle of the glacier are opposite or in the superglacial/englacial environment |
| evaporation rate | The quantity of water which evaporates from a given surface per unit of time, usually expressed in inches or depth per day, month, or year. |
| water vapor | Water in gaseous form |
| piedmont glacier | A valley glacier that flows out of a mountainous area onto a gentle slope or plain and spreads out over the surrounding terrain. |
| nitrogen oxides | Consists of two gases nitric oxide (NO) and nitrogen dioxide (NO2) |
| sea-wall | a steel and concrete wall built at the back of a beach, usually to protect a high value land area such as a town. |
| perchloroethylene | a chlorinated solvent commonly used in dry cleaning |
| anabatic wind | A wind that is created by air flowing uphill |
| geologic time scale | see http://www.geosociety.org/science/timescale/timescl.htm |
| non-man entry sewers | Those sewers considered to be too small for manual inspection, survey and work activities (e.g., renovation and repair) |
| saltwater barrier | A physical facility or method of operation designed to prevent the intrusion of saltwater into a body of freshwater. |
| pedestal | A generic radar term for the structure supporting the antenna dish |
| stevenson screen | a white, usually wooden, box with louvre sides and raised on stilts used to hold thermometers at weather recording stations. |
| convective condensation level | The height at which a parcel of air, if heated sufficiently from below, will rise adiabatically until it is just saturated. |
| atoll | a ring-shaped coral reef. |
| priority date | the date of establishment of a water right |
| refraction of waves | The change in the direction of movement of waves which encounter shallow water. See Reflection of Waves. |
| horn | The sharp-pointed, Matterhorn-like mountain peak that remains when several cirques attain their maximum growth by headward erosion and intersect. |
| aspect | direction in which a slope faces. |
| awos | An acronym for Automated Weather Observation System. |
| tidal marsh | low, flat marshlands traversed by channels and tidal hollows, subject to tidal inundation; normally, the only vegetation present is salt-tolerant bushes and grasses. |
| wet microburst | A microburst accompanied by heavy precipitation at the surface |
| hummocked ice | Ice piled haphazardly one piece over another to form an uneven surface. |
| excess rainfall | Effective rainfall in excess of infiltration capacity, resulting in runoff. |
| fold | Wavelike layers in rock strata that are the result of compression. |
| watt | The unit of power in the MKS system of units; energy per unit time, one Joule/second. |
| oxbow | a U-shaped bend in a river or stream that may or may not be cut off from the mainstem. |
| dwell time | Time over which a signal estimate is made |
| drift | material deposited by glacial and fluvioglacial processes. |
| infiltration index | The average rate of infiltration, in inches per hour, derived from a time intensity graph of rainfall, so that the volume of rainfall in excess of this rate equals the total direct runoff |
| nondischarging treatment plant | A treatment plant that does not discharge treated wastewater into any stream or river |
| clarification | Clearing action that occurs during wastewater treatment when solids settle out |
| major flooding | A general term including extensive inundation and property damage |
| pressure release | the removal of overlying rock which releases pressure on underlying strata causing them to expand and crack. |
| clarifier | :A tank in which solids settle to the bottom and are subsequently removed as sludge. |
| business park | purpose-built or redeveloped areas for companies requiring office space rather than industrial space |
| stage | The elevation of the water surface in a stream channel. |
| neutrons | Uncharged building blocks of an atom that play a part in radio-activity |
| indicator organisms | microorganisms, such as coliforms, whose presence is indicative of pollution or of more harmful microorganism. |
| interstadial | a relatively short and temporary period of warming during a glacial |
| sheeting | A form of physical weathering of rock where surface sheets of material fracture and exfoliate because of pressure release |
| ground water system | All the components of subsurface materials that relate to water, including Aquifers (confined and unconfined), Zones of Saturation, and Water Tables. |
| baroclinic zone | A region in which a temperature gradient exists on a constant pressure surface. Baroclinic zones are favored areas for strengthening and weakening systems; barotropic systems, on the other hand, do not exhibit significant changes in intensity. Also, wind shear is characteristic of a baroclinic zone. |
| parent material | The mineral material from which a soil forms. |
| utility | an industry providing a service such as power and water. |
| bathymetric | related to the measurement of water depth within a water body. |
| thematic map | Map that displays the geographical distribution of one phenomenon or the spatial associations that occur between a few phenomena |
| succulent | a plant that has adapted to drought conditions by being able to store water in its stem or leaves. |
| prior appropriation doctrine | The system for allocating water to private individuals used in most Western states |
| sand ripples | Another term used for wind ripples. |
| fossil fuel | coal, oil and gas |
| sinkhole | A pit like hole in found in areas of karst |
| discharge | The rate at which water passes a given point |
| pressure ridge | A discernible rise or ridge, up to 90 feet (30 meters) high and sometimes several miles (kilometers) long, in pressure ice. |
| epilimnion | warm, less dense top layer in a stratified lake |
| tornado warning | This is issued when a tornado is indicated by the WSR-88D radar or sighted by spotters; therefore, people in the affected area should seek safe shelter immediately. They can be issued without a Tornado Watch being already in effect. They are usually issued for a duration of around 30 minutes. |
| olivine | Common silicate mineral found in rocks formed from mafic magma |
| cumuliform | Clouds composed of water droplets that exhibit vertical development |
| primary pollutant | Air pollutants that enter the atmosphere directly |
| sewer service condition | Assessment of the service condition of the sewer, reflecting the sewer conduit's capacity, potential for blockage, and water tightness. |
| ecological niche | Is all of the physical, chemical and biological conditions required by a species for survival, growth and reproduction |
| cryology | The science of the physical aspects of snow, ice, hail, and sleet and other forms of water produced by temperatures below Zero degrees Celsius. |
| biological oxidation | decomposition of complex organic materials by microorganisms |
| methoxychlor | pesticide that causes adverse health effects when found in domestic water supplies |
| pathogenic microorganisms | Microorganisms that can cause disease in other organisms or in humans, animals, and plants. |
| trash rack | A screen located at an intake to prevent debris from entering. |
| field moisture deficiency | The quantity of water, which would be required to restore the soil moisture to field moisture capacity. |
| corrosion | Breakdown of the material (metal) of which a wastewater component is made |
| storm surge | Relatively rapid rise in the height of the ocean along a coastline |
| navigable waters | Traditionally, waters sufficiently deep and wide for navigation by all, or specific sizes of, vessels. |
| brontophobia | The fear of thunder and lightning. |
| probable maximum flood | The largest flood for which there is any reasonable expectancy in a particular climatic era. |
| sludge | A semi-liquid mass of accumulated settled solids deposited from the treatment plant process |
| baseflow | Streamflow which results from precipitation that infiltrates into the soil and it eventually moves through the soil to the stream channel. |
| backflow prevention | Prevention of the flow of any foreign liquids, gases or substances into the distribution pipelines of a potable water supply; accomplished by an air gap or mechanical backflow obstacle. |
| cost | the outlay or expenditure (as of money, effort or sacrifice) made to achieve an object or advantage cost-effective - able at least to pay for itself or make a profit county water authority - a public water district serving a county-wide area cubic foot of water - the amount of water needed to fill a cube that is one foot on all sides; about 7.5 gallons |
| thermal highs | Areas of high pressure that are shallow in vertical extent and are produced primarily by cold surface temperatures. |
| porous | the ability to allow water to occupy pore spaces. |
| microrganisms | Organisms that are so small that they can only be observed through a microscope, for instance bacteria, fungi or yeasts. |
| island arc | A line of volcanic islands found of the ocean that have been created by the convergence of two tectonic plates and the subsequent subduction of one of the plates beneath the other |
| aquiculture | the raising or fattening of fish in enclosed ponds |
| cryopreservation | Preservation of gametes at very low temperature (e.g., use of liquid nitrogen to freeze sperm for later propagative use). |
| dam failure | Catastrophic event characterized by the sudden, rapid, and uncontrolled release of impounded water. |
| underflow | movement of water through subsurface material. |
| esa | The U.S |
| floater | A Wetland plant that floats on the surface of the water. |
| diffusion | spread through space over time |
| brownfield site | a site, either derelict or holding very old buildings, which could be redeveloped for new uses. |
| sea level | refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)--a geodetic datum derived from a general adjustment of the first-order level nets of the United States and Canada, formerly called Sea Level Datum of 1929. |
| kelvin scale | Scale for measuring temperature |
| mostly sunny | When the predominant/average sky condition is covered 1/8 to 2/8 with opaque (not transparent) clouds. Same as Mostly Clear. |
| european central bank | controlling institution of monetary policy for the single European currency -the Euro. |
| condensation | the process of water vapor in the air turning into liquid water, the opposite of evaporation; the water that is condensed. |
| coalescence | Liquid particles in suspension that unite to create particles of a greater volume. |
| permit | (1) (Water Right) A written document which grants authority to take unused water and put it to Beneficial Use |
| calorie | The amount of heat required to raise the temperature of 1 gram of water by 1° Celsius. |
| potential evapotranspiration | Is a measure of the ability of the atmosphere to remove water from the surface through the processes of evaporation and transpiration assuming no limitation on water supply. |
| hydraulic grade line | A line whose plotted ordinate position represents the sum of pressure head plus elevation head for the various positions along a given fluid flow path, such as along a pipeline or a ground water streamline. |
| furrow | A long, narrow, shallow trench made in the ground by a plow for planting and irrigation. |
| dredging | The scooping, or suction of underwater material from a harbor, or waterway |
| prescribed burn | Fire applied to wildland fuels, in a definite place for a specific purpose under exacting weather and fuel conditions (the prescription), to achieve a specific objective of resource management. |
| infrared radiation | Form of electromagnetic radiation with a wavelength between 0.7 and 100 micrometers (µm) |
| gelifluction | a form of mass movement in which thawed upper soil layers move over permafrost. |
| th | Total Hardness |
| flanking line | A line of attached cumulus or towering cumulus clouds of descending height, appearing as stair steps (usually on the southwest side) of the most active part of a supercell. |
| absorption | When a solid takes up molecules into its structure. |
| intermittent stream | A stream that carries water only part of the time, generally in response to periods of heavy runoff either from snowmelt or storms |
| rockfall | Type of mass movement that involves the detachment and movement of a small block of rock from a cliff face to its base |
| shanty town | an area of informal housing built by its residents on the edge of a city |
| instantaneous unit hydrograph | The theoretical, ideal, unit hydrograph that has a infinitesimal duration. |
| competition | Interaction where two or more organisms in the same space require the same resource (e.g., food, water, nesting space, and ground space) which is in limiting supply to the individuals seeking it |
| nva | An acronym for Negative Vorticity Advection. See Negative Vorticity Advection. |
| phosphorous | a plant nutrient that can cause an overabundance of bacteria and algae when high amounts are present, leading to a depletion of oxygen and fish kills |
| vertical wind shear | It is the change in the wind's direction and speed with height |
| syncline | A fold in rock layers that forms a trough-like bend. |
| hydrometeor | A particle of condensed water (liquid, snow, ice, graupel, hail) in the atmosphere. |
| inner-city | the older parts of large urban areas found near to the CBD and containing both residential and industrial landscapes, sometimes integrated |
| fold mountains | mountains produced by folding |
| water table | The level below the earth's surface at which the ground becomes saturated with water |
| hurricane watch | A formal advisory issued by forecasters at the National Hurricane Center when they have determined that hurricane conditions are a potential threat to a coastal area or group of islands within a 24 to 36 hour period |
| flow duration curve | a measure of the range and variability of a stream's flow |
| permit | An authorization, license, or equivalent control document issued by EPA or an approved state agency to implement the requirements of an environmental regulation; e.g |
| inbreeding | Mating or crossing of individuals more closely related that average pairs in the population. |
| swash | the running of water up a beach under the momentum of a breaking wave. |
| natural return ratio | An estimate of the ratio of naturally produced spawners in one generation to total natural spawners (both naturally and hatchery produced) in the previous generation. |
| cathode | A site in electrolysis where cations in solution are neutralized by electrons that plate out on the surface or produce a secondary reaction with water. |
| water resources | The supply of groundwater and surface water in a given area. |
| striations | Grooves of scratches found in surface rock that are the result of glacial abrasion. |
| inland freshwater wetlands | Swamps, marshes, and bogs found inland beyond the coastal saltwater wetlands. |
| saprophyte | an organism which lives off other dead or dying organisms. |
| stagnation | lack of motion in water that holds pollutants in place. |
| rod | A graduated staff used in determining the difference in elevation between two points |
| biofilm | Population of various microrganisms, trapped in a layer of slime and excretion products, attached to a surface. |
| nunatak | a mountain peak rising out from and above an ice sheet. |
| dune field | An extensive region covered by numerous sand dunes. |
| reclamation of wastewater | The process of treating salvaged water from municipal, industrial, or agricultural waste water sources for beneficial uses, whether by means of special facilities or through natural processes. |
| gravity flow | The downhill flow of water through a system of pipes, generated by the force of gravity. |
| stream order | A hydrologic system of stream classification |
| hamada | flat, exposed bedrock in an arid area. |
| outlet discharge structure | A structure built to protect the downstream end of a dam's outlet pipe from erosion and is often designed to slow the velocity of released water to prevent erosion of the stream channel. |
| warning | A product issued by NWS local offices indicating that a particular weather hazard is either imminent or has been reported |
| estuary | a place where fresh and salt water mix, such as a bay, salt marsh, or where a river enters an ocean. |
| drainage basin | the area from which a river channel receives water. |
| silica | most common mineral component of rock. |
| grazing food chain | Model describing the trophic flow of organic energy in a community or ecosystem. |
| free flow | (Hydraulics) Flow through or over a structure not affected by submergence or backwater. |
| cyclone | Area of low pressure in the atmosphere that displays circular inward movement of air |
| length frequency | An arrangement of recorded lengths which indicates the number of times each length or length interval occurs. |
| vapor plumes | flue gases that are visible because they contain water droplets. |
| point bar | Stream bar deposit that is normally located on the inside of a channel bend. |
| high-yield variety | grain crop which has been selectively bred to produce seeds which produce far more than otherwise. |
| swamp | Low, wet land on which grass and trees grow. |
| state revolving funds | a program, capitalized in part by federal funds, that provides low-interest loans for construction of publicly owned wastewater treatment and water recycling facilities, for implementation of nonpoint source and storm drainage pollution control management programs, and for the development and implementation of estuary conservation and management programs. |
| bmps | Methods that have been determined to be the most effective, practical means of preventing or reducing pollution from non-point sources. |
| pressure pipe | Pipe used to distribute potable water throughout the city for fire fighting and domestic purposes. |
| fermentation layer | the lower layer of the litter where decomposition is in progress. |
| life expectancy | average number of years that individuals are expected to live depending on where and when they are born and spend their lives |
| relative abundance | An estimate of actual or absolute abundance; usually stated as some kind of index; for example, as bottom trawl survey stratified mean catch per tow. |
| mlcape | CAPE calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level. See Convective Available Potential Energy (CAPE). |
| catastrophism | the belief that landscape is the result of sudden, catastrophic events, rather than slow, day-to-day processes |
| patterned ground | in periglacial areas, the appearance of lines and polygonal layouts of stones on the surface produced by the sorting of different sizes of material during the expansion and contraction of the soil with diurnal temperature variation. |
| residual flood damages | Those flood damages which are not prevented by a flood plain management program |
| trace of icing | Ice becomes perceptible on an aircraft. The rate of ice accumulation is slightly greater than the rate of sublimation. It is not hazardous even though de-icing/anti-icing equipment is not utilized, unless encountered for an extended period of time--over one hour. This standard of reporting this type of icing was based on a recommendation set forth by the subcommittee for Aviation Meterorological Services in the Office of the Federal Coordinator for Meteorology in November 1968. The convetion has been to designate icing intensity in terms of its operational effect upon reciprocating engine, straight wing transport aircraft as used by commuter operators. |
| inorganic chemicals | Chemical substances of mineral origin, not of basically carbon structure. |
| constant pressure surface | A surface along which the atmospheric pressure is equal everywhere. |
| noctilucent clouds | Rarely seen clouds of tiny ice particles that form approximately 75 to 90 kilometers above the earth's surface |
| groundwater | Generally, all subsurface water as distinct from surface water; specifically, that part of the subsurface water in the saturated zone (a zone in which all voids, large and small, ideally are filled with water under pressure equal to or greater than atmospheric). |
| cliff | A tall steep rock face. |
| slump | See rotational slip. |
| cubic centimeter | The space occupied by one milliliter of water at 20° C and 1 atm; also a cube one centimeter on each side. |
| conurbation | large, effectively continuous urban area produced as urban sprawl leads formerly separate settlements to coalesce. |
| salinity | The concentration of mineral salts dissolved in water |
| cirrus | They are thin, feather like clouds composed entirely of ice crystals |
| detritus food chain | Model describing the conversion of organic energy in a community or ecosystem into inorganic elements and compounds through decomposition |
| hdrain | An Hourly Digital Rainfall Product of the WSR-88D. |
| synchronous detection | Radar processing that retains the received signal amplitude and phase but that removes the intermediate frequency carrier. |
| downdraft | A small-scale column of air that rapidly sinks toward the ground, usually accompanied by precipitation as in a shower or thunderstorm |
| peat | Partially decomposed plants and other organic material that build up in poorly drained wetland habitats. |
| tailrace | The channel that is downstream of the draft tube that carries the water discharged from a turbine |
| solvent | Substances (usually liquid) capable of dissolving or dispersing one or more other substances. |
| bi-polar test | the provision of two opposite views between which strength of feeling can be measured e.g |
| interdependence | the connections between different components of systems or between separate systems which mean that changes in one will necessarily cause changes in another. |
| hydraulic radius | The right cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter |
| mudflow | a fairly rapid mass movement usually occurring after heavy rainfall. |
| ice cliff | Walls of ice where glaciers meet the sea, such as at the edge of land or the edge of an ice shelf. |
| zone of accumulation | Area of a glacier where additions of snow exceed losses of ice from melting, evaporation, and sublimation. |
| light air | Direction of wind shown by smoke drift not by wind vanes |
| fen | A type of wetland that accumulates peat deposits |
| dew point front | A narrow zone (mesoscale feature) of extremely sharp moisture gradient and little temperature gradient |
| evaporation ponds | (Water Quality) Shallow ponds in which sewage sludge is placed to dry and then be removed for further treatment and/or disposal |
| surface water | water that is on the Earth's surface, such as in a stream, river, lake, or reservoir. |
| anomalous propagation | Radio wave propagation that occurs due to non-standard atmospheric conditions |
| bastion | A large or massive rock outcrop which projects forward from a valley wall or icefield. |
| dyke | Thin vertical veins of igneous rock that form when magma enters and cools in fractures found within the crust |
| acid lava | lavas containing high percentage of silica |
| endemic | Native to or limited to a specific region. |
| porosity | The ratio of openings (voids) to the total volume of soil or rock. |
| salt marsh | an area of semi-vegetated tidal mudflat that becomes increasingly vegetated as sediments accumulate in sheltered waters allowing salt-tolerant plants to colonise them. |
| cliff effect | The dramatic alteration in direction of an onshore wind by a cliff face. The offshore equivalent is called the Lee Effect. |
| valve | A device fitted to a pipeline or orifice in which the closure member is either rotated or moved transversely or longitudinally in the waterway so as to control or stop the flow. |
| closed basin | A basin is considered closed with respect to surface flow if its topography prevents the occurrence of visible surface outflow |
| impound | To accumulate and store water as in a reservoir. |
| sea | A sea is a large body of salty water that is often connected to an ocean |
| fitness | The relative ability of an individual (or population) to survive and reproduce (pass on it's genes to the next generation) in a given environment. |
| qpf | A spatial and temporal precipitation forecast that will predict the potential amount of future precipitation for a |
| caisson | (1) A watertight structure within which construction work is carried on under water |
| ecosystem diversity | The variety of species and ecological processes that occur in different physical settings. |
| barrage | An artificial obstruction, such as a dam or an irrigation channel, built in a watercourse to increase its depth or to divert its flow either for navigation or irrigation |
| model | A simulation, by descriptive, statistical, or other means, of a process or project that is difficult or impossible to observe directly. |
| cirque | see corrie |
| knuckles | Slang for lumpy protrusions on the edges, and sometimes the underside, of a thunderstorm anvil |
| katabatic wind | A wind that flows from a glacier, caused by air cooled by the ice becoming heavier than surrounding air, then draining down-valley. |
| thermokarst | Landscape dominated by depressions, pits, and caves that is created by the thawing of ground ice in high latitude locations |
| freezing drizzle | Drizzle, falling as a liquid, but freezing on impact with the colder ground or other exposed surfaces |
| catch | The act of landing a fish at which point the fisher has the option of releasing or retaining it. |
| walker cell | a convectional cell in the tropical South Pacific which generally moves air in an east-west direction and is associated with el Ni?o.. |
| flowing well/spring | a well or spring that taps ground water under pressure so that water rises without pumping |
| spill | Releasing water through the spillway rather than through the turbine units. |
| till plain | A gently irregular plain of till deposited by an actively retreating glacier. |
| geographic range | Spatial distribution of a species |
| maxillae or maxillaries | The upper jaw, the upper jaw bones. |
| free liquids | (Water Quality) Liquids capable of migrating from waste and contaminating ground water |
| fcexec | A component of the NWSRFS FCST Program. |
| datanet | Hydrologic Data Network Analysis Software. |
| jetty | A structure (e.g.; a pier, or mole of wood or stone) extending into a sea, lake, or river to influence the current or tide or to protect a harbor. |
| nonrenewable resources | Natural resources that do not naturally replenish themselves within the limits of human time |
| slush limit | The highest point from which runoff occurs. |
| cb | An acronym for Cumulonimbus. See Cumulonimbus. |
| wind deposition | the return of wind-borne particles to the surface. |
| freshwater | (1) Of, relating to, living in, or consisting of water that is not salty |
| fern | A group of about 11,000 species of vascular seedless plants that belong to the division Pterophyta |
| barotropy | The state of a fluid in which surfaces of constant density or temperature are coincident with surfaces of constant pressure |
| plant | Organisms belonging to the kingdom Plantae |
| warm front | A front that moves in such a way that warm air replaces cold air. |
| isotropic | Having the same characteristics in all directions, as with isotropic antennas |
| third world | see economically less developed countries. |
| normal | A central value (such as an arithmetic average or median) of annual quantities for a 30-year period ending with the first year of a decade, e.g., 1931-1960, 1961-1990. |
| inflow notch | A radar signature characterized by an indentation in the reflectivity pattern on the inflow side of the storm |
| c-band radar | A radar operating in the 3900 to 6200 megahertz range whose wavelength is generally accepted as 5 centimeters |
| emergency action plan | A predetermined plan of action to be taken to reduce the potential for property damage and loss of lives in a downstream area affected by a dam break or excessive spillway discharges. |
| glacial budget | the net result of accumulation and ablation. |
| urban runoff | Storm water from city streets and gutters that usually carries a great deal of litter and organic and bacterial wastes into the sewer systems and receiving waters. |
| renewable resources | flows or living things which are either never-ending or grow quickly enough that their use does not lead to exhaustion. |
| mackerel sky | The name given to cirrocumulus clouds with small vertical extent and composed of ice crystals |
| self-sustaining population | "A population that perpetuates itself, in the absence of (or despite) human intervention, without chronic decline, in its natural ecosystem |
| large-scale | See synoptic-scale. |
| liquid | a state of matter, neither gas nor solid, that flows and takes the shape of its container. |
| minimum discernible signal | In a receiver, it is the smallest input signal that will a produce a detectable signal at the output |
| main stem | The reach of a river/stream formed by the tributaries that flow into it. |
| monitor | To systematically and repeatedly measure conditions in order to track changes. |
| development | use of resources, natural and human, to achieve higher standards of living |
| maximum spillway discharge | Spillway discharge (cfs) when reservoir is at maximum designed water surface elevation. |
| backwater curve | The longitudinal profile of the surface of a liquid in a non-uniform flow in an open channel, when the water surface is not parallel to the invert owing to the depth of water having been increased by the interposition of an obstruction such as a dam or weir |
| pool | A reach of stream that is characterized by deep low velocity water and a smooth surface. |
| high seas forecasts | This National Weather Service (NWS) marine forecast are designed to meet the needs of ships making ocean transits; therefore, the primary focus is on major weather systems and sea states affecting oceangoing vessels. NWS units issuing High Seas Forecasts are the Marine Forecasting Branch of the National Meteorological Center (NMC), the Tropical Satellite Analysis and Forecast Unit of the Tropical Prediction Center (formerly called the National Hurricane Center), and the marine forecast section of the WFO Honolulu. |
| west virginia high | An area of stagnant high pressure located over West Virginia during Indian Summer. |
| permian | Last geologic period in the Paleozoic era |
| restoration | The renewing or repairing of a natural system so that its functions and qualities are comparable to its original, unaltered state. |
| dalmation coast | numerous elongated islands lying just offshore and parallel to the mainland. |
| pangaea | Hypothetical super continent that existed in the geological past |
| meteorology | The scientific study of the atmosphere and its associated phenomena. |
| c horizon | Soil horizon normally found below the B horizon and above the R horizon |
| lacustrine deposits | Stratified materials deposited in lake waters and later become exposed either by the lowering of the water level or by the elevation of the land. |
| producer | two types: in human geography, a company making physical goods from raw materials. physical geography, see autotroph. |
| plain | Plains are flat lands that have only small changes in elevation. |
| anabranch | A diverging branch of a river which re-enters the main stream. |
| orogenesis | The process of mountain building through tectonic forces of compression and volcanism. |
| ice caps | Smaller ice sheets which cap many islands in the Arctic Ocean and in and near Iceland. |
| equilibrium | Equilibrium describes the average condition of a system, as measured through one of its elements or attributes, over a specific period of time. |
| volcanic ash | Small sized particles ejected from explosive volcanoes. |
| forecast point | A location that represents an area (reach of a river), where a forecast is made available to the public |
| lava flow | Stream of lava flowing from a volcanic vent. |
| wildlife refuge | An area designated for the protection of wild animals, within which hunting and fishing are either prohibited or strictly controlled. |
| crop coefficient | The ratio of evapotranspiration occurring with a specific crop at a specific stage of growth to potential evapotranspiration at that time. |
| drainage network | System of interconnected stream channels found in a drainage basin. |
| transmissibility | the capacity of a rock to transmit water under pressure |
| bimetallic thermometer | A temperature measuring devise usually consisting of two dissimilar metals that expand and contract differentially as the temperature changes. |
| peaking | Typically describes the peak water demand for a municipal water system and is expressed as a ratio of the base demand level, e.g., 2:1 peaking represents a peak demand that is twice the base demand. |
| test hole | (Hydraulics) A well hole drilled for experimental or exploratory purposes. |
| hypersaline | lit |
| commuter village | a village near to an urban area where former residents of the urban area have moved to while retaining their original jobs |
| beheaded stream | The lower section of a stream that has lost its upper portion through diversion or Stream Piracy. |
| windward | The direction from which the wind is blowing |
| landfall | The point at which a tropical cyclone's eye first crosses a land mass. |
| irrigation diversion | Generally, a ditch or channel that deflects water from a stream channel for irrigation purposes. |
| unhcr | the United Nations High Commissioner for Refugees |
| continental glacier | Largest type of glacier with a surface coverage in the order of 5 million square kilometers. |
| alberta clipper | A fast moving, snow-producing weather system that originates in the lee of the Canadian Rockies |
| shoreline | The line that separates a land surface from a water body |
| convective clouds | The vertically developed family of clouds are cumulus and cumulonimbus |
| affinity | The keenness with which an ion exchanger takes up and holds on to a counter-ion |
| equilibrium surface discharge | The steady rate of surface discharge which results from a long-continued, steady rate of net rainfall, with discharge rate equal to net rainfall rate. |
| stream | A long narrow channel of water that flows as a function of gravity and elevation across the Earth's surface |
| normal distribution | A common probability distribution displayed by population data |
| ground water divide | A line on a water table where on either side of which the water table slopes downward |
| allogenic recharge | recharge that occurs in a sinking stream, entering an aquifer through sinkholes or fault planes |
| seif | a sand dune found in desert areas where the alignment is with the prevailing wind direction. |
| endogenetic | all factors and processes internal to the Earth. |
| regolith | rock material that has been weathered from the original bedrock |
| catch basin | A sedimentation area designed to remove pollutants from runoff before being discharged into a stream or pond. |
| wet bulb depression | Dependent on the temperature and the humidity of the air, it is the difference between the dry bulb and the wet bulb readings. |
| rate of utilization | Similar to rate of exploitation, except that only the fish landed are considered |
| outwash plain | A flat or gentle sloping surface of glaciofluvial sediments deposited by meltwater streams at the edge of a glacier |
| groundwater | The supply of fresh water found beneath the Earth's surface, usually in aquifers, which supply wells and springs |
| glacial | of or pertaining to: or a cooler period of climate during which glaciers advance (ice age) |
| advisory | 1) Highlights special weather conditions that are less serious than a warning |
| cirque | A bowl-shaped depression carved out of a mountain by an alpine glacier. |
| radar reflectivity factor | z = the sum (over i) of (N_i * D_i^6), where N_i is the number of drops of diameter D_i in a pulse resolution volume |
| effective porosity | The ratio, usually expressed as a percentage, of the volume of water or other liquid which a given saturated volume of rock or soil will yield under any specified hydraulic condition, to the given volume of soil or rock. |
| phylum | A group or category used in the taxonomic and/or phylogenic classification of organisms |
| retrogression | Movement of a weather system in a direction opposite to that of the basic flow in which it is embedded, usually referring to a closed low or a longwave trough which moves westward. |
| indicator species | Species that can be used as a early indicator of environmental degradation to a community or an ecosystem |
| clarke-fisher model | theoretical change in the relative importance of primary, secondary, tertiary and quaternary employment sectors over time as an economy develops from pre-industrial, through industrial to post-industrial stages. |
| mesolow | A mesoscale low-pressure center |
| equator | The equator is an imaginary circle around the earth, halfway between the north and south poles. |
| net duty of water | The amount of water delivered to the land to produce a crop, measured at the point of delivery to the field. |
| levee system | A flood protection system which consists of a levee, or levees, and associated structures, such as closure and drainage devices, which are constructed and operated in accord with sound engineering practices. |
| canopy | A layer of continuous foliage in a forest stand |
| algae | collective name for a group of chlorophyll-containing plants, ranging in size from single cells to stems, including seaweeds and freshwater forms. |
| equilibrium drawdown | The ultimate, constant drawdown for a steady rate of pumped discharge. |
| gully | a deeply eroded channel caused by the concentrated flow of water. |
| mercator projection | Map projection system that presents true compass direction |
| maf | Million acre feet |
| side channel spillway | A spillway whose crest is roughly parallel to the channel immediately downstream of the |
| aquiclude | A formation which contains water but cannot transmit it rapidly enough to furnish a significant supply to a well or spring. |
| meridional transport | Transport of atmospheric and oceanic energy from the equator to the poles. |
| sustainable management | method of exploiting a resource that can be carried on indefinitely |
| specific conductance | a measure of the ability of water to conduct an electrical current as measured using a 1-cm cell and expressed in units of electrical conductance, i.e., Siemens per centimeter at 25 degrees Celsius |
| cross-contamination | a condition created when a drill hole, boring, or improperly constructed well forms a pathway for fluid movement between a saturated zone which contains pollutants and a formerly separated saturated zone containing uncontaminated groundwater |
| turbine | A mechanism in a dam that rotates with the force of water and produces electricity. |
| upstream slope | The part of the dam which is in contact with the reservoir water |
| mixture | Various elements, compounds or both, that are mixed. |
| medial moraines | Concentrations of till in septa dividing ice streams deposits as medial moraines after complete ablation |
| underflow | The lateral motion of water through the upper layers until it enters a stream channel |
| ionizing radiation | The emission of alpha or beta particles or gamma rays from radioisotopes |
| measurement uncertainty | The estimated amount by which the measured quantity may depart from the true value. |
| filter bed | A layer of sand or gravel on the bottom of a reservoir or tank, used to filter water or sewage. |
| adhesion | the molecular attraction asserted between the surfaces of bodies in contact |
| stormwater discharge | precipitation that does not infiltrate into the ground or evaporate due to impervious land surfaces but instead flows onto adjacent land or water areas and is routed into drain/sewer systems. |
| ice islands | Bodies of land ice calved from sheet or shelf. |
| sun pillar | Horizontal ice crystals in the form of plates, which occur in clouds and ice fog near the earth's surface, reflect sunlight into vertical sun pillars for a spectacular display. |
| activated carbon adsorption | the process of pollutants moving out of water and attaching on to activated carbon. |
| watt | A measure of the rate at which energy is produced, exchanged, or consumed. |
| other water use | Water used for such purposes as heating, cooling, irrigation (public-supplied only), lake augmentation, and other nonspecific uses |
| wind gust | They are rapid fluctuations in the wind speed with a variation of 10 knots or more between peaks and lulls |
| ground receive sites | A satellite dish and associated computer which receives signals from the GOES satellite, decodes the information, and transmits it to a another site for further processing |
| water law | A law that has been instigated to control the right to the use of water. |
| degasification | The process of removing dissolved gasses from water, using vacuum or heat. |
| stage | See Gage height |
| roche moutonnee | A feature of glacial erosion that resembles an asymmetrical rock mound |
| cured-in-place | A pipe rehabilitation system in which a flexible lining (either epoxy resin or polyester resin) is inserted into an existing sewer and heat cured |
| convective rain | Rain associated with convective or cumuliform clouds characterized by vertical development in the form of rising mounds, domes, or towers. |
| centrifugation | A separation process, which uses the action of centrifugal force to promote accelerated settling of particles in a solid-liquid mixture. |
| forage fish | Small fish which breed prolifically and serve as food for predatory fish. |
| ground fog | Fog of little vertical extent (usually 20 feet or less). |
| quicksilver water | a solution of mercury nitrate used in gilding. |
| isochrone | A line on a chart connecting equal times of occurrence of an event. In a weather analysis, a sequence plotted on a map of the frontal positions at several different observation times would constitute a set of isochrones. |
| cold desert | Desert found in the high latitudes and at high altitudes where precipitation is low |
| water demand schedule | A time distribution of the demand for prescribed quantities of water for specified purposes |
| photosphere | The intensely bright portion of the sun visible to the unaided eye; the "surface" of the sun |
| transnational corporation | one which operates in more than one country |
| cyclogenesis | Development or intensification of a low-pressure center (cyclone). |
| fresnel scatter | Scatter which occurs if several or many refractive index discontinuities exist along the pointing direction |
| wholesale | the buying of goods in bulk from manufacturers or suppliers, either to be sold on in bulk or to reduce unit costs for retail. |
| membrane | A thin barrier that allows some compounds or liquids to pass through, and troubles others |
| present movement | The best estimate of the movement of the center of a tropical cyclone at a given time and given position. This estimate does not reflect the short-period, small scale oscillations of the cyclone center. |
| high clouds | A term used to signify cirriform clouds that are composed of ice crystals and generally have bases above 20,000 feet |
| aftershock | ground tremors occurring after a major earthquake but associated with the same focus point. |
| snow pellets | A form of precipitation also known as graupel |
| intrusive igneous rock | A mass of igneous rock that forms when magma from the mantle migrates upward and cools and crystallizes near, but not at, the Earth's surface |
| pump | A device which moves, compresses, or alters the pressure of a fluid, such as water or air, being conveyed through a natural or artificial channel. |
| stage iv precipitation processing | The fourth level of precipitation processing, performed automatically and/or interactively at NCEP |
| blowing | A descriptor used to amplify observed weather phenomena (dust, sand, snow, and spray) whenever the phenomena are raised to a height of 6 feet or more above the ground and reduces horizontal visibility to less than 7 statue miles. |
| restoration | The return of an ecosystem to a close approximation of its condition prior to disturbance. |
| slackwater channel | A navigation channel in a canal or river where the water surface elevation is controlled by a dam or dams with locks. |
| biosolids | The organic by-product of wastewater treatment (also called âsludgeâ).Biosolids contain essential plant nutrient and organic matter and are recycled as a fertilizer and soil amendment. |
| active groups | Really fixed ions bolted on to the matrix of an ion exchanger |
| aerobic treatment | process by which microbes decompose complex organic compounds in the presence of oxygen and use the liberated energy for reproduction and growth |
| flat rates | The rate when customers are charged the same amount per bill based on a pre-determined formula (square footage, irrigable area and water-using devices) rather than being charged for actual consumption. |
| wind shear | The rate of wind speed or direction change with distance |
| zone of saturation | Underground region within which all openings are filled with water |
| rotation | The spinning of a body, such as the earth, about its axis. |
| evad | See VAD. |
| indirect discharge | Introduction of pollutants from a non-domestic source into a publicly owned wastewater treatment system |
| hudson bay low | An area of low pressure over or near the Hudson Bay area of Canada that often introduces cold air to the north central and northeast United States. |
| theory | Proposed explanation for the causal mechanisms responsible for a phenomenon or a set of facts |
| deciduous vegetation | Type of vegetation that sheds its leaves during winter or dry seasons |
| reservoir | A body of water collected and stored in an artificial lake behind a dam. |
| cavern | a large underground opening in rock (usually limestone) which occurred when some of the rock was dissolved by water |
| core | The core is a layer rich in iron and nickel found in the interior of the Earth |
| regulation | (Hydrology) The artificial manipulation of the flow of a stream. |
| aggradation | a progressive build up of a channel bed with sediment over several years due to a normal sequence of scour and deposition, as distinguished from the rise and fall of the channel bed during a single flood. |
| potential supply | That part of the resource base that has the potential for development or further expansion. |
| drifting ice | Pieces of floating ice moving under the action of wind and/ or currents. |
| oblique aerial photograph | Photograph taken from a non-perpendicular angle from a platform in the atmosphere. |
| geology | The field of knowledge that studies the origin, structure, chemical composition, and history of the Earth and other planets. |
| interstitial pressure | (Hydraulics) The upward pressure of water in the pores or Interstices of a material. |
| physiographic province | an area with similar characteristics based on geology, soil type, and topography. |
| coherent radar | A radar that utilizes both signal phase and amplitude to determine target characteristics (e.g., velocity, spectrum width). |
| mineralization | (1) The general process by which elements present in organic compounds are eventually converted into inorganic forms, ultimately to become available for a new cycle of plant growth |
| bioremediation | The biological treatment of wastewater and sludge, by inducing the breakdown of organics and hydrocarbons to carbon dioxide and water. |
| hydroelectric power water use | the use of water in the generation of electricity at plants where the turbine generators are driven by falling water. |
| retarding reservoir | Ungated reservoir for temporary storage of flood water. |
| main | A relatively large pipe in a distribution system for drinking water or in a collection system for municipal wastewater |
| farm efficiency | The consumptive crop irrigation requirement divided by the farm delivery. |
| streambed erosion | The movement of material, causing a lowering or widening of a stream at a given point or along a given reach. |
| bathythermograph | A device for obtaining a record of temperature against depth (strictly speaking pressure) in the upper 300 meters of the ocean from a ship underway. Some of these devices are expendable and designated as XBT. |
| urban/small stream flooding | Flooding that occurs after heavy rains of relatively short duration, and it is generally not life threatening |
| water level | (1) An instrument to show the level by means of the surface of water in a trough or in a U-shaped tube |
| collector well | A well located near a surface water supply used to lower the water table and thereby induce infiltration of surface water through the bed of the water body to the well. |
| milligrams per liter | the weight in milligrams of any substance dissolved in one liter of liquid; nearly the same as parts per million by weight. |
| sediment storage | The accumulation, in a reservoir, of sediment that would normally be carried downstream without the project. |
| adjudication | a court proceeding to determine all rights to the use of water on a particular stream system or ground water basin. |
| floodway | The channel of a river or stream and those parts of the adjacent floodplain adjoining the channel that are required to carry and discharge the base flood. |
| ecotourism | maintenance of very small-scale, low density tourist developments, usually in locations where the environment is particularly fragile or sensitive to human activity, so that degradation does not occur in those areas. |
| datacol | The Software System that supports RFC gateway functions. |
| silviculture | The science and practice of controlling the establishment, composition, and growth of the vegetation of forest stands. |
| s-wave | A seismic wave that moves material it encounters perpendicular to its direction of travel |
| military grid reference system | A simplified subset of the Universal Transverse Mercator (UTM) Grid System |
| colonizer plants | the first plants to establish themselves in a virgin environment as the pioneer community. |
| fingerling | Refers to a young fish in its first or second year of life. |
| float recording precipitation gage | A rain gage where the rise of a float within the instrument with increasing rainfall is recorded |
| tributary ground water | Water below the Earth's surface that is physically or hydrologically connected to natural stream water so as to affect its flow whether in movement to or from that stream. |
| sbli | Lifted Index (LI) calculated using surfaced based parcel. See Lifted Index. |
| valley | An area of land that is lower than the land on either side of it. |
| seamount | an undersea volcano in a shield area. |
| vegetative controls | non-point source pollution control practices that utilize vegetative cover to reduce erosion and minimize loss of pollutants. |
| pennsylvanian | a period of geologic time lasing from 320m to 286m years ago. |
| stratiform rain | Horizontally widespread rain, uniform in character, typically associated with macroscale fronts and pressure systems. |
| urban runoff | Storm water from city streets and gutters that usually contains a great deal of litter and organic and bacterial wastes into the sewer systems and receiving waters. |
| dependent variable | one which is directly affected by another e.g |
| nexrad | An acronym that stands for NEXt generation of weather RADar. It is a technologically-advanced weather radar deployed to replace WSR-57 and WSR-74 units |
| climate | General pattern of weather conditions for a region over a long period time (at least 30 years). |
| radionuclide | a radioactive particle, man-made or natural, with a distinct atomic weight number |
| evapotranspiration | the sum of evaporation and transpiration. |
| hydrant | A discharge pipe with a valve and spout at which water may be drawn from a water main (as for fighting fires) called also fireplug; (2) Faucet. |
| chlorine contact chamber | the part of a wastewater treatment plant where treated water is disinfected by chlorine. |
| ecology | The study of the inter-relationships of living things to one another and to the environment. |
| ferrel cell | the mid-latitude cell in the tricellular model of atmospheric circulation. |
| sea smoke | See evaporation fog. |
| carboniferous limestone | a sedimentary rock laid down in the geological period 280-345 million years BP (the Carboniferous period) |
| covariance | A measure of the degree of association between two variables |
| drainage divide | The boundary line, along a topographic ridge or along a subsurface formation, separating two adjacent drainage basins. |
| föhn wind | European equivalent of chinook wind. |
| unknown stock | This description is applied to stocks where there is insufficient information to identify stock origin or stock status with confidence. |
| u.s. geological survey | The Federal Agency chartered in 1879 by congress to classify public lands, and to examine the geologic structure, mineral resources, and products of the national domain |
| river flood warning | This is product is issued by the local National Weather Service Forecast Office (NWFO) when forecast points (those that have formal gaging sites and established flood stages) at specific communities or areas along rivers where flooding has been forecasted, is imminent, or is in progress. Flooding is defined as the inundation of normally dry areas as a result of increased water levels in an established water course. The flood warning is based on the RVF product from the River Forecast Center (RFC) in Minneapolis, Minnesota. The flood warning normally specifies crest information. It usually occurs 6 hours or later after the causative event and it is usually associated with widespread heavy rain and/or snow melt or ice jams. |
| proterozoic | Geologic eon that occurred from 570 to 2500 million years ago |
| zooplankton | tiny aquatic animals eaten by fish. |
| off-site enhancement | The improvement in conditions for fish and wildlife species away from the site or development activities that may have detrimental effects on fish and/or wildlife, as part or total compensation for those effects. |
| difluence | A pattern of wind flow in which air moves outward (in a "fan-out" pattern) away from a central axis that is oriented parallel to the general direction of the flow |
| urban flash flood guidance | A specific type of flash flood guidance which estimates the average amount of rain needed over an urban area during a specified period of time to initiate flooding on small, ungaged streams in the urban area. |
| megalopolis | vast expanse of essentially continuous built-up area created by merging urban centres |
| gaining stream | A river, or reach of a stream or river, that gains flow from ground water seepage or from springs in, or alongside, the channel--sometimes called an effluent stream. |
| hyphae | Thread like structures found on a fungus. |
| float recording precipitation gage | A rain gage where the rise of a float within the instrument with increasing rainfall is recorded |
| carbonate | Compound consisting of a single atom of carbon and three atoms of oxygen |
| heat balance | The equilibrium which exists on the average between the radiation received by the earth and atmosphere from the sun and that emitted by the earth and atmosphere |
| interception | Is the capture of precipitation by the plant canopy and its subsequent return to the atmosphere through evaporation or sublimation |
| wastewater | The used water, liquid waste, or drainage from a community, industry, or institution. |
| treaty indians | Indian tribes with treaties with the US Government which guarantee certain fishing rights on and off the reservations. |
| river gage datum | The arbitrary zero datum elevation which all stage measurements are made from. |
| fjord | A deep glacial trough submerged with seawater. |
| permeability | A measure of the ability of soil, sediments, and rock to transport water horizontally and vertically |
| deis | Draft Environmental Impact Statement. |
| channelization | The artificial enlargement or realignment of a stream channel. |
| oceanic crust | The outer layer of the Earth surface that lies beneath the oceans |
| echo | Energy back scattered from a target (precipitation, clouds, etc.) and received by and displayed on a radar screen. |
| cryptosporidium | A protozoan microbe associated with the disease cryptosporidiosis in man |
| free-flowing | Flowing without artificial restrictions. |
| opec | see Organisation of Oil Exporting Countries. |
| concentration | The amount of material dissolved in a unit of solution, expressed in mg/L. |
| reflected wave | A water wave that reflects off the shore or another obstacle and is redirected towards the sea or lake. |
| dust storm | Severe weather conditions marked by strong winds and dust filled air over an extensive area |
| flood profile | A graph showing the relationship of water surface elevation to location, the latter generally expressed as distance above mouth for a stream of water flowing in an open channel |
| carbonate hardness | Hardness of water caused by carbonate and bicarbonate by-products of calcium and magnesium. |
| overland flow | The topographic movement of a thin film of water from precipitation to lower elevations |
| land reclamation | the improving or recovering or even creation of land for human use |
| mass marking | The marking of all individuals in a population of fish so that individuals can be identified in subsequent life history stages. |
| riparian habitat | Areas adjacent to rivers and streams with a high density, diversity, and productivity of plant and animal species relative to nearby uplands. |
| indirect water uses | Uses of water that are not immediately apparent to the consumer |
| maunder minimum | Period from 1645 to 1715 during which the Sun had very little sunspot activity. |
| market economy | one run on laissez-faire principles. |
| logarithmic scale | 10^x, where x is a number. |
| evapotranspiration | The loss of water from a land area through evaporation from the soil and through plant transpiration. |
| food web | The complex intermeshing of individual food chains in an ecosystem. |
| mainstem | The principle channel of a drainage system into which other smaller streams or rivers flow. |
| flash flood | A flood which follows within a few hours (usually less than 6 hours) of heavy or excessive rainfall, dam or levee failure, or the sudden release of water impounded by an ice jam. |
| rule curves | Water levels, represented graphically as curves, that guide reservoir operations. |
| gyro | A device used for measuring changes in direction |
| shortwave | A disturbance in the mid or upper part of the atmosphere which induces upward motion ahead of it |
| leaching | the process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water. |
| dip | One of the directional properties of a geologic structure such as a fold or a fault |
| usfs | The U.S |
| non-renewable resource | those resources considered to be finite as our rate of use far outstrips the rate at which they are formed e.g |
| livestock water use | water used for livestock watering, feed lots, dairy operations, fish farming, and other on-farm needs. |
| shear wave | A seismic wave that creates wave-like motion perpendicular to the direction of seismic energy propagation |
| topography | The relief exhibited by a surface. |
| thermal low | Area of low pressure in the atmosphere caused by the area having cooler temperatures relative to the air around it. |
| inflow design flood | The maximum probable flood defined as the largest flood that can be expected to occur on a given stream at a selected point |
| disinfection byproducts | halogenated organic chemicals formed when water is disinfected. |
| complex signal | A signal containing both amplitude and phase information. |
| heat advisory | This product is issued by the National Weather Service when excessive heat may pose a hazard or is life threatening if action is not taken. The criteria for this advisory varies from state to state. In Michigan, the criteria is a heat index of 105 degree F or higher for a period of 3 hours or more. |
| tree | A large woody plant that has a trunk which supports branches and leaves. |
| oxbow lake | An abandoned meander isolated from the main stream channel by deposition, and filled with water. |
| coral | Simple marine animals that live symbiotically with algae |
| vascular plant | Plant that has vascular tissues to transport water, nutrients, and other metabolic products. |
| interference | A change in the water level of one well caused by the pumping at another well |
| stratocumulus clouds | Low altitude gray colored cloud composed of water droplets that has a patchy appearance |
| negative-tilt trough | An upper level system which is tilted to the west with increasing latitude (i.e., with an axis from southeast to northwest) |
| temporary wetland | A type of Wetland in which water is present for only part of the year, usually during the wet or rainy seasons (e.g., spring). |
| gas supersaturation | The overabundance of gases in turbulent water, such as at the base of a dam spillway |
| produced water | As crude oil is extracted from a well, the water that comes to the surface with the oil |
| instantaneous rate of mortality | The natural logarithm (with sign changed) of the survival rate |
| heat stroke | Introduced to the body by overexposure to high temperatures, particularly when accompanied by high humidity |
| ocean current | Large scale horizontal flow of ocean water that is persistent and driven by atmospheric circulation. |
| slope failure | The downslope movement of soil and sediment by processes of mass movement. |
| entrainment | the taking up of river sediment into transport. |
| recovery | Action that is necessary to reduce or resolve the threats that caused a species to be listed as threatened or endangered. |
| midstream | The middle part of a stream. |
| macroscale | The meteorological scale covering an area ranging from the size of a continent to the entire globe. |
| moisture convergence | A measure of the degree to which moist air is converging into a given area, taking into account the effect of converging winds and moisture advection |
| hydrologic unit | A geographical area representing part or all of a surface drainage basin or distinct hydrologic feature such as a reservoir, lake, etc. |
| capillary potential | The work required to move a unit mass of water from the reference plane to any point in the soil column. |
| cirque glacier | Small glacier that just occupies a cirque. |
| community boundary | Spatial edge of a unique community. |
| rural settlement | small settlements such as hamlets and villages, up to market towns which are tied to the countryside by function |
| snow density | The mass of snow per unit volume which is equal to the water content of the snow divided by its depth. |
| detention time | The actual time that a small amount of water is in a settling basin or flocculating basin |
| stream gradient | A general slope or rate of change in vertical elevation per unit of horizontal distance of the water surface of a flowing stream. |
| water supply | (1) Any quantity of available water; a Water System |
| inland freshwater wetlands | swamps, marshes, and bogs found inland beyond the coastal saltwater wetlands. |
| mare liberum | A navigable body of water, such as a sea, that is open to navigation by vessels of all nations. |
| nephelococcygia | A term applied when people find familiar objects within the shape of a cloud. |
| residual discharge | Direct surface discharge at the end of a period of excess rain. |
| conservative plate margin | in plate tectonics, a plate boundary where the relative movement of the two crustal plates is lateral, or past each other. |
| fish passage center | Part of the water budget program, the center plans and implements the annual smolt monitoring program; develops and implements flow and spill requests; and monitors and analyzes research results to assist in implementing the water budget |
| marxism | a political theory and/or practice where the emancipation of the working classes through class struggle is seen both as the driving force of history and the goal of modern society |
| cloud streets | Rows of cumulus or cumulus-type clouds aligned parallel to the low-level flow |
| periodic table | Table that describes some of the chemical properties of the known elements. |
| columbia river compact | An interstate compact between the states of Oregon and Washington by which the states jointly regulate fish in the Columbia River. |
| settlement morphology | the pattern and/or shape of a settlement. |
| basal thermal regime | Due to their different basal thermal characteristics, cold-glaciers and warm-glaciers have different basal effects and behaviors. |
| cirrocumulus | They are thin clouds, the individual elements which appear as small white flakes or patches of cotton, usually sowing brilliant and glittering quality suggestive of ice crystals |
| hydrostatic loads | Forces imposed on a flooded structure due to the weight of the water. |
| facultative bacteria | bacteria that can live under aerobic or anaerobic conditions. |
| continental divide | An imaginary boundary line that runs north to south through the Rocky Mountains, separating rivers that flow west to the Pacific Ocean from those that flow south and east toward the Gulf of Mexico and the Atlantic Ocean. |
| leaching | a process where soluble materials such as nutrients or salts in the soil (as well as contaminants) are washed into lower layers of soil or are dissolved and carried away by water. |
| showalter stability index | A measure of the local static stability of the atmosphere |
| impermeable layer | a layer of solid material, such as rock or clay, which does not allow water to pass through. |
| total storage | The volume of storage below the maximum designed water surface level, including Dead Storage. |
| primary succession | the colonization of a previously barren area by a plant community and its development to a climax community. |
| benthic | pertaining to the bottom of a body of water, on or within the bottom substrate material. |
| levee | a natural or man-made earthen obstruction along the edge of a stream, lake, or river |
| altocumulus castellanus | A middle cloud with vertical development that forms from altocumulus clouds |
| hydrostatic pressure | The pressure in a fluid in equilibrium which is due solely to the weight of fluid above. |
| yield-per-recruit | The expected lifetime yield-per-fish of a specific age (e.g., per age 2 individual) |
| headwater advisory table | A table developed by a River Forecast Center for a Headwater Guidance Point; a pre-computed matrix of values allows a forecaster to ascertain an anticipated crest or rise on a small river or stream for a variety of rainfall events and soil moisture conditions. |
| green flash | A brilliant green coloration of the upper edge of the sun, occasionally seen as the sun's apparent disk is about to set below a clear horizon. |
| squall line | A line or narrow band of active thunderstorms |
| drizzle | Fairly uniform precipitation composed exclusively of fine drops with diameters less than 0.02 inch (0.5 mm) which are very close together |
| hydrologic model | A conceptual or physically-based procedure for numerically simulating a process or processes which occur in a watershed. |
| delta | Large deposit of alluvial sediment located at the mouth of a stream where it enters a body of standing water. |
| talus | An accumulation of angular rock debris from rockfalls. |
| hic | 1) Hydrologist in Charge of an RFC |
| basin recharge | Rainfall that adds to the residual moisture of the basin in order to help recharge the water deficit |
| deduction | Inference in which the conclusion about particulars follows necessarily from general theory |
| mces | Metropolitan Council Environmental Services |
| cache site | A secure storage area for equipment. Normally a location owned and operated by user agencies where fire fighting equipment is stored and dispatched when needed. Single agency and multiagency cache site securely store and, upon proper request, dispatch the National Weather Service (NWS) Air Transportable Mobile Unit (ATMU) when needed at the site of an incident. |
| cumulus fractus | Cumulus clouds that appear in irregular fragments, as if they had been shred or torn |
| contour-furrow irrigation | The application of irrigation water in furrows that run across the slope with a forward grade in the furrows. |
| bird | Group of warm blooded vertebrate animals whose body is covered with feathers. |
| depletion curve | in hydraulics, a graphical representation of water depletion from storage stream channels, surface soil, and groundwater |
| slope | The side of a hill or mountain, the inclined face of a cutting, canal or embankment or an inclination from the horizontal. |
| feldspar | A group of common aluminum silicate minerals that contains potassium, sodium, or calcium. |
| pond | A small natural body of standing fresh water filling a surface depression, usually smaller than a lake. |
| raw sludge | The material settled out during the primary clarification of sewage. |
| frontogenesis | The birth or creation of a front |
| flow path | The subsurface course a water molecule or solute would follow in a given ground-water velocity field. |
| beta particle | Electron emitted from the nucleus of a radioactive isotope |
| drawdown | The depression or decline of the water level or potentiometric surface in a pumped well or in nearby wells caused by pumping |
| braiding | Successive division and rejoining of riverflow with accompanying islands. |
| pennsylvanian | Geologic period that occurred roughly 286 to 320 million years ago |
| consent decree remediation deadlines | All construction associated with meeting the terms of the CSO Consent Decree and the First Amended Consent Decrees (FACD) must be completed by November 2007 and July 2014, respectively |
| foresight | A sighting on a point of unknown elevation from an instrument of known elevation |
| biocide | A chemical that is toxic to microrganisms |
| farm surface runoff | A portion of the Farm Headgate Delivery that flows off the lower portion of the farm or field surface (drain ditch) flow |
| altimeter setting | The pressure value to which an aircraft altimeter scale is set so that it will indicate the altitude above mean sea level of an aircraft on the ground at the location for which the value was determined. |
| primary settling tank | (Water Quality) A holding tank where raw sewage or other wastewater is retained to allow the settling and removal of particulate material |
| mesocyclone | It is a sufficiently strong circulation detected on two or more elevation angles which are symmetrically linked within a thunderstorm. It is indicated on the radar display as a thick yellow circle. |
| streambank erosion control | Vegetative or mechanical control of erodible stream banks, including measures to prevent stream banks from caving or sloughing, such as jetties, revetments, riprap and plantings necessary for permanent protection. |
| bowen reaction series | Model that explains the origin of the various types of igneous rocks |
| abiota | Those non-living factors which are present in and affect the characteristics of a given ecosystem. |
| milligrams per liter | a unit of the concentration of a constituent in water or wastewater |
| erratic | A large boulder that a glacier deposits on a surface made of different rock. |
| intertropical convergence zone | An area where the Northern and Southern Hemispheric trade winds converge, usually located between 10 degrees North and South of the equator |
| pacific northwest coordination agreement | An agreement between federal and non federal owners of hydropower generation on the Columbia River system |
| underdrain | A drain that carries away water from prepared beds or agricultural fields to which water or wastewater has been applied. |
| channel lining | Protection of the channel bottom and banks with concrete or Riprap. |
| commensialism | Biological interaction between tospecies where one species benefits in terms of fitness while they other experiences no effect on its fitness. |
| irrigation return flow | Part of irrigation water that is not consumed by evapotranspiration and that drains from the irrigated area to an aquifer or surface water body. |
| aquifuge | A geologic formation which has no interconnected openings and cannot hold or transmit water. |
| greywater | wastewater from clothes washing machines, showers, bathtubs, hand washing, lavatories and sinks. |
| invertebrate drift | Stream and terrestrial invertebrates that float with the current. |
| model output statistics | The Hydrometeorological Center of the National Environmental Prediction Centers (formerly National Meteorological Center) produces a short range (6 to 60 hours) |
| spring | the emergence of water from the ground, usually leading to the formation of a channel flow. |
| confined ground water | A body of ground water covered by material so impervious as to sever the hydraulic connection with overlying ground water except at the intake or recharge area |
| particulate matter | Particles of dust, soot, salt, sulfate compounds, pollen, or other particles suspended in the atmosphere. |
| multidimensional scaling | A nonmetric ordination technique used to visualize genetic relationships among populations in two or three dimensions |
| pou-treatment | Point-Of-Use treatment |
| catch curve | A graph of the logarithm of number of fish taken at successive ages or sizes. |
| coastal waters | The marine area, including bays, harbors, and sounds, from a line approximating the mean high water mark (average height over a 19-year period) along the mainland or near-shore islands out to as much as 100 nautical miles offshore. |
| tropical depression | An organized group of thunderstorms often found over a tropical ocean that generates a cyclonic flow of between 37 and 63 kilometers per hour |
| gross duty of water | (Irrigation) The irrigation water diverted at the intake of a canal system, usually expressed in depth on the irrigable area under the system. |
| csi | An acronym for Conditional Symmetric Instability. See Conditional Symmetric Instability. |
| steam | the vapor phase of water. |
| aquifer | A layer in the soil that is capable of transporting a significant volume of groundwater. |
| capillary rise | The height above a free water surface to which water will rise by Capillary Action. |
| pumped storage | (1) A reservoir that has a pumping plant as the main source of water supply |
| mindel | European glaciation related to North American Kansan glaciation. |
| alkalinity | the measurement of constituents in a water supply which determine alkaline conditions |
| design criteria | The hypothetical flood used in the sizing of the dam and the associated structures to prevent dam failure by overtopping, especially for the spillway, outlet works, channel culvert, and inlet sizing. |
| astrapophobia | The fear of thunder and lightning. See Astraphobia, Brontophobia, Ceraunophobia, Keraunophobia, and Tonitrophobia |
| melting | An endothermic physical process in which solid ice changes into liquid water (0° C at 1 atm) |
| pre-treatment | Processes used to reduce or eliminate wastewater pollutants from before they are discharged. |
| triassic | Geologic period that occurred roughly 208 to 245 million years ago |
| in-line filtration | a pretreatment method in which chemicals are mixed by flowing water; commonly used in pressure filtration installations. |
| civil twilight | The period of time before sunrise and after sunset when the sun is not more than 6 degrees below the horizon. |
| sphere of influence | the area surrounding a settlement which is influenced by it in economic, political and social terms. |
| back door cold front | A cold front moving south or southwest along the Atlantic seaboard and Great Lakes. |
| productivity | the efficiency with which a company turns inputs into outputs. |
| southern oscillation | A periodic reversal of the pressure pattern across the tropical Pacific Ocean during El NiÑo events |
| inner core | Inner region of the Earth's core |
| backscatter | A radar echo that is reflected, or scattered, at 180 degrees to the direction of the incident wave |
| biotransformation | Conversion of a substance into other compounds by organisms; including biodegradation. |
| detritus | 1) the heavier mineral debris moved by natural watercourses, usually in bed-load form |
| potable water | water of a quality suitable for drinking. |
| evaporation pan | A pan used to hold water during observations for the determination of the quantity of evaporation at a given location |
| ethnic segregation | the clustering of people by ethnic group into spacially distinct parts of urban areas. |
| volcanic ash | Fine particles of mineral matter from a volcanic eruption which can be dispersed long distances by winds aloft |
| overbank flows | the component of an instream flow regime that represents infrequent, high flow events that exceed the normal channel |
| availability | 1 |
| social elite | the wealthiest section of society. |
| policy | (Water Planning) A statement of governmental intent against which individual actions and decisions are evaluated |
| riparian land | Land situated along the bank of a stream or other, generally flowing bodies of water. |
| plunge | To thrust or cast oneself into, or as if into, water. |
| hydrocarbon | Organic compounds that are built of carbon and hydrogen atoms and are often used in petroleum industries. |
| low flow frequency curve | A graph showing the magnitude and frequency of minimum flow for a specified period of time (duration). |
| navigational water use | Water utilized as a means of commercial (and sometimes recreational) transportation |
| emigration | Referring to the movement of organisms out of an area |
| nivation | the expansion of a hollow through freeze-thaw under a patch of snow and the subsequent washing out of the debris by meltwater. |
| blackwater | Water that contains waste of humans, animals or food. |
| radioactive | Having the property of releasing radiation. |
| state forecast discussion | This National Weather Service product is intended to provide a well-reasoned discussion of the meteorological thinking which went into the preparation of the Zone Forecast Product. The forecaster will try to focus on the most particular challenges of the forecast. The text will be written in plain language or in proper contractions. At the end of the discussion, there will be a list of all advisories, non-convective watches, and non-convective warnings. The term non-convective refers to weather that is not caused by thunderstorms. Intermediate State Forecast Discussion will be issued when either significant forecast updates are being made or if interesting weather is expected to occur. Most states are going away from this product and more toward the Area Forecast Discussion (AFD). |
| subsequent stream | a tributary created by headward erosion. |
| infiltration/inflow study | Inspection and analysis to identify and understand vulnerabilities in a wastewater system that allow the undesirable ingress of infiltration and inflow into the wastewater system. |
| undercurrent | a current below the upper currents or surface of a fluid body. |
| cycloid scales | Smooth, flat, round scales that have concentric lines called circuli, found on trout, herring, and other fish. |
| pyramid of numbers | Graphical model describing the number of organisms that exist at each trophic level in a community or an ecosystem |
| overthrust fault | Fault produced by the fracturing of rock in a fold because of intense compression. |
| viscosity | lit |
| wildfire | Any free burning uncontainable wildland fire not prescribed for the area which consumes the natural fuels and spreads in response to its environment. |
| pilot report | A report of inflight weather by an aircraft pilot or crew member. A complete coded report includes the following information in this order: location and/or extent of reported weather phenomenon: type of aircraft (only with reports turbulence or icing. |
| parts per million | the number of "parts" by weight of a substance per million parts of water |
| lowland flooding | Inundation of the very lowest portions of floodplain areas near a river, stream or lake, which are normally subject to frequent flooding; usually considered nuisance flooding. |
| snow telemetry | An automated network of snowpack data collection sites |
| differential motion | Cloud motion that appears to differ relative to other nearby cloud elements, e.g |
| runoff | Water which is not absorbed by the soil or landscape to which it is applied |
| bank-full channel width | The top surface width of a stream channel when flowing at a bank-full discharge. |
| water table | The surface of groundwater in the soil. |
| consumptive irrigation requirement | The quantity of irrigation water, exclusive of precipitation, stored soil moisture, or ground water that is required consumptively for crop production. |
| capillary water | (1) Water held in the soil above the Phreatic Surface by capillary forces; or soil water above hydroscopic moisture and below the field capacity |
| residual saturation | saturation level below which fluid drainage will not occur. |
| gravitational water | Water that moves through soil due to gravitational forces |
| colonialism | the establishment of direct rule by one country over another, separate country, fundamentally to improve and protect the economic situation of the dominant power. |
| beach depletion | net loss of sand and/or shingle from a beach due to reduced replenishment while removal processes such as longshore drift continue unabated |
| intensive crops | Crops generally grown under irrigation in the Western United States requiring large inputs of labor and capital |
| weathering | Physical, chemical or biological breakdown of rocks and minerals into smaller sized particles. |
| landscape features | The land, water, vegetation, and structures that compose the characteristic landscape. |
| meteoric water | Water derived from precipitation. |
| forebay | A reservoir or pond situated at the intake of a pumping plant or power plant to stabilize water levels; also, a storage basin for regulating water for percolation into groundwater basins. |
| appropriative rights | "first in time, first in right” principle of allocating water rights based |
| whiteout | When visibility is near zero due to blizzard conditions or occurs on sunless days when clouds and surface snow seem to blend, erasing the horizon and creating a completely white vista. |
| earthquake focus | Point of stress release in an earthquake. |
| dechlorination | Removal of chlorine from treated wastewater before discharge into a receiving stream. |
| water requirement | The total quantity of water, regardless of its source, required for a specified use under a predetermined or prescribed situation. |
| radiometer | General name for an instrument used to measure radiation over a specific wavelength range. |
| ground water hydrology | The branch of hydrology that specializes in ground water; its occurrence and movements; its replenishment and depletion; the properties of rocks that control ground water movement and storage; and the methods of investigation and utilization of ground water. |
| ridge | A line or wall of broken ice forced up by pressure |
| ice fall | An area of crevassed ice on a glacier |
| regional metamorphism | Large scale metamorphic modification of existing rock through the heat and pressure of plutons created at tectonic zones of subduction. |
| resident fish substitutions | The enhancement of resident fish to address losses of salmon and steelhead in those areas permanently blocked to anadromous (ocean migrating) fish as a result of hydroelectric dams. |
| s-band radar | These were in use as network radars in the National Weather Service prior to the installation of the WSR 88-D radars |
| spillway | A structure over or through which excess or flood flows are discharged |
| light icing | The rate of ice accumulation that may create a problem if the flight is prolonged in this environment (over one hour). Occasional use of de-icing equipment removes/prevents accumulation. It does not present a problem if de-icing/anti-icing equipment is used. This standard of reporting this type of icing was based on a recommendation set forth by the subcommittee for Aviation Meterorological Services in the Office of the Federal Coordinator for Meteorology in November 1968. The convetion has been to designate icing intensity in terms of its operational effect upon reciprocating engine, straight wing transport aircraft as used by commuter operators. |
| environmental gradient | Spatial gradient where abiotic and biotic factors vary. |
| nutrient cycle | The cycling of a single element by various abiotic and biotic processes through the various stores found in the biosphere, lithosphere, hydrosphere, and atmosphere. |
| sand sheet | Deposit of sometimes stratified less well sorted sand that almost resemble dunes |
| interceptor sewers | Large sewer lines that, in a combined system, control the flow of sewage to the treatment plant |
| pyrogen | Substance that is produces by bacteria and it fairly stable |
| ground water storage capacity | The space or voids contained in a given volume of soil and rock deposits |
| sublimation | the transition of water directly from the solid state to the gaseous state, without passing through the liquid state; or vice versa |
| market gardening | highly intensive (in capital terms) farming of flowers, fruit and very perishable vegetables on a commercial basis |
| negative correlation | where the rise of one variable corresponds to the fall of another |
| crustal rebound | The earth's crust slowly expands, after the removal of intense confining pressure from the mass of continental ice sheets |
| satellite hydrology program | A NOHRSC program that uses satellite data to generate areal extent of snow cover data over large areas of the western United States. |
| channel bank | The sloping land bordering a channel |
| salinity | usually found in estuaries where the amount of salinity is constantly fluctuating. |
| recycling | Reusing materials and objects in original or changed forms rather than discarding them as wastes. |
| succession | the development of a plant community over time. |
| hybridization | The crossing or mating of two different varieties of plants or animals. |
| urban sprawl | the unchecked spread in the land area occupied by an urban area when development is low-rise and it is felt that space efficiency is not an issue. |
| freeport | an area at a sea or air port where commercial activity is allowed free of any taxation regardless of origins or destinations of goods or profits |
| frontal lifting | Lifting of a warmer or less dense air mass by a colder or more dense air mass at a frontal transitional zone. |
| contour plowing | A soil tilling technique that follows the shape of the land to minimize erosion. |
| current velocity | the velocity of water flow in a stream, measured in units of length per unit of time, such as feet per second (fps). |
| paternoster lakes | A linear series of mountain valley lakes that are formed from glacial erosion |
| replacement rate | the fertility rate required to maintain a population at its current size |
| mwmo | Mississippi Watershed Management Organization |
| duration curve | A cumulative frequency curve that shows the percent of time during which specified units of items (e.g |
| duff layer | The layer of loosely compacted debris underlying the litter layer on the forest floor. |
| coagulation | in water treatment, the use of chemicals to make suspended solids gather or group together into small flocs. |
| explosive deepening | A decrease in the minimum sea-level pressure of a tropical cyclone of 2.5 mb/hr for at least 12 hours or 5 mb/hr for at least six hours. |
| intensive agriculture | the application of high levels of capital and/or labour inputs to units of land area |
| calcification | A dry environment soil-forming process that results in the accumulation of calcium carbonate in surface soil layers. |
| mixed tide | Tides that have a higher high water and lower high water as well as higher low water and lower low water per tidal period. |
| lava | Molten magma released from a volcanic vent or fissure. |
| diorite | A coarse grained igneous rock of intrusive origin that is darker and chemically more mafic than granite. |
| hand watering | The application of water for irrigation purposes through a hand-held hose, including hoses moved into position by hand and left to flow freely or through a shut-off nozzle. |
| in-situ flushing | introduction of large volumes of water, at times supplemented with cleaning compounds, into soil, waste, or groundwater to flush hazardous contaminants from a site. |
| minor flooding | A general term indicating minimal or no property damage but possibly some public inconvenience. |
| basement rock | Very old granite and metamorphic rocks found in continental crust |
| flocculation | (Water Quality) In water and wastewater treatment, the agglomeration or clustering of colloidal and finely divided suspended matter after coagulation by gentle stirring by either mechanical or hydraulic means such that they can be separated from water or sewage. |
| alluvial cone | an alluvial fan with highly steep slopes usually found where mountain streams exit narrow valleys. |
| exit region | The region downstream from a wind speed maximum in a jet stream (jet max), in which air is moving away from the region of maximum winds, and therefore is decelerating |
| siphon spillway | A spillway with one or more siphons built at crest level |
| filter medium | The permeable material that separates solids from liquids passing through it. |
| generalist species | Species that can survive and tolerate a broad range of environmental conditions. |
| man entry sewers | Those sewers considered to be large enough for safe manual (physical) inspection, survey and work activities (e.g., manual renovation and repair) |
| percolation path | The course followed by water moving or percolating through any other permeable material, or under a dam which rests upon a permeable foundation. |
| trophic structure | the feeding relationships among species within a food web. |
| wilderness | areas of land that have never experienced any meaningful human activity. |
| infiltration | The absorption and downward movement of water into the soil layer. |
| abandoned water right | a water right which was not put to beneficial use for a number of years, generally five to seven years. |
| acid neutralizing capacity | Measure of the buffering capacity of water; the ability of water to resist changes in pH. |
| ion | An atom in a solution that is charged, either positively (cations) or negatively (anions). |
| intermediate zone | The subsurface water zone below the Root Zone and above the Capillary Fringe. |
| clear slot | A local region of clearing skies or reduced cloud cover, indicating an intrusion of drier air; often seen as a bright area with higher cloud bases |
| surface erosion | The detachment and transport of soil particles by wind, water, or gravity |
| geography | The study natural and human constructed phenomena relative to a spatial dimension. |
| hydrologic cycle | The natural pathway water follows as it changes between liquid, solid, and gaseous states. |
| forestry | see forest management. |
| squall line | A band of thunderstorm development found ahead of a cold front. |
| bog | Freshwater wetlands that are poorly drained and characterized by a buildup of peat. |
| wet-bulb depression | The value calculated by subtracting a wet-bulb thermometer reading from a dry-bulb thermometer reading |
| polymorphic locus | If different alleles can be detected at a gene locus, the locus is considered to be polymorphic |
| saltation | the transport of load by bouncing along the bed of a river channel. |
| chromosome | Organic structure that carries an organism's genetic code (DNA). |
| reflectivity cross section | This WSR-88D radar product displays a vertical cross section of reflectivity on a grid with heights up to 70,000 feet on the vertical axis and distance up to 124 nm on the horizontal axis. Cross Section is similar to the Range Height Indicator (RHI) slices observed on conventional radar, but it is not limited to alignments along the radar radials. Instead the 2 end points are operator selected anywhere within 124 nm of the radar that are less than 124 nm apart. It is used to: 1) Examine storm structure features such as overhang, tilt, Weak Echo Regions (WER), and Bounded Weak Echo Regions (BWER); 2) Estimate height of higher dBZ's and echo tops; and 3) Locate the bright band (where snow is melting and becoming rain). |
| mean | Statistical measure of central tendency in a set of data |
| flood forecasting | Flood forecasts are primarily the responsibility of the National Weather Service, National Oceanic and Atmospheric Administration (NOAA), and are used to predict flood stages and times and indicate areas subject to flooding. |
| density | a measure of how heavy a specific volume of a solid, liquid, or gas is in comparison to water. |
| freezeup date | Date on which the water body was first observed to be completely frozen over. |
| floating-leaved plants | see aquatic plants. |
| veering wind | It is the clockwise turning of the wind direction as we move up through the atmosphere |
| base flow | sustained flow of a stream in the absence of direct runoff |
| hypothesis testing | Process where an alternative and a null hypothesis are statistically tested for the purpose of falsifying a hypothesis. |
| mid-latitude areas | Areas between 30o and 60o north and south of the Equator. |
| inhibition model of succession | This model of succession suggests that the change in plant species dominance over time is caused by death and small scale disturbances and variations is plant species longevity and ability to disperse |
| total solids | All the solids in wastewater or sewage water, including suspended solids and filterable solids. |
| desertification | Conversion of marginal rangeland or cropland to a more desert like land type |
| radiation | the emission of energy as electromagnetic waves. |
| artificial recharge | an process where water is put back into ground-water storage from surface-water supplies such as irrigation, or induced infiltration from streams or wells. |
| power | A radar equation to describe the amount of power that a radar emits. P = I * V = V * V / R = I * I / R, where I is current (amps), V is voltage (volts), R is resistance (ohms), P is power (watts) |
| visitor-day | See recreation-day. |
| polar high | Surface area of atmospheric high pressure located at about 90° North and South latitude |
| ahos | Automatic Hydrologic Observing System |
| mining | Withdrawal over a period of time of ground water that exceeds the rate of recharge of the aquifer. |
| gradient | Degree of incline; slope of a stream bed |
| convection | Generally, transport of heat and moisture by the movement of a fluid |
| regosol soil | Soil order (type) of the Canadian System of Soil Classification |
| seal | A tight and perfect closure as against the passage of water. |
| sustainable development | development strategies that do not compromise the ability of future generations to meet their needs. |
| dendrite | Snow dendrites are hexagonal ice crystals with complex and often fernlike branches. |
| lateritic soil | Land that consist of minerals that are rich in iron and aluminum compounds, other minerals having been removed by Leaching |
| gulf stream | Warm ocean current that originates in and around the Caribbean and flows across the North Atlantic to northwest Europe. |
| wind couplet | It is an area on the radar display where you have two maximum wind speeds which are blowing in opposite directions. |
| occluded front | A complex frontal system that ideally forms when a cold front overtakes a warm front |
| neutral soil | A soil in which the surface layer, at least to normal plow depth, is neither acid nor alkaline in reaction, approximately 7.0 pH. |
| lid | see Cap Strength |
| flume | (1) A narrow gorge, usually with a stream flowing through it |
| irrigation | Generally, the controlled application of water to arable lands to supply water requirements of crops not satisfied by rainfall |
| climate change | long term variations in climate, particularly related to average annual temperatures and annual rainfall. |
| intermittent stream | one that flows periodically |
| j/kg | Joules per Kilogram. These are the units for CAPE and CIN. See Cape and Cin. |
| smolt | Refers to the salmonid or trout developmental life stage between parr and adult, when the juvenile is at least one year old and has adapted to the marine environment. |
| water consumption | The complete removal of water from some type of source, like groundwater, for some use by humans |
| leaching | the removal of minerals in solution from soils when water moves down through the soil and drains away. |
| landscape impoundment | A body of reclaimed water which is used for aesthetic enjoyment or which otherwise serves a function not intended to include contact recreation. |
| marram grass | a species of grass that is tolerant of dry, sand dune environments |
| low level jet | It often forms at 1-1.5 km under the exit region (the place just ahead of a speed maximum) of an upper-level jet (ULJ) streak |
| third law of thermodynamics | This law states if all the thermal motion of molecules (kinetic energy) could be removed, a state called absolute zero would result and all energy would be randomly distributed. |
| polar jet stream | Relatively fast uniform winds concentrated within the upper atmosphere in a narrow band |
| confluent growth | in coliform testing, abundant or overflowing bacterial growth which makes accurate measurement difficult or impossible. |
| reservoir | a pond or lake where water is collected and stored until it is needed rills - small grooves, furrows, or channels in soil made by water flowing down over its surface; also another name for a stream - usually a small stream runoff - liquid water that travels over the surface of the Earth, moving downward due to the law of gravity; runoff is one way in which water that falls as precipitation returns to the ocean |
| discharge table | 1) A table showing the relation between two mutually dependent quantities or variable over a given range of magnitude |
| initial water deficiency | The quantity, usually expressed in depth of water in inches upon a unit area, by which the actual water content of a given soil zone (usually the root zone) in such area is less than the field capacity of such zone at the beginning of the rainy season |
| rainfall intensity frequency | The average time interval between the occurrence of the rainfall or precipitation of a given or greater intensity. |
| deregulation | the removal of rules, regulations and laws previously imposed on an industry |
| chemical autotroph | Organism that uses the external energy found in chemical compounds to produce food molecules |
| tropical | of the tropics, commonly relating to areas between them. |
| descaling | A condition in which a fish has lost a certain percentage of scales. |
| cloud seeding | attempt to create or grow clouds by the introduction of condensation nuclei in order to cause greater precipitation. |
| haystack | A vertical standing wave in turbulent river waters. |
| evaporation | sublimation, vapourization, transpiration, evapotranspiration). |
| permian | a period of geologic time lasting from 286m to 245m years ago. |
| isobar | Lines of equal barometric pressure as shown on a weather map. |
| elutriation | Freeing sludge of its mother liquor by washing it with water. |
| relative greenness maps | These maps portray how green the vegetation is compared to how green it has been historically (since 1989) |
| hydraulic permeability | The flow of water through a unit cross-sectional area of soil normal to the direction of flow when the hydraulic gradient is unity. |
| cutoff | where the stream cuts through the neck of a meander bend. |
| potential vorticity | This plays an important role in the generation of vorticity in cyclogenesis, especially along the polar front |
| contaminant | Any foreign component in a substance, for example in water. |
| meniscus | The curved surface of the liquid at the open end of a capillary column. |
| maritime air mass | An air mass influenced by the sea |
| index of wetness | The ratio of precipitation for a given year over the mean annual precipitation. |
| nitrous oxide | Gas found in the atmosphere that contributes to the greenhouse effect |
| kinetic energy | Energy possessed by moving water. |
| anticipated convection | The Day 1 and Day 2 Convective outlooks issued by the Storm Prediction Center in Norman, Oklahoma. The term originates from the header coding (ACUS1) of the transmitted product. |
| north atlantic drift | the name for the warm ocean current in the North-East Atlantic that originates in the Caribbean as the Gulf Stream. |
| food and agricultural organisation | an agency of the United Nations charged with eradicating hunger and malnutrition globally. |
| phreatic water | Water within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table |
| nonpoint source | source of pollution in which wastes are not released at one specific, identifiable point but from a number of points that are spread out and difficult to identify and control |
| secondary treatment | Treatment of wastewater to a non-Potable level so that it may be returned to the stream |
| nongame wildlife | All wild vertebrate and invertebrate animals not subject to sport hunting. |
| infiltration capacity | The ability of a soil to absorb surface water. |
| european currency unit | the forerunner of the Euro, this was a stable means of exchange between the former national currencies as they prepared to give way to the single currency. |
| towering cumulus | Another name for cumulus congestus, it is a rapidly growing cumulus or an individual dome-shaped clouds whose height exceeds its width |
| qpf discussion | This Meteorological Operations Division (MOD) forecast discussion is directed completely to explaining manual forecasts of areas in the contiguous 48 states expected to receive 1/4 inch or more precipitation during a 24-hour period. The manual forecasts are explained in terms of initial conditions and differences and/or similarities in the numerical model forecasts. General confidence in the manual forecast is expressed where it is appropriate and possible alternatives may be offered. This product is issued 3 times a day as described below: |
| humid | Containing or characterized by perceptible moisture |
| cloud bank | A well-defined cloud mass that can be observed at a distance |
| hydrologic balance | An accounting of all water inflow to, water outflow from, and changes in water storage within a hydrologic unit over a specified period of time. |
| variance | A measure of variability. |
| scenic rivers | Rivers or sections of rivers that are free of impoundments, with shoreline and watersheds still largely primitive, and shorelines largely undeveloped, but accessible in places by roads. |
| brash ice | Accumulation of floating ice made up of fragments not more than 2 meters across; the wreckage of other forms of ice. |
| hydrolysis | The splitting (lysis) of a compound by a reaction with water |
| impervious surface | A surface that does not allow water or other liquids to pass through it (for example, pavement). |
| aerobic | A process that takes place in the presence of oxygen, such as the digestion of organic matter by bacteria in an oxidation pond. |
| substation | A location where observations are taken or other services are furnished by people not located at NWS offices who do not need to be certified to take observations. |
| free-floating plants | see aquatic plants. |
| bermuda high | High pressure system that develops over the western subtropical North Atlantic |
| flood crest | The maximum stage or elevation reached by the waters of a flood at a given location. |
| impoundment | a body of water such as a pond, confined by a dam, dike, floodgate or other barrier |
| sediments | generally referring to algae. |
| angler day | One person angling for any part of 1 day. |
| net primary productivity | the amount of organic material available for consumption in a given area |
| capillary action | A function of hydrogen bonding in the water molecule results in the movement of water into small openings due to the attraction between the liquid and the walls of the opening |
| thermal equator | Continuous area on the globe that has the highest surface temperatures because of the presence of the Intertropical Convergence Zone. |
| rainfall intensity-duration-frequency curve | Curves showing the relationship between rainfall or precipitation intensity and duration for different levels of frequency; each curve represents the rainfall intensity-duration which will be equaled or exceeded once in a certain number of years, indicated as the frequency of that curve. |
| estuarine zone | The area near the coastline that consists of estuaries and coastal saltwater wetlands. |
| cloud tags | Ragged, detached cloud fragments; fractus or scud. |
| supply management | Methods by which a utility maximizes use of available untreated water. |
| trans-basin diversion | The conveyance of water from its natural basin into another basin. |
| stream gradient | The change in elevation from a stream's headwaters to its mouth expressed in degrees, percentage, or as a distance ratio (rise/run). |
| delta | A fan-shaped alluvial deposit at a river mouth formed by the deposition of successive layers of sediment. |
| deuterium | Isotope of hydrogen, with a nucleus containing one proton and one neutron, and an atomic mass number of 2. |
| grade stabilization structure | A structure for the purpose of stabilizing the grade of a gully or other watercourse, thereby preventing further head-cutting or lowering of the channel grade. |
| disinfectants | Fluids or gasses to disinfect filters, pipelines, systems, etc. |
| distillation | Water treatment method where water is boiled to steam and condensed in a separate reservoir |
| stratus fractus | Stratus clouds that appear in irregular fragments, as if they had been shred or torn |
| sand dune | A hill or ridge of aeolian sand deposits with a minimum height of less than one meter and a maximum height of about 50 meters |
| tectonics | See plate tectonics. |
| eluviation | Movement of humus, chemical substances, and mineral particles from the upper layers of a soil to lower layers by the downward movement of water through the soil profile |
| draft | the act of drawing or removing water from a tank, reservoir or groundwater supply. |
| nonconsumptive use | using water in a way that does not reduce the supply |
| interspecific competition | The condition of rivalry that exists when a number of organisms of different species use common resources. |
| dew | Condensation in the form of small water drops that forms on grass and other small objects near the ground when the temperature has fallen to the dew point, generally during the nighttime hours. |
| tonitrophobia | The fear of thunder. See Astraphobia, Astrapophobia, Brontophobia, Ceraunophobia, and Keraunophobia. |
| left mover | A thunderstorm which moves to the left relative to the steering winds, and to other nearby thunderstorms; often the northern part of a splitting storm |
| attenuation | The process of reduction of a compound's concentration over time |
| vapor | The gas given off by substances that are solids or liquids at ordinary atmospheric pressure and temperatures. |
| biodiversity | The diversity of different species (species diversity), genetic variability among individuals within each species (genetic diversity), and variety of ecosystems (ecosystem diversity) |
| entrepreneur | a risk taker in the business world |
| permeability | the ability of a water bearing material to transmit water |
| overstory | Trees that provide the uppermost layer of foliage in a forest with more that one roughly horizontal layer of foliage. |
| aerobic | Characterizing organisms able to live only in the presence of air or free oxygen, and conditions that exist only in the presence of air or free oxygen |
| wind shift line | A long, but narrow axis across which the winds change direction (usually veer). |
| embeddedness | The degree to which dirt is mixed in with spawning gravel. |
| nadir | The point on any given observer's celestial sphere diametrically opposite of one's zenith. |
| speed of light | Velocity of light in a vacuum |
| base data | Those digital fields of reflectivity, mean radial velocity, and spectrum width data in spherical coordinates provided at the finest resolution available from the radar. |
| oxbow | An abandoned meander in a river or stream, caused by neck cutoff |
| levee | A long, narrow embankment usually built to protect land from flooding |
| datanet | Hydrologic Data Network Analysis Software |
| gage zero | The elevation of zero stage |
| water use efficiency | A measure of the crop production per unit of water used, irrespective of water source, expressed in units of weight per unit of water depth per unit area |
| moderate icing | The rate of ice accumulation on an aircraft is such that even short encounters becomes potentially hazardous and the use of de-icing/anti-icing equipment or a diversion is necessary. This standard of reporting this type of icing was based on a recommendation set forth by the subcommittee for Aviation Meterorological Services in the Office of the Federal Coordinator for Meteorology in November 1968. The convetion has been to designate icing intensity in terms of its operational effect upon reciprocating engine, straight wing transport aircraft as used by commuter operators. |
| solute | Matter dissolved in a liquid, such as water. |
| european free trade association | established in 1959 to rival the EEC |
| hemisphere | half of a sphere; half of the earth |
| river system | All of the streams and channels draining a river basin. |
| condensation | The process by which a vapour becomes a liquid or solid; the opposite of evaporation |
| nacreous clouds | Clouds of unknown composition that have a soft, pearly luster and that form at altitudes about 25 to 30 km above the Earth's surface |
| ground water flow | Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel |
| energy content curves | A set of curves that establishes limits on the amount of reservoir draw-down permitted to produce energy in excess of FELCC. |
| powerhouse | A primary part of a hydroelectric dam where the turbines and generators are housed and where power is produced by falling water rotating turbine blades. |
| bedrock | the solid rock beneath the soil and superficial rock |
| medial moraine | Deposit of material found down the center of a glacier |
| reservoir | A manmade facility for the storage, regulation and controlled release of water. |
| evaporation | The physical process by which a liquid, such as water is transformed into a gaseous state, such as water vapor |
| storm hydrograph | A hydrograph representing the total flow or discharge past a point. |
| soil profile | the variation in soil characteristics through its depth. |
| curvature | The reciprocal of the radius of a circle; the rate of change in the deviation of a given arc from any tangent to it. |
| ph | Scale used to measure the alkalinity or acidity of a substance through the determination of the concentration of hydrogen ions in solution |
| latent heat | (1) The quantity of heat absorbed or released by a substance undergoing a change of state, such as ice changing to water or water to steam, at constant temperature and pressure |
| desertification | the spread of desert, or desert conditions, from an established desert area into the surrounding area |
| river recreation statement | A statement released by the NWS to inform river users of current and forecast river and lake conditions |
| stage iii precipitation processing | The third level of precipitation processing, performed interactively at RFCs |
| aqueous | Something made up of water. |
| glaciofluvial | Geomorphic feature whose origin is related to the processes associated with glacial meltwater. |
| pacific rim | the countries at the margins of the Pacific ocean. |
| lfws | A generic term for any type of Local Flood Warning System. |
| big crunch | Collapse of the Universe into its original form before the Big Bang |
| percolation rate | The rate, usually expressed as a velocity , at which water moves through saturated granular material |
| siberian high | High pressure system that develops in winter over northern central Asia. |
| baseline | A quantitative level or value from which other data and observations of a comparable nature are referenced |
| isallobar | A line of equal change in atmospheric pressure during a specified time period. |
| water recycling | Using water again for the same or another process step, after a small form of purification is applied. |
| population density | Number of individuals of a particular species found in a specified area. |
| nexrad base data | Those digital fields of reflectivity, mean radial velocity and spectrum width data in spherical coordinates provided at the finest resolution available. |
| protoplasm | Substances making up a cell including its exterior membrane. |
| law of basin areas | Morphometric relationship observed in the mean basin area size of stream segments of a particular classification order in stream channel branching |
| hinterland | (also periphery) the area surrounding a core settlement from which the settlement gains resources. |
| dapm | The Data Acquisition Program Manager. |
| usfs | The U.S |
| dendritic | Term used to describe the stream channel pattern that is completely random |
| uvm | An acronym for Upward Vertical Motion. |
| nivation | Process where snow patches initiate erosion through physical weathering, meltwater flow, and gelifluction. |
| aqueduct | a pipe, conduit, or channel designed to transport water from a remote source, usually by gravity. |
| monitoring well | a well used to obtain water quality samples or measure groundwater levels. |
| solar constant | A term used to describe the average quantity of solar insolation received by a horizontal surface at the edge of the Earth's atmosphere |
| polar orbiting satellite | A weather satellite which travels over both poles each time it orbits the Earth |
| fault scarp | The section of the fault plane exposed in a fault |
| argon | A colorless, odorless inert gas that is the third most abundant constituent of dry air, comprising 0.93% of the total. |
| ionosphere | A complex atmospheric zone of ionized gases that extends between 50 and 400 miles (80 to 640 kilometers) above the earth's surface |
| sinkhole | a depression in the Earth's surface caused by dissolving of underlying limestone, salt, or gypsum |
| 3-dimensional correlated shear | It is a sufficiently strong circulation detected on two or more elevation angles within a thunderstorm, but less than two of the features are symmetrical. It is displayed on the radar display as a thin yellow circle. |
| lined waterway or outlet | A waterway or outlet with an erosion-resistant lining of concrete, stone, or other permanent material |
| pitch | In climbing, a unit of measure approximately equal to the length of your rope, or the distance between fixed anchor positions |
| ahos-t | Automatic Hydrologic Observing System - Telephone |
| entropy | Entropy is the measure of the disorder or randomness of energy and matter in a system. |
| potential rate of evaporation | The rate of evaporation under the existing atmospheric conditions from a surface of water that is chemically pure and has the temperature of the atmosphere. |
| lock | A chambered structure on a waterway closed off with gates for the purpose of raising or lowering the water level within the lock chamber so ships, boats, and tugs/barges can move from one elevation to another along the waterway. |
| extratropical | A term used in advisories and tropical summaries to indicate that a cyclone has lost its "tropical" characteristics |
| pathogens | Disease-producing microrganisms. |
| high | A region of high pressure, marked as "H" on a weather map. A high is usually associated with fair weather. See Anticyclone. |
| influent seepage | Movement of gravity water in the zone of aeration from the ground surface toward the water table. |
| insulated streams | Streams or a reach of a stream that neither contribute water to the zone of saturation nor receive water from it |
| heat island | the warm air found around and above an urban area, distinct from the air temperature above the surrounding rural land. |
| bolson | An alluvium-floored basin, depression, or wide valley, mostly surrounded by mountains and drained by a system that has no surface outlet |
| tcu | An acronym for Towering Cumulus. See Towering Cumulus. |
| dissolved oxygen | The amount of free (not chemically combined) oxygen dissolved in water, wastewater, or other liquid, usually expressed in milligrams per liter, parts per million, or percent of saturation. |
| outflow channel | A natural stream channel that transports reservoir releases. |
| riparian zone | A stream and all the vegetation on its banks. |
| residual detention storage | Detention storage existing at the end of a period of excess rain. |
| type s coho | A coho stock that rears in ocean waters off the mouth of the Columbia River and southerly to northern California. |
| reforestation | The natural or artificial restocking of an area with forested trees. |
| firn limit | The lower boundary of the zone of accumulation on a glacier where snow accumulates on an annual basis |
| anemometer | An instrument used for measuring the speed of the wind. |
| fcexec | A component of the NWSRFS FCST Program. |
| glacial portal | Cavernous openings in subglacial ice and debris above meltwater streams. |
| phasor diagram | A diagram used to represent complex numbers |
| topographic profile | A two-dimensional diagram that describes the landscape in vertical cross-section. |
| raindrop | A drop of rain. |
| genetic introgression | The entry or introduction of a gene from one gene complex into another, as in introgressive hybridization, which is the spread of genes of one species into the gene complex of another as a result of hybridization between numerically dissimilar populations in which extensive backcrossing prevents formation of a single stable population. |
| epicentre | the point on the surface directly above the focus of an earthquake. |
| site | the point at which a settlement is located. |
| sub-glacial | lit |
| length | The distance in the direction of flow between two specific points along a river, stream, or channel. |
| ph | The negative logarithm of the molar concentration of the hydrogen ion, or, more simply acidity. |
| depression | In meteorology, it is another name for an area of low pressure, a low, or trough |
| thalweg | The line of maximum depth in a stream |
| tertiary treatment | Advanced cleaning of wastewater that goes beyond the secondary or biological stage, removing nutrients such as phosphorus, nitrogen, and most BOD and suspended solids. |
| special fire weather | Meteorological services uniquely required by user agencies which cannot be provided at an NWS office during normal working hours. Examples are on-site support, weather observer training, and participation in user agency training activities. |
| forest fragmentation | The change in the forest landscape, from extensive and continuous forests of old-growth to mosaic of younger stand conditions. |
| gabion | A wire basket or cage that is filled with gravel and generally used to stabilize stream banks and improve degraded aquatic habitat. |
| underpopulation | when the population is not sufficient to make full use of all the resources available and so standards of living are not as high as they could be. |
| candle filter | A relatively coarse aperture filter, designed to retain a coat of filter medium on an extended surface. |
| calcium carbonate | Compound consisting of calcium and carbonate |
| run-off | That part of precipitation, snow melt, or irrigation water that runs off the land into streams or other surface water |
| fetch | distance wind has travelled over open water to create waves. |
| pitting | The construction of pits or basins of suitable capacity and distribution to retain water and increase infiltration on rangeland. |
| pipebursting | A system by which a burster unit splits the existing pipe while simultaneously installing a new polyethylene pipe |
| disaster awareness | All local National Weather Service Offices (NWSFO or NWFO) are responsible for public safety education, cooperation with outside agencies and organizations, and providing assistance to communities and counties in their county warning area (CWA) regarding the development of local warning systems and spotter networks. |
| delmarva | An acronym for Delaware/Maryland/Virginia. |
| pup | This is where the WSR-88D radar operator will call up and look at the various products that the RPG produces. Some of the products that the radar operator will look at are in the last section of this report. |
| submersible traveling screen | A wire mesh screen that acts like a conveyor belt when installed in the intakes of turbines at dams guiding and transporting juvenile fish into bypass channels. |
| orographic uplift | Uplift of an air mass because of a topographic obstruction |
| critical slope | That slope that will sustain a given discharge at uniform, Critical Depth in a given channel. |
| cold advection | The horizontal movement of colder air into a location |
| tidal flats | Saltwater wetlands that are characterized by mud or sand and daily tidal fluctuations. |
| hydrologic service area | A geographical area assigned to Weather Service Forecast Office's/Weather Forecast Office's that embraces one or more rivers. |
| till | Many writers use till for any glacial deposit |
| tertiary | a period of geologic time lasting from 65m to 1.6m years ago. |
| physiological | Pertaining to the functions and vital processes of living organisms and the organs within them. |
| tidal cycle | The periodic changes in the intensity of tides caused primarily by the varying relations between the earth, moon, and sun. |
| hydrolysis | Chemical weathering process that involves the reaction between mineral ions and the ions of water (OH- and H+), and results in the decomposition of the rock surface by forming new compounds, and by increasing the pH of the solution involve through the release of the hydroxide ions. |
| jetty | a structure (as a pier or mole of wood or stone) extending into a sea, lake, or river to influence the current or tide or to protect a harbor. |
| continental shelf | The zone around the continents extending from the low-water mark seaward, typically ending in steep slope to the depths of the ocean floor. |
| stoss | the exposed side of a slope. |
| on-site | Usually refers to projects or activities designed to address harm caused to fish and wildlife at the site of the harm. |
| permeability | The ability of a material to transmit fluid through its pores when subjected to a difference in head. |
| instream use | Use of water that does not require diversion from its natural watercourse |
| potentiometric surface | A surface which represents the static head of ground water in tightly cased wells that tap a water-bearing rock unit (i.e., aquifer) |
| gully | A deeply eroded channel created by the concentrated flow of water. |
| evapotranspiration | Combination of evaporation from free water surfaces and transpiration of water from plant surfaces to the atmosphere. |
| surface tension | the attraction of molecules to each other on a liquid's surface |
| gravel | See cobble. |
| straight-line hodograph | The name pretty well describes what it looks like on the hodograph |
| terminal spill | Refers to those releases made at the terminal ends of the project conveyance or reservoir system |
| soil organic matter | Organic constituents of soil. |
| barograph | A recording barometer. |
| gymnosperm | Plant that bears naked seeds |
| meteorology | the study of the atmosphere. |
| leaf drip | The rain water that fall to the ground surface from plant leaves after it has been intercepted by these structures. |
| mudflow | Form of mass movement where fine textured sediments and soil mix with water to create a liquid flow. |
| captive brood stock | Fish raised and spawned in captivity. |
| low-water mark | The lowest level attained by a varying water surface level. |
| reservoir volume | The volume of a reservoir when filled to normal pool or water level. |
| median particle size | value for which half the particles in a sample have a greater diameter and half a lesser diameter. |
| fall overturn | A physical phenomenon that may take place in a body of water during early autumn |
| mountain | A mountain is a very tall high, natural place on Earth - higher than a hill |
| combined sewer overflow | the discharge of a mixture of storm water and domestic waste when the flow capacity of a sewer system is exceeded during rainstorms. |
| tube settler | device using bundles of tubes to let solids in water settle to the bottom for removal by conventional sludge collection means |
| mixed stock | A stock whose individuals originated from commingled native and non-native parents; or a previously native stock that has undergone substantial genetic alteration. |
| snow banner | A plume of snow blown off a mountain crest, resembling smoke blowing from a volcano. |
| birth-pulse population | A population assumed to produce all of its offspring at an identical and instantaneous point during the annual cycle. |
| offstream use | Water withdrawn from a surface water source for uses such as irrigation, municipal and industrial (M&I) water supply, steam electric power generation, etc. |
| infiltration | Movement of water through the soil surface into the soil |
| influent | water, wastewater, or other liquid flowing into a reservoir, basin, or treatment plant. |
| transitional storage reserve | The quantity of water in storage in a particular groundwater aquifer that is extracted during the transition period between natural equilibrium conditions and new equilibrium conditions with groundwater pumped at perennial yield levels. |
| halosere | plant succession in a saline environment e.g |
| autonomy | the right of self-government |
| basal sapping | the undercutting and retreat of a slope caused when erosion and/or weathering are concentrated at its base. |
| pitot tube | A device for measuring the velocity of flowing water using the velocity head of the stream as an index of velocity |
| fissionable isotope | Isotope that can undergo nuclear fission when hit by a neutron at the right speed |
| discharge curve | A curve that expresses the relation between the discharge of a stream or open conduit at a given location and the stage or elevation of the liquid surface at or near that location |
| backsight | A rod reading taken on a point of known elevation, a benchmark or a turning point |
| dissolved solids | Chemical compounds in solution. |
| piezometric surface | the imaginary surface to which groundwater rises under hydrostatic pressure in wells or springs. |
| moor | open, often hilly, expanse of land characterized by wet, spongy, peaty soils and vegetation such as moss, coarse grass and heather. |
| smoltification | Refers to the physiological changes anadromous salmonids and trout undergo in freshwater while migrating toward saltwater that allow them to live in the ocean. |
| soil erodibility | An indicator of a soil's susceptibility to raindrop impact, runoff, and other eroding processes. |
| rime | very heavy frost created when fog touches surfaces which are below 0˚C |
| tropical cyclone | a severe low pressure weather system which develops over tropical maritime areas |
| liner | a relatively impermeable barrier designed to keep leachate inside a landfill; an insert or sleeve for sewer pipes to prevent leakage or infiltration. |
| bioremediation | a process that uses living organisms to remove pollutants. |
| subtropical jet | Marked by a concentration of isotherms and vertical shear, this jet is the boundary between the subtropical air and the tropical air |
| irrigation period | The number of hours or days that it takes to apply one irrigation to a given design area during the peak consumptive-use period of the crop being irrigated. |
| thermodynamics | In general, the relationships between heat and other properties (such as temperature, pressure, density, etc.) In forecast discussions, thermodynamics usually refers to the distribution of temperature and moisture (both vertical and horizontal) as related to the diagnosis of atmospheric instability. |
| stable atmosphere | Condition in the atmosphere where isolated air parcels have a tendency to sink |
| river banks | The portion of the channel cross section that restricts lateral movement of water at normal discharges |
| pressure gradient force | Force due to spatial differences in atmospheric pressure |
| endogenic | Refers to a system that is internal to the Earth. |
| hyporheic zone | The area under the stream channel and floodplain that contributes to the stream. |
| disturbed slopes | Slopes that have been altered from their natural configuration or vegetative cover by human activity. |
| fuel moisture | The water content of fuel particle expressed as a percent of the oven dried weight of the fuel particle. Fuel moisture observations are generally for the 10-hour time lag fuels (medium-sized roundwood 1/4 to 1 inch in diameter). |
| inselberg | A German term used to describe a steep-sided hill composed of rock that rises from a pediplain. |
| progressive succession | Succession where the developing plant community becomes complex and contains more species and biomass over time. |
| peak annual flow | The largest discharge produced by a stream during a one year period. |
| rate of removal | An inexactly-defined term that can mean either rate of exploitation or rate of fishing--depending on the context . |
| pulse radar | A type of radar, designed to facilitate range (distance) measurements, in which are transmitted energy emitted in periodic, brief transmission. |
| ponding | In flat areas, runoff collects, or ponds in depression and cannot drain out |
| levee | Ridge of coarse deposits found alongside the stream channels and elevated above the floodplain |
| levee | A long, narrow embankment usually built to protect land from flooding |
| irrigation canal | A permanent irrigation conduit constructed to convey water from the source of supply to one or more farms. |
| landfill | (Water Quality) A disposal site which disposes of solid wastes on land |
| lentic | Characterizing aquatic communities found in standing water. |
| columbia river treaty | The treaty between the United States and Canada for the joint development of the Columbia River |
| headcut | A break in the slope at the top of a gully or section of a gully that forms a "waterfall" which in turn causes the underlying soil to erode and the gully to expand uphill. |
| tidewater | (1) Water that inundates land at flood tide |
| canopy drip | Redirection of a proportion of the rain or snow falling on a plant to the edge of its canopy. |
| angels | Radar echoes caused by birds, insects, and localized refractive index discontinuities. |
| carnivorous | Feeding on animal tissues. |
| nondegradation | an environmental policy that does not allow any lowering of naturally occurring water quality regardless of pre-established health standards. |
| heat | Heat is defined as energy in the process of being transferred from one object to another because of the temperature difference between them |
| jet | A forceful stream of fluid (as water or gas) discharged from a narrow opening or a nozzle. |
| pop's | Persistent Organic Pollutants, complex compounds that are very persistent and difficultly biologically degradable. |
| sea stack | A steep pillar of rock located in the ocean a short distance from the coastline |
| farm efficiency | The consumptive Crop Irrigation Requirement (CIR) divided by the farm water delivery. |
| quickwater | the part of a stream that has a strong current; an artificial current or bubbling patch of water just astern of a moving boat. |
| net balance | The change in the amount of mass of a glacier from one year to the next. |
| deprivation cycle | much the same as the cycle of poverty but as applied to EMDW inner city areas |
| finite | lit |
| wave-cut notch | A rock recess at the foot of a sea cliff where the energy of water waves is concentrated. |
| common agricultural policy | the system of organization of farming in the European Union (EU) |
| thermal infrared radiation | Form of electromagnetic radiation with a wavelength between 3 to 14 micrometers (µm). |
| cavitation | Process of intense erosion due to the surface collapse of air bubbles found in constricted rapid flows of water |
| aquitard | geological formation that may contain groundwater but is not capable of transmitting significant quantities of it under normal hydraulic gradients |
| fetch | An area of the sea surface over which a wind with constant direction and velocity is blowing. |
| drip irrigation | a common irrigation method where pipes or tubes filled with water slowly drip onto crops |
| hiv | see human immunodeficiency virus. |
| debris | any fragmented rock material i.e |
| decomposer | an organism that converts organic matter into its inorganic chemical components which are then recycled through an ecosystem |
| pressure couplet | It is an area where you have a high pressure area located adjacent to a low pressure area. |
| hod | 1) The Hydrologist on Duty at an RFC. 2) The Hydrologic Operations Division of the Office of Hydrology (OH). |
| surcharge capacity | The volume of a reservoir between the maximum water surface elevation for which the dam is designed and the |
| moulin | A vertical shaft at the downslope end of a transverse fissure |
| losing stream | A stream or reach of a stream that is losing water by seepage into the ground. |
| channel routing | The process of determining progressively timing and shape of the flood wave at successive points along a river. |
| mollusca | the snails and similar organisms with an asymmetrical, spirally-coiled shell. |
| incised river | A river which cuts its channel through the bed of the valley floor, as opposed to one flowing on a floodplain; its channel formed by the process of degradation. |
| landscape | comprises the visible features of an area of land, including physical elements such as landforms, living elements of flora and fauna, abstract elements such as lighting and weather conditions, and human elements. |
| hrl | The Hydrological Research Laboratory at the Office of Hydrology (OH). |
| aquatic habitat | Habitat that occurs in free water. |
| glacial milk | Term used to describe glacial meltwater which has a light colored or cloudy appearance because of clay-sized sediment held in suspension. |
| mountain breeze | A katabatic wind, it is formed at night by the radiational cooling along mountainsides |
| thoracic pelvics | Said of the pelvic fins when attached immediately below the pectorals and connected internally with the pectoral girdle. |
| falsification | Falsification is a procedure used in science to test the validity of a hypothesis or theory |
| overland flow | The flow of rainwater or snowmelt over the land surface toward stream channels |
| invisible import | the buying of a service from an overseas provider. |
| barrage | any artificial obstruction placed in water to increase water level or divert it |
| system planning | A coordinated systemwide approach to planning in which each subbasin in the Columbia system will be evaluated for its potential to produce fish in order to contribute to the goal of the overall system |
| friable | lit |
| critical low flow | low flow conditions below which some standards do not apply |
| unit hydrograph | The discharge hydrograph from one inch of surface runoff is distributed uniformly over the entire basin for a given time period |
| attm | An acronym for "at this time". |
| nonthreshold pollutant | substance or condition harmful to a particular organism at any level or concentration. |
| gradient wind | A steady horizontal air motion along curved parallel isobars or contours in an unchanging pressure or contour field, assuming there is no friction and no divergence or convergence. |
| parr marks | Distinctive vertical bars on the sides of young salmonids. |
| rate of exploitation | The fraction, by number, of the fish in a population at a given time, which is caught and killed by man during the year immediately following |
| cirrostratus clouds | High altitude sheet like clouds composed of ice crystals |
| anode | A site in electrolysis where metal goes into solution as a cation leaving behind an equivalent of electrons to be transferred to an opposite electrode, called a cathode. |
| escherichia coli | a common bacterium found in fecal matter; member of the coliform group evaporation - water changing into vapor and rising into the air exchange - the act of trading goods or services for those produced by people who are located elsewhere expense - something spent (such as money, time or effort) to secure a benefit or bring about a result |
| reclaimed sewage | Wastewater treatment-plant effluent that has been diverted or intercepted for use before it reaches a natural waterway or aquifer. |
| pre-hurricane squall line | It is often the first serious indication that a hurricane is approaching |
| coarse woody debris | Portion of a tree that has falled or been cut and left in the woods |
| run-of-river dam | A hydroelectric generating power plant that operates based only on available streamflow and some short-term storage (hourly, daily, or weekly) |
| yield | The weight or number of fish removed by fishing during a defined time period. |
| water desalination | The removal of salts, such as from a saline water supply, usually by Electrodialysis or Reverse Osmosis. |
| upwelling | (1) The appearance of water from the deep ocean at the surface |
| inphase or 'i' component | The component of a complex signal along the real axis in the complex plane. |
| boulder clay | see till. |
| channel capacity | The maximum rate of flow that may occur in a stream without causing overbank flooding. |
| tailwater | The water surface immediately downstream from a dam or hydroelectric powerplant. |
| secondary succession | Succession on a previously vegetated surface |
| celestial sphere | The apparent sphere of infinite radius having the earth as its center |
| outwash | Stratified sands and gravels washed out from glaciers by meltwater streams and deposited in the proglacial environment, or beyond the active glacial margin. |
| social provision | the basic needs that a society should provide or aspire to provide for its members such as housing, healthcare, education and the like. |
| riverine | Relating to, formed by, or resembling a river including tributaries, streams, brooks, etc. |
| palmer drought severity index | An index whereby excesses or deficiencies of precipitation are determined in relation to average climate values |
| ducting | The phenomenon by which the radar signal propagates along the boundary of two dissimilar air masses |
| interbasin transfer of water | See Water exports; Water imports. |
| seeps | Groundwater/surface water connections caused by river or stream erosion into a near-surface aquifer. |
| steady state inhibition | The time point at which continued dosing at the same level results in no further increase in cholinesterase inhibition. |
| curtain drain | A drain constructed at the upper end of the area to be drained, to intercept surface or ground water flowing toward the protected area from higher ground, and carry it away from the area |
| saturation | The condition of a liquid when it has taken into solution the maximum possible quantity of a given substance. |
| ozonosphere | Another name for the ozone layer. |
| soft water | any water that does not contain a significant amount of dissolved minerals such as salts of calcium or magnesium. |
| kelp beds | significant aggregations of a large, fast growing marine algae throughout the water column. |
| sample | A sample is a subset group of data selected from a larger population group |
| hair hygrometer | Hygrometer that uses the expansion and contraction of hair to determine atmospheric humidity. |
| flume | a natural or artificially made channel that diverts water. |
| shear stress | Stress caused by forces operating parallel to each other but in opposite directions. |
| corn snow ice | Rotten granular ice. |
| channel | In instances sub-lacustrine channels appear where a lake has been formed by the submergence of a valley, or the drowning of a river; the channels formed under subaerial conditions by stream cutting may remain unfilled by sediments, on the lake bottom |
| ground water recharge | Inflow of water to a ground water reservoir (Zone of Saturation) from the surface |
| warm front | the front edge of a body of warm air where it meets and rises above a body of colder air. |
| aphelion | The point on the earth's orbit that is farthest from the sun |
| fracture | Any break or rupture formed in an ice cover or floe due to deformation. |
| succulent vegetation | Group of plants that have the ability to survive in deserts and other dry climates by having no leaves |
| percolation deep | In irrigation or farming practice, the amount of water that passes below the root zone of the crop or vegetation. |
| relative humidity | The ratio of the amount of water vapor in the atmosphere to the amount necessary for saturation at the same temperature |
| mineral | Component of rocks |
| client agency | As used in connection with reimbursable National Weather Service (NWS) fire weather services, a public fire service or wildlands management agency, Federal or non-Federal, which requires and uses NWS fire and forestry meteorological services |
| eustatic adjustment | changes in sea level due to changes in the volume of water held in the ocean store. |
| erosion | the process in which a material is worn away by a stream of liquid (water) or air, often due to the presence of abrasive particles in the stream. |
| barrier winds | Refers to the westerly flow of air along the northern slope of the Brooks Range in northern Alaska that precedes the arrival of colder air from the north. |
| effeciveness of fishing | A general term referring to the percentage removal of fish from a stock, but not as specifically defined.as either rate of exploitation or instantaneous rate of fishing. |
| wildlands | Any nonurbanized land not under extensive agricultural cultivation, e.g., forests, grasslands, rangelands. |
| langelier saturation index | an index reflecting the equilibrium pH of a water with respect to calcium and alkalinity; used in stabilizing water to control both corrosion and scale deposition. |
| oceanic plate | a segment of the earth crust made up of sima |
| return flow | The portion of withdrawn water not consumed by evapotranspiration or system losses that returns to its source or to another body of water. |
| track | The path that a storm or weather system follows. |
| karst tower | in areas of carboniferous limestone where certain portions of the rock contains fewer weaknesses, especially joints, then weathering of these portions will be slower than the surrounding rock mass, eventually leaving them standing separately as towers above the surrounding plain |
| streamflow | The discharge that occurs in a natural channel |
| reservoir surface area | The surface area of a reservoir when filled to the normal pool or water level. |
| flood plain information studies | Reports usually prepared by the U.S |
| benthos | marine organisms which dwell on the seabed. |
| runoff | The topographic flow of water from precipitation to stream channels located at lower elevations |
| distance ratio | gradient of a slope measured by dividing vertical change by horizontal change |
| gravity dam | A dam constructed of concrete and/or masonry that relies on its weight for stability. |
| chaparral | A type of plant community common to areas of the world that have a Mediterranean climate (for example, California and Italy) |
| closed talik | Is a form of localized unfrozen ground (talik) in an area of permafrost |
| cold high | A high pressure system that has its coldest temperatures at or near the center of circulation, and horizontally, is thermally barotropic |
| spit | A long and narrow accumulation of sand and/or gravel that projects into a body of ocean water |
| sewerage | the entire system of sewage collection, treatment, and disposal. |
| recycled water | used more than one time before it passes back into the hydrologic system. (See gray water, reclaimed water.) |
| frontal passage | It is the passage of a front over a specific point on the surface |
| channeled | Having one or more longitudinal grooves. |
| pelvic fins | Posterior paired fins, located in the abdominal position or towards the rear. |
| basaltic magma | Mafic magma that forms basaltic igneous rocks. |
| problem | An obstacle to achieving a goal or objective. |
| pulse | A short burst of electromagnetic energy that a radar sends out in a straight line to detect a precipitation target |
| froude number | a dimensionless number comparing inertial and gravitational forces |
| global dimming | the term to describe the blocking and/or scattering of insolation by particulate matter in the atmosphere, both natural (e.g |
| control structure | a structure on a stream or canal that is used to regulate the flow or stage of the stream or to prevent the intrusion of salt water. |
| carbon dating | a means of dating organic material based on the fact that carbon-14, a radioactive component of all living things, decays at a known rate over time from death. |
| best-fit line | a line drawn on a scatter-graph, as close to all the points as possible, which thus indicates any trend in the pattern |
| parietals | Pared bones on posterior roof of skull, lateral to supraoccipital. |
| canadian shield | Very old igneous and metamorphic shield rock that covers much of northern Canada |
| basal melting | Known specific melting rates for different substances including ice |
| impurities | Particles or other objects that cause water to be unclear. |
| viable population | A population in a state that maintains its vigor and its potential for evolutionary change. |
| electromagnetic spectrum | See spectrum. |
| chaff | Small strips of metal foil, usually dropped in large quantities from aircraft or balloons |
| cartel | a group of producers within a single industry who agree to limit supply to keep prices high |
| secondary treatment | second step in most waste treatment systems, in which bacteria break down the organic parts of sewage wastes; usually accomplished by bringing the sewage and bacteria together in trickling filters or in the activated sludge process |
| cnif | Calibration Network Information Files |
| shallow well | A well with a pumping head of 20 feet or less, permitting use of a suction pump. |
| centripetal force | Force required to keep an object moving in a circular pattern around a center of rotation |
| pluvial period | A period of increased rainfall and decreased evaporation, which prevailed in nonglaciated areas during the time of ice advance elsewhere. |
| per capita water use | The water produced by or introduced into the system of a water supplier divided by the total residential population; normally expressed in gallons per capita per day (gpcd). |
| aquatic | growing in, living in, or frequenting water. |
| backwater | (1) A small, generally shallow body of water attached to the main channel, with little or no current of its own. |
| swe | Snow Water Equivalent |
| embankment | An artificial deposit of material that is raised above the natural surface of the land and used to contain, divert, or store water, support roads or railways, or for other similar purposes. |
| interface | the common boundary between two substances such as water and a solid, water and a gas, or two liquids such as water and oil. |
| embankment | Fill material, usually earth or rock, placed with sloping sides and usually with length greater than height |
| unclassified waters | those waters for which no classification has been assigned and which have not been identified in Appendix A of 31 Texas Administrative Code, Chapter 307.10 of Title 31 (relating to definitions). |
| geohydrology | a term which denotes the branch of hydrology relating to subsurface or subterranean waters; that is, to all waters below the surface. |
| trickle channel | A longitudinal channel constructed along the center and lowest part of a channel or through a detention or retention facility and intended to carry low flows. |
| hydrologic benchmark | A hydrologic unit, such as a basin or a ground-water body, that because of its expected freedom from the effects of man, has been designated as a benchmark |
| bar | An obstacle formed at the shallow entrance to the mouth of a river or bay which empties into the ocean. |
| slum | an area of old, rundown housing where living and social conditions are very poor. |
| probability | Statistical chance that an event will occur. |
| pervious zone | A part of the cross section of an embankment dam comprising material of high permeability. |
| overland flow | (1) The flow of rainwater or snowmelt over the land surface toward stream channels |
| scenic rivers | Rivers or sections of rivers that are free of impoundments, with shorelines or watersheds still largely primitive, and shorelines largely undeveloped but accessible in places by roads. |
| retrofitting | installing modern pollution control devices at facilities without making major changes to the facility's design. |
| sediments | Soil, sand, and minerals washed from land into water, usually after rain. |
| valley breeze | An anabatic wind, it is formed during the day by the heating of the valley floor |
| pyrophytes | plants adapted to withstand fire, and to require fire for regeneration. |
| flowing artesian well | a special case of an artesian well where a water well drilled into a confined aquifer has enough hydraulic pressure for the water to rise to a height above ground surface and to flow at the surface without pumping. |
| flood forecasting | Prediction of stage, discharge, time of occurrence, and duration of a flood, especially of peak discharge at a specified point on a stream, resulting from precipitation and/or snowmelt. |
| soil structure | The physical properties of different soils |
| horn | A peak or pinnacle thinned and eroded by three or more glacial cirques |
| objective | A specific statement of planned results to be achieved by a predetermined date |
| undercast | In aviation, it is an opaque cloud layer viewed from an observation point above the layer |
| streamlet | A small stream. |
| p-wave | A seismic wave that moves material in push-pull fashion in the direction of its travel |
| early seral stage forest | Stage of forest development that includes seedling, sapling, and pole-sized trees. |
| suspended-sediment concentration | the ratio of the mass of dry sediment in a water-sediment mixture to the mass of the water-sediment mixture |
| edge wave | A wave of water that moves parallel to the shore |
| pollutant | or the pollutant or substance itself, such that the final concentration after mixing is lower than that in the effluent or of the pure substance. |
| biotic potential | Maximum rate that a population of a given species can increase in size (number of individuals) when there are no limits on growth rate. |
| forecast models | Forecasters use numerical weather models to make their forecasts. These numerical models are classified into four main classes |
| chinook | the N |
| plow wind | A term used in the midwestern United States to describe strong, straight-line winds associated with the downdrafts spreading out in advance of squall lines and thunderstorms. Resulting damage is usually confined to narrow zones like that caused by tornadoes; however, the winds are all in one direction (straight-line winds). |
| wastewaters | sludges, liquid wastes or spent nuclear fuel, a shallow sound, channel or pond, near and generally connected to, a larger body of water. |
| fmax | The rate of fishing mortality for a given exploitation pattern rate of growth and natural mortality, that results in the maximum level of yield-per-recruit |
| soil colloids | Very small organic and inorganic particles found in a soil |
| stockpond | a pond used primarily for watering livestock. |
| pressure | Is defined as the force acting on a surface from another mass per unit area. |
| solar system | The collection of celestial bodies that orbit around the Sun. |
| submarine canyon | V-shaped canyons cut into the continental slope to a deep of up to 1200 meters |
| grass | Type of plant that has long slender leaves that extend from a short stem or the soil surface. |
| allozymes | Alternate forms of an enzyme produced by different alleles and often detected by protein electrophoresis. |
| denitrification | Removal of nitrate and nitrate product from water to produce a quality that answeres common water standards. |
| shale | Fine grained sedimentary rock composed of lithified clay particles. |
| augmentation | Increasing steam flow under normal conditions, by releasing storage water from reservoirs. |
| gage zero | The elevation of zero stage |
| convective sigmets | These NWS aviation products are issued in the conterminous U.S |
| canal check gate structure | A structure designed to control the water surface level and flow in a canal, maintaining a specified water depth or head on outlets or turnout structures |
| easterly wave | An inverted, migratory wave-like disturbance or trough in the tropical region that moves from east to west, generally creating only a shift in winds and rain |
| permafrost | Zone of permanently frozen water found in high latitude soils and sediments |
| greenbelt | Strip of natural vegetation growing parallel to a stream that provides wildlife habitat and an erosion and flood buffer zone |
| prairie | A prairie is a wide, relatively flat area of land that has grasses and only a few trees. |
| rootwad | The mass of roots associated with a tree adjacent or in a stream that provides refuge and nutrients for fish and other aquatic life. |
| weir | a) A low dam built across a stream to raise the upstream water level (fixed-crest weir when uncontrolled); b) A structure built across a stream or channel for the purpose of measuring flow (measuring or gaging weir). |
| sand trap | (Irrigation) A device, often a simple enlargement in a ditch or conduit, for arresting the heavier particles of sand and silt carried by the water. |
| weather | How hot or cold, wet or dry, stormy or calm it is in an area over a short period of time |
| oligopoly | supply of a good or service to a market is dominated and controlled by a handful of companies e.g |
| cut off | A channel cut across the neck of a bend. |
| super-saturation | Atmospheric condition where saturation occurs at a relative humidity greater than 100% because of a shortage of deposition or condensation nuclei. |
| solution load | that portion of a river load held in solution. |
| private sector | the firms in an economy owned by shareholders or individuals. |
| absorption | the uptake of water, other fluids, or dissolved chemicals by a cell or an organism (as tree roots absorb dissolved nutrients in soil). |
| liquid | A state of matter where molecules have the ability to flow and the surface of this mass displays the property of surface tension. |
| holding pond | A pond or reservoir, usually made of earth, built to store polluted runoff. |
| hurricane warning | A warning that sustained winds 64 kt (74 mph or 119 kph) or higher associated with a hurricane are expected in a specified coastal area in 24 hours or less |
| stream channel | Long trough-like depression that is normally occupied by the water in a stream. |
| illinoian | North American glaciation related to European Riss glaciation. |
| refraction | Process where insolation is redirect to a new direction of travel after entering another medium. |
| glacial ice | Consolidated, relatively impermeable ice crystal aggregates with a density greater than 0.84. |
| unmeasured sediment discharge | The difference between Total Sediment Discharge and measured Suspended-Sediment Discharge. |
| continental plate | a segment of the earth crust made up of sial |
| non-degradation | An environmental policy which disallows any lowering of naturally occurring quality regardless of preestablished health standards. |
| cryptosporidium | A microorganism in water that causes gastrointestinal illness in humans |
| node | in a transport network, a point where links join. |
| tail cloud | A horizontal, tail-shaped cloud (not a funnel cloud) at low levels extending from the precipitation cascade region of a supercell toward the wall cloud (i.e., it usually is observed extending from the wall cloud toward the north or northeast) |
| periglacial | Landforms created by processes associated with intense freeze-thaw action in an area high latitude areas or near an alpine or continental glacier. |
| evaporation ponds | Areas where sewage sludge is dumped and dried. |
| wave | a movement of energy |
| water year | The time period form October 1 through September 30. |
| downdraft | Downward movement of air in the atmosphere. |
| trade bloc | a collection of countries who agree to make trade between themselves easier and to maintain barriers to trade with countries outside of the bloc. |
| slickensides | a smooth striated polished surface produced on rock by movement along a fault. |
| itcz | see Intertropical Convergence Zone. |
| conservation recommendations | Suggestions by the Fish and Wildlife Service or National Marine Fisheries Service in biological opinions regarding discretionary measures to minimize or avoid adverse effects on a proposed action of federally listed threatened or endangered species or designated critical habitat. |
| overflow rate | (1) The flow into a basin divided by its total surface area, often expressed in units of gallons per day per square foot |
| limestone | rock that consists mainly of calcium carbonate and is chiefly formed by accumulation of organic remains. |
| water pollution | The presence in water of enough harmful or objectionable material to damage water quality. |
| perigee | The closest distance between moon and earth or the earth and sun. |
| terrace | an area of flat ground set into or onto a steep slope. |
| valley fog | Fog formed by the movement of cooler, more dense air from higher elevations to the warm valley bottom. |
| stock status | The current condition of a stock, which may be based on escapement, run size, survival, or fitness level. |
| load allocation | (Water Quality) The portion of the pollution Load of a stream attributable to human Nonpoint Sources (NPS) of pollution |
| piezometric surface | An imaginary surface that everywhere coincides with the static level of the water in the aquifer |
| severe icing | The rate of ice accumulation on an aircraft is such that de-icing/anti-icing equipment fails to reduce or control the hazard. Immediate diversion is necessary. This standard of reporting this type of icing was based on a recommendation set forth by the subcommittee for Aviation Meterorological Services in the Office of the Federal Coordinator for Meteorology in November 1968. The convection has been to designate icing intensity in terms of its operational effect upon reciprocating engine, straight wing transport aircraft as used by commuter operators. |
| upstream | Toward the source or upper part of a stream; against the current |
| coniferous | Pertaining to Conifers, which bear woody cones containing naked seeds. |
| sinkhole | see swallow hole. |
| hydrologic cycle | Model that describes the movement of water between the hydrosphere, lithosphere, atmosphere, and biosphere. |
| tilt sequence | Radar term indicating that the radar antenna is scanning through a series of antenna elevations in order to obtain a volume scan. |
| ramus | A branch; a projecting part. |
| ice age | Reoccuring periods in Earth history when the climate was colder and glaciers expanded to cover larger areas of the Earth's surface. |
| hazardous waste | Waste that poses a risk to human health or the environment and requires special disposal techniques to make it harmless or less dangerous. |
| ejector | (1) A device using a jet of water to withdraw a fluid from a space |
| semi-confined aquifer | an aquifer partially confined by soil layers of low permeability in which recharge and discharge can still occur. |
| acre-foot | Volume of water required to cover 1 acre of land (43,560 square feet) to a depth of 1 foot, equivalent to 325,851 gallons. |
| heliophobia | The fear of the sun. |
| contact time | The length of time a substance is in contact with a liquid, before it is removed by filtration or the occurrence of a chemical change. |
| sparging | Injection of air below the water table to strip dissolved volatile organic compounds and to facilitate aerobic biodegradation of organic compounds. |
| nic | see newly industrialised country. |
| flow | The rate of water discharged from a source given in volume with respect to time. |
| permanent control | A stream gaging control which is substantially unchanging and is not appreciably affected by scour, fill, or backwater. |
| milankovitch theory | Theory proposed by Milutin Milankovitch that suggests that changes in the Earth's climate are cause by variations in solar radiation received at the Earth's surface |
| silicate | Group of minerals that have crystal structures based on a silica tetrahedron (SiO4). |
| water imports | The artificial transfer (pipes, canals, aqueducts, etc.) of water into one region or subregion from another region. |
| system | any set of components which are gathered into a working whole. |
| natural resource | any form of matter or energy obtained from the environment that meets human needs. |
| oxisol | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| gravel | A mixture composed primarily of rock fragments 2 mm (0.08 inch) to 7.6 cm (3 inches) in diameter |
| directional shear | The shear created by a rapid change in wind direction with height. |
| inundate | (1) To cover with water, especially floodwaters |
| seed dispersal | Movement of a plant seed away from the parent plant by a passive or active mechanism. |
| graupel | Variations in temperature, migration of liquid and vapor water, and pressure of snow cover may result in rounded snow pellets from 2 to 5 mm diameter |
| ablation | In glaciers, refers to melting, erosion and evaporation which reduces the area of the ice. |
| precipitate | a solid which has come out of an aqueous solution |
| conservation recommendations | Suggestions by conservation agencies regarding discretionary measures to minimize or avoid adverse effects on a proposed action of federally listed threatened or endangered species or designated critical habitat. |
| stormwater discharge | Precipitation that does not infiltrate into the ground or evaporate due to impervious land surfaces but instead flows onto adjacent land or water areas and is routed into drain/sewer systems. |
| mammatus clouds | Rounded, smooth, sack-like protrusions hanging from the underside of a cloud (usually a thunderstorm anvil) |
| injection well | Refers to a well constructed for the purpose of injection treated wastewater directly into the ground |
| native species | Species that normally exists and reproduces in a specific region of the Earth |
| instantaneous rate of growth | The natural logarithm of the ratio of final weigl1t to initial weight of a fish in a unit of time, usually a year |
| equilibrium line | The boundary between the accumulation area and the ablation area. |
| hydroelectric plant | electric power plant in which the energy of falling water is used to spin a turbine generator to produce electricity. |
| sewage system | Pipelines or conduits, pumping stations, force mains, and all other structures, devices, and facilities used for collecting or conducting wastes to a point for treatment or disposal. |
| ahos-t | Automatic Hydrologic Observing System - Telephone |
| commercial forest land | Land declared suitable for producing timber crops and not withdrawn from timber production for other reasons. |
| cooling degree day | see Degree Day |
| convection | The process of heat transfer through gas or liquid due to its own movement. |
| reverse osmosis | (1) (Desalination) The process of removing salts from water using a membrane |
| saturation point | The point when the water vapor in the atmosphere is at its maximum level for the existing temperature. |
| loaded gun | Slang for a sounding characterized by extreme instability but containing a cap, such that explosive thunderstorm development can be expected if the cap can be weakened or the air below it heated sufficiently to overcome it. |
| penetrating top | Same as overshooting top. |
| mg/l | Milligrams per liter; a measurement describing the amount of a substance (such as a mineral, chemical or contaminant) in a liter of water |
| meander length | The distance in the general course of the meanders between corresponding points of successive meanders of the same phase. |
| pedology | The scientific study of soils. |
| apogee | The point farthest from the earth on the moon's orbit |
| irrigation efficiency | The percentage of the water diverted from a water source that is consumed |
| vort max | This short for vorticity maximum |
| anvil | The flat, spreading top of a Cumulonimbus Cloud (Cb) |
| upper air/upper level | The portion of the atmosphere which is above the lower troposphere |
| dbz | A logarithmic expression for reflectivity factor, referenced to (1 mm^6 / 1 m^3) |
| biological reference points | Fishing mortality rates that may provide acceptable protection against growth overfishing and/or recruitment overfishing for a particular stock |
| supercooled water | Cooling of water below 0° Celsius without freezing |
| resource management | the control of resources so that they do not become depleted or exhausted. |
| header | (1) A pipe that serves as a central connection for two or more smaller pipes |
| sustainable yield | The number or weight of fish in a stock that can be taken by fishing without reducing the stock biomass from year to year, assuming that environmental conditions remain the same. |
| vent | a pipe-like gap in the ground which allows volcanic material to pass through to the surface. |
| irrigation efficiency | The efficiency of water application and use |
| center-pivot irrigation | See Irrigation. |
| cloud height | The height of the base of a cloud or cloud layer above the surface of the earth. |
| wisconsinan | North American glaciation related to European Wurm glaciation. |
| commercial tree species | Conifer species used to calculate the commercial forest land allowable sale quantity |
| u.s./canada pacific salmon treaty | Signed in 1984 and ratified by Congress in 1985 as the Salmon Treaty Act, this treaty governs the harvest and rebuilding of certain salmon stocks in Alaskan, Canadian and the continental United States. |
| coniferous vegetation | Cone-bearing vegetation of middle and high latitudes that are mostly evergreen and that have needle-shaped or scale like leaves |
| chi-squared test | the comparison of an actual distribution of points with a random distribution of the same number of points to establish whether or not there is a significant enough difference to say that the actual distribution has occurred for a particular reason. |
| isostatic rebound | The upward movement of the Earth's crust following isostatic depression. |
| sewerage | The entire system of sewage collection, treatment, and disposal. |
| captive broodstock program | A form of artificial propagation involving the collection of individuals (or gametes) from a natural population and the rearing of these individuals to maturity in captivity |
| hyporheic zone | The area under the stream channel and floodplain where groundwater and the surface waters of a stream are exchanged freely. |
| preorbital | The membrane bone lying in front of and below the eye. |
| matric force | Force that holds soil water from 0.0002 to 0.06 millimeters from the surface of soil particles |
| watershed | A land area from which water drains to a particular water body. |
| lygophobia | The fear of darkness. |
| slush | Snow or ice on the ground that has been reduced to a softy watery mixture by rain and/or warm temperatures. |
| feeder bands | Lines or bands of low-level clouds that move (feed) into the updraft region of a thunderstorm, usually from the east through south (i.e., parallel to the inflow). Same as inflow bands. |
| place | A term used in geography that describes the factors that make the location of natural and human-made phenomena unique. |
| ice run | Flow of ice in a river |
| indicator bacteria | (Water Quality) Nonpathogenic bacteria whose presence in water indicate the possibility of pathogenic species in the water. |
| leeward | Downwind side of an elevated area like a mountain |
| sea-level change | two types: |
| dissolved solids | Disintegrated organic and inorganic material in water |
| periphery | lit |
| fill dam | Any dam constructed of excavated natural materials or of industrial wastes. |
| pingo | A large frost mound of more than one-year duration. |
| stationary front | A front which is nearly stationary or moves very little since the last synoptic position |
| habitat indicator | a physical attribute of the environment measured to characterize conditions necessary to support an organism, population, or community in the absence of pollutants |
| prevailing wind | A wind that blows from one direction more frequently than any other during a given period, such as a day, month, season, or year. |
| tropical disturbance | An organized group of thunderstorms often found over a tropical ocean that generates a slight cyclonic flow of less than 37 kilometers per hour |
| unconfined | Conditions in which the upper surface of the Zone of Saturation forms a water table under atmospheric pressure. |
| interstate waters | According to law, interstate waters are defined as: (1) rivers, lakes and other waters that flow across or form a part of state or international boundaries; (2) waters of the Great Lakes; and (3) coastal waters whose scope has been defined to include ocean waters seaward to the territorial limits and waters along the coastline (including inland steams) influenced by the tide. |
| salt balance | A condition in which specific or total dissolved solids removed from a specified field, stratigraphic zone, political area, or drainage basin equals the comparable dissolved solids added to that location from all outside sources during a specified period of time. |
| spoils | Dirt or rock that has been removed from its original location, destroying the composition of the soil in the process, as with strip-mining or dredging. |
| food web | where food chains overlap and intertwine with each other within and between ecosystems |
| flocculate | To aggregate or clump together individual, tiny particles into small clumps or clusters. |
| perched ground water | Ground water in a saturated zone of material underlain by a relatively impervious stratum which acts as a barrier to downward flow and which is separated from the main ground water body by a zone of unsaturated material above the main ground water body. |
| reflectivity | The radar operator uses this radar product to determine the strength or the intensity of a precipitation target |
| basin boundary | The topographic dividing line around the perimeter of a basin, beyond which overland flow (i.e.; runoff) drains away into another basin. |
| true south | Direction of the South Pole from an observer on the Earth. |
| outlet | An opening through which water can be freely discharged from a reservoir. |
| free-flowing well | An Artesian Well in which the potentiometric surface is above the land surface. |
| regeneration | see redevelopment. |
| neap tide | Tide that occurs every 14 to 15 days and coincides with the first and last quarter of the moon |
| average annual runoff | For a specified area, it is the average value of annual runoff amounts calculated for a whole hydrologic cycle of record that represents average hydrologic conditions. |
| predation | Biological interaction between species where a predator species consumes a prey species. |
| infiltration capacity | The maximum rate at which water can enter the soil at a particular point under a given set of conditions. |
| isopleth map | a map which uses lines joining points of an equal value to show variations in that value e.g |
| feeder bands | In tropical parlance, the lines or bands of thunderstorms that spiral into and around the center of a tropical system |
| caudal fin | The tail fin. |
| transparency | The ability of a medium to allow light to pass through it. |
| conditional water permit | An authorization for the permittee to construct any facilities (such as a well and irrigation system) and to begin utilization of the water |
| water recycling | the treatment of wastewater making it suitable for reuse. |
| severe supercell thunderstorm | It is potentially the most dangerous of the convective storm types |
| intermittently flooded | A water regime in wetland classification in which the substrate is usually exposed, but surface water is present for variable periods without detectable seasonal periodicity. |
| per capita use | The average amount of water used per person during a standard time period, generally per day. |
| arete | a sharp, steed-sided ridge in an upland area |
| afterbay | A reservoir that regulates fluctuating discharges from a hydroelectric power plant or a pumping plant. |
| earthquake | A sudden, transient motion or trembling of the earth's crust, resulting from the waves in the earth caused by faulting of the rocks or by volcanic activity. |
| polymorphic | Having more than one form (e.g., polymorphic gene loci have more than one allele). |
| natural control | A stream gaging control which is natural to the stream channel, in contrast to an artificial control structure by man. |
| sand filters | devices that remove suspended solids from a wastewater treatment plant effluent or water treatment plant product. |
| isothermal layer | Any layer where the temperature is constant with altitude, such that the temperature lapse rate is zero. Specifically, the approximately isothermal region of the atmosphere immediately above the tropopause. |
| lag | The time it takes a flood wave to move downstream. |
| lake | A lake is a large body of water surrounded by land on all sides |
| groundwater | Water that flows below the ground surface through saturated soil, glacial deposits or rock. |
| solstice | Dates when the declination of the Sun is at 23.5° North or South of the equator |
| lapse rate | The rate of change of an atmospheric variable, usually temperature, with height |
| glacial landform | a landform produced by glacial erosion or deposition. |
| jetty | A structure (e.g.; a pier, or mole of wood or stone) extending into a sea, lake, or river to influence the current or tide or to protect a harbor. |
| kettle moraine | An area of glaciofluvial influenced moraine deposits pitted with kames and kettle holes. |
| erosion flood plain | A flood plain that has been created by the lateral erosion and the gradual retreat of the valley walls. |
| sheet flow | Unrestricted glaciers including ice caps and ice sheets flow independently of underlying topography |
| irrigate | (1) To supply (dry land) with water by means of ditches, pipes, or streams; to water artificially |
| recharge area | The area on the Earth's surface that receives water for storage into a particular aquifer. |
| humus | Dark colored semi-soluble organic substance formed from decomposition of soil organic matter. |
| total water used | Total water withdrawal which does not include recirculation. |
| rough fish | Those species of fish considered to be of either poor fighting quality when taken on tackle or of poor eating quality, such as carp, gar, suckers, etc |
| treated water | Water that has been filtered and disinfected |
| "zulu" time | For practical purposes, the same as Coordinated Universal Time (UTC). The notation formerly used to identify time Greenwich MeanTime. The word "Zulu" is notation in the phonetic alphabet corresponding to the letter "Z" assigned to the time zone on the Greenwich Prime Meridian. |
| typhoon | Another name for hurricane. |
| mpw | Minneapolis Public Works |
| soil creep | slow mass movement of soil downslope due to outward expansions brought on by water infiltration which lead to downward movements under gravity as water moves out of the soil. |
| revolution | See Earth revolution. |
| suspended load | specific sediment particles maintained in the water column by turbulence and carried with the flow of water. |
| soil profile | Vertical arrangement of layers or horizons in a soil. |
| aggressive water | water which is soft and acidic and can corrode plumbing, piping, and appliances. |
| interference | Form of competition where an individual directly prevents the physical establishment of another individual in a portion of a habitat. |
| solifluction | A slow, viscous, downslope flow of saturated sediment and rock debris especially in areas underlain by frozen ground. |
| snow pillow | An instrument used to measure snow water equivalents |
| esturine zone | The area near the coastline that consists of estuaries and coastal saltwater wetlands. |
| localized | restricted to a point in space in a landscape |
| demographics | the statistical characteristics of a population births, deaths, age/sex structure etc. |
| homodyning | The transfer of signal intelligence from one carrier to another by mixing of signals at different frequencies. |
| flood control | measures used to reduce the frequency and the magnitude of flooding |
| anchor ice dam | An accumulation of anchor ice which acts as a dam and raises the water level. |
| evaporites | Sediments deposited from an aqueous (water) solution as a result of extensive or local evaporation of a solvent, such as salts in the Great Salt Lake in the western United States. |
| few | The amount of sky cover for a cloud layer between 1/8th and 2/8ths, based on the summation layer amount for that layer. |
| profiler | A type of Doppler radar that typically measures both wind speed and direction from the surface to 55,000 feet in the atmosphere. |
| wet deposition | The transport of gases and minute liquid and solid particles from the atmosphere to the ground surface with the aid of precipitation or fog |
| rehabilitation | Short-term management techniques that restore fish stocks decimated or destroyed by natural or man-made events. |
| ring of fire | See Circum-Pacific Belt. |
| parts per million | A unit used to measure contamination concentration (parts of contamination per million parts of water) |
| eddy current | A circular current of water, usually resulting from an obstruction, that develops when the main flow becomes separated from the bank. |
| evaporation | process of liquid water becoming water vapor |
| el ni隳 | Name given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru |
| ddt | an insecticide (dichlorodiphenyltrichloroethane) |
| vadose | Of, relating to, or being water that is located in the Zone of Aeration in the earth's crust above the ground water level. |
| saturation | The condition of a liquid when it has taken into solution the maximum possible quantity of a given substance at a given temperature and pressure. |
| macrophyte | macroscopic plants in the aquatic environment |
| crystal lattice | The definite arrangement of atoms in a solid crystalline substance |
| eta model | One of the operational numerical forecast models run at NCEP |
| entrainment | One of three distinct processes involved in erosion |
| volcanic pipe | A dyke reaches the surface of the Earth |
| operational mode | A combination of scanning strategies and product mixes tailored to one or more meteorological situations. |
| gross primary productivity | Total amount of chemical energy fixed by the processes of photosynthesis. |
| recruits | The total numbers of fish of a specific stock available at a particular stage of their life history. |
| acclimate | The adaptation of an organism to environmental changes. |
| drawdown | The release of water from a reservoir for power generation, flood control, irrigation or other water management activity. |
| horizon | One of several lines or planes used as reference for observation and measurement relative to a given location on the surface of the earth |
| guyot | an undersea mountain which is characterized by a flattened summit. |
| overfall | An abrupt change in stream channel elevations |
| structural landform | Is a landform created by massive Earth movements due to plate tectonics |
| calcium carbonate | (CaCO3) The principal hardness and scale-causing compound in water |
| particulate loading | The mass of Particulates per unit volume of water. |
| hurricane warning | A formal advisory issued by forecasters at the National Hurricane Center when they have determined that hurricane conditions are expected in a coastal area or group of islands within a 24 hour period |
| pilot balloon | A small balloon whose ascent at a constant rate is followed by a theodolite in order to obtain data for the computation of the speed and direction of winds at various levels in the upper air above the station. |
| down log | Portion of a tree that has fallen or been cut and left in the woods. |
| greenhouse effect | The warming of the earth's atmosphere caused by a build-up of carbon dioxide or other trace gases; it is believed by many scientists that this build-up allows light from the sun's rays to heat the earth but prevents a counterbalancing loss of heat. |
| centripetal force | The force required to keep an object moving in a curved or circular path |
| meander bend | a windings or sinuous section of a stream channel |
| calorie | amount of energy required to raise the temperature of 1 gram of water 1 degree Celsius. |
| ecosystem | a system existing in a particular region, at a variety of scales, where organisms exist in communities and interact with the abiotic environment around them. |
| request identification number | A number assigned by EPA to identify your Freedom of Information Act request (e.g., 1234-99) |
| twilight | Often called dusk, it is the evening period of waning light from the time of sunset to dark |
| specific conductance | a measure of the ability of water to conduct an electrical current. Used to approximate the total dissolved solids (TDS) content of water. A basic field test in water quality; distilled water does not conduct electricity, sea water is extremely conductive. |
| amplitude | The maximum magnitude of a quantity. |
| ombrophobia | The fear of rain or of being rained on. |
| gage height | the height of the water surface above the gage datum (zero point) |
| grade | (Hydraulics) The slope of a stream bed. |
| weir | A structure to control water levels in a stream |
| conjunctive management | integrated management and use of two or more water resources, such as an aquifer and a surface water body. |
| resource partitioning | The evolutionary process of species living in the same ecosystem dividing up resources so that each species develops dissimilar resource requirements to avoid competition |
| trash rack | A screen located at an intake to prevent debris from entering. |
| property protection | Measures that are undertaken usually by property owners in order to prevent, or reduce flood damage |
| endangered species | Any species of plant of animal defined through the Endangered Species Act as being in danger of extinction throughout all or a significant portion or its range, and published in the Federal Register. |
| convection | transfer of heat in a gas or liquid by upward movement of the hotter, less dense portion |
| rain | Water falling to earth in drops that have been condensed from moisture in the atmosphere. |
| blizzard | A severe weather condition characterized by low temperatures, winds 35 mph or greater, and sufficient falling and/or blowing snow in the air to frequently reduce visibility to 1/4 mile or less for a duration of at least 3 hours |
| dnr | Department of Natural Resources |
| firm capacity | For public drinking water supplies, the system delivery capacity with the largest single water well or production unit out of service. |
| pollutant | A contaminant at a concentration high enough to endanger the life of organisms. |
| gating | The use of electric circuits in radar to eliminate or discard the target signals from all targets falling outside certain desired range limits. |
| groundwater mining | The condition that exists when the withdrawal of water from an aquifer exceeds the recharge causing a decline in the ground water level. |
| interglacial | a period of warmer climate conditions between glacial periods. |
| plateau basalt | An accumulation of horizontal flows of basaltic lava |
| critical rainfall probability | The probability that the actual precipitation during a rainfall event has exceeded or will exceed the flash flood guidance value. |
| phenotype | The sum total of the observable or measurable characteristics of an organism produced by its genotype interacting with the environment. |
| mean depth | The average depth of water in a stream channel or conduit |
| flood crest | The maximum height of a flood wave as it passes a location. |
| magma plume | A rising vertical mass of magma originating from the mantle. |
| hydrometer | An instrument used to determine specific gravity, especially a sealed, graduated tube, weighted at one end, that sinks in a fluid to a depth used as a measure of the fluid's specific density. |
| storm warning | A warning of 1-minute sustained surface winds of 48 kt (55 mph or 88 kph) or greater, either predicted or occurring, not directly associated with tropical cyclones. |
| basin lag | The time it takes from the centroid of rainfall for the hydrograph to peak. |
| transpiration | Transpiration is the process of water loss from plants through stomata |
| root zone | The subsurface zone from the land surface to the depth interwoven by plant roots. |
| dissolution | The process of a substance dissolving and dispersing into a liquid. |
| water supply system | The collection, treatment, storage, and distribution of water from source to consumer. |
| toe wall | The downstream wall of a structure. |
| leaching | The flushing of minerals or pollutants from soil or other material by the percolation of applied water. |
| cctv | Sewer inspection method that uses a remote controlled color television camera to capture and transmit images from the inside of a sewer. |
| theodolite | An optical instrument used to track the motion of a pilot balloon, or pibal, by measuring the elevation and azimuth angles. |
| geomorphology | The field of knowledge that investigates the origin of landforms on the Earth and other planets. |
| ngm | Nested Grid Model; one of the operational forecast models run at NCEP |
| air | This is considered the mixture of gases that make up the earth's atmosphere |
| kelvin temperature scale | A temperature scale with the freezing point of +273°K (Kelvin) and the boiling point of +373° K |
| mid-oceanic ridge | Chain of submarine mountains where oceanic crust is created from rising magma plumes and volcanic activity |
| garrigue | the shrub vegetation of the Mediterranean region where soils are thin and dry and have been converted to growth of herb plants e.g |
| lotic waters | Describing the waters of rivers and streams (flowing waters) as compared to Lentic Waters of ponds or marshes (standing waters). |
| weather | The state of the atmosphere at a specific time and place. |
| phanerozoic | the current eon of geologic time that began 2500m years ago. |
| alluvial | An adjective referring to alluvium. |
| pool | A reach of a stream that is characterized by deep, low-velocity water and a smooth surface. |
| map scale | Ratio between the distance between two points found on a map compared to the actual distance between these points in the real world. |
| physical weathering | Breakdown of rock and minerals into small sized particles through mechanical stress. |
| tds | Total Dissolved Solids |
| relative humidity | Relative humidity is actual humidity of a packet of air divided by maximum possible humidity that air can hold |
| spillway | "The channel or passageway around or over a dam through which excess water is released or ""spilled"" past the dam without going through the turbines |
| wastewater treatment | Any of the mechanical or chemical processes used to modify the quality of waste water in order to make it more compatible or acceptable to man and his environment. |
| connate water | water trapped in the pore spaces of a sedimentary rock at the time it was deposited |
| thermocline | That layer of water in a lake in which the temperature changes 10C with each meter increase in depth. |
| gas chromatograph | an instrument that identifies the molecular composition and concentrations of various chemicals in water and soil samples. |
| pediplain | An arid landscape of little relief that is occasionally interrupted by the presence of scattered inselbergs |
| primary wastewater treatment | The removal of suspended, floating and precipitated solids from untreated wastewater. |
| heterotroph | Organism that must consume energy rich organic molecules for survival |
| surfacewater | ground water). |
| hail | Precipitation in the form of balls or lumps usually consisting of concentric layers of ice |
| greenhouse effect | The greenhouse effect causes the atmosphere to trap more heat energy at the Earth's surface and within the atmosphere by absorbing and re-emitting longwave energy |
| taf | This NWS aviation product is a concise statement of the expected meteorological conditions at an airport during a specified period (usually 24 hours) |
| ground receiver site | A satellite dish and associated computer which receives signals from the GOES satellite, decodes the information, and transmits it to a another site for further processing |
| evaporimeter | An instrument which measures the evaporation rate of water into the atmosphere. |
| earthen dam | An embankment dam in which more than 50% of the total volume is formed of compacted fine-grained material |
| cumuliform anvil | A thunderstorm anvil with visual characteristics resembling cumulus-type clouds (rather than the more typical fibrous appearance |
| anabatic | the movement of air up slopes due to convection. |
| runoff | That part of precipitation that flows toward the streams on the surface of the ground or within the ground |
| field permeability | Permeability corresponding to the temperature which occurs under field conditions. |
| input | Addition of matter, energy, or information to a system |
| frequency distribution | An arrangement of quantities pertaining to a single event, in order of magnitude and frequency of occurrence. |
| arroyo | approximate rectangular shaped valley cut in floodplain alluvium, with a smaller stream in the base |
| frictional unemployment | period of unemployment when a worker is between jobs. |
| unstable atmosphere | Condition in the atmosphere where isolated air parcels have a tendency to rise |
| scheduled delivery | Operation of a water delivery system to meet predetermined needs, generally based on user water orders. |
| ecosystem | (1) Recognizable, relatively homogeneous units, including the organisms they contain, their environment, and all the interactions among them |
| baseline | The condition that would prevail if no action were taken. |
| groundwater recharge | The replenishment of groundwater with surface water. |
| peak discharge | Highest rate of discharge of a volume of water passing a given location during a given period of time (during the year, or a flood event, etc..). |
| dual doppler | The use of two Doppler radars to measure two different radial velocities; with some math, these two radial wind components can be synthesized to a spatial distribution of fully 2-D (horizontal) winds. |
| brown earth | type of soil associated with northern Europe in deciduous woodland areas |
| porous | something which allows water to pass through it |
| weir | (a) A low dam built across a stream to raise the upstream water level (fixed-crest weir when uncontrolled); (b) A structure built across a stream or channel for the purpose of measuring flow (measuring or gaging weir); (c) A structure built into a levee or river bank that allows water to flow from the main river channel into a bypass channel during time of high flows. |
| ceratomyxa shasta | A freshwater myxosporean parasite of salmonids that causes high mortalities in susceptible strains of fish |
| weir | A spill over device used to measure or control water flows. |
| ice | The solid form of water |
| twilight | The intervals of incomplete darkness following sunset and preceding sunrise. The time at which evening twilight ends or morning twilight begins is determined by arbritrary convention, and several kinds of twilight have been defined and used; most commonly civil, nautical, and astronomical twilight. |
| kcfs-month | One kcfs-month is a flow of 1,000 cubic feet per second for one month or 0.0595 million acre-feet. |
| fair | This is a subjective description |
| flood plain information studies | Reports usually prepared by the U.S |
| accessory pelvic appendage | A tapered fleshy lobe above the base of the pelvic fin. |
| rainfall | (1) A shower or fall of rain |
| late seral state forest | Stage in forest development that includes mature and old-growth forest. |
| affluent | A stream or river that flows into a larger one; a tributary. |
| grassed waterway or outlet | A natural or constructed waterway, usually broad and shallow and covered with erosion-resistant grasses, suitable to resist potential damages resulting from runoff. |
| dead fuel moisture | Dead fuel moisture responds solely to ambient environmental conditions and is critical in determining fire potential |
| coastal landforms | those landforms unique to erosional and depositional processes at coasts, or due to sea level changes. |
| flash multiplicity | The number of return strokes in a lightning flash. |
| decomposer | Any of various organisms (as many bacteria and fungi) that feed on and break down organic substances (such as dead plants and animals). |
| zone of contribution | The area surrounding a pumping well that encompasses all areas or features that supply ground-water recharge to the well. |
| facilitation model of succession | This model of succession suggests that the change in plant species dominance over time is caused by modifications in the abiotic environment that are imposed by the developing community |
| eutrophication | an increase in the chemical nutrients to be found in any particular ecosystem |
| in-situ | In place |
| peak load | The maximum electrical demand in a stated period of time. |
| perihelion | The point of the earth's orbit that is nearest to the sun |
| mollweide projection | Map projection system that tries to present more accurate representations of area |
| cirrostratus | They are thin, whitish cloud layers appearing like a sheet or veil |
| periodic chart | Arrangement of elements in order of increasing atomic numbers, created by a scientist called Mendelejef. |
| karst hydrology | The branch of Hydrology that deals with the hydrology of geological formations having large underground passages or fractures which enable underground movement of large quantities of water. |
| scattered | The amount of sky cover for a cloud layer between 3/8ths and 4/8ths, based on the summation layer amount for that layer. |
| glacial surge | A rapid forward movement of the snout of a glacier. |
| pressure altimeter | An aneroid barometer calibrated to indicate altitude in feet instead of units of pressure |
| flood plain | a strip of relatively flat and normally dry land alongside a stream, river, or lake that is covered by water during a flood. |
| barrier | A physical block or impediment to the movement or migration of fish, such as a waterfall (natural barrier) or a dam (man-made barrier). |
| schist | A medium to coarse grained metamorphic rock with well developed bedding planes derived from the foliated recrystrallization of platy like minerals like mica. |
| bifurcation ratio | in a drainage basin, the relationship between the streams of one order of magnitude and those of the next highest order, obtained by dividing the number of lower order streams with the number of the higher order |
| little ice age | Time period from 1550 to 1850 AD |
| upslope fog | It forms as air is cooled adiabatically by blowing up sloping terrain |
| movable bed | A stream bed made up of materials readily transportable by the stream flow. |
| log and safety boom | A net-like device installed in a reservoir, upstream of the principal spillway, to prevent logs, debris and boaters from entering a water discharge facility or spillway. |
| separation | The isolation of the various compounds in a mixture. |
| sleet | a form of precipitation where snow falls through warmer air and arrives at the surface partially melted. |
| fontanelle | Unossified gap between cranial bones. |
| percolation | The movement of water, under hydrostatic pressure, through the interstices of a rock or soil, except the movement through large openings such as caves. In other words, the movement of water within the soil. |
| collar cloud | A generally circular ring of cloud that may be observed on rare occasions surrounding the upper part of a wall cloud. This term sometimes is used (incorrectly) as a synonym for wall cloud. |
| halo | The ring of light that seems to encircle the sun or moon when veiled by cirrus clouds |
| graded profile | the long-section or profile of a river from source to mouth |
| ice contact deposit | The multiple types of accumulated stratified sediment left behind when meltwater flows over, within, and at the base of a motionless, melting terminus |
| population viability | Probability that a population will persist for a specified period across its range despite normal fluctuations in population and environmental conditions. |
| freeze | (1) To pass from the liquid to the solid state by loss of heat |
| digester | A closed tank for wastewater treatment, in which bacterial action is induced to break down organic matter. |
| aqueous solubility | the maximum concentration of a chemical that will dissolve in pure water at a reference temperature. |
| barrier net | A net system that is placed across a river, stream or channel to block the passage of fish from dam turbine intakes or other hazards without blocking the water flow. |
| flow velocity | The volume of water flowing through a unit cross-sectional area of an aquifer. |
| hydrograph | a graph which combines a bar chart of precipitation in a particular event with a line graph of discharge for a particular river channel in the catchment area of that event and thus the reaction of the channel to the precipitation. |
| salt water | The water of the ocean, distinguished from fresh water by its appreciable salinity. |
| snow density | The mass of snow per unit volume which is equal to the water content of the snow divided by its depth. |
| advanced treatment | A level of wastewater treatment more stringent than secondary treatment; goes beyond the secondary or biological water treatment stage and includes the removal of nutrients such as phosphorus and nitrogen and requires an 85-percent reduction in conventional pollutant concentration or a significant reduction in non-conventional pollutants |
| unaccounted-for water | The difference between the total amount of water leaving treatment facilities and the total amount of water measured at customers' meters |
| dumping | large-scale selling of a good in another country at below-cost price to earn foreign currency, get rid of excess production or attack that country domestic producers. |
| low-level drawdown | A discharge feature of a dam allowing water to be removed from the bottom of a reservoir. |
| concentration | amount of a chemical or pollutant in a particular volume or weight of air, water, soil, or other medium. |
| fluvial | lit |
| broken | The amount of sky cover for a cloud layer between 5/8ths and 7/8ths, based on the summation layer amount for that layer. |
| flow augmentation | The addition of water to meet flow needs. |
| low | (1) Situated below the surrounding surfaces as in water standing in low spots |
| firm energy | the amount of energy that can be generated given the region's worst historical water conditions |
| system relationship | Is the association that exist between the elements and attributes of a system based on cause and effect. |
| vulcanism | the study of volcanic activity. |
| crop rotation | A pattern of changing the crops grown in a specific field from year to year in order to control pests and maintain soil fertility. |
| coefficient of storage | The volume of water an aquifer releases from or takes into storage per unit surface area of the aquifer per unit change in head. |
| zone of saturation | The locus of points below the water table where soil pores are filled with water |
| tank | An artificial pool, pond, reservoir, cistern, or large container for holding and storing water for drinking or irrigation. |
| bankfull width | The width of a river or stream channel between the highest banks on either side of a stream. |
| mcidas | An acronym for Man-computer Interactive Data Access System. |
| renewable resource | Natural resources that continuously can be replenished in the course of natural events within the limits of human time. |
| noaaport broadcast system | This provides a one-way broadcast communication of NOAA environmental data and information in near-real time to NOAA and external users |
| spring | a water body formed when the side of a hill, a valley bottom or other excavation intersects a flowing body of groundwater at or below the local water table, below which the subsurface material is saturated with water. |
| destructive plate margin | in plate tectonics, a plate boundary where the relative movement of the crustal plates is towards each other and where one is subducted beneath the other thus being destroyed as it returns to the mantle |
| dog days | The name given to the very hot summer weather that may persists for four to six weeks between mid-July through early September in the United States |
| gigawatt hour | One billion Watt-hours (Wh). |
| bottomset beds | layers of sediment in a delta found furthest from the river mouth and formed from flocculated clay particles. |
| venturi | An increase in the velocity of a fluid or gas due to the constriction of flow. |
| stream clearance | The removal of natural or man-caused debris from stream channel areas by mechanical means. |
| watershed | the land area that drains water to a particular stream, river, or lake |
| pool height | The height of the water behind a dam |
| sediment | Soil or mineral material transported by water or wind and deposited in streams or other bodies of water. |
| oecd | see Organisation for Economic Cooperation and Development. |
| flow restriction device | Device applied by the water utility to the customer's meter that restricts the volume of flow to the customer. |
| decomposition | The break down of organic matter by bacteria and fungi, to change the chemical structure and physical appearance of matter. |
| wideband communications | The high speed (1.54 megabits per second of data) communication lines between the Radar Data Acquisition (RDA) and the Radar Product Generator (RPG) on the WSR-88D radar. There are 4 ways that this data is transmitted from the RDA to the RPG: |
| steady state equilibrium | In this type of equilibrium the average condition of the system remains unchanged over time. |
| nwsh | National Weather Service Headquarters. |
| base velocity | This WSR-88D radar product depicts a full 360 degree sweep of radial velocity data. It is available for every elevation angle that is sampled in a volume scan. It is used to estimate wind speed and direction; determine regions of significant shear (convergence, etc.); locate boundaries (cold front, outflow, lake breeze, etc.); identify areas of circulation; and determine storm structure. |
| uptime | (Irrigation) The total time that a system is available for service. |
| specific capacity | In ground water hydrology, the yield of a well in gallons per minute per foot of drawdown after a period of sustained pumping. |
| pentachorophenol | toxic substance usually used as a wood preservative. |
| nivation hollow | a circular depression in the ground, usually seen in periglacial areas, that has been created by nivation. |
| steelhead | The anadromous form of the species Oncorhynchus mykiss |
| storm scale | Referring to weather systems with sizes on the order of individual thunderstorms |
| tipping-bucket rain gage | A precipitation gage where collected water is funneled into a two compartment bucket; 0.01, 0.1 mm, or some other designed quantity of rain will fill one compartment and overbalance the bucket so that it tips, emptying into a reservoir and moving the second compartment into place beneath the funnel |
| temporal extent | Guidance and forecasts are issued for time periods where useful skill exists out to 48 hours for seas and 120 hours for weather systems. |
| background extinction | Normal extinction of species that occurs as a result of changes in local environmental conditions |
| pluton | intrusive igneous rock of any mass. |
| combined shear | This WSR-88D radar product displays a combined radial and azimuthal shear of the mean radial velocity. It is available for all elevation angles; however, its high computational load on the system may result in load shedding of other radar products. It is used to identify low-level wind shear associated with gust fronts, downbursts, and mesoscale rotational phenomena |
| basin | (1) A geographic area drained by a single major stream; consists of a drainage system comprised of streams and often natural or man-made lakes |
| snowflakes | An ice crystal or an aggregate of ice crystals which fall from clouds. |
| influent seepage | Movement of gravity water in the zone of aeration from the ground surface toward the water table. |
| exogenetic | all factors and processes external to the Earth i.e |
| interbasin transfer | The physical transfer of water from one watershed to another. |
| hydrogeologic parameters | Numerical parameters that describe the hydrogeologic characteristics of an aquifer such as Porosity, Permeability, and Transmissivity. |
| teratogen | A substance capable of causing birth defects. |
| air mass thunderstorm | A thunderstorm that is produced by convection within an unstable air mass through an instability mechanism |
| waveguide | A hollow conductor, usually rectangular or round in cross-section, used to carry radar waves between various components of a radar. |
| prevailing wind | A wind that consistently blows from one direction more than from any other. |
| low drifting | A descriptor used to describe snow, sand, or dust raised to a height of less than 6 feet above the ground. |
| backshore | Area behind the shore |
| climatic cycle | The periodic changes of climate, including a series of dry years following a series of years with heavy rainfall. |
| hydrologic cycle | natural pathway water follows as it changes between liquid, solid, and gaseous states; biogeochemical cycle that moves and recycles water in various forms through the ecosphere |
| threshold runoff | The runoff in inches from a rain of specified duration that causes a small stream to slightly exceed bankfull. When available, flood stage is used instead of slightly over bankfull. |
| compass | Navigation instrument that uses the Earth's magnetic field to determine direction. |
| translocation | the movement of soil components within the soil. |
| raised beach | a relict beach left dry by a relative fall in sea-level. |
| instream use | The use of water that does not require withdrawal or diversion from its natural watercourse; for example, the use of water for navigation, recreation, and support of fish and wildlife. |
| diversion channel | (1) An artificial channel constructed around a town or other point of high potential flood damages to divert floodwater from the main channel to minimize flood damage |
| fresnel reflection | The reflection of a radar signal from a single, dominating discontinuity of the refractive index, usually with a large horizontal extent |
| invasive plant | A plant that moves in and takes over an Ecosystem to the detriment of other species; often the result of Environmental Manipulation. |
| blinds | Water samples containing a chemical of known concentration given a fictitious company name and slipped into the sample flow of the lab to test the impartiality of the lab staff. |
| alert flood warning system | A cooperative, community-operated flood warning system; the acronym stands for Automated Local Evaluation (in) Real Time. |
| sediment | Topsoil, sand, and minerals washed from the land into water, usually after rain or snow melt |
| primary wastewater treatment | the first stage of the wastewater-treatment process where mechanical methods, such as filters and scrapers, are used to remove pollutants |
| coefficient of variation | A statistical term describing the percentage variation in a population. |
| command economy | an economic system in which all decisions are made centrally by the national government, usually through the establishment of sequential five-year plans |
| thermoelectric power | Electrical power generated by using fossil-fuel (coal, oil, or natural gas), geothermal, or nuclear energy. |
| thermal pollution | a reduction in water quality caused by increasing its temperature, often due to disposal of waste heat from industrial or power generation processes |
| recruitment | survival of young plants and animals from birth to a life stage less vulnerable to environmental change. |
| cascade | A short, steep drop in streambed elevation often marked by boulders and agitated white water. |
| extended forecast discussion | This discussion is issued once a day around 2 PM EST (3 PM EDT) and is primarily intended to provide insight into guidance forecasts for the 3- to 5-day forecast period. The geographic focus of this discussion is on the United States (including Alaska and Hawaii). Although portions of this narrative will parallel the Hemispheric Map Discussion, a much greater effort is made to routinely relate the model forecasts and necessary modifications to weather forecasts, mainly in terms of temperature and precipitation. Other significant parameters, such as wind, may be discussed when deemed reliably predictable. This discussion serves as primary guidance to local National Weather Service offices for the preparation of their extended forecasts in the State Forecast Product and some Zone Forecast Products. |
| felcc | Firm energy load carrying capability (FELCC) is the amount of energy the region's generating system, or an individual utility or project, can be called on to produce on a firm basis during actual operations |
| basic solution | Any water solution that is basic (pH greater than 7) or has less hydrogen ions (H+) than hydroxide ions (OH-) |
| thirst | sensation of dryness in the mouth and throat; the need/desire to drink. |
| entrapment zone | An area of an estuary or other watercourse where seaward-flowing fresh water overlays more dense, saline ocean water resulting in a two-layer mixing zone characterized by Flocculation, aggregation, and accumulation of suspended materials from upstream. |
| pluviophobia | The fear of rain or of being rained on. See Ombrophobia. |
| normal water level | For a reservoir with a fixed overflow, the lowest crest level of that overflow |
| sustained overdraft | Long-term withdrawal from the aquifer of more water than is being recharged. |
| heritage | lit |
| tailwater | (1) The area immediately downstream of a spillway |
| bellot winds | Refers to the winds in the Canadian Arctic that blow through the narrow Bellot Strait between Somerset Island and the Boothia Peninsula, connecting the Gulf of Boothia and Franklin Strait. |
| groundwater basin | A groundwater reservoir, defined by an overlying land surface and the underlying aquifers that contain water stored in the reservoir |
| ichthyology | The scientific study of fishes. |
| preservation | The natural resources policy that stresses the aesthetic aspects of forests, rivers, wetlands, and other areas and tends to favor leaving such areas in an undisturbed state. |
| landslide | a movement of earth mass down a steep slope. |
| surface runoff | Surface runoff is water flow on the land that occurs when the soil is saturated with water and the excess water (from precipitation or snowmelt) runs over the surface. |
| free trade | trade taking place between countries free of any barrier such as taxation, tariffs or quotas. |
| potential drop | Difference in total head between two Equipotential Lines. |
| rime | Deposit of ice crystals that occurs when fog or super cooled water droplets comes in contact with an object with a temperature below freezing (0° Celsius) |
| venturi meter | A meter, developed by Clemens Herschel, for measuring flow of water or other fluids through closed conduits or pipes |
| 100-year flood | A flood so large, it has a 1% chance of occurring in any given year |
| core area | The area of habitat essential in the breeding, nesting and rearing of young, up to the point of dispersal of the young. |
| pore | An opening in a membrane or medium that allows water to pass through. |
| groundwater reservoir | an aquifer or aquifer system in which ground water is stored |
| well | a bored, drilled, or driven shaft or a dug hole whose depth is greater than the largest surface dimension and whose purpose is to reach underground water supplies or oil or to store or bury fluids below ground. |
| partial-duration flood series | A list of all flood peaks that exceed a chosen base stage or discharge, regardless of the number of peaks occurring in a year. |
| manning roughness coefficient | after Robert Manning |
| interfacial tension | the strength of the film separating two immiscible fluids (e.g., oil and water) measured in dynes per, or millidynes per, centimeter. |
| ecological succession | An orderly, directional and therefore predictable process of development that involves changes in species structure and community processes over time |
| base flood | The national standard for floodplain management is the base, or one percent chance flood |
| ceiling balloon | A small balloon used to determine the height of the cloud base |
| biomass | The total quantity (at any given time) of living organisms of one or more species per unit of space (species biomass), or of all the species in a biotic community (community biomass). |
| quadrat | a square frame with a measured grid of wire within it used to lay over surfaces and enable systematic sampling. |
| emulsifier | A chemical that helps suspending one liquid in another. |
| advection | The horizontal movement of an air mass that causes changes in the physical properties of the air such as temperature and moisture. |
| biomass | total amount of organic material. |
| storage | Water held in a reservoir for later use. |
| laterite | Hard subsurface deposit of oxides of aluminum and iron found in tropical soils where the water table fluctuates with seasonal changes in precipitation. |
| fjord | A fjord is a long, narrow sea inlet that is bordered by steep cliffs. |
| canal system operation | Water transfer from its source to points of diversion for irrigation, municipal and industrial, fish and wildlife, and drainage purposes. |
| specific gravity | The ratio of the mass of a body to the mass of an identical volume of water at a specific temperature. |
| brood year | The year in which the eggs were spawned |
| adaptive management areas | Landscape units designated for development and testing of technical and social approaches to achieving desired ecological, economic, and other social objectives. |
| cloud seeding | An experimental process used to weaken hurricanes or make rain in dry areas. |
| cloud layer | An array of clouds whose bases are at approximately the same level. |
| surface runoff | The runoff that travels overland to the stream channel |
| accretion | a gradual increase in land area adjacent to a river. |
| ice lens | in periglacial areas, as winter sets in, land not under continuous permafrost will experience freezing of water in the surface layer |
| pore pressure | The interstitial pressure of water within a mass of soil, rock, or concrete. |
| pathogens | often used instead of fecal coliform bacteria as an indicator of water contamination. |
| npdes | National Pollutant Discharge Elimination System |
| subirrigation | See Irrigation. |
| multi-family residential | A planning term used to describe a building in which two or more families live in separate but attached dwellings, e.g., apartment houses, townhomes and condominiums. |
| transpiration | process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, such as leaf pores. |
| continental crust | Granitic portion of the Earth's crust that makes up the continents |
| solar eclipse | An eclipse of the sun occurs when the moon is in a direct line between the sun and the earth, casting some of the earth's surface in its shadow |
| diablo winds | Dry winds in the Diablo mountain range in central California that can exceed 60 miles per hour |
| crater | Circular depression in the ground surface created by volcanic activity or asteroid impact. |
| corona | A pastel halo around the moon or sun created by the diffraction of water droplets |
| percolating waters | waters passing through the ground beneath the Earth's surface without a definite channel. |
| ground | (1) The solid surface of the earth |
| comet | A large mass of ice and dust that has an orbit around a star. |
| gatt | see General Agreement on Tariffs and Trade. |
| flatboat | A boat with a flat bottom and square ends used for transportation of bulky freight, especially used in shallow waters. |
| rilling | a series of small channels which form on a slope after heavy rainfall |
| naturalization | The process by which introduced fish successfully establish a naturally spawning population. |
| fill | (1) (Geology) Any sediment deposited by any agent such as water so as to fill or partly fill a channel, valley, sink, or other depression |
| active layer | the upper few metres of soil in a periglacial area which undergoes thawing in summer and is prone to mass movement relative to the permafrost layer below. |
| rope stage | The dissipating stage of a tornado, characterized by thinning and shrinking of the condensation funnel into a rope (or rope funnel) |
| water table | level below the earth's surface at which the ground becomes saturated with water |
| precocious | Fish that have matured quickly, or faster than the remaining fish of its age-class. |
| rating table | A table of stage values and the corresponding discharge for a river gaging site. |
| stratovolcano | See composite volcano. |
| snowpack | The amount of annual accumulation of snow at higher elevations. |
| spring | an issue of water from the earth; a natural fountain; a source of a body or reservoir of water. |
| threshold | The level of magnitude of a system process at which sudden or rapid change occurs. |
| adaptive management | The process of implementing policy decisions as scientifically driven management experiments that test predictions and assumptions in management plans, and using the resulting information to improve the plans. |
| spodosols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| effluent streams | Effluent streams are those leaving a lake. |
| metamorphic rock | rocks created by the chemical alteration of existing rocks under the influence of temperature, pressure, or both. |
| sewer inspection | Viewing the sewer primarily with the aid of sewer CCTV equipment, and or manually, to assess overall condition |
| albedo | the amount of insolation reflected from the atmosphere and surface back to space |
| geoid | True shape of the Earth, which deviates from a perfect sphere because of a slight bulge at the equator. |
| diseconomies of scale | at large-scale levels of output inefficienies may creep in and cause unit costs to rise. |
| windy | 20 to 30 mph winds |
| transmissibility | The capacity of a rock to transmit water under pressure |
| debris flow | A rapid moving mass of rock fragments, soil, and mud, with more that half of the particles being larger that sand size. |
| bedrock | solid rock underlying other surface materials. |
| continent | A large land mass rising abruptly from the deep ocean floor, including marginal regions that are shallowly submerged |
| representative fraction | The expression of map scale as a mathematical ratio. |
| latosol | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| elastic rebound theory | Theory that describes how earthquakes arise from the horizontal movement of adjacent tectonic plates along a linear strike-slip fault |
| conventional systems | (Water Quality) Systems that have been traditionally used to collect municipal wastewater in gravity sewers and convey it to a central primary or secondary treatment plant prior to discharge to surface waters. |
| landscape impoundment | body of reclaimed water which is used for aesthetic enjoyment or which otherwise serves a function not intended to include contact recreation. |
| bay-mouth bar | A narrow deposit of sand and/or gravel found across the mouth of a bay. |
| hydrologic cycle | the cyclic transfer of water vapor from the Earth's surface via evapotranspiration into the atmosphere, from the atmosphere via precipitation back to earth, and through runoff into streams, rivers, and lakes, and ultimately into the oceans. |
| glacial budget | The annual relationship between accumulation and wastage |
| offshore | holds different meanings in different contexts: geomorphology -features found on the seaward side of the wave breakpoint. meteorology -wind moving from the land to the sea. |
| aquaduct | A pipe or conduit made to bring water from a source. |
| tariff | a duty or tax placed on imports as part of protectionist policy. |
| sustainable management | A method of exploiting a resource that can be carried on indefinitely |
| remedial action | The actual construction or clean-up phase of a Superfund site cleanup |
| perched groundwater | Local saturated zones above the water table which exist above an impervious layer of limited extent. |
| instream flows | (1) Portion of a flood flow that is contained by the channel |
| push factor | a negative quality of a place which pushes people to migrate away from it. |
| silcretes | Sedimentary rock created by the chemical precipitation of silica. |
| connector system | Conveys water from a single source to a different location typically without intermediate collection of diversions |
| retail park | an out-of-town centre which allows several stores to operate around some shared resources such as car park and restaurants. |
| place of use | The specific location, typically documented in a water right permit, where water is applied or used |
| milky way galaxy | Aggregation of about 400 billion stars in a flattened, disk-shaped structure in space |
| intangible flood damage | Estimates of the damage done by disruption of business, danger to health, shock, and loss of life and in general all costs not directly measurable which require a large element of judgment for estimating. |
| hydrolysis | the decomposition of organic compounds by interaction with water. |
| degradation | The geologic process by means of which various parts of the surface of the earth are worn down and carried away and their general level lowered, by the action of wind and water. |
| pluvial | In hydrology, anything that is brought about directly by precipitation. |
| heat exchanger | A component that is utilized to remove heat from or ad heat to a liquid. |
| starch | Complex carbohydrate composed of thousands of glucose units |
| cold air funnel | A funnel cloud or (rarely) a small, relatively weak tornado that can develop from a small shower or thunderstorm when the air aloft is unusually cold (hence the name) |
| zone of transport | The area surrounding a pumping well, bounded by an Isochrone and/or isoconcentration contour, through which a contaminant may travel and reach the well. |
| air mass | A large body of air that has nearly uniform conditions of temperature and humidity. |
| cap | see common agricultural policy. |
| inches of runoff | The volume of water from runoff of a given depth over the entire drainage basin. |
| biological weathering | The disintegration of rock and mineral due to the chemical and/or physical agents of an organism. |
| dissolved load | those minerals that have been taken into solution and are carried along by a river. |
| upwelling | The movement of nutrient-rich deep seawater to the ocean's surface. |
| aoa | An acronym for "At or Above". |
| turbine | A propeller or wheel device driven by the pressure of liquid or gas. |
| landspout | Slang for a tornado that does not arise from organized storm-scale rotation and therefore is not associated with a wall cloud (visually) or a mesocyclone (on radar) |
| stemflow | the flow of water down stems and trunks after interception of rainfall. |
| phreatophyte | A plant that habitually obtains its water supply from the zone of saturation, either directly or through the capillary fringe. |
| anchor ice | Submerged Frazil ice attached or anchored to the river bottom, irrespective of its formation. |
| nitrogen saturation | Over abundance of nitrogen in natural ecosystems because of human induced inputs related to agriculture and fossil fuel combustion. |
| flow rate | The rate, expressed in gallons or liters-per-hour, at which a fluid escapes from a hole or fissure in a tank |
| non-ionizing radiation | A form of electromagnetic radiation that does not have enough energy to cause ionization of atoms in living tissue |
| mean discharge | (MEAN) is the arithmetic mean of individual daily mean discharges during a specific period. |
| high tide | the highest point to which the sea rises against the land in its daily vertical movement. |
| coriolis force | An apparent force due to the Earth's rotation |
| photoperiod | The duration of the daylight period. |
| vortex | In its most general use, any flow possessing vorticity |
| relief | The vertical difference between the surface in valleys and hilltops or the vertical between the base of a glacier and its top. |
| cross-profile | cut away view through a feature from side to side. |
| snow line | The elevation above which snow can form and remain all year. |
| evapotranspiration | combination of evaporation and transpiration of water into the atmosphere from living plants and soil |
| native stock | An indigenous stock of fish that has not been substantially affected by genetic interactions with non-native stocks or by other factors, and is still present in all or part of its original range. |
| temperature | Measure of how hot or cold it is in an area. |
| mediterranean scrubland | See chaparral. |
| success | Catch per unit of effort. |
| fresh water | Water that is relatively free of salts. |
| surge | The increase in sea water height from the level that would normally occur were there no storm |
| wave attack | Impact of waves on a stream bank. |
| market town | a town whose main function is to act as a market place for the surrounding area. |
| filter | porous material through which a liquid or gas is passed in order to separate out suspended particulate matter. (FILTRATION-act of filtering.) |
| flash flood table | A table of pre-computed forecast crest stage values for small streams for a variety of antecedent moisture conditions and rain amounts |
| channel storage | The volume of water at a given time in the channel or over the flood plain of the streams in a drainage basin or river reach |
| thunder | The sound emitted by rapidly expanding gases along the channel of a lightning discharge |
| trunk myomeres of lampreys | The number of body segments between the last gill opening and the cloacal slit. |
| natant | Floating or swimming win water. |
| lateral moraine | Moraine that is found along the sides of a glacier |
| right mover | A thunderstorm that moves appreciably to the right relative to the main steering winds and to other nearby thunderstorms |
| downburst | A strong down draft, initiated by a thunderstorm, that induces an outburst of damaging straight line winds on or near the ground |
| chemical weathering | Dissolving of rock by exposure to rainwater, surface water, oxygen, and other gases in the atmosphere, and compounds secreted by organisms. |
| isohyet | line that connects points of equal rainfall. |
| salt water intrusion | the invasion of fresh surface or ground water by salt water |
| drawdown | The lowering of the surface elevation of a body of water, the water surface of a well, the water table, or the piezometric surface adjacent to the well, resulting from the withdrawal of water therefrom. |
| fish ladder | See Fishway. |
| bayhead beach | An extensive deposit of sand and/or gravel in the form of a beach at the back of a bay. |
| geothermal energy | The heat energy available in the earth's subsurface, extracted from three basic sources: (1) steam; (2) hot water; and (3) hot rocks or near surface intrusions of volcanic molten rock |
| maritime | of the sea. |
| labor | the mental and/or physical talents contributed by people for the production of goods or services lactose - a white organic substance made from milk that is used in infant foods, bakery products and confections; also used as a "culture" in laboratories landfill - an open area where trash is buried leach - to remove components from the soil by the action of water trickling through levees - dikes or other embankments which contain water within a given course local runoff - water running off a local area, such as rainfall draining into a nearby creek |
| benchmark | Data used as a base for comparative purposes with comparable data. |
| tundra | the biome found in the Arctic circle across North America, Greenland and Europe |
| collector well | a well located near a surface water supply used to lower the water table and thereby induce infiltration of surface water through the bed of the water body to the well. |
| coliform | type of bacteria whose presence in water may indicate contamination by disease-causing microorganisms; removed by disinfection at treatment plants. |
| taiga | See Boreal Forest. |
| insolation weathering | Form of physical weathering |
| peridotite | Coarse grained ultramafic igneous rock composed mainly of olivine and pyroxene |
| cyclomatic number | the number of circuits in a network. |
| carrying capacity | the idea that any given environment can only support a finite population |
| morphology | The structure, form and appearance of an organism. |
| cooling tower | large tower used to transfer the heat in cooling water from a power or industrial plant to the atmosphere either by direct evaporation or by convection and conduction. |
| specific humidity | The ratio of the density of the water vapor to the density of the air, a mix of dry air and water vapor |
| old-growth associated species | Plant and animal species that exhibit a strong association with old-growth forests. |
| nitrate | Form of nitrogen commonly found in the soil and used by plants for building amino acids, DNA and proteins |
| optimum yield | (OY) The yield from a fishery which provides the greatest overall benefit to the nation with particular reference to food production and recreational opportunities; it is based on MSY as modified by economic, social or ecological factors |
| reproduce | To produce offspring. |
| well plug | a seal installed in a borehole or well preventing movement of fluids. |
| organic matter | substances from plants and animals (living organisms); based on carbon compounds. |
| alluvium | Sediment or loose material such as clay, silt, sand, gravel, and larger rocks deposited by moving water. |
| storage coefficient | (1) For surface water, the relation of storage capacity in a reservoir to the mean annual flow of a stream above the dam forming the reservoir |
| bankfull stage | An established river stage at a certain point along a river which is intended to represent the maximum safe water level which will not overflow the river banks or cause any significant damage within the reach of the river. |
| centralized control | Control of a canal project from a central location by the watermaster. |
| fracture zone | An area which has a great number of fractures. |
| alluvial | Deposited by running water. |
| pascal | The unit of pressure produced when one newton acts on about one square meter. |
| fresh water inflow requirements | freshwater flows required to maintain the natural salinity, nutrient, and sediment delivery in a bay or estuary that supports their unique biological communities and ensures a healthy ecosystem. |
| reservoir | Any natural or artificial holding area used to store, regulate, or control water prior to distribution into homes and businesses. |
| alluviation | the process of depositing alluvium. |
| homogenous aquifer | an aquifer that has similar forms or characteristics throughout, such as a uniform gravel aquifer |
| day-second feet | Often abbreviated as SDF |
| wire | It is used for distances between 0 and 400 feet. |
| oml | An Operations Manual Letter |
| range resolution | The ability of radar to distinguish between targets on the same azimuth but at different ranges. |
| water balance | Allocation of water uses by specific sites to compare with meter records. |
| clay | a particle size classification for rock |
| lake | A body standing water found on the Earth's continental land masses |
| gaging station | is a particular site on a stream, canal, lake, or reservoir where systematic observations of hydrologic data are obtained. |
| lipid | Is an organic compound composed of carbon atoms that have two hydrogen atoms attached |
| probable maximum precipitation | The maximum amount of precipitation for a given period that can reasonably be expected to occur in a specific drainage basin. |
| slope stability | The resistance of a natural or artificial slope or other inclined surface to failure by landsliding (mass movement). |
| earthlight | The faint illumination of the dark part of the moon's disk produced by sunlight reflected onto the moon from the earth's surface and atmosphere. |
| wind chill warning | The National Weather Service issues this product when the wind chill is life threatening |
| irrigation leaching requirement | The amount of water required to move residual salts out of the root zone and maintain an adequate soil-salt balance for crop production. |
| channel | The deeper, narrow elogated or more sharply trenched part of a lake bottom. |
| pondage | (1) The holding back of water for later release for power development above the dam of a hydroelectric plant to (a) equalize daily or weekly fluctuations of streamflow or (b) to permit irregular hourly use of water by the wheels to care for fluctuations in the load demand |
| isothermal layer | Vertical layer in the atmosphere where temperature remains unchanged |
| oasis | a wet-point site in an arid area. |
| vapour | The gaseous phase of substances such as water. |
| commuter | a person undertaking commuting. |
| moderate flooding | The inundation of secondary roads; transfer to higher elevation necessary to save property -- some evacuation may be required. |
| riparian zone | A stream and all the vegetation on its banks. |
| total gross reservoir capacity | The total amount of storage capacity available in a reservoir for all purposes from the streambed to the normal water or normal water or normal pool surface level |
| reg | A rocky desert landscape |
| tertiary | Geologic period that occurred roughly 1.6 to 65 million years ago |
| snow | Precipitation of snow crystals, mostly branched in the form of six-pointed stars |
| short-fuse warning | A warning issued by the NWS for a local weather hazard of relatively short duration |
| deprivation | a situation where quality of life is below that of what can be expected for a particular place at a particular time. |
| dissolved oxygen | The amount of oxygen dissolved in water at a certain time, expressed in ppm mg/L. |
| slough | A shallow backwater inlet that is commonly exposed at low tide. |
| dissociation | Chemical process where a compound or molecule breaks up into simpler constituents. |
| evaporation fog | A type of fog produced from the advection of cold air over warm water or warm or moist land |
| bar chart | bars of equal width placed within perpendicular axes and used to represent varied amounts or frequencies through variations in length. |
| oceanic crust | Basaltic portion of the Earth's crust that makes up the ocean basins |
| cove | A cove is small, horseshoe-shaped body of water along the coast; the water is surrounded by land formed of soft rock. |
| metamorphism | Process that creates metamorphic rocks. |
| composites | Plants of the compositae family (Asteraceae) |
| return flow | irrigation water that is applied to an area and which is not consumed in evaporation or transpiration and returns to a surface stream or aquifer. |
| wetting and drying | Physical weathering process where rocks are mechanically disintegrated by the accumulation of successive layers of water molecules in between the mineral grains of a rock |
| flow | The discharge rate of a resource, expressed in volume during a certain period of time. |
| load | The amount of electric power or energy delivered or required at any specified point or points on a system. |
| back-sheared anvil | Slang for a thunderstorm anvil which spreads upwind, against the flow aloft |
| dissolved gas concentrations | The amount of chemicals normally occurring as gases, such as nitrogen and oxygen, that are held in solution in water, expressed in units such as milligrams of the gas per liter of liquid |
| magnetic south | See South Magnetic Pole. |
| gall-peters projection | Map projection system that reduces the area distortion found in Mercator projections. |
| meander breadth | The distance between the lines used to define the Meander Belt. |
| saltwater intrusion | Replacement of freshwater by saline water in an aquifer or body of water. |
| wadi | steep-sided valley or ravine in desert and semi-arid areas |
| freshwater | marine, brackish). |
| nebraskan | North American glaciation related to European Gunz glaciation. |
| flood of record | The highest observed river stage or discharge at a given site during the period of record keeping |
| density | The weight of a certain amount of water |
| agribusiness | corporations organized to provide vertical linkages both below and above the farm itself. |
| azimuth | A direction in terms of a 360o compass |
| public corporation | an economic enterprise that has been nationalized. |
| quench | (1) To slake one's thirst |
| raceway | A concrete, rectangular fish-rearing unit generally associated with a hatchery. |
| gray water | Waste water from a household or small commercial establishment which specifically excludes water from a toilet, kitchen sink, dishwasher, or water used for washing diapers. |
| channelization | The process of changing and straightening the natural path of a waterway. |
| capillary zone | The soil area above the water table where water can rise up slightly through the cohesive force of Capillary Action. |
| esker | A long, snakelike ridge of sediment deposited by a stream that ran under or within a glacier. |
| siltation | The deposition or accumulation of fine soil particles. |
| tertiary sector | those industries providing services, both private and public. |
| relief | The range of topographic elevation within a specific area. |
| dye testing | A testing process using non-toxic dye to assist in the location and quantifying of specific defects in a sewer line |
| urban fringe | the mixed marginal area lying outside the established urban area where the rural characteristics are increasingly overshadowed by encroaching urban features such as new housing, shopping centres, industrial estates and the like. |
| littoral zone | The area on, or near the shore of a body water. |
| fluvial | Involving running water |
| graphic scale | Way of expressing the scale of a map with a graphic. |
| coastal flooding | Flooding that occurs from storms where water is driven onto land from an adjacent body of water |
| bid-rent theory | the idea that land is acquired by the highest bidder which is in turn a function of the user who can make the most profit from the site |
| greywater | wastewater from clothes washing machines, showers, bathtubs, handwashing, lavatories and sinks that are not used for disposal of chemical or chemical-biological ingredients. |
| boiler scale | mineral deposits from water, such as those found inside pipes or teakettles bond - a promise to repay money borrowed, plus interest, over a specified period of time bond issue - a means of raising large amounts of money for major projects by selling bonds brackish - water containing too much salt to be useful to people but less salt than ocean water by-products - something produced in addition to the principal product |
| snow melt | Conversion of snow into runoff and groundwater flow with the onset of warmer temperatures. |
| harvest controls | Regulations established for commercial and sport fisheries to ensure that the correct proportion of the different stocks escape to spawn. |
| quantitative analysis | (Data Analysis) The examination of phenomena using actual observed data with an intention to explain historical behavior and/or predict the future behavior of some phenomenon. |
| sea-run | Synonymous to anadromous but is usually used only in reference to the anadromous component of species such as O |
| petroleum derivatives | chemicals formed when gasoline breaks down in contact with water. |
| ground water flow | Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel |
| alternative technology | (usually interchangeable with appropriate or intermediate technology) the use of low-cost, often labour-intensive, technology, based on local resources, that is appropriate to Economically Less Developed Countries |
| million gallons per day | A rate of flow of water of one million gallons per twenty-four hour period. |
| quartz | a mineral commonly found in continental crust. |
| slight chance | A National Weather Service precipitation descriptor for a 20 percent chance of measurable precipitation (0.01 inch). When the precipitation is convective in nature, the term widely scattered is used. See Precipitation Probability (PoP). |
| a-run steelhead | Summer steelhead crossing Bonneville Dam on or before August 25. |
| pumping station | Mechanical devices installed in sewer or water systems or other liquid-carrying pipelines to move the liquids to a higher level. |
| ecological interaction | The sum total of impacts of one species on another species, or on other members of the same species. |
| ihn | Infectious Hematopoietic Necrosis; a viral disease endemic to salmonid fishes of the Pacific Coast of North America that can cause high mortality in 3-week to 6-month-old fish. |
| water supply system | Includes the works and auxiliaries for collection, treatment, storage, and distribution of the water from the sources of supply to the free-flowing outlet of the ultimate consumer. |
| artesian well | a water well drilled into a confined aquifer where enough hydraulic pressure exists for water rise in the well to a height above the top of the aquifer in the subsurface |
| stadial moraine | See recessional moraine. |
| smpdbk | The Simplified Dam Break (DAMBRK) Model. |
| corrosivity | Ability of water to dissolve or break down certain substances, particularly metals. |
| magnetic north | See North Magnetic Pole. |
| clay-humus complex | a soil particle made up of clay and some humus. |
| supersaturation | In water, the condition which occurs in the atmosphere when the relative humidity is greater than 100 percent. |
| wsr-88d unit | Weather Service Radar, commissioned in 1988 |
| transpiration | direct transfer of water from the leaves of living plants to the atmosphere |
| percolation | The movement of water downward through the subsurface to the zone of saturation. |
| kilowatt hour | One kilowatt of power applied for one hour. |
| wind direction | The true direction from which the wind is moving at a given location |
| rain | liquid precipitation from the atmosphere in drops of at least 0.5mm in diameter. |
| middle clouds | In the middle family are the altostratus, altocumulus, and nimbostratus clouds |
| sustained yield | Achievement and maintenance, in perpetuity, of a high-level annual or regular periodic output or harvest of the various renewable land and water resources. |
| bedrock | Rock at or near (beneath soil and regolith) the Earth's surface that is solid and relatively unweathered. |
| ebris flow | A type of mass movement where there is a downslope flow of a saturated mass of soil, sediment, and rock debris. |
| tractive force | The drag on a streambed or bank caused by passing water, which tends to pull soil particles along with the streamflow. |
| phreatic line | The line marking the upper surface of the Zone of Saturation in the soil. |
| irrigation efficiency | the percentage of water applied, and which can be accounted for, in the soil moisture increase for consumptive use. |
| volume scan | A radar scanning strategy in which sweeps are made at successive antenna elevations (i.e., a tilt sequence), and then combined to obtain the three-dimensional structure of the echoes |
| coagulate | to gather together or form into a mass or group. |
| plantae | Group, at the kingdom level, in the classification of life |
| disinfection | the killing of the larger portion of the harmful and objectionable bacteria in the sewage |
| bergschrund | The ice wall commonly found at the head of a glacier which has separated slightly from the rock wall of its cirque. |
| sand sea | A large region of sand and sand dunes in a desert |
| confined groundwater | Groundwater trapped between two impervious layers of rock. |
| ahos | Automatic Hydrologic Observing System |
| saturated | lit |
| keraunophobia | The fear of thunder and lightning. |
| glacial outburst flood | A sudden release of melt water from a glacier or glacier-dammed lake sometimes resulting in a catastrophic flood, formed by melting of a channel or by subglacial volcanic activity. |
| upflow | an upward flow. |
| celsius scale | Scale for measuring temperature |
| buoyancy | the tendency of a body to float or rise when immersed in a fluid; the power of a fluid to exert an upward force on a body placed in it. |
| t rolls | Slang term for transverse rolls. |
| riparian vegetation | Plants adapted to moist growing conditions found along waterways and shorelines |
| coliform | A bacteria that originates in the digestive system of mammals |
| dry slot | An area of dry, and usually cloud-free, air that wraps into the southern and eastern sections of a synoptic scale or mesoscale low pressure system |
| fertilizer | Substance that adds inorganic or organic nutrients to soil for the purpose of increasing the growth of crops, trees, or other vegetation. |
| stratocumulus | A low cloud composed of layers or patches of cloud elements |
| acequia | acequias are gravity-driven waterways, similar in concept to a flume |
| climate change | The slow variations of climatic characteristics over time at a given place. |
| headwater | Referring to the source of a stream or river. |
| volcanic vent | An opening on a volcano through which lava is released and rock fragments and ash are ejected. |
| moraine | debris deposited by a glacier |
| area-capacity curve | A graph showing the relation between the surface area of the water in a reservoir, the corresponding volume, and elevation. |
| mode | Statistical measure of central tendency in a set of data |
| refraction | The bending of light or radar beam as it passes through a zone of contrasting properties, such as atmospheric density, water vapor, or temperature. |
| tap allocation | The process used for distributing 3/4-inch taps among applicants when shortages of treatment, transmission or distribution facilities and/or water supplies require a method of rationing taps. |
| stratus | It is a low, uniform sheet-like cloud |
| specific conductance | Method to estimate the dissolved solid content of a water supply by testing its conductivity. |
| inorganic | Non-living thing |
| design capacity | The average daily flow that a treatment plant or other facility is designed to accommodate. |
| engineer's level | A telescope which is attached to a spirit-tube level, all revolving around a vertical axis and is mounted on a tripod |
| core | two main associations in geography: |
| aerosol | Very small liquid or solid particles dispersed in air. |
| pressure | The force exerted by the weight of the atmosphere, also known as atmospheric pressure. When measured on a barometer, it is referred to as barometric pressure and it is expressed in inches of mercury, millibars, or kiloPascals. |
| site factors | those characteristics of a site which make it suitable for settlement. |
| lithosphere | the crust and upper mantle |
| sprinkler irrigation | A pressurized irrigation system where water is distributed through pipes to the field and applied through a variety of sprinkler heads or nozzles |
| leaching field | The area used for disposal of liquid through a non-water-tight artificial structure, conduit, or porous material by downward or lateral drainage, or both, into the surrounding permeable soil. |
| creep | extremely slow downslope movement of soil |
| chemical oxygen demand | The amount of oxygen (measured in mg/L) that is consumed in the oxidation of organic and oxidasable inorganic matter, under test conditions |
| multiple use | Use of bodies of water for more than one purpose, such as recreational purposes, fishing, and water supply. |
| high-order good/service | one which is high in value and long-lasting and therefore generally bought infrequently e.g |
| endangered species | A species found in nature that has so few surviving individuals that the it could soon become extinct in all or most of its natural range |
| agricultural chain | every step in the process(es) that lead to the consumption of food. |
| complex gale/storm | In the National Weather Service High Seas Forecast, an area for which gale/storm force winds are forecast or are occurring, but for which no single center is the principle generator of these winds. |
| catchment area | An area having a common outlet for its surface runoff (also see Drainage Area or Basin, Watershed). |
| trimlines | Sharp boundaries in vegetation abundance or community type showing the upper margin of a former glaciation |
| cokriging | A technique for estimating values of a spatial process (e.g., a precipitation field) given point observations of the process (e.g., rain gage observations) and possibly auxiliary observations (e.g., radar and satellite observations). |
| dry weather flow | Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel |
| environmental impact assessment | the identification, prediction and evaluation of the impact that a proposed development may have so that either strict regulations can be laid down governing its construction or the project can be rejected. |
| anistropic aquifer | an aquifer in which permeability varies with direction of flow |
| subsurface drainage | Rainfall that is not evapotranspirated or does not become surface runoff. |
| eutrophication | Physical, chemical and biological changes in a water body as a result of the input nitrogen and phosphorus. |
| eye | The relatively calm center in a hurricane that is more than one half surrounded by wall cloud |
| mean velocity | The average cross-sectional velocity of water in a stream channel |
| extinction | complete disappearance of a species because of failure to adapt to environmental change. |
| chalk | a porous, sedimentary rock formed mostly from the skeletal remains of marine organisms |
| kilogram | The base unit of mass in the International System of Units that is equal to the mass of a prototype agreed upon by international convention and that is nearly equal to 1,000 cubic centimeters of water at the temperature of its maximum density |
| lightning stroke | Any of a series of repeated electrical discharges comprising a single lightning discharge (strike) |
| ground water reservoir storage | The amount of water in storage within the defined limit of the aquifer. |
| inclined staff gage | A staff gage that is placed on the slope of a stream bank and graduated so that the scale reads directly in vertical depth. |
| zoned embankment dam | An embankment dam which is comprised of zones of selected materials having different degrees of porosity, permeability and density. |
| hazardous materials | Anything that poses a substantive present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed. |
| turkey tower | Slang for a narrow, individual cloud tower that develops and falls apart rapidly |
| omnivore | an organism that consumes plants ( producers) and animals (consumers). |
| geyser | a geothermal feature of the Earth where there is an opening in the surface that contains superheated water that periodically erupts in a shower of water and steam. |
| upriver bright stock | A stock of fall chinook destined for the Columbia River and several tributaries upstream from The Dalles Dam |
| mndot | Minnesota Department of Transportation |
| back scatter | It refers to the portion of the radar beam energy that returns back towards the radar after striking a target. |
| convergence | A contraction of a vector field; the opposite of divergence |
| three-hour rainfall rate | This WSR-88D Radar product displays precipitation total (in inches) of the current and past two clock hours as a graphical image |
| polycyclic landform | Landform that shows the repeated influence of one or more major geomorphic processes over geological time |
| tornado alley | A geographic corridor in the United States which stretches north from Texas to Nebraska and Iowa |
| frequency | The number of recurrences of a periodic phenomenon per unit time |
| depression storage | The volume of water contained in natural depressions in the land surface, such as puddles. |
| peak load | The maximum load in a stated period of time |
| µg/l | A measurement describing the amount of a substance (such as a mineral, chemical or contaminant) in a liter of water |
| water system | (1) A river and all its tributaries |
| water well | An excavation where the intended use is for location, acquisition, development, or artificial recharge of ground water. |
| check dam | a small dam constructed in a gully or other small water course to decrease the streamflow velocity, minimize channel erosion, promote deposition of sediment and to divert water from a channel. |
| black blizzard | A local term for a violent duststorm on the south-central Great Plains that darkens the sky and casts a pall over the land |
| guild | a group of species or organisms that use the same environmental resources (habitat, food source, etc.) or life history strategy (such as reproduction) in the same way. |
| distributary | A smaller branching stream channel that flows away from a main stream channel |
| crown | the upper part of a tree or other woody plant that carries the main system of branches and the foliage. |
| estuary | The thin zone along a coastline where freshwater systems and rivers meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon). |
| alluvium | river deposits found either on the floodplain or historic point-bars. |
| residential type | the housing tenure of an area: owner-occupied, rented privately, or rented from the government. |
| keyway | The notch excavated into the side of a gully or stream to anchor a check dam or other structure. |
| back siphonage | A reverse flow condition created by a difference in water pressures that causes water to flow back into the distribution pipes of a drinking water supply from any source other than the intended one. |
| low | A region of low pressure, marked as "L" on a weather map. A low center is usually accompanied by precipitation, extensive cloudiness, and moderate winds. See Cyclone. |
| compound | A compound is the atoms of different elements joined together. |
| npu | The Neighborhood Planning Unit System was established to provide an opportunity for citizens to participate actively in the Comprehensive Development Plan: the City's vision for the next 5, 10, and 15 years |
| product water | Water that has passed through a water treatment plant and is ready to be delivered to consumers. |
| perigee | The point nearest the earth on the moon's orbit |
| mollisols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| circulate | to move in a circle, circuit or orbit; to flow without obstruction; to follow a course that returns to the starting point. |
| stable/stability | Occurs when a rising air parcel becomes denser than the surrounding air |
| cirrocumulus standing leticular | These clouds are formed on the crests of waves crested by barriers in the wind flow |
| estuary | Region of interaction between rivers and near-shore ocean waters, where tidal action and river flow mix fresh and salt water |
| cut-off high | A warm high which has become displaced and is on the polarward side of the jet stream |
| fish | Group of vertebrate animals that inhabit aquatic habitats. |
| alluvium | Sediments deposited by erosional processes, usually by streams. |
| current meter | Device used to measure the water velocity or current in a river. |
| linear | lit |
| condensate | Water obtained by condensation of water vapour. |
| macrophytes | Aquatic plants that are large enough to be seen with the naked eye. |
| secondary succession | the process of revegetation of an area that has been cleared for some reason. |
| u-shaped valley | see glacial valley. |
| fohn | warm, dry wind descending in the Alps |
| first law of thermodynamics | See Law of Conservation of Energy. |
| data buoys | Buoys placed throughout the Gulf of Mexico and along the Atlantic and Pacific coasts of the United States that relay information on air and water temperature, wind speed, air pressure, and wave conditions via radio signals. |
| sferic | A transient electric or magnetic field generated by any feature of lightning discharge (entire flash). |
| potable water | Water that is safe for drinking or cooking. |
| thalweg | (1) The lowest thread along the axial part of a valley or stream channel |
| blowing sand | Sand that is raised by the wind to heights of six feet or greater |
| mean low water | The average height of the daily low tides recorded over a 19-year period at a specific location. |
| scattering | The change in direction, frequency, or polarization of electromagnetic waves |
| human ecology | (1) A branch of sociology dealing particularly with the spatial and temporal interrelationships between humans and their economic, social, and political organization; (2) The ecology of human communities and populations, especially as concerned with preservation of environmental quality (as of air or water) through proper application of conservation and civil engineering practices. |
| underground storage tank | A tank and any underground piping connected to the tank that has 10% or more of its volume (including pipe volume) beneath the surface of the ground |
| rolled fill dam | An embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment. |
| thermodynamic laws | Laws that describe the physical processes, relationships, and phenomena associated with heat. |
| chemosphere | A vaguely defined region of the upper atmosphere in which photochemical reactions take place |
| unconfined aquifer | An aquifer containing water that is not under pressure; the water level in a well is the same as the water table outside the well |
| interspecific | Occurring among members of different species. |
| forest land | Land that is now, or is capable of becoming, at least 10 percent stocked with forest trees and that has not been developed for nontimber use. |
| aerated lagoon | a holding and/or treatment pond that speeds up the natural process of biological decomposition of organic waste by stimulating the growth and activity of bacteria that degrade organic waste. |
| system element | System elements are the kinds of things or substances composing the system |
| quantitative precipitation forecast | A forecast of the amount of precipitation which will fall during a specific time period |
| interflow | The lateral motion of water through the upper layers until it enters a stream channel |
| peninsula | A peninsula is a body of land that is surrounded by water on three sides. |
| void | the pore space or other openings in rock |
| environment | The sum total of all the external conditions that effect an organism, community, material, or energy. |
| infiltration | Penetration of water into a medium, for instance the soil. |
| intertropical convergence zone | The boundary zone separating the northeast trade winds of the Northern Hemisphere from the southeast trade winds of the Southern Hemisphere. |
| harvested water | Precipitation or irrigation runoff collected, stored, and available for reuse for irrigation purposes. |
| bar screen | in wastewater treatment, a device used to remove large solids from the incoming wastewater stream. |
| weather | the day-to-day state of the atmosphere. |
| colloids | Matter of very small particle size, in the range of 10-5 to 10-7 in diameter. |
| family of services | Since 1983, the National Weather Service (NWS) has provided external user access to U.S |
| lightning flash | The total luminous phenomenon accompanying a lightning discharge |
| hardpan | A layer of nearly impermeable soil beneath a more permeable soil, formed by natural chemical cementing of the soil particles. |
| tss | Total Suspended Solids |
| firn line | The highest level to which the fresh snow on a glacier's surface retreats during the melting season |
| gabion | A wire basket or cage that is filled with gravel or cobble and generally used to stabilize streambanks. |
| pump curve | The relationship between the head developed by a pump and the capacity (flow) for a constant rotative speed. |
| mulching | The use of plant residues or other suitable materials on the soil surface, primarily to reduce evaporation of water and erosion of soil. |
| post-storm report | A report issued by a local National Weather Service office summarizing the impact of a tropical cyclone on it's forecast area |
| competition | where more than one company provides a good or service |
| watershed | the line where drainage basins meet and which determines to which basin precipitation will go. |
| quarry water | the moisture content of freshly quarried stone, esp |
| snow water equivalent | The water content obtained from melting accumulated snow. |
| sample and hold | The process of sampling (measuring) the signal strength at a particular point in space (i.e., at a range gate). |
| travel corridors | Paths animals use during their migrations. |
| gill rakers | A series of projections located along the front edge of the gill arch. |
| geomorphic threshold | The amount of slow accumulated change a landform can take before it suddenly moves into an accelerated rate of change that takes it to a new system state. |
| watershed | Catchment area of a drainage basin. |
| ceilometer | A device used to evaluate the height of clouds or the vertical visibility into a surface-based obscuration. |
| rosa | Remote Observation System Automation |
| overflow rate | one of the guidelines for design of the settling tanks and clarifiers in a treatment plant. |
| second-day feet | The volume of water represented by a flow of one cubic foot per second for 24 hours; equal to 86,400 cubic feet |
| odd-year pink salmon | Pink salmon that spawn in odd-numbered years |
| gradually varied flow | (Hydraulics) Non-uniform flow in which depth of flow changes gradually through a reach |
| abandoned well | a well which is no longer used |
| appropriation doctrine | the system for allocating water to private individuals used in most Western states |
| taku | Name for a katabatic type of cold wind that occurs in Alaska. |
| neo-colonialism | the holding of political or economic influence (or both) by one country over another. |
| recharge area | An area where rainwater soaks through the ground to reach an aquifer. |
| pumping head | Energy given to a fluid by a pump, usually expressed in feet of fluid (foot pounds per pound). |
| terminus | The leading edge of a glacier; also known as the glacier snout. |
| biotope | non-living part of an ecosystem with the idea of the space in which the biota exist. |
| face | The external surface of a structure, such as the surface of a dam. |
| meridional flow | Atmospheric circulation in which the north and south, or meridional, component of motion is unusually pronounced |
| prognostic chart | A chart of forecast predictions that may include pressure, fronts |
| horst | a raised block of land bordered by fault lines. |
| population density | (1) The number per unit area of individuals of any given species at a given time |
| clouds | visible masses of water droplets and/or ice crystals formed by condensation in the atmosphere. |
| hydrology | The study of the waters of the earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of water in streams, lakes, and on or below the land surface. |
| ozone | An unstable oxidizing agent, that consists of three oxygen atoms and can be found in the ozone layer in the atmosphere |
| uvv | An acronym for Upward Vertical Velocity |
| collector system | Conveys water from several individual sources such as groundwater wells and drains and surface inlet drains for rainstorm and snowmelt runoff to a single point of diversion |
| consumptive use | The quantity of water used in a given area in transpiration, building of plant tissue, and evaporated from adjacent soil, water surface, snow or intercepted precipitation in a specific period of time. |
| absorption | the absorbing of insolation to solids, liquids and gases on the surface and in the atmosphere. |
| loam | A soil that contains a roughly equal mixture of clay, sand, and silt |
| specific conductance | a measure of the ability of a water to conduct an electrical current |
| publicly-owned treatment works | a wastewater treatment plant that is owned by a state, unit of local government or Indian tribe, usually designed to treat domestic wastewaters |
| emdw | economically more developed world -collectively all the economically more developed countries (EMDCs). |
| hydrologic unit | A geographical area representing part or all of a surface drainage basin or distinct hydrologic feature such as a reservoir, lake, etc. |
| typhoon | a tropical cyclone forming in the western Pacific/South China Sea and posing a hazard to SE and East Asia. |
| playa | a temporary shallow lake with extremely high salinity |
| newton | A unit of force that creates an acceleration on a mass of 1 kilogram equal to 1 meter per second with no friction and under the conditions of a vacuum. |
| headwater advisory table | A table developed by a River Forecast Center for a Headwater Guidance Point; a pre-computed matrix of values allows a forecaster to ascertain an anticipated crest or rise on a small river or stream for a variety of rainfall events and soil moisture conditions. |
| primary carnivore | See secondary consumer. |
| carbon tax | taxes levied on fossil fuel products as a disincentive to consume them as a strategy to slow global warming. |
| jetteau | a jet of water. |
| bubbler gage | A water stage recording device that is capable of attaching to a LARC for data automation purposes. |
| salt marsh | Coastal wetland ecosystem that is inundated for some period of time by seawater |
| gap | A spatial opening in a plant community |
| erratic | a large, extremely heavy boulder found in an area of entirely different geology |
| discharger | any person who discharges waste that could affect the quality of state waters |
| system attribute | A system attribute is the perceived characteristic of a system element |
| riser | A vertical pipe as for water. |
| spatial analysis | The examination of the spatial pattern of natural and human-made phenomena using numerical analysis and statistics. |
| specific storage | The volume of water removed or added within the unit volume of an aquifer per unit change in head. |
| pumping head | Energy given to a fluid by a pump; usually expressed in feet of fluid (foot-pounds per pound). |
| energy budget | for the Earth, the net balance between insolation and outgoing radiation |
| el niño current | An intermittent warm water current that originates from the tropics and overrides the normal cold water currents that persist along the Pacific coast, resulting in warmer than normal ocean conditions. |
| organic matter | Substances of (dead) plant or animal matter, with a carbon-hydrogen structure. |
| carcinogen | Any dissolved pollutant that can induce cancer. |
| salmonid | Fish of the family Salmonidae, that includs salmon and steelhead. |
| delta | a depositional feature found at river mouths under certain conditions |
| secchi depth | A relatively crude measurement of the turbidity (cloudiness) of surface water |
| stage iii precipitation processing | The third level of precipitation processing, performed interactively at RFCs |
| equator | the line of latitude (0- bisecting the northern and southern hemispheres equally and thus at the maximum circumference of the globe and perpendicular to the polar circumference. |
| sustained wind | Wind speed determined by averaging observed values over a 2-minute period. |
| rain gage | any instrument used for recording and measuring time, distribution, and the amount of rainfall. |
| nor'easter | A strong low pressure system that affects the Mid Atlantic and New England States |
| flood crest | The Maximum height of a flood wave as it passes a location. |
| shear line | A line of maximum horizontal wind shear |
| cloud-ground lightning | Lightning occurring between cloud and ground. |
| genetic stock identification | A method that can be used to characterize populations of organisms based on the genetic profiles of individuals. |
| creek | a small stream of water which serves as the natural drainage course for a drainage basin |
| pva | Advection of higher values of vorticity into an area, which often is associated with upward motion (lifting) of the air. PVA typically is found in advance of disturbances aloft (i.e., shortwaves), and is a property which often enhances the potential for thunderstorm development. |
| storage equation | The equation for the conservation of mass. |
| rossby waves | The movement of ridges and troughs in the upper wind patterns, primarily the jet stream, circling the earth |
| blockfield | extensive area of large angular rock fragments in periglacial regions. |
| euro | the single European currency. |
| channel lead | An elongated opening in the ice cover caused by a water current. |
| price current meter | A current meter with a series of conical cups fastened to a flat framework through which a pin extends |
| orographic precipitation | Precipitation which is caused by hills or mountain ranges deflecting the moisture-laden air masses upward, causing them to cool and precipitate their moisture. |
| negative feedback | when the action of a system leads to a reduction in that action |
| water solubility | the maximum possible concentration of a chemical compound dissolved in water. |
| agglomeration | the grouping together of businesses in the same area to minimize costs through linkages. |
| drought | A period of abnormally dry weather sufficiently prolonged from the lack of precipitation to cause a serious hydrologic imbalance. |
| european union | see http://europa.eu/index_en.htm |
| ccf | Hundreds of cubic feet - the measure of water consumption used in computing water bills. |
| coastal cutthroat trout | A cutthroat trout of the subspecies Oncorhynchus clarki clarki |
| mesosphere | the layer of the atmosphere above the stratosphere |
| orthographic projection | Map projection that presents the Earth's surface in two-dimensions as if it were being observed from a great distance in space |
| filterable | Of particles that are sufficiently small to allow their passage through filters capable of retaining most particles |
| isohyet | A line on a weather map connecting points receiving equal precipitation amounts. |
| talik | An unfrozen section of ground found above, below, or within a layer of discontinuous permafrost |
| doh | Development and Operations Hydrologist. |
| glacial ice | A very dense form frozen water that is much harder than snow, névé, or firn. |
| river observing station | An established location along a river designated for observing and measuring properties of the river. |
| jurassic | a geologic time period lasting from 208m to 144m years ago. |
| myomeres | The muscle segments. |
| centrally planned economy | see command economy. |
| pigment | Organic substance found in plant and animal cells that creates coloring. |
| gross national product | Gross domestic product plus net income from abroad |
| dew | condensation of water directly onto ground surfaces such as leaves or car windscreens |
| gelisols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| perennial plant | Plant species that lives for more than two years. |
| declination | Location (latitude) on the Earth where the Sun on a particular day is directly overhead (90° from horizon) at solar noon |
| floodproofing | The process of protecting a building from flood damage on site |
| arch dam | Curved masonry or concrete dam, convex in shape upstream, that depends on arch action for its stability; the load or water pressure is transferred by the arch to the Abutments. |
| feedwater | (Water Quality) Water input into a desalting or water treatment plant. |
| genetic distance | A quantitative measure of genetic differences between a pair of samples. |
| return flow | South winds on the back (west) side of an eastward-moving surface high pressure system |
| dyke | three meanings: |
| blanket | A portion of the physical structure of a dam designed to affect the dams hydrologic characteristics, particularly its seepage and strength characteristics |
| sublimation | The process of a solid (ice) changing directly into a gas (water vapor), or water vapor changing directly into ice, at the same temperature, without ever going through the liquid state (water) |
| mining water use | water use during quarrying rocks and extracting minerals from the land. |
| capture zone | The zone around a well contributing water to the well; the area on the ground surface from which a well captures water. |
| geographical coordinate system | System that uses the measures of latitude and longitude to locate points on the spherical surface of the Earth. |
| updraft | Upward movement of air. |
| interstate water | according to law, interstate waters are defined as (1) rivers, lakes and other waters that flow across or form a part of state or international boundaries; (2) waters of the Great Lakes; (3) coastal waters whose scope has been defined to include ocean waters seaward to the territorial limits and waters along the coastline (including inland streams) influenced by the tide. |
| recession constant | Constant used to reduce the API value daily in the API method of estimating runoff. |
| warm desert | Desert found in the subtropics or interiors of continents at the middle latitudes where precipitation is low and surface air temperatures are high. |
| meadow | An area of moist low-lying grassland usually along a watercourse supporting a more dense stand of grasses and perhaps dwarf shrubs as compared to adjacent more arid uplands. |
| atomic number | A specific number that differs for each element, equal to the number of protons in the nucleus of each of its atoms. |
| liquid | A state of matter in which the molecules are closer and held more tightly by one another than in the gaseous state |
| salinity | amount of dissolved salts in a given volume of water. |
| maximum sustainable yield | The largest average catch or yield that can continuously be taken from a stock under existing environmental conditions |
| solar energy | See insolation. |
| cyclic storm | A thunderstorm that undergoes cycles of intensification and weakening (pulses) while maintaining its individuality |
| point discharge | Instantaneous rate of discharge, in contrast to the mean rate for an interval of time. |
| helical flow | Movement of water within a stream that occurs as spiral flows. |
| myctophobia | The fear of darkness. |
| field capacity | The water remaining in a soil after the complete draining of the soil's gravitational water. |
| island | Land completely surrounded by water. |
| hatchery stock | A stock that depends upon spawning, incubation, hatching, or rearing in a hatchery or other artificial production facility. |
| appropriate technology | see alternative technology |
| flow augmentation | The addition of water to a stream especially to meet instream flow needs. |
| excess rain | Effective rainfall in excess of infiltration capacity. |
| indicator species | (Environmental) Any organism that by its presence or absence, its frequency, or its vigor indicates a particular property of its surrounding environment |
| flashboards | A length of timber, concrete, or steel placed on the crest of a spillway to raise the retention water level but which may be quickly removed in the event of a flood by a tripping device, or by deliberately designed failure of the flashboard or its supports. |
| mixed layer | It is the upper portion of the boundary layer in which air is thoroughly mixed by convection |
| hungry water | Clear water minus its expected suspended sediment load, usually released from an impoundment that has excess energy, which erodes sediment from the downstream channel. |
| trap efficiency of reservoirs | Ratio of sediment retained to sediment inflow expressed as a percentage. |
| rotenone | A substance derived from the Derris root that is commonly used to kill fish during lake rehabilitation programs. |
| public hearing | A formal meeting called by a regulatory agency (such as EPA or EPD) to hear the public's views and concerns about a regulatory action or proposal |
| carbonation | Is a form of chemical weathering where carbonate and bicarbonate ions react with minerals that contain calcium, magnesium, potassium, and sodium. |
| eukaryote | Organisms whose cells have a membrane-bound nucleus and many specialized structures located within their cell boundary |
| contaminant | Any physical, chemical, biological, or radiological substance or matter that has an adverse affect on air, water, or soil. |
| biomass | The weight of living tissues usually measured per unit area over a particular time interval |
| percolating waters | Underground waters whose course and boundaries are incapable of determination |
| force of acceleration | Force resulting in the speed of a moving body to increase. |
| severe thunderstorm warning | This is issued when either a severe thunderstorm is indicated by the WSR-88D radar or a spotter reports a thunderstorm producing hail 3/4 inch or larger in diameter and/or winds equal or exceed 58 miles an hour; therefore, people in the affected area should seek safe shelter immediately. Severe thunderstorms can produce tornadoes with little or no advance warning. Lightning frequency is not a criteria for issuing a severe thunderstorm warning. They are usually issued for a duration of one hour. They can be issued without a Severe Thunderstorm Watch being already in effect. |
| stratocumulus | It has globular masses or rolls unlike the flat, sometimes definite, base of stratus |
| screening | Use of screens to remove coarse floating and suspended solids from sewage. |
| molecule | the smallest division of a compound that still retains or exhibits all the properties of the substance. |
| glacial drift | A general term for all material transported and deposited directly by or from glacial ice. |
| general circulation | in the atmosphere, the general pattern of wind and pressure at a global scale |
| divergence | Horizontal outflow of wind from an area |
| solidification | Removal of wastewater from a waste or changing it chemically to make it less permeable and susceptible to transport by water. |
| talik | unfrozen ground in an area of permafrost. |
| proterozoic | an eon of geologic time lasting from 2500m to 570m years ago. |
| glaze | Coating of ice that forms when rain falls on a surface with a temperature below freezing. |
| scree | highly angular rock pieces produced by freeze-thaw weathering and found at the base of a steep or vertical cliff face. |
| desert pavement | A veneer of coarse particles left on the ground after the erosion of finer particles by wind. |
| bay | A bay is a body of water that is partly enclosed by land (and is usually smaller than a gulf). |
| ntu | nephlometric turbidity units. |
| air mass | large body of air with shared temperature and humidity characteristics associated with its area of origin e.g |
| sanitary sewers | underground pipes that carry off only domestic or industrial waste, not storm water. |
| fish and wildlife agencies | This category includes the Fish and Wildlife Service, U.S |
| administrative messages | Meteorological Operations Division (MOD) is responsible for issuing routine and special administrative messages that provide information to the field and outside users. These messages contain the following information: 1) the current status of the model run cycles (e.g., any delays in model guidance); 2) upper-air sounding data that were edited or deleted before their use by the models; 3) delays in the creation and/or distribution of MOD products; and 4) delays in the creation and/or distribution of data sets processed on the Hydrometeorological Prediction Center (HPC). At a minimum, this administrative message is issued once every model cycle at approximately 9:45 AM/PM EST (10:45 AM/PM EDT) by the Senior Duty Meteorologist. Additional messages are issued as required. |
| land application | The reuse of reclaimed water or the utilization or disposal of effluents on, above, or into the surface of the ground through spray fields or other methods. |
| calm | A condition when no air motion is detected. |
| juvenile water | Water formed chemically within the earth and brought to the surface in intrusive rock. |
| wave-cut notch | the undercut portion of a cliff where the base has been eroded by wave action. |
| parts per billion | Expressed as ppb; a unit of concentration equivalent to the µg/l. |
| firn | Névé on a glacier that survives the year's ablation season |
| irrigation water | water which is applied to assist crops in areas or during times where rainfall is inadequate. |
| sewer cleanout | A vertical section of pipe leading from the surface to a service line or mainline |
| isodapane | line connecting points of equal total transport cost. |
| load | rock material being transported by an agent of erosion. |
| interventionist | belief in significant government presence in modifying markets to improve their efficiency and to protect consumers from unscrupulous or irresponsible business behaviour |
| environmental indicator | A measurement, statistic or value that provides a proximate gauge or evidence of the effects of environmental management programs or of the state or condition of the environment. |
| migrating | Moving from one area of residence to another. |
| adsorption | the adhesion of a substance to the surface of a solid or liquid |
| residual | amount of a pollutant remaining in the environment after a natural or technological process has occurred. |
| jack salmon | A young male salmon that matures precociously(earlier than other fish in its age-class). |
| snow flurry/flurries | Light showers of snow, generally very brief without any measurable accumulation |
| check valve | A valve that allows water to stream in one direction and will then close to prevent development of a back-flow. |
| nonpotable | not suitable for drinking |
| climatic optimum | Warmest period during the Holocene epoch |
| turbulence | The irregular and instantaneous motions of air which is made up of a number of small of eddies that travel in the general air current |
| primary succession | Succession on soil or sediments that do not contain an active seed bank. |
| foliar leaching | Process in which water from precipitation removes plant nutrients from the surface of leaves. |
| withdrawal | water removed from a ground- or surface-water source for use. |
| whirlwind | A small-scale, rapidly rotating column of wind, formed thermally and most likely to develop on clear, dry, hot afternoons |
| flood zone | A natural area adjacent to a stream or river where water overflows during extreme storm events |
| pendant echo | Radar signature generally similar to a hook echo, except that the hook shape is not as well defined. |
| convergence | Horizontal inflow of wind into an area |
| propagation | The transmission of electromagnetic energy as waves through or along a medium. |
| assimilative capacity | The capacity of natural water to receive wastewaters or toxic materials without negative effects and without damage to aquatic life or humans who consume the water. |
| gene-2 | The basic unit of heredity passed from parent to offspring. |
| coastal zone | Relatively nutrient-rich, shallow part of the ocean that extends from the high-tide mark on land to the edge of the continental shelf. |
| capital improvements | Expenditures for improvements to land or existing buildings, that will increase their value, extend their life or make it adaptable for a different use. |
| subsidence | A sinking or downward motion of air, often seen in anticyclones |
| open system | system in which energy and matter are exchanged between the system and its environment, for example, a living organism. |
| nccf | NOAA Central Computer Facility |
| recreation | any activity people do during their leisure time |
| erosion control | Anything that will keep soil on site and out of streets and storm drains |
| cso | Designed discharge from a combined sewer system into a stream |
| initial detention | The volume of water on the ground, either in depressions or in transit, at the time active runoff begins. |
| in-cloud lightning | Lightning that takes place within the cloud. |
| quicksilver water | A solution of mercury nitrate used in gilding. |
| grid north | The direction north as measured on the Universal Transverse Mercator grid system. |
| warm core low | A low pressure area which is warmer at its center than at its periphery |
| reservoir | A natural or artificial holding area used to store water. |
| public sector | all enterprises and activities owned and funded by the government. |
| flood warning | This warning signifies a longer duration and more gradual flooding of counties, communities, streams, or urban areas. Floods usually begin after 6 hours of excessive rainfall. They are issued by the local National Weather Service Forecast Office (NWFO) for 6 hours or less. |
| stream channel | The bed where a natural stream of water runs or may run; the long narrow depression shaped by the concentrated flow of a stream and covered continuously or periodically by water. |
| blowdown | Trees felled at the base by high winds. |
| ice density | Pure ice density is rarely attained except in individual crystals but is assigned the value of 0.917. |
| aquatic life use | a beneficial use designation in which the water body provides suitable habitat for survival and reproduction of desirable fish, shellfish, and other aquatic organisms. |
| ceilometer | An instrument that is used to measure the angular elevation of a projected light on the base of a cloud |
| impact zone | The spot on a wave where the water is just about to collapse and explode, the spot of greatest danger to and opportunity for a surfer. |
| trihalomethanes | chemical compounds in which three of the four hydrogen atoms of methane (CH4) are replaced by halogen atoms |
| stream bed | Bottom of the stream channel. |
| edge effect | "The drastically modified environmental conditions along the margins, or ""edges,"" of forest patches surrounded partially or entirely by harvested lands." |
| fabric | In tills which have been oriented by flowing water, fabric indicates the preferred orientation of the grains |
| riverwash | Barren alluvial land, usually coarse-textured, exposed along streams at low water, and subject to shifting during normal high water. |
| plucking | The process of loosening and lifting pieces of rock by a flowing glacier |
| frigophobia | The fear of the cold and cold things. |
| distal | Away from the point of attachment or origin. |
| lake | A considerable body of inland water or an expanded part of a river. |
| run-of-river dams | Hydroelectric generating plants that operate based only on available inflow and a limited amount of short-term storage (daily/weekly pondage). |
| accessibility | the level of difficulty associated with getting to a location or feature within a larger area measured in distance, time and/or cost. |
| worms | distinguished from non-segmented roundworms and flatworms, (see worms, polychaetes and oligochaetes). |
| gills | The fleshy, and highly vascular organs comparable to lungs used in aquatic respiration. |
| sea breeze | Local thermal circulation pattern found at the interface between land and water |
| outfall | The point where wastewater or drainage discharges from a sewer pipe, emptying into a receiving body of water. |
| low clouds | The bases of these clouds range from near the surface to about 6,500 feet in middle latitudes |
| crack | Defective line visible on the sewer wall, with the pieces of the wall still in place |
| confined aquifer | Aquifer between two layers of relatively impermeable earth materials, such as clay or shale. |
| backwashing | In a wastewater or water treatment facility, the flow of clean water in a direction opposite (upward) to the normal flow of raw water through rapid sand filters in order to clean them. |
| finished water | (Water Quality) Water that has completed a purification or treatment process; water that has passed through all the processes in a water treatment plant and is ready to be delivered to consumers |
| b.p. - before present | an alternative, more accurate, means of identifying past years. |
| supplementation | The release and management of artificially propagated fish in streams with the intent to increase or establish wild fish populations while minimizing associated genetic and ecological risks. |
| wasteload allocation | term used in conjunction with the TMDL Program, a WLA is the portion of a receiving water's loading capacity that is allocated to one of its existing or future point sources of pollution |
| interception | when precipitation deposits onto a surface that Is not the actual land such as vegetation or animals. |
| mariculture | a branch of aquaculture specializing in the cultivation of marine organisms in salt water usually by enclosing a cubic volume of a natural waterway |
| key habitats | flow-sensitive habitats as well as habitats that support key species. |
| furrow irrigation | irrigation method in which water travels through the field by means of small channels between each group of rows. |
| rod | A graduated staff used in determining the difference in elevation between two points |
| cambrian explosion | Great diversification of multicellular life forms in the Earth's oceans that started during the Cambrian about 570 million years ago. |
| mudstone | Fine grained sedimentary rock composed of lithified silt and clay particles. |
| ice bridge | A continuous ice cover of limited size extending from shore to shore like a bridge. |
| mid-columbia coordinating committee | A committee whose primary purpose is to improve fish passage at the mid-Columbia dams |
| egg-to-smolt survival | The numerical difference between the number of fertilized eggs produced by a groups of fish and the number of smolts resulting from those eggs. |
| underdrain | a concealed drain with openings through which the water enters when the water table reaches the level of the drain. |
| elevation angle | The vertical pointing angle of the antenna |
| map projection | Cartographic process used to represent the Earth's three-dimensional surface onto a two-dimension map |
| plankton | Minute floating forms of microscopic plants and animals in water which cannot get about to any extent under their own power |
| sustainability | the long-term capacity of an ecosystem to maintain ecological processes and functions, biological diversity, and productivity. |
| freezing point | (1) The temperature at which a liquid of specified composition solidifies under a specified pressure |
| imbricated | Lying lapped over each other in regular order (like scales of a fish or shingles on a roof). |
| floodplain | land next to a river that becomes covered by water when the river overflows its banks . |
| limiting factor | Abiotic condition that most controls the growth of a species |
| silt | Substrate particles smaller than sand and larger than clay (3 to 60 um). |
| hazard | Phenomenon which can cause loss of life, injury, disease, economic loss, or environmental damage. |
| gumbotill | Highly weathered till which becomes sticky and plastic when wet. |
| surface irrigation | A water application whereby water is applied to the soil either by controlled flooding or through some kind of furrow. |
| reference dose | The particular concentration of a chemical that is known to cause health problems |
| transmission lines | Pipelines that transport raw water from its source to a water treatment plant, then to the distribution grid system. |
| gas | A state of matter where molecules are free to move in any direction they like |
| fault | A fracture in rock caused by stress. |
| buffer | A substance that reacts with hydrogen or hydroxyl ions in a solution, in order to prevent a change in pH. |
| coe | U.S |
| condensation | The process by which water vapor undergoes a change in state from a gas to a liquid |
| sensible heat flux | Process where excess heat energy is transferred into the atmosphere |
| irrigation lateral | A branch of a main canal conveying water to a farm ditch; sometimes used in reference to farm ditches. |
| stratopause | The stratopause is a relatively thin atmospheric transition layer found between the stratosphere and the mesosphere |
| bolson | Is a closed desert basin with no drainage outlet, surrounded by mountains. |
| mental | Pertaining to the chin or mentum. |
| distance ratio | Method for measuring the gradient of a slope |
| dredging | removal of mud from the bottom of water bodies |
| biosphere | a reference to the totality of the earth surface and atmosphere that is inhabited by living organisms. |
| headwaters | Upper portion of stream's drainage system. |
| best track | A subjectively smoothed path, versus a precise and very erratic fix-to-fix path, used to represent tropical cyclone movement |
| groundwater runoff | the portion of runoff which has passed into the ground, has become ground water, and has been discharged into a stream channel as spring or seepage water. |
| demand | The numerical expression of the desire for goods and services associated with an economic standard for acquiring them. |
| saline water | water containing more than 1,000 parts per million (ppm) of dissolved solids of any type |
| epa | Environmental Protection Agency. The federal regulatory agency responsible for protecting environmental quality throughout the nation |
| evaporation | The physical process by which a liquid (or a solid) is transformed to the gaseous state |
| irrigation water use | Artificial application of water on lands to assist in the growing of crops and pastures or to maintain vegetative growth on recreational lands such as parks and golf courses |
| farm headgate delivery | That amount of water in acre feet (AF) delivered through a farm headgate. |
| hill | Smaller than a mountain, a raised part of the earth. |
| mcl | The maximum permissible level of a contaminant in water delivered to any user of a public system |
| pore spaces | the space between particles in a rock or soil, usually filled with air or water. |
| zoned embankment dam | An embankment dam which is comprised of zones of selected materials having different degrees of porosity, permeability and density. |
| hypolimnion | The lower zone of a thermally stratified lake, below the thermocline, and usually depleted in oxygen during summer stagnation. |
| eyed egg | A fish egg containing an embryo that has developed enough so the eyes are visible through the egg membrane. |
| cappilary membranes | Membranes about the thickness of a human hair, used for Reverse Osmosis, nanofiltration, ultrafiltration and microfiltrtion. |
| brine | Seawater with a salinity greater than 35 parts per thousand |
| evaporation | A process by which liquid changes into a gas or vapor. |
| shrub | a plant which has a thick woody stem but not thick or sturdy enough to be described as a trunk |
| hydrologic cycle | Movement or exchange of water between the atmosphere and earth. |
| waterspout | A vortex of rapidly moving air over water that is associated with some thunderstorms. |
| westerlies | Usually applied to the broad patterns of persistent winds with a westerly component |
| interbasin transfer | The diversion of water from one drainage basin to one or more other drainage basins. |
| dead end | the end of a water main that is not connected to other parts of the distribution system. |
| growth pole | a particular site, or small area, where economic development is focused setting off wider growth through cumulative causation |
| fosse | a long narrow trench often found at an old fortified site. |
| density-dependent | A process, such as fecundity, whose value depends on the number of animals in the population per unit area. |
| mean doppler velocity | Reflectivity-weighted average velocity of targets in a given pulse resolution volume |
| mull | a dark, crumbly, nutrient rich humus layer. |
| frontogenesis | The process in which a front forms |
| fujiwhara effect | A binary interaction where tropical cyclones within a certain distance (300-750 nm depending on the sizes of the cyclones) of each other begin to rotate about a common midpoint. |
| solvent | a substance that dissolves other substances to form a solution. Water dissolves more substances than any other and is known as the universal solvent. |
| reflected infrared radiation | Form of electromagnetic radiation with a wavelength between 0.7 to 3.0 micrometers (µm). |
| treatment | any method, technique, or process designed to remove solids and/or pollutants from solid waste, waste-streams, and effluents. |
| morphology | lit |
| sewer cleaning | Techniques used to clean sewer lines either hydraulically or mechanically |
| secondary forest | forest which is regrowing after the original vegetation was cleared. |
| multicell thunderstorms | These thunderstorms are organized in clusters of at least 2-4 short-lived cells |
| import penetration | the proportion of the market for a particular product-type taken up by imports. |
| compensation level | The level in a body of water, usually occurring at the depth of 1 percent light penetration, which forms the lower boundary of the Zone of Net Metabolic Production. |
| r horizon | Soil horizon found beneath the C horizon |
| breakup date | Date on which a body of water is first observed to be entirely clear of ice and remains clear thereafter. |
| severe thunderstorm | A thunderstorm that produces either of the following: winds of 58 miles an hour or greater (these speeds can result in structural or tree damage), hail 3/4 of an inch in diameter or larger, or a tornado |
| engineer's level | A telescope which is attached to a spirit-tube level, all revolving around a vertical axis and is mounted on a tripod |
| greywater | Wastewater from clothes washing machines, showers, bathtubs, hand washing, lavatories and sinks that are not used for disposal of chemicals or chemical-biological ingredients. |
| coded-wire tag | A small (0.25mm diameter x 1 mm length) wire etched with a distinctive binary code and implanted in the snout of s salmon or steelhead, which, when retrieved, allows for the identification of the origin of the fish bearing the tag. |
| spine | A single, median supporting element of a fin, usually stiff |
| low water use plants | Plants which are able to survive without supplemental water once established. |
| south pole | Surface location defined by the intersection of the polar axis with Earth's surface in the Southern Hemisphere |
| z/r relationship | The empirical conversion relationship between radar reflectivity and precipitation rate. |
| gradient | The steepness of a slope as measured in degrees, percentage, or as a distance ratio (rise/run). |
| symbiotic | Mutual relationship between two organisms which is necessary for either to survive. |
| battery farming | intensive, commercial livestock (usually poultry or cattle) production where animals are reared in cages and fed and watered automatically to reduce the per unit cost |
| continental plate | A rigid, independent segment of the lithosphere composed of mainly granite that floats on the viscous plastic asthenosphere and moves over the surface of the Earth |
| jugular pelvics | Pelvic fins in front of the pectoral fins. |
| fall | Season between summer and winter |
| radarsat | Satellite program established by the Canadian Space Agency for the purpose of remotely sensing the Earth's resources |
| call | A demand that upstream water rights with more recent (junior) priority dates than the calling right cease diverting; the exercise of a senior water right holder in "calling" for his or her water rights, requiring junior water right holders to allow water to pass to the senior right holder. |
| chlorination | A water purification process in which chlorine is added to water for disinfection, for the control of present microrganisms |
| beginning of freezup | Date on which ice forming a stable winter ice cover is first observed on the water surface. |
| intangible flood damage | Estimates of the damage done by disruption of business, danger to health, shock, and loss of life and in general all costs not directly measurable which require a large element of judgment for estimating. |
| yellow snow | Snow given a golden or yellow appearance by the presence in it of pine, cypress pollen, or anthropogenic material or animal-produced material. Compare with Brown Snow. |
| snowboard | A flat, solid, white material, such as painted plywood, approximately two feet square, which is laid on the |
| deep well | A well whose pumping head is too great to permit use of a suction pump. |
| finite element | a method of solving the governing equations of a numerical model by dividing the spatial domain into elements in each of which the solution of the governing equations is approximated by a continuous function. |
| divergence | Wind movement that results in a horizontal net outflow of air from a particular region |
| mutation | Change in the structure of a gene or chromosome. |
| conjunctive use | The combined use of surface and ground water systems and sources to optimize resource use and prevent or minimize adverse effects of using a single source. |
| correlation | A measure of the similarity between variables or functions. |
| cuttoff | An impervious construction or material which reduces |
| firn line | See firn limit. |
| levee | An embankment, generally constructed on or parallel to the banks of a stream, lake or other body of water, for the purpose of protecting the land side from inundation by flood water or to confine the stream flow to its regular channel. |
| peat | Partially decomposed remains of plants that once flourished in a waterlogged environment. |
| global cooling | the cooling of the atmosphere, or more properly the decrease over time in average annual global temperature |
| main stem | The principal channel of a drainage system into which other smaller streams or rivers flow. |
| natural resources | the things we use that are provided in the natural environment e.g |
| eustacy | Variations in sea-level that are related to changes in the volume of seawater in the oceans. |
| classic supercell | See supercell. |
| known-stock fishery | A fishery taking place in an area and during a time where only fish of a certain stock are present. |
| specialist species | Species that have a relatively narrow ecological niche |
| attrition | a process of erosion where the collisions between parts of the load lead to comminution. |
| hydrosere | a freshwater environment in which primary plant succession takes place. |
| toe drain and outfall | A drainage conduit from a dam's structure used to carry seepage water away from the dam and can allow seepage quantities to be measured. |
| assemblage | an organism group of interacting species in a given ecosystem, for example, a fish assemblage or a benthic macroinvertebrate assemblage. |
| drought | Term applied to periods of less than average precipitation over a certain period of time. |
| valley train | A linear accumulation of glaciofluvial outwash sediments found in a once glaciated valley. |
| grout curtain | A barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the foundation to reduce seepage under a dam. |
| bank storage | The water absorbed into the banks of a stream, lake, or reservoir, when the stage rises above the water table in the bank formations, then returns to the channel as effluent seepage when the stage falls below the water table |
| concentration | The amount of Solute present in proportion to the total Solution |
| ecliptic | The sun's apparent path across the sky that tracks a circle through the celestial sphere. |
| specific heat | Is the heat capacity of a unit mass of a substance or heat needed to raise the temperature of 1 gram (g) of a substance 1 degree Celsius. |
| relative humidity | the ratio of the amount of moisture in the air to the maximum amount of moisture the air could hold under the same conditions; usually expressed as a percentage reservoir - a pond or lake where water is collected and stored until it is needed rills - small grooves, furrows, or channels in soil made by water flowing down over its surface; also another name for a stream - usually a small stream runoff - liquid water that travels over the surface of the Earth, moving downward due to the law of gravity; runoff is one way in which water that falls as precipitation returns to the ocean |
| turbulence | A state of fluid flow in which instantaneous velocities exhibit irregular and apparently random fluctuations. |
| seismograph | Instrument that measures the energy contained in seismic waves from an earthquake or other type of ground displacement. |
| ppb | See parts per billion. |
| precipitation | rain, snow, dew, frost, hail and sleet. |
| alkalinity | the capacity of water for neutralizing an acid solution. |
| vvp | Volume Velocity Processing |
| fall-run fish | Anadromous fish that return to spawn in the fall. |
| mixed liquor | A mixture of activated sludge and water containing organic matter undergoing activated sludge treatment in an aeration tank. |
| stream gage | A site along a stream where the stage (water level) is read either by eye or measured with recording equipment. |
| irrigation systems tailwater recovery | A water runoff collection and storage system to provide a constant quantity of water back to the initial system or to another field. |
| estimator | An estimator is any value calculated from the sample data For example, the sample mean is an estimator of the population mean. |
| knot | Unit of speed used in aviation and marine activities which is equal to 1 nautical mile per hour or about 1.15 statue miles an hour. |
| environmental impact statement | a document that analyzes the effects of major federal projects on the environment |
| spawner trap | A barrier erected in a stream or in a fish ladder intended to divert adult salmon or steelhead for holding prior to taking their eggs or sperm for culturing. |
| spot forecasts | These are NWS site-specific fire weather forecasts. They are issued upon request of User Agencies for wildfires, prescribed burns, or special projects. |
| surface impoundment | an indented area in the land's surface, such a pit, pond, or lagoon. |
| portal ** | Cavernous openings in subglacial ice and debris above meltwater streams. |
| drawdown | the drop in the water table or level of groundwater when water is being pumped from a well; the amount of water used from a tank or reservoir; the drop in the water level of a tank or reservoir. |
| even-year pink salmon | Pink salmon that spawn in even-numbered years |
| parapet wall | A solid wall built along the top of the dam for ornament, safety, or to prevent overtopping. |
| halos | Rings or arcs that encircle the sun or moon |
| gain | A change in signal power, voltage or current |
| hail | Precipitation that originates in convective clouds, such as cumulonimbus, in the form of balls or irregular pieces of ice, which comes in different shapes and sizes |
| ph | An expression of both acidity and alkalinity on a scale of 0 to 14, with 7 representing neutrality; numbers less than 7 indicate increasing acidity and numbers greater than 7 indicate increasing alkalinity. |
| ford | A shallow place in a body of water, such as a river, where one can cross by walking or riding on an animal or in a vehicle. |
| percolation rate | The rate, usually expressed as a velocity, at which water moves through saturated granular material |
| hectare | (Abbreviation ha) A metric unit of area equal to 100 Ares (2.471 acres) and equivalent to 10,000 square meters (107,639 square feet). |
| density current | A flow of water maintained by gravity through a large body of water, such as a reservoir or lake, and retaining its unmixed identity because of a difference in density. |
| near gale | Whole trees in motion; inconveniences felt against wind; sea heaps up and white foam from breaking waves begins to be blown in streaks along the direction of the wind. |
| symbiotic mutualism | Mutualistic interaction where the species interact physically and their relationship is biologically essential for survival. |
| natural flow | The rate of water movement past a specified point on a natural stream from a drainage area for which there have been no effects caused by stream diversion, storage, import, export, return flow, or change in Consumptive Use caused by man-controlled modification to land use |
| overhead irrigation | A pressurized irrigation system where water is distributed through pipes to the field and applied through a variety of sprinkler heads or nozzles |
| organotins | chemical compounds used in antifoulant paints to protect the hulls of boats and ships, buoys, and pilings from marine organisms such as barnacles. |
| radioisotope snow gage | A snow water equivalent gage based on the absorption of gamma radiation by snow; this gage can measure up to 55 inches water equivalent with a 2 to 5 percent error. |
| geostationary orbit | Satellite that has an orbit that keeps it over the same point on the Earth at all times |
| watershed | The total area drained by a river and its tributaries |
| elevated convection | A thunderstorm which occurs above a frontal inversion on the cold side of the surface cold front |
| parasite | Consumer organism that feeds on a host for an extended period of time |
| gust | A sudden significant increase in or rapid fluctuations of wind speed |
| polar plateau | The relatively flat, elevated central region of the East Antarctic Ice Sheet. |
| producer | An organism that can synthesize the organic nutrients in requires for growth through processes like photosynthesis. |
| settling | The process of sinking of a substance sinking in water |
| latent heat of vaporization | The amount of heat absorbed by a unit mass of substance, without change in temperature, while passing from the liquid to the vapor state. |
| bypass flow | Water that is allowed to flow past a diversion structure or storage facility. |
| infiltration | The movement of water into soil or porous rock |
| moisture tension | The equivalent negative pressure in the soil water |
| bwer | An acronym for Bounded Weak Echo Region. See Bounded Weak Echo Region. |
| peak flow | in a wastewater treatment plant, the highest flow expected to be encoutered under any operational conditions, including periods of high rainfall and prolonged periods of wet weather. |
| tuberculation | development or formation of small mounds of corrosion products on the inside of iron pipe |
| dystrophic lakes | Acidic bodies of water that contain many plants but few fish, due to the presence of great amounts of organic matter. |
| deforestation | removal of forest cover due to cutting or burning, or a combination of the two. |
| positive feedback | in a system, those changes which serve to increase the effect. |
| escarpment | the topographic expression of a fault. |
| rain shield | It is a solid or nearly solid area of rain that typically becomes heavier as one approaches the eye of the hurricane |
| groundwater | Subsurface water and underground streams that can be collected with wells, or that flow naturally to the earth's surface though springs. |
| eutrophic | having a large or excessive supply of plant nutrients (nitrates and phosphates) |
| turbidity | the amount of solid particles that are suspended in water and that cause light rays shining through the water to scatter |
| open field system | a farming system developed in Anglo-Saxon culture |
| diffraction | The bending of light around objects, such as clouds and fog droplets, producing fringes of light and dark colored bands. |
| unconsolidated deposits | Sediment not cemented together; may consist of sand, silt, clay, and organic material. |
| industrial revolution | a fundamental change in the way that goods are produced and the behaviour of the people who produce them |
| gene pool | The total genes in a breeding population. |
| pondage | 1) The holding back of water for later release for power development above the dam of a hydroelectric plant to a) equalize daily or weekly fluctuations of streamflow or b) to permit irregular hourly use of water by the wheels to care for fluctuations in the load demand |
| bacteria | plants and animals. |
| channel control | The condition under which the stage-discharge relation of a gaging station is governed by the slope, size, geometry, and roughness of the channel. |
| filter fabric | A polypropylene textile used to keep soil separate from water |
| easting | First measurement of a grid reference used to specific the location of a point on a rectangular coordinate system |
| guest worker | English translation of a German term for economic migrants, mostly from Turkey |
| vertical transfer | the transfer or transmission of energy from the surface to the atmosphere, and up through the atmosphere. |
| contiguous habitat | Habitat suitable to support the life needs of species that is distributed continuously or nearly continuously across the landscape. |
| basin fill | Unconsolidated material such as sand, gravel, and silt eroded from surrounding mountains and deposited in a valley. |
| isotope | Form of an element where the number of neutrons in its atomic nucleus is different than the number of protons. |
| berm | Low hill of sand that forms along coastal beaches. |
| tropics/tropical | The region of the earth located between the Tropic of Cancer, at 23.5 degrees North latitude, and the Tropic of Capricorn, at 23.5 degrees South latitude |
| decarbonation | The process of removing carbon dioxide from water, using contact towers or air scrubbers. |
| milligrams per liter | The weight in milligrams of any substance contained in 1 liter of liquid |
| upwelling | The movement of nutrient rich waters from the bottom of the ocean to the surface. |
| advanced water treatment | The level of water treatment that requires an 85-percent reduction in pollutant concentration, also known as tertiary treatment. |
| hydration | A form of chemical weathering that involves the rigid attachment of H+ and OH- ions to the atoms and molecules of a mineral. |
| unambiguous range | See maximum unambiguous range. |
| head loss | The decrease in total head caused by friction. |
| snag | Any standing dead, partially dead, or defective (cull) tree at least 10 in |
| cuesta | A ridge with a gentle slope on one side and a steep slope on the other, often resulting from the movement of a glacier over a rock outcrop |
| maximum contaminant level | The highest allowable amount of a constituent in water |
| evaporation rate | The quantity of water, expressed in terms of depth of liquid water, which is evaporated from a given surface per unit of time |
| homosphere | The lower layer in a two part classification of the atmosphere based on the general homogeneity of chemical composition |
| erosion | The gradual wearing away of Earth surfaces through the action of wind and water. |
| coliform bacteria | that are not in themselves harmful but whose presence is indicative of possible pollution or the presence of other more harmful microorganisms which, through its population size or condition, mirrors environmental conditions within an ecosystem. |
| critical entrainment velocity | Velocity required to entrain a particular sized particle into the moving medium of air or water. |
| transfer | Refers to the movement of water from one reservoir or storage facility to another. |
| topological map | a map which uses points and straight lines to show relative positions and linkages e.g |
| pressure relief pipes | Pipes used to relieve uplift or pore pressure in a dam foundation or in the dam structure. |
| hydrocompaction | The settling and hardening of land due to application of large amounts of water for irrigation. |
| hydrometer | an instrument used to measure the density of a liquid. |
| zone of aeration | a region in the Earth above the water table |
| regulatory floodway | Some maps show an area where construction regulations require special provisions to account for this extra hazard |
| equi-potential line | A line, in a field of flow, such that the total head is the same for all points on the line, and therefore the direction of flow is perpendicular to the line at all points. |
| morphoedaphic index | The most widely used index of potential fish production in lakes |
| white-out | A weather condition in which the horizon cannot be identified and there are no shadows |
| perched water table | groundwater standing unprotected over a confined zone. |
| extinct species | A species that no longer exists. |
| pteryhoids | Bones of the roof of the mouth lying behind and articulating with the palatines. |
| pressure rising rapidly | An increase in station pressure at a rate of 0.06 inch of mercury or more per hour which totals 0.02 inch or more. |
| miners' inch | A rate of discharge through an orifice one inch square under a specific head. |
| abundance index | Information obtained from samples or observations and used as a measure of the weight or number of fish which make up a stock. |
| urban development corporations | bodies set up in the 1980s to oversee partnerships between government and the private sector whose goal was to regenerate inner city areas in the UK which had suffered urban decay. |
| muli | Lifted Index (LI) calculated using a parcel from the pressure level that results in the Most Unstable value (lowest value) of LI possible. See Lifted Index. |
| psychrometer | Instrument used to measure atmospheric humidity |
| pan | see hardpan. |
| response time | The amount of time in which it will take a watershed to react to a given rainfall event. |
| mass | Refers to the amount of material found in an object (usually of unit volume). |
| bilharziasis | disease caused by a parasitic worm which enters the human body by penetrating the skin while swimming/bathing/working in infected waters |
| basic | Describing a solution, sediment, or other material that has a pH greater than 7.0 |
| sky cover | The amount of the celestial dome that is hidden by clouds and/or obscurations. |
| pre-smolt | A juvenile salmon or steelhead that has not yet reached the physiological state known as a smolt. |
| surface area | of a lake is that area, in acres, outlined on the latest USGS topographic map as the boundary of the lake and measured by a planimeter |
| rotational movement | slip or slide over a curved path. |
| era | Geologic time unit that is shorter than an eon but longer than a period. |
| base flow | that portion of river discharge derived from groundwater flow. |
| manufacturing industry | businesses that convert raw materials into finished products or component products, and those that convert or assemble component products into finished products. |
| energy dissipator | A structure for slowing the fast moving spillway flows of a dam in order to prevent erosion of the stream channel below the dam. |
| open | An unobstructed area of land or water. |
| sublimation | The transitions of water directly from the solid state to the gaseous state, without passing through the liquid state. |
| tidal energy | the energy involved in tidal movements of water which is available to be harnessed if those movements can be used to turn turbines. |
| hygroscopic water | that water in the soil which exists as a microscopic level as a layer around particle of clay |
| kymophobia | The fear of waves. |
| leaching | The process by which soluble constituents are dissolved and filtered through the soil by a percolating fluid. |
| northeast trade winds | See trade winds. |
| mean annual precipitation | The average of all annual precipitation values known, or an estimated equivalent value derived by such methods as regional indexes or Isohyetal maps. |
| race | (1) A strong or swift current of water |
| macrointervebrate | an animal without a backbone, large enough to be seen without magnification and unable to pass through a 0.595 mm mesh. |
| ogee | A reverse curve, shaped like an elongated letter S |
| humboldt current | Also known as the Peru Current, this ocean current flows northward along the western side of South America, offshore Chile and Peru |
| bar screen | In wastewater treatment, a device used to remove large solids. |
| cone of influence | The depression, roughly conical in shape, produced in a water table, or other piezometric surface, by the extraction of water from a well at a given rate |
| vadose zone | The locus of points just above the water table where soil pores may either contain air or water |
| kinetic energy | energy possessed by a moving object or water body. |
| watercourse | Any surface flow such as a river, stream, or tributary. |
| regeneration | Putting the desired counter-ion back on the ion exchanger, by displacing an ion of higher affinity with one of lower affinity. |
| vernal equinox | One of two days during the year when the declination of the Sun is at the equator |
| percolation | the movement of water through the subsurface soil layers, usually continuing downward to the groundwater or water table reservoirs. |
| dissolved air flotation | A procedure of induced flotation with very fine air bubbles or 'micro bubbles', |
| basin yields | The amount of water which will flow from a drainage or catchment area in a given storm. |
| ground water discharge | (1) The flow of water from the Zone of Saturation |
| genetic drift | The random fluctuation of allele frequencies in a population resulting from the sampling of gametes to produce a finite number of individuals in the next generation. |
| interstitial monitoring | The continuous surveillance of the space between the walls of an underground storage tank. |
| pulse-pair processing | Nickname for the technique of mean velocity estimation by calculation of the signal complex covariance argument |
| saturated zone | the area below the water table where all open spaces are filled with water under pressure equal to or greater than that of the atmosphere. |
| risk communication | The process of exchanging information about levels or significance of health or environmental risk. |
| few | 1) An official sky cover classification for aviation weather observations, descriptive of a sky cover of 1/8 to 2/8. This is applied only when obscuring phenomenon aloft are present--that is, not when obscuring phenomenon are surface-based, such as fog |
| silurian | a period of geologic time lasting from 438m to 408m years ago. |
| precipitant | An agent added to a liquid mixture to encourage the formation of solid materials that will settle from the mixture |
| pioneer species | Plant species that dominate a community in the early stages of succession. |
| solar altitude | Height of the Sun above the horizon from either True North or True South. |
| anadramous | any fish which spends a portion of its life cycle in freshwater and a portion in the sea aquifer - an underground layer of rock, sediment or soil that is filled or saturated with water aquifer system - a heterogeneous body of introduced permeable and less permeable material that acts as a water-yielding hydraulic unit of regional extent aqueduct - man-made canal or pipeline used to transport water |
| undercut bank | Steep bank found on the inside of stream meanders |
| redevelopment | the regeneration of urban areas that have fallen into poverty and disrepair |
| pater noster lakes | A string of glacial lakes along the path of a mountain glacier |
| toxicity test | the means to determine the toxicity of a chemical or an effluent using living organisms |
| porosity | a measure of the ratio of open space within a rock or soil to its total volume POTWs (Public Owned Treatment Works) - sewage treatment plants precipitation - water falling toward the Earth's surface in the form of rain, drizzle, hail, sleet, or snow pumping lift - distance water must be lifted in a well from the pumping level to the ground surface pumping plant - facility that lifts water up and over hills |
| joint-use storage | Reservoir storage space which is used for more than one purpose |
| depression storage | The volume of water contained in natural depressions in the land surface, such as puddles. |
| median | Statistical measure of central tendency in a set of data |
| oxbow lake | a U-shaped water body formed when a meander bend is cut off from the mainstem of a river or stream to create a lake. |
| tropical weather summary | The National Hurricane Center issues a monthly summary of tropical weather is included at the end of the month or as soon as feasible thereafter, to describe briefly the past activity or lack thereof and the reasons why. |
| spill water | Water released from a reservoir because the reservoir lacks sufficient storage capacity. |
| tropical disturbance | An area of organized convection, originating in the tropics and occasionally the subtropics, that maintains its identity for 24 hours or more |
| policy | A specific decision or set of decisions with related actions. |
| azonal soil | a soil which does not demonstrate much, if any, evidence of soil-forming processes |
| small craft advisory | An advisory issued for marine interests, especially for operators of small boats or other vessels |
| confluent growth | (Water Quality) A continuous bacterial growth covering all or part of the filtration area of a membrane filter in which the bacteria colonies are not discrete |
| electrophoresis | A technique that allows biologists to determine fish origins by analyzing the genetic variation in fish body fluid and muscle tissue |
| weathering | The decay and breakup of rocks on the earth's surface by natural chemical and mechanical processes |
| arctic jet | The jet stream that is situated high in the stratosphere in and around the Arctic or Antarctic Circles |
| doh | Development and Operations Hydrologist |
| fire behavior | A complex chain-reaction process that describes the ignition, buildup, propagation, and decline of any fire in wildland fuels. |
| meridian | A circular arc that meets at the poles and connects all places of the same longitude. |
| lotic | (1) Of, relating to, or living in moving water |
| bright band | A narrow, intense radar echo due to water-covered ice particles at the melting level where reflectivity is at its greatest. |
| langley | Unit of the intensity of radiation measured per minute and equal to one calorie. |
| snow devil | A small, rotating wind that picks up loose snow instead of dirt (like a dust devil) or water (like a waterspout) |
| laser land leveling | The use of instruments featuring laser beams to guide earth-moving equipment for leveling land for surface-type irrigation. |
| severe weather probability | This WSR-88D radar product algorithm displays numerical values proportional to the probability that a storm will produce severe weather within 30 minutes. Values determined using a statistical regression equation which analyzes output from the VIL algorithm. It is used to quickly identify the most significant thunderstorms. |
| gape | To open the mouth wide |
| effluent seepage | Diffuse discharge of ground water to the ground surface. |
| batholith | A large mass of subsurface intrusive igneous rock that has its origins from mantle magma. |
| continuous permafrost | within the Arctic Circle average temperatures rarely rise above zero |
| base products | Those radar products that present some representation of the data base |
| gage datum | The arbitrary zero datum elevation which all stage measurements are made from. |
| caliche | An accumulation of calcium carbonate at or near the soil surface. |
| misoscale | The scale of meteorological phenomena that ranges in size from a 40 meters to about a 4 kilometers |
| single-family residential | A lot or premises upon which is established one dwelling only |
| lateral moraines | A moraine which forms on the side of the ice stream, often where the ice meets the rock wall |
| range normalization | A receiver gain function in the radar which compensates for the effect of range (distance) on the received power for an equivalent reflectivity. |
| divergence | A measure of the the expansion or spreading out of a vector field; usually said of horizontal winds. It is the opposite of convergence. Divergence at upper levels of the atmosphere enhances upward motion, and hence the potential for thunderstorm development (if other factors also are favorable). |
| rating curve | A graph showing the relationship between the stage, usually plotted vertically (Y-axis) and the discharge, usually plotted horizontally (X-axis). |
| inversion | Generally, a departure from the usual increase or decrease in an atmospheric property with altitude |
| effective precipitation | precipitation available for actual use by plants. |
| artificial recharge | The addition of water to the ground water reservoir by man's activities, such as irrigation or induced infiltration from streams or wells. |
| activated sludge | Oxygen dependent biological process that serves to convert soluble organic matter to solid biomass, that is removable by gravity or filtration. |
| mammatocumulus | An obsolete term for cumulonimbus mammatus, it is a portion of a cumulonimbus cloud that appears as a pouch or udder on the under surface of the cloud |
| radius of influence | the radial distance from the center of a wellbore to the point where there is no lowering of the water table or potentiometric surface; the edge of the cone of depression. |
| holding pond | A pond or basin, usually built in a depression in the ground, built to store excess stormwater runoff for a limited time |
| outer core | Outer region of the Earth's core |
| hydraulic control | a feature in a stream (such as a constriction or a weir) that controls the upstream water surface elevation. |
| srh | An acronym for Storm-relative Helicity. |
| mean tide level | A plane midway between mean high water and mean low water. |
| wastewater | water containing waste including greywater, blackwater or water contaminated by waste contact, including process-generated and contaminated rainfall runoff. |
| skimming | using a machine to remove oil or scum from the surface of the water. |
| carr | an area of swamp whose dominant flora is a mixture of trees, bushes and shrubs. |
| biodegradable pollutants | Pollutants that are capable of decomposing under natural conditions. |
| infrastructure | The massive foundation or basic framework of pipes, wells, storage tanks, treatment facilities, and pump stations that are mostly below ground. |
| concentric-ring model | a theory of how urban land use develops over time |
| piezometer | A well structure or tube which allows the level of saturation within a dam to be measured. |
| gap analysis | A method for determining spatial relationships between areas of high biological diversity and the boundaries of National Parks, National Wildlife Refuges (NWR), and other preserves. |
| frequency curve | A graphical representation of the frequency of occurrence of specific events. |
| morphometry | The measurement of shape |
| heat equator | the tilt of the earth means that during an orbit cycle the line of latitude receiving the most concentrated insolation igrates-between the tropics |
| stack | a pinnacle of rock standing just off a headland and formed when an arch collapses. |
| cap | Composed of a layer of warmer, dryer air aloft which may suppress or delay the development of thunderstorms |
| unconsolidated formations | naturally occurring earth formations that have not been lithified |
| yearling | A one year old fish. |
| isodrosotherm | A line on a chart connecting points of equal dewpoint. |
| wetland | area that is regularly wet or flooded and has a water table that stands at or above the land surface for at least part of the year, such as a bog, pond, fen, estuary, or marsh. |
| ecologically significant | Species, stands, and forests considered important to maintain the structure, function, and processes of particular ecosystems. |
| southern oscillation index | An oceanographic indicator of environmental conditions that allows for the prediction of global climate events such as El Nino |
| diversion structure | A structure specifically designed to divert wastewater from one sewer to another sewer, containment structure, or facility. |
| set-up | The process whereby strong winds blowing down the length of a lake cause water to "pile up" at the downwind end, raising water levels there and lowering them at the upwind end of the lake. |
| human immunodeficiency virus | a virus which forms DNA while replicating its RNA leading to the development of Aids. |
| enhanced wording | An option used by the Storm Prediction Center (SPC) in Norman, Oklahoma in tornado and severe thunderstorm watches when the potential for strong/violent tornadoes, or unusually |
| flood insurance | There are two types of Flood Insurance that compensate for physical property damage resulting from flooding: |
| infiltration capacity curve | A graph showing the time-variation of infiltration capacity |
| meander length | The lineal distance downvalley between two corresponding points of successive meanders of the same phase. |
| cloudy | When the predominant/average sky condition is covered completely by opaque (not transparent) clouds. In other words, 8 octants of the sky is covered by opaque clouds. |
| evapotranspiration | Combined loss of water to the atmosphere via the processes of evaporation and transpiration. |
| cooperative observer | An individual (or institution) who takes precipitation and temperature observations-and in some cases other observations such as river stage, soil temperature, and evaporation-at or near their home, or place of business |
| parallel | Another word for latitude lines. |
| isentropic surface | A two-dimensional surface containing points of equal potential temperature. |
| mudflow | Flow of a well-mixed mass of rock, earth, and water that behaves like a fluid and flows down slopes with a consistency similar to that of newly mixed concrete. |
| drainage well | a well drilled to carry excess water off agricultural fields |
| fountainhead | The upper end of a confined-aquifer conduit, where it intersects the land surface. |
| headgate | The gate that controls water flow into irrigation canals and ditches |
| propagule | Structure that develops into a plant. |
| stream gage | A site along a stream where the stage (water level) is read either by eye or measured with recording equipment. |
| energy flux | The rate of energy flow from, into, or through a substance. |
| wind transport | smaller rock particles may be carried by the wind, moved by saltation, or rolled along the surface. |
| lotic system | a flowing body of fresh water, such as a river or stream |
| backwashing | reversing the flow of water through a home treatment device filter or membrane to clean and remove deposits. |
| slow sand filter | Essentially, a concrete basin covered with graded gravel and about 3 feet of sand used to pass raw water through at low velocity, resulting in substantial removal of chemical and biological contaminants |
| carbon dioxide | A heavy, colorless gas that is the fourth most abundant constituent of dry air, comprising 0.033% of the total. |
| glacier | A large body of ice that formed on land by the compaction and recrystallization of snow, survives year to year, and shows some sign of movement downhill due to gravity. |
| dendritic | description of a stream pattern that is random and creates a tree-like pattern. |
| mass production | the production of finished goods on a very large scale i.e |
| rockfill dam | An Embankment Dam in which more than 50 percent of the total volume comprises compacted or dumped pervious natural or crushed rock. |
| watershed management | The analysis, protection, development, operation or maintenance of the land, vegetation and water resources of a drainage basin for the conservation of all its resources for the benefit of its residents. |
| biomagnification | A cumulative increase in the concentrations of a persistent substance in successively higher levels of the food chain. |
| surface runoff | That part of the runoff which travels over the soil surface to the nearest stream channel |
| urban heat island | the higher temperature found over and around an urban area created by the release of solar energy from the solid fabric of the buildings, roads etc., coupled with energy released by human activity such as lighting, heating, air-conditioning and/or vehicles and industry. |
| linkages | relationships between industries. |
| conus | An acroynm for Continental United States. |
| bay | A body of sheltered water found in a crescent shaped coastal configuration of land. |
| offpeak hours | Period of relatively low demand for electrical energy, as specified by the supplier (such as the middle of the night). |
| hydrosphere | Region that includes all the earth's liquid water, frozen water, floating ice, frozen upper layer of soil, and the small amounts of water vapour in the atmosphere. |
| pancake ice | Circular flat pieces of ice with a raised rim; the shape and rim are due to repeated collisions. |
| liquor | (Water Quality) A liquid solution containing dissolved substances |
| hydrostatic head | a measure of pressure at a given point in a liquid in terms of the vertical height of a column of the same liquid which would produce the same pressure. |
| very severe thunderstorm warning | It is issued for sustained winds over 75 mph in the 7-county Minneapolis/St |
| limnology | The study of life in lakes, ponds, and streams. |
| sustained overdraft | Long-term withdrawal from the aquifer of more water than is being recharged. |
| tropopause | a narrow layer of the atmosphere between the troposphere and the stratosphere |
| carnivore | an animal that consumes other animals for food. |
| mouth | where a river meets a body of water. |
| noctilucent clouds | High altitude clouds composed of ice crystals that appear to glow silver or bright blue shortly after sunset. |
| aquaduct | A pipe or conduit made for bringing water from a source. |
| solar wind | Mass of ionized gas emitted to space by the Sun |
| national hurricane center | One of three branches of the Tropical Prediction Center (TPC). This center maintains a continuous watch on tropical cyclones over the Atlantic, Caribbean, Gulf of Mexico, and the Eastern Pacific from 15 May through November 30 |
| headland | (1) A point of land, usually high and with a sheer drop, extending out into a body of water; a promontory |
| subsea permafrost | Form of permafrost that exists beneath the sea in ocean sediments. |
| salvaged water | The part of a particular stream or other water supply that is saved from loss and made available for use. |
| cap or cap strength | It measures the ability of stable air aloft (a layer of relatively warm air) to inhibit low-level parcel ascent |
| laminar | Smooth, non-turbulent |
| adsorb pollutants | used in some water treatment systems to remove certain organic chemicals and radon gas. |
| swody2 | The Day 2 Convective Outlook is very similar to the Day 1 Outlook |
| flow boundaries | Anything which inhibits ground water flow, such as a ground water divide or an impermeable geologic unit. |
| carriage losses | A term used to describe the operational losses associated with conveying water from its point of diversion to its point of use |
| overflow | The excess water that flows over the ordinary limits of the sewer, manhole, or containment structure |
| atmospheric pressure | The weight of air pushing down on a unit area of a planet's surface. |
| tetrahedron | Silicon atom joined by four oxygen atoms (SiO4) |
| tornado watch | A forecast issued to the public that a tornado may occur in a specified region. |
| scs | The Soil Conservation Service. |
| thermometer | An instrument for measuring temperature. |
| substrate | The composition of a streambed, including either mineral or organic materials. |
| finite difference | a method of solving the governing equations of a numerical model by dividing the spatial domain into a mesh of nodes |
| puddle | a small pool of water, usually a few inches in depth and from several inches to several feet in its greatest dimension. |
| wind | the horizontal movement of air created by differing pressures of adjacent air masses |
| flood frequency curve | 1) A graph showing the number of times per year on the average, plotted as abscissa, that floods of magnitude, |
| precision | The accuracy with which a number can be represented, i.e., the number of digits used to represent a number. |
| primary data | (Data Analysis) Typically, data acquired by direct interaction, such as direct observation through measurements, tabulation, or surveys |
| peak land value point | the location of the highest land value in an urban area. |
| hydraulic mining | Mining by washing sand and dirt away with water, leaving the desired mineral. |
| rank-size rule | the size of a settlement is inversely proportional to its rank i.e |
| airborne snow survey program | Center (NOHRSC) program that makes airborne snow water equivalent and soil moisture measurements over large areas of the country that are subject to severe and chronic snowmelt flooding. |
| surface runoff | The part of runoff, caused by precipitation and/or snowmelt, that moves over the soil surface to the nearest stream channel. Rain that falls on the stream channel is often lumped with |
| surplus | In a fisheries sense, the number of fish in excess of those needed to maintain a population at some level. |
| litter layer | The loose, relatively undecomposed organic debris on the surface of the forest floor made up typically of leaves, bark, small branches, and other fallen material. |
| altithermal | A period of time in the mid-Holocene when climate was generally warmer |
| landscape features | The land and water form vegetation, and structures that compose the characteristic landscape. |
| establishment | Subsequent growth and/or reproduction of a colonized species in a new territory. |
| flush | to open a cold-water tap to clear out all the water which may have been sitting for a long time in the pipes; to force large amounts of water through a system to clean out piping or tubing and storage or process tanks. |
| construction | The process of building. |
| cytoplasm | All of the protoplasm in a cell except for what is contained in the nucleus. |
| head ditch | The water supply ditch at the head end of an irrigated field. |
| prokaryote | Organisms whose cells have their genetic material in the form of loose strands of DNA found in the cytoplasm |
| canyon | Steep-sided valley where depth is considerably greater than width |
| fertigation | The use of irrigation water as a vehicle for spreading fertilizer on the land. |
| sanitary sewer | A sewer intended to carry only sanitary or sanitary and industrial wastewater from residences, commercial buildings, industrial parks, and institutions. |
| nfip | National Flood Insurance Program |
| fracture | Wall of sewer visibly separated along the length and/or circumference of the sewer with the pieces of the sewer wall in place |
| oolith | a calcareous sphere, approximately 1 mm in diameter, formed by precipitation of concentric layers of calcium carbonate around a nucleus such as a grain of sand or shell fragment as it is rolled around by wave action in warm, shallow, tropical seas. |
| contour | A line on a map that indicates a line of equal elevation on the land or water in feet over mean sea level |
| fountain | (1) An artificially created jet or stream of water; a structure, often decorative, from which a jet or stream of water issues |
| floodwall | A long, narrow concrete, or masonry embankment usually built to protect land from flooding |
| local flooding | Flooding conditions over a relatively limited (localized) area. |
| pesticide | A substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest |
| scattered | 1) An official sky cover classification for aviation weather observations, descriptive of a sky cover of 3/8 to 4/8. This is applied only when obscuring phenomenon aloft are present--that is, not when obscuring phenomenon are surface-based, such as fog |
| ice shelf | A large flat-topped sheet of ice that is attached to land along one side and floats in an ocean or lake |
| recharge area | The area in which water reaches the Zone of Saturation by surface infiltration |
| infield-outfield | farming system, largely obsolete now, where the fields closest to the farm buildings receive the most attention and most intensive cropping |
| precipitation | rain, snow, hail, sleet, dew, and frost. |
| watershed restoration | Improving current conditions of watersheds to restore degraded habitat and provide long-term protection to aquatic and riparian resources. |
| flood frequency | how often, on average, a discharge of a given magnitude occurs at a particular location on a stream |
| frequency carrier | The fundamental transmitted microwave frequency between 2700 and 3000 MHz |
| demand | The rate at which electric energy is used, whether at a given instant, or averaged over any designated period of time. |
| columnar ice | Ice consisting of columnar shaped grain |
| water banking | An administrative system for renting surplus water. |
| visibility | The greatest distance an observer can see and identify prominent objects. |
| nutrient cycle | the movement of nutrients in the ecosystem between the three major stores of the soil, biomass and litter |
| seepage | slow movement of water through small cracks or pores in rocks and soil. |
| apogee | The farthest distance between the moon and earth or the earth and sun. |
| sheepback | See roche moutonnée. |
| global brand | technically any brand that has been marketed extensively around the world to a wide variety (economically, socially and politically) of countries |
| infiltration | the entrance or flow of water into the soil, sediment or rocks of the Earth's surface inorganic - chemicals not containing the element carbon interest - payments made to an investor for the use of borrowed money intrusion - the entrance of an unwanted element, such as saltwater, into freshwater supplies inundation - covering over or flooding, such as flood waters covering a valley irrigation - supplying water to agriculture by artificial means, such as pumping water onto crops in an area where rainfall is insufficient |
| overdetermined multiple doppler analysis | A multiple Doppler analysis technique in which there are more radars than the desired number of wind components to be retrieved |
| impaired water body | a water body that has been determined under state and federal law as not meeting water quality standards, or having the potential to do so in the future. |
| dredging | Digging up and removing material from wetlands or waterways, usually to make them deeper or wider. |
| bed roughness | A measure of the irregularity of the streambed as it contributes to flow resistance |
| initial loss | Rainfall which precedes the beginning of surface runoff |
| irrecoverable losses | Water lost to a salt sink or lost by evaporation or evapotranspiration from a conveyance facility, drainage canal, or in fringe areas. |
| outgassing | The release of gas from cooling molten rock or the interior of the Earth |
| well monitoring | measurement by on-site instruments or laboratory methods of well water quality. |
| generator | A machine that changes water power, steam power, or other kinds of mechanical energy into electricity. |
| gis | see Geographical Information System. |
| floc | A cluster of frazil particles. |
| granular activated carbon | The heating of carbon to encourage active sites to absorb pollutants. |
| inland freshwater wetlands | Swamps, marshes, and bogs found inland beyond the coastal saltwater wetlands. |
| intake | opening through which a fluid is admitted into a container or conduit. |
| anchor ice dam | An accumulation of anchor ice which acts as a dam and raises the water level. |
| land application | Discharge of wastewater onto the ground for treatment or reuse. |
| tabular iceberg | A flat-topped iceberg, usually formed by breaking off an ice shelf. |
| detritus | Undissolved organic and inorganic matter, such as small pieces of vegetation, and animal remains, that result from decomposition and help form the base of the food chain. |
| stream morphology | The form and structure of streams. |
| instream cover | The layers of vegetation, like trees, shrubs, and overhanging vegetation, that are in the stream or immediately adjacent to the wetted channel. |
| bankfull stage | An established river stage at a certain point along a river which is intended to represent the maximum safe water level which will not overflow the river banks or cause any significant damage within the reach of the river. |
| navigate | (Nautical) To voyage over water in a boat or ship; to travel by water; sail. |
| metabolise | Conversion of food, for instance soluble organic matter, to cellular matter and gaseous by-products through a biological process. |
| saffir-simpson hurricane intensity scale | This scale was developed in an effort to estimate the possible damage a hurricane's sustained winds and storm surge could do to a coastal area |
| late seral condition | Synonymous with good ecological conditions. |
| point precipitation | Precipitation at a particular site, in contrast to the mean precipitation over an area. |
| hydraulic head | The vertical distance between the surface of the reservoir and the surface of the river immediately downstream from the dam. |
| radarsonde observation | An upper air observation used to determine winds and other meteorological data, by tracking the range, elevation, and azimuth of a radar target carried aloft |
| nwp | Numerical Weather Prediction. |
| cobble | Substrate particles that are smaller than boulders and larger than gravels, and are generally 64-256 mm in diameter |
| saline/poor quality aquifer | An aquifer containing water that is high in total dissolved solids, and is unacceptable for use as drinking water. |
| ribbon falls | Spectacular narrow waterfalls that occur at the edge of a hanging valley. |
| armoring | A natural or artificial process where an erosion-resistant layer of relatively large particles is established on the surface of the streambed through the removal of finer particles by stream flow |
| compact call | The requirement that an upstream state cease or curtail diversions of water from the river system that is the subject of the compact to satisfy the downstream state's compact entitlements. |
| seasonal or intermittent streams | Streams which flow only at certain times of the year when it receives water from springs, rainfall, or from surface sources such as melting snow. |
| coagulation | Destabilisation of colloid particles by addition of a reactive chemical, called a coagulant |
| sewage treatment | The processing of wastewater for the removal or reduction in the level of dissolved solids or other undesirable constituents. |
| pseudo-warm front | A boundary between a supercell's inflow region and the forward-flank downdraft (or FFD) |
| isostatic depression | Large scale sinking of the crust into the asthenosphere because of an increase in weight on the crustal surface |
| subsurface drains | Subsurface drains are buried, perforated pipelines designed to collect and convey subsurface water from an irrigated area. |
| xeriscape | Landscaping concept that requires less water on vegetation that is suited to soils and climate |
| papillose | Covered with papilla. |
| silurian | Geologic period that occurred roughly 408 to 438 million years ago |
| river basin | A term used to designate the area drained by a river and its tributaries. |
| kondratieff cycle | a contentious economic theory of price behaviour |
| recreational fishery | A fishery limited to use of certain gear types (usually rod and reel) where fish can only be used for personal consumption (not sold) or must be released unharmed. |
| cultured stock | A stock that depends upon spawning, incubation, hatching, or rearing in a hatchery or other artificial production facility. |
| herbivore | any organism which feeds exclusively on plants ( producers). |
| isotopic dating | Dating technique used to determine the age of rock and mineral through the decay of radioactive elements. |
| tap | A valve and spout used to regulate delivery of a fluid at the end of a pipe. |
| pluvial | pertaining to precipitation. |
| pumping station /lift station | A mechanical device in a sewer or water system that moves liquids to a higher level via a pump and a forcemain. |
| bed stability | occurs when the average elevation of the streambed does not change significantly over time |
| overcast | An official sky cover classification for aviation weather observations, when the sky is completely covered by an obscuring phenomenon. This is applied only when obscuring phenomenon aloft are present--that is, not when obscuring phenomenon are surface-based, such as fog. |
| bahada | gently sloping plain formed when a number of alluvial fans exiting closely spaced wadis in desert areas coalesce into a larger feature. |
| benthic invertebrates | Aquatic animals without backbones that dwell on or in the bottom sediments of fresh or salt water |
| retention basin | A permanent lake or pond used to slow stormwater runoff. |
| ocean | such as a bay, mouth of a river, salt marsh or lagoon, deepwater tidal habitat and tidal wetland, they are usually partially enclosed by land but have free access to the ocean and are at least occasionally diluted by fresh water runoff from the land. |
| mitigating measures | Modifications of actions that (1) avoid impacts by not taking a certain action of parts of an action; (2) minimize impacts by limiting the degree or magnitude of the action and its implementation; (3) rectify impacts by repairing, rehabilitating, or restoring the affected environment; (4) reduce or eliminate impacts over time by preservation and maintenance operations during the life of the action; or (5) compensate for impacts by replacing or providing substitute resources or environments. |
| breakup jam | Ice jam that occurs as a result of the accumulation of broken ice pieces. |
| hurricane | An intense cyclonic storm consisting of an organized mass of thunderstorms that develops over the warm oceans of the tropics |
| entrain | to trap bubbles in water either mechanically through turbulence or chemically through a reaction. |
| headgate | the gate that controls water flow into irrigation canals and ditches |
| nitrification | The biochemical oxidation of ammonium to nitrite and nitrite to nitrate |
| cohort | Individuals all resulting from the same birth-pulse, and thus all of the same age. |
| antecedent drainage | the maintenance of course by an old river over more recent uplifting of the land surface. |
| photodissociation | The splitting of a molecule by photon normally from the Sun. |
| arcus | A dense, arched-shaped, menacing-looking accessory cloud to a cumulonimbus that can occur along the leading edge of a thunderstorm's gust front as the consequence of uplift of stable warm air. Same as a shelf cloud. |
| siberian high | The semi-permanent high pressure area that forms over Siberia during the winter |
| snow pellets | Frozen precipitation in the form of white, round or conical opaque grains of ice |
| downstream slope | The slope or face of the dam away from the reservoir water |
| amprometric titration | a way of measuring concentrations of certain substances in water using the electric current that flows during a chemical reaction. |
| trickle down | the movement of wealth from a core region into the periphery. |
| crest gage | A gage used to obtain a record of flood crests at sites where recording gages are installed. |
| sky condition | Used in a forecast to describes the predominant/average sky condition based upon octants (eighths) of the sky covered by opaque (not transparent) clouds. |
| soil structure | the pattern of aggregated soil particles into certain shapes of peds. |
| microwave line-of-site | It is used between from 3,280 feet to 25 miles. The problem with this type of link is that it will experience loss of data from thunderstorms. Only 4 sites |
| well or water well | a bored, drilled or driven shaft or a dug hole for the purpose of withdrawing water from an underground aquifer. Ground water is then retrieved by windlass and bucket, hand pump or motorized pump into a pipe system. |
| matter | Is the material (atoms and molecules) that constructs things on the Earth and in the Universe. |
| explosive eruption | Volcanic eruption where high-viscosity granite-rich magma causes an explosion of ash and pyroclastic material |
| irrigation return flow | water which is not consumptively used by plants and returns to a surface or ground water supply |
| ria coast | An extensively carved out coast with conspicuous headlands and deep re-entrants. |
| littoral zone | The zone along a coastline that is between the high and low-water spring tide marks. |
| maximum water surface | The maximum water-surface elevation is the highest water surface elevation for which the dam is designed |
| irrigated area | The gross farm area upon which water is artificially applied for the production of crops, with no reduction for access roads, canals, or farm buildings. |
| mare's tail | The name given to thin, wispy cirrus clouds composed of ice crystals that appear as veil patches or strands, often resembling a horse's tail. |
| canal prism | The cross-sectional shape of a typical canal. |
| special weather statement | This is used by the National Weather Service to provide additional information about expected or ongoing significant weather changes not covered in other statements. This would include non-severe convective, winter weather, and non-precipitation events. |
| branch | (1) A tributary of a river or other body of water |
| qpfpfd | NCEP Precipitation Forecast Discussion |
| excessive rainfall discussion | This message discusses the potential for excessive rainfall in the contiguous United States until 7 AM EST (8 AM EDT) the next day. This includes mentioning the areas where rainfall is forecast to be locally heavy, approach or exceed flash flood guidance, or exceed 5 inches. This product includes evaluation of initial conditions and short-term numerical model forecasts and analysis of radar and satellite data. This product is issued 3 times a day as described below. There is an accompanying graphic for each forecast under the AFOS identifier 94E. |
| neutralism | Interspecific interaction where the species do not directly influence each other fitness. |
| moraine | A general term for a ridge or mound of till deposited by a glacier. |
| restricted plants | Plants which are classified as restricted due to their high water use requirements and their potential for extensive use in landscaping |
| cheyenne fog | An upslope fog formed by the westward flow of air from the Missouri River Valley, producing fog on the eastern slopes of the Rockies. |
| rotten ice | Ice in an advanced stage of disintegration. |
| trophic level | in ecosystems, each level of energy storage which is also a food supply for the next. |
| flash flood statement | A statement by the NWS which provides follow-up information on flash flood watches and warnings |
| available chlorine | A measure of the amount of chlorine available in chlorinated lime, hypochlorite compounds, and other materials. |
| fin ray | A soft or hard cartilaginous rod in fins. |
| drought | Generally, the term is applied to periods of less than average or normal precipitation over a certain period of time sufficiently prolonged to cause a serious hydrological imbalance resulting in biological losses (impact flora and fauna ecosystems) and/or economic losses (affecting man) |
| varve | a two-layered deposit in a lake near to a glacial area |
| water exports | Artificial transfer (pipe, canals) of water to one region or subregion from another. |
| galaxy | An assemblage of millions to hundreds of billions of stars. |
| rapid | A reach of stream that is characterized by small falls and turbulent, high-velocity water. |
| oceanic plate | A rigid, independent segment of the lithosphere composed of mainly basalt that floats on the viscous plastic asthenosphere and moves over the surface of the Earth |
| frost creep | a form of mass movement where expansion due to freezing of water in the upper soil leads to downslope collapse on thawing and thus a net downslope movement. |
| trough | An elongated area of low atmospheric pressure that is associated with an area of minimum cyclonic circulation |
| ecosystem | The biological community considered together with the land and water that make up its environment |
| emarginate | Having the margin notched. |
| cartography | map and chart making. |
| derecho | A line of intense, widespread, and fast-moving thunderstorms that moves across a great distance |
| median streamflow | the rate of discharge of a stream for which there are equal numbers of greater and lesser flow occurrences during a specified period. |
| giardia | A microrganism that is commonly found in untreated surface water and can be removed by filtration |
| polygenetic landform | Landform that shows the influence of two or more major geomorphic processes |
| tornado watch | This is issued by the National Weather Service when conditions are favorable for the development of tornadoes in and close to the watch area. Their size can vary depending on the weather situation. They are usually issued for a duration of 4 to 8 hours. They normally are issued well in advance of the actual occurrence of severe weather. During the watch, people should review tornado safety rules and be prepared to move a place of safety if threatening weather approaches. |
| landtype | A land system with a designated soil, vegetation, geology, topography, climate, and drainage situation. |
| best management practice | Conservation measures intended to minimize or mitigate impacts from a variety of land-use activities. |
| limiting factor | "A requirement such a food, cover or spawning gravel that is in shortest supply with respect to all resources necessary to sustain life and thus ""limits"" the size or retards production of a fish population." |
| combined sewer | A sewer that conveys both stormwater and sanitary sewage in the same pipe. |
| aquifer | a permeable rock which stores and transfers water |
| graupel | A type of precipitation that consists of a snow crystal and a raindrop frozen together |
| decentralization | movement of people, government functions or employment opportunities out from an established central area to a relatively peripheral one |
| dyne | A unit of force that creates an acceleration on a mass of 1 gram equal to 1 centimeter per second |
| purge | to force a gas through a water sample to liberate volatile chemicals or other gases from the water so their level can be measured. |
| unstable equilibrium | In an unstable equilibrium the system returns to a new equilibrium after disturbance. |
| process water | Water that serves in any level of the manufacturing process of certain products. |
| indicator tests | tests for a specific contaminant, group of contaminants, or constituent which signals the presence of something else (ex., coliforms indicate the presence of pathogenic bacteria). |
| bed slope | The inclination of the channel bottom, measured as the elevation drop per unit length of channel. |
| estuary | The thin zone along a coastline where freshwater systems and rivers meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon). |
| shefpars | A software decoder for SHEF Data. |
| porosity | the water-bearing capacity of subsurface soil or rock. |
| diversion dam | A barrier built to divert part or all of the water from a stream into a different course. |
| earth rotation | Refers to the spinning of the Earth on its polar axis. |
| national trust | in the UK, an organisation tasked with preserving historic and/or architecturally important buildings as well as areas of beautiful landscape |
| distilled water | water that has been treated by boiling and condensation to remove solids, inorganics, and some organic chemicals. |
| mayordomo | Executive Officer or ditch boss of the community ditch or acequia. |
| convection current | The movement of a gas or a fluid in chaotic vertical mass motions because of heating. |
| pumped hydroelectric storage | storing water for future use in generating electricity |
| center | The vertical axis or core of a tropical cyclone |
| random | Process or event that occurs by chance. |
| landscape | (Geography) All the natural features, such as fields, hills, forests, and water that distinguish one part of the earth's surface from another part |
| erosion | The wearing down or washing away of the soil and land surface by the action of water, wind, or ice. |
| fauna | (1) A term used to describe the animal species of a specific region or time |
| advis | A program which combines the Antecedent Precipitation Index (API) method of estimating runoff with unit hydrograph theory to estimate streamflow for a headwater basin. |
| lifting condensation level | The height at which a parcel of moist air becomes saturated when it is lifted dry adiabatically. |
| onshore | Coming or moving from the water toward or onto the shore, as a breeze or prevailing wind. |
| balanced operation | Operation of a canal system where the water supply exactly matches the total flow demand. |
| micron | A unit to discribe a measure of length, equal to one millionth of a metre. |
| glacial trough | Glaciers transform v-shaped stream valleys to u-shaped glacial troughs by erosion. |
| freeze | It is when the surface air temperature is expected to be 32oF or below over a widespread area for a climatologically significant period of time |
| chezy's equation | the empirical equation used to estimate the hydraulic conditions of flow within a channel cross section |
| 'i' | See inphase. |
| in-situ vitrification | technology that treats contaminated soil in place at high temperatures, at 3,000 degrees Fahrenheit or more. |
| burn index | A fire control management system that integrates the effects of selected fire danger factors into one or more qualitative or numerical indices from which ease of ignition and probable fire behavior may be estimated. This is also called a Fire Danger Rating. |
| eutrophic | Usually refers to a nutrient-enriched, highly productive body of water. |
| acid | donate an unshared pair of electrons to an acid or react with an acid to form a salt, a substance that has fewer free hydrogen ions, H+, than hydroxyl ions, OH-, (see alkaline). |
| wet-bulb thermometer | Thermometer on a psychrometer that has a moisten wick on its reservoir bulb |
| convectional lifting | The vertical lifting of parcels of air through convective heating of the atmosphere |
| discount rate | The interest rate used in evaluating water (and other) projects to calculate the present value of future benefits and future costs or to convert benefits and costs to a common time basis. |
| stream power | Directly related to the sediment transport rates of a stream and measured as the loss of potential energy per unit length of stream channel |
| biosphere reserve | a designation given and coordinated by UNESCO to conserve natural systems through education and research. |
| movable bed | A stream bed made up of materials readily transportable by the stream flow. |
| fissure | a crack in the crust through which lava may erupt. |
| soluble minerals | Naturally occurring substances capable of being dissolved. |
| land farming | A technique for the controlled biodegradation of organic waste that involves the mixture of waste sludges with soil |
| salinity | The presence of soluble minerals in water. |
| site-specific | Term used in conjunction with "forecast" or "warning" to convey the fact that a hydrologic (stream) forecast is produced for an individual stream gage location as opposed to a general area (e.g., a city, zone, or county) as is commonly done in many types of weather forecasts. |
| mean solar day | Time it takes to complete one Earth rotation relative to the position of the Sun (for example, from midnight to midnight) |
| elevation | Height in feet above sea level. |
| fossil fuel | Carbon based remains of organic matter that has been geologically transformed into coal, oil and natural gas |
| total dissolved solids | minerals present in water, measured in ppm, parts per million or by mg/l, milligrams per liter. |
| sea level | The level of the surface of the sea, especially measured at its mean position midway between mean high and low water. |
| fecal coliform bacteria | Bacteria that are present in the gut or the feces of warm blooded animals; they are indicators of possible sewage pollution. |
| coral | a tiny animal (polyp) which exists in large colonies in warm, shallow, clear salt-water. |
| head | the pressure of a fluid owing to its elevation, usually expressed in feet of head or in pounds per square inch, since a measure of fluid pressure is the height of a fluid column above a given or known point. |
| spawning | The depositing and fertilizing of eggs (or roe) by fish and other aquatic life. |
| wet-bulb zero | It is the height where the wet-bulb temperature goes below 0 o F |
| geosphere | Considered the solid portions of the earth, including the hydrosphere and the lithosphere, as opposed to the atmosphere, which lies above it |
| outplanting | Hatchery reared fish released into streams for rearing and maturing away from the hatchery sites. |
| alluvium | Sediments deposited by erosion processes, usually by streams. |
| channelling | The tendency of the wind to follow the axis of a channel or be steered by sloping land, resulting in a change in its direction. |
| aeration | Technique that is used with water treatment that demands oxygen supply, commonly known as aerobic biological water purification |
| leachate collection system | An arrangement of reservoirs and pipes underlying a waste disposal site designed to accumulate and remove Leachate, water that migrates through the waste, and pump it to the surface for treatment. |
| frost | a covering of minute ice crystals on a cold surface. |
| microwave radiation | Form of electromagnetic radiation with a wavelength between 0.1 to 100 centimeters. |
| montmorillonite | A type of clay that has a large capacity to shrink and expand with wetting and drying. |
| migration | Movement of organisms in an intentional way between two points in space |
| subimpoundment | An isolated body of water created by a dike within a reservoir or lake. |
| water quality indicators | Constituents or characteristics of water that can be measured to determine its suitability for use. |
| intermediate zone | The subsurface water zone below the root zone and above the capillary fringe. |
| year class | Fish in a stock born in the same year |
| visibility | A measure of the opacity of the atmosphere, and therefore, the greatest distance one can see prominent objects with normal eyesight |
| cape | (1) A point or head of land projecting into a body of water |
| rain shadow | Also referred to as a precipitation shadow, it is the region on the lee side of a mountain or similar barrier where the precipitation is less than on the windward side |
| drawdown | the change in the level of the upper water surface in a well or reservoir which is due to the withdrawal of water. |
| datacol | The Software System that supports RFC gateway functions. |
| nitrogen cycle | Model that describes the movement of nitrogen in its many forms between the hydrosphere, lithosphere, atmosphere and biosphere. |
| exogenic | Refers to a system that is external to the Earth. |
| hydrology | The science of waters of the earth; water's properties, circulation, principles, and distribution. |
| sand | a particle of rock/mineral that has a diameter between 0.1 and 1.0mm. |
| catalyses | Chemical that increases the rate of a reaction but does not take a direct part in the reaction, so that it is still intact after the reaction has taken place. |
| omega high | A blocking ridge of high pressure that forms in the middle or upper troposphere |
| frost shattering | see freeze-thaw weathering. |
| coastal flood warning | This National Weather Service product alerts residents along the Atlantic, Pacific, and Gulf Coasts that coastal flooding is either imminent or occurring. |
| plant succession | the sequence of plant species that inhabit an area from the pioneers that first arrive, through to the climax community. |
| subdrainage | A land area (basin) bounded by ridges or similar topographic features, encompassing only part of a watershed, and enclosing on the order of 5,000 acres; smaller than, and part of, a watershed. |
| extrusive igneous rock | Igneous rock that forms on the surface of the Earth |
| incineration | (Water Quality) A treatment technology involving the destruction of waste by controlled burning at high temperatures, e.g., burning sludge to remove the water and reduce the remaining residues to a safe, non-burnable ash that can be disposed of safely on land, in some waters, or in underground locations. |
| mie scattering | Any scattering produced by spherical particles whose diameters are greater than 1/10 the wavelength of the scattered radiation |
| gravel envelope | In well construction, a several-inch thickness of uniform gravel poured into the annular space between the well casing and the drilled hole. |
| navigation methods | Three basic methods of providing and managing inland waterways - 1) Run-of-the-River: no provision of upstream storage; 2) Slack-Water: locks and dams provide slack water or pools with adequate depth for the draft of heavy barges and area to prevent excessive velocities; 3) Canalization: in lieu of a series of dams on the river a canal with locks adjoins the river. |
| emergency spillway | A dam spillway built to carry runoff in excess of that carried by the principal spillway; a secondary spillway designed to operate only during exceptionally large floods |
| 100-year storm | A precipitation event used for stormwater drainage system design, based on a frequency analysis of historical data |
| wsr-88d | Weather Surveillance Radar - 1988 Doppler; NEXRAD unit. |
| hydrologic unit | (1) A geographic area representing part or all of a surface drainage basin or distinct hydrologic feature |
| reduction | A chemical reaction in which ions gain electrons to reduce their positive valence. |
| punchcard | A card (alternatively called a tag or stamp) used by steelhead and salmon anglers to record catch information; it is returned to management agency after the fishing season. |
| rearing pond | An artificial impoundment in which juvenile fish are raised prior to release into the natural habitat. |
| subsurface storm flow | The lateral motion of water through the upper layers until it enters a stream channel |
| perennial stream | A stream that flows all year round |
| porosity | The ratio of the total volume of pore space (voids) in a rock or soil to its total volume, usually stated as a percentage |
| bank-full width | the width of a river or stream channel between the highest banks on either side of a stream. |
| conservation storage | Storage of water for later release for usual purposes such as municipal water supply, power, or irrigation in contrast with storage capacity used for flood control.. |
| closed drain | Subsurface drain, tile, or perforated pipe that receives surface water through surface inlets. |
| vicinity | A proximity qualifier used to indicate weather phenomena observed between 5 and 10 statue miles of the usual point of observation, but not at the station. |
| percolation path | The course followed by water moving or percolating through any permeable material or under a dam which rests on a permeable foundation. |
| aquatic plants | fall into four categories |
| prescribed water rights | Water rights to which legal title is acquired by long possession and use without protest of other parties |
| habitat indicator | A physical attribute of the environment measured to characterize conditions necessary to support an organism, population, or community in the absence of pollutants, e.g., salinity of estuarine waters or substrate type in streams or lakes. |
| vernal equinox | Taking place in the Northern Hemispheric spring, it is the point at which the ecliptic intersects the celestial equator |
| nonreimbursable costs | Water project costs allocated to general statewide or national beneficial purposes and funded from general fund revenues. |
| zooplankton | Tiny aquatic animals eaten by fish. |
| efta | see European Free Trade Association. |
| light breeze | Wind felt on face; leaves rustle; wind vanes moved by wind; small wavelets form on water, still short, but more pronounced; crests have glassy appearance. |
| sediment rating curve | Numerical expression or graphical curve that describes the quantitative relationship between stream discharge and the sediment transported by a particular stream. |
| bank stability | The ability of a streambank to counteract erosion or gravitational forces. |
| secondary drinking water regulations | Non-enforceable regulations applying to public water systems and specifying the maximum contamination levels that, in the judgment of EPA, are required to protect the public welfare |
| incident power density | Energy per unit area incident on the radar target. |
| correlative rights | rights that are coequal or that relate to one another, so that any one owner cannot take more than his share. |
| decant | To draw off the upper layer of liquid after the heaviest material (a solid or another liquid) has settled. |
| bacteria | a class of organisms known as Prokaryotes in which the cell has no nucleus |
| fry | A stage of development in young salmon or trout |
| grassland | Ecosystem whose dominant species are various types of grass |
| hydrology | The scientific study of the water of the earth, its occurrence, circulation and distribution, its chemical and physical properties, and its interaction with its environment, including its relationship to living things. |
| capital | three forms can be identified: |
| augmentation | the addition of water to meet flow needs. |
| nitric acid | Acid with the chemical formula: HNO3. |
| woodland | Forest land producing trees not typically used as saw timber products and not included in calculation of the commercial forest land allowable sale quantity. |
| snowfall | The rate at which snow falls, usually expressed in inches of snow depth over a six hour period. |
| development gap | the disparity in development between the EMDW and ELDW. |
| transient snowline | The line separating transient accumulation and ablation areas, also a transient equilibrium line. |
| barometer | An instrument used to measure atmospheric pressure |
| calving | The loss of glacier mass when ice breaks off into a large water body like an ocean or a lake. |
| liquid | A state of matter, neither gas nor solid, that flows and takes the shape of its container. |
| chinook wind | A warm dry wind on the east side of the Rocky Mountains. |
| isobaric process | Any thermodynamic change of state of a system that takes a place at constant pressure. |
| toxicant | a substance or a mixture of substances. |
| birth rate | number of live births per thousand people per year. |
| trash rack | A barrier placed at the upstream end of a culvert to trap debris but allow water to flow through. |
| connate water | water that is trapped in the interstices, or breaks, between adjacent strata of sedimentary rock |
| priority | The concept that the person first using water has a better right to it than those commencing their use later |
| perched water table | Water table that is positioned above the normal water table for an area because of the presence of a impermeable rock layer. |
| strategic plan | A comprehensive long-term plan that identifies goals and objectives, and the problems in meeting them, together with strategies or actions needed to overcome the problems. |
| slip-face | The lee side of a dune where material accumulates and slides or rolls downslope. |
| standardization | The procedure of maintaining methods and equipment as constant as possible. |
| sediment | soil and rock particles in water that settle out as water slows down. |
| urban area | Geographic area with a high density of people over a limited area |
| french drain | An underground passageway for water through the interstices among stones placed loosely in a trench. |
| sea level pressure | The atmospheric pressure at mean sea level, usually determined from the observed station pressure. |
| half-life | The time required for a pollutant to lose one-half of its original concentraton. |
| furrow irrigation | Spreading water by directing it into small channels across the field. |
| primary sector | in industry, those activities concerned with extraction and or exploitation of raw materials. |
| afos | Automation of Field Operations and Services |
| b scope | An intensity-modulated rectangular display with azimuth angle as the horizontal coordinate and range as the vertical coordinate |
| thermocline | Boundary in a body of water where the greatest vertical change in temperature occurs |
| langelier index | An index reflecting the equilibrium pH of a water with respect to calcium and alkalinity; used in stabilizing water to control both corrosion and scale deposition. |
| index of wetness | The precipitation for a given year expressed as a ratio to the mean annual precipitation. |
| consumptive use | that part of water withdrawn that is evaporated, transpired by plants, incorporated into products or crops, consumed by humans or livestock, or otherwise removed from the immediate water environment |
| semiarid | A term applied to regions or climates where moisture is normally greater than under arid conditions but still definitely limits the growth of most crops |
| crest of dam | The elevation of the uppermost surface of a dam excluding any parapet walls, railings, etc. |
| non-clastic sedimentary rock | Sedimentary rocks that are created either from chemical precipitation and crystallization, or by the lithification once living organic matter. |
| terrestrial | Land above sea level. |
| ground water | (1) water that flows or seeps downward and saturates soil or rock, supplying springs and wells |
| inorganic compounds | mineral-based compounds such as metals or nitrates |
| water pollution | degradation of a body of water by a substance or condition to such a degree that the water fails to meet specified standards or cannot be used for a specific purpose. |
| cape verde islands | A group of volcanic islands in the eastern Atlantic Ocean off the coast of West Africa |
| defluoridation | The removal of fluoride from drinking water to prevent teeth damage. |
| weather | day to day variation in atmospheric conditions |
| squall line | A narrow band or line of active thunderstorms that is not associated with a cold front |
| paleoclimatology | Scientific study of the Earth's climate during the past. |
| baseflow | Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel |
| station pressure | The atmospheric pressure with respect to the station elevation. |
| gis | A computer system designed for storing, manipulating, analyzing, and displaying data in a geographic context |
| dyke | An artificial embankment constructed to prevent flooding. |
| index of wetness | The ratio of precipitation for a given year over the mean annual precipitation.. |
| heat exhaustion | The effect of excessive heat, particularly when combined with high humidity, on a human being |
| precipitation attenuation | The loss of energy that radar beam experiences as it passes through an area of precipitation. |
| orogenic belt | A major range of mountains on the continents. |
| shrub | A woody plant species that is smaller than a tree |
| channel morphology | shape and dimensions of the cross-section of a channel. |
| index of refraction | See refractive index. |
| hydraulic barrier | Modifications to a ground-water flow system that restrict or impede movement of water and contaminants |
| streambanks | The usual boundaries, not the flood boundaries, of a stream channel |
| dry crack | Crack visible at the surface but not going right through the ice cover, and therefore it is dry. |
| nyquist velocity or interval | The maximum unambiguous velocity that can be measured by a Doppler radar. |
| balance of payments | net sum of a country income from and expenditure on foreign trade which can run to a surplus or a deficit. |
| buys ballot's law | Describes the relationship of the horizontal wind direction to the pressure distribution |
| mid-columbia | The section of the Columbia River between the junction with the Snake River and Chief Joseph Dam. |
| runoff | surface water entering rivers, freshwater lakes, or reservoirs. |
| asaptran | The software component of ASAP. |
| region | A term used in geography that describes an area of the Earth where some natural or human-made phenomena display similar traits. |
| caudal | Pertaining to the tail. |
| imprinting | The physiological and behavioral process by which migratory fish assimilate environmental cues to aid their return to their stream of origin as adults. |
| inter-basin transfer | A transfer or diversion of water (either groundwater or surface water) from one Drainage or Hydrographic Basin to another. |
| control system | A system that is intelligently controlled by the activities of humans |
| carbohydrate | Is an organic compound composed of carbon, oxygen, and hydrogen atoms |
| front | Transition zone between air masses with different weather characteristics. |
| tributary | one river joining another |
| species association | A particular grouping of species in an area. |
| thunder | Sound created when lightning causes the rapid expansion of atmospheric gases along its strike path. |
| catchment basin | The entire area from which drainage is received by a river or a lake; most generally used in reference to surface runoff. |
| feeder cloud | The flanking lines of developing cumulus congestus clouds that sometimes merge with and appear to intensify supercells. |
| national municipal plan | a U.S |
| karst | Landform type with limestone bedrock and dominated by geomorphic features created from solution chemical weathering. |
| naturally spawning populations | Populations of fish that have completed their entire life cycle in the natural environment without human intervention. |
| range gate | The discrete point in range along a single radial of radar data at which the received signal is sampled |
| epiphytes | plants in tropical rainforest which live on the branches or trunks of larger trees |
| isolated storm | An individual cell or a group of cells that are identifiable and separate from other cells in a geographic area. |
| white goods | domestic appliances. |
| safety factor | An amount of water added to demand projections to protect against unforeseen changes in water supply and demand. |
| flashboards | A length of timber, concrete, or steel placed on the crest of a spillway to raise the retention water level but which may be quickly removed in the event of a flood by a tripping device, or by deliberately designed failure of the flashboard or its supports. |
| nonstructural flood control measures | Measures such as zoning ordinances and codes, flood forecasting, flood proofing, evacuation and channel clearing, flood fight activities, and upstream land treatment or management to control flood damages without physically restraining flood waters. |
| detention storage | The volume of water, other than depression storage, existing on the land surface as flowing water which has not yet reached the channel. |
| mud balls | (Water Quality) Accretions of siliceous incrustations on the exterior of sand grains in a rapid sand filter; typically removed by backwashing |
| groyne | a wooden wall built across a beach from land to sea |
| tsunami | An ocean wave with a long period that is formed by an underwater earthquake or landslide, or volcanic eruption |
| source region | the type of area from which an air mass originates. |
| reach | in general, a length of stream with relatively homogenous characteristics. |
| backflow | The backing up of water through a conduit or channel in the direction opposite to normal flow. |
| air stagnation | A meteorological situation in which there is a major buildup of air pollution in the atmosphere |
| storm surge | the pushing of water against a coastline to abnormally high levels, usually a combination of extreme low pressure and winds pushing water into a narrowing feature such as a bay or estuary. |
| mistral | Term used to describe a katabatic wind in southern France. |
| trade winds | The winds that occupy most of the tropics and blow from subtropical highs to the equatorial low. |
| tidal zone | the area between the low water mark and the high water mark. |
| blowing dust | Wind-driven dust that significantly reduces surface visibility to less than 7 miles. |
| sanitary seal | The neat cement seal at the top of a water well intended to prevent well contamination from surface water or shallow ground water flows containing potential contaminants. |
| synoptic scale | Scale of geographic coverage used on daily weather maps to describe large scale atmospheric phenomenon (for example, mid-latitude cyclone, air masses, fronts, and hurricanes). |
| acre-foot | The amount of water required to cover one acre to a depth of one foot |
| ecosystem structure | Attributes related to instantaneous physical state of an ecosystem; examples include species population density, species richness or evenness, and standing crop Biomass. |
| ground water hydrology | The branch of hydrology that specializes in ground water; its occurrence and movements; its replenishment and depletion; the properties of rocks that control ground water movement and storage; and the methods of investigation and utilization of ground water |
| enhanced v | A pattern seen on satellite infrared photographs of thunderstorms, in which a thunderstorm anvil exhibits a V-shaped region of colder cloud tops extending downwind from the thunderstorm core |
| newhall winds | The local name for winds blowing downward from desert uplands through the Newhall Pass southward into the San Fernando Valley, north of Los Angeles. |
| spring melt/thaw | the process whereby warm temperatures melt winter snow and ice |
| conservation storage | Storage of water for later release for usual purposes such as municipal water supply, power, or irrigation in contrast with storage capacity used for flood control.. |
| capillarity | (1)The degree to which a material or object containing minute openings or passages, when immersed in a liquid, will draw the surface of the liquid above the hydrostatic level |
| snow squall | A heavy snow shower accompanied by sudden strong winds, or a squall. |
| dependency ratio | the proportion of working (economically active) people to non-working (non-economically active) people in a country by the formula: |
| open sea | That part of the ocean that extends from the continental shelf |
| kype | The distinctive hooked jaw that male salmon develop during spawning. |
| tropical storm watch | An announcement that a tropical storm poses or tropical storm conditions pose a threat to coastal areas generally within 36 hours |
| parameter | "A ""constant"" or numerical description of some property of a population (which may be real or imaginary) |
| pingo | a dome-shaped hill in a flat tundra plain, often having a depression in the summit |
| deionisation | Process that serves to remove all ionised substances from a solution |
| hsa | A geographical area assigned to Weather Service Forecast Office's/Weather Forecast Office's that embraces one or more rivers. |
| spearhead echo | A radar echo associated with a Down burst with a pointed appendage extending toward the direction of the echo motion |
| trade winds | Two belts of prevailing winds that blow easterly from the subtropical high pressure centers towards the equatorial trough |
| volatile | Any substance which evaporates quickly. |
| antecedent precipitation index | A measure of how much moisture in the top layer of soil within a drainage basin |
| lag | The measure of the time between the center of mass of precipitation to the center of mass of runoff (on the hydrograph); basin lag is a function of not only basin characteristics, but also of storm intensity and movement |
| electromagnetic radiation | Also called radiation, it is waves of energy propagated though space or through a material media. |
| polyphyletic | Relating to or characterized by development from more than one ancestral type. |
| weak stock | "Listed in the Integrated System Plan's list of stocks of high or highest concern; listed in the American Fisheries Society report as at high or moderate risk of extinction; or stocks the National Marine Fisheries Service has listed |
| overfall dam | A dam constructed to allow water to overflow the dam's crest. |
| macroburst | A large downburst with an outflow diameter of 2.5 miles (4 kilometers) or larger and damaging winds. |
| bottleneck | A sharp reduction of a breeding population's size to a few individuals |
| topography | The shape of a landscape, composed of its relief and position of natural and man-made features. |
| potential temperature | The temperature a parcel of dry air would have if brought adiabatically (i.e., without transfer of heat or mass) to a standard pressure level of 1000 mb. |
| impervious | The ability to repel water, or not let water infiltrate. |
| infiltration capacity curve | A graph showing the time variation of infiltration capacity |
| thermoelectric power water use | water used in the process of the generation of thermoelectric power |
| effluent | water that flows from a sewage treatment plant after it has been treated. |
| county warning area | All the counties or parishes assigned to a specific National Weather Service Office (NWSO) for the purpose of warnings issuance and hazard awareness responsibility. |
| radiational cooling | The cooling of the Earth's surface |
| managed forest | Any forestland that is treated with silvicultural practices and/or harvested. |
| pressure relief pipes | Pipes used to relieve uplift or pore pressure in a dam foundation or in the dam structure. |
| drawdown | The lowering of the surface elevation of a body of water, the water surface of a well, the water table, or the piezometric surface adjacent to the well, resulting from the withdrawl of water therefrom. |
| autotroph | an organism that can produce nutritional organic substances from simple inorganic substances |
| mesozoic | Geologic era that occurred from 245 to 65 million years ago. |
| mantle | Layer of the Earth's interior composed of mostly solid rock that extends from the base of crust to a depth of about 2,900 kilometers. |
| runs | An area of swiftly flowing water, without surface agitation or waves, which approximates uniform flow and in which the slope of the water surface is roughly parallel to the overall gradient of the stream reach. |
| rain induced fog | When warm rain falls through cooler air, water evaporates from the warm rain |
| inhibitor | chemical that interferes with a chemical reaction, such as precipitation. |
| profile | A graph showing variation of elevation with distance along a traverse or profile cross section. |
| turbulent flow | Movement of water within a stream that occurs as discrete eddies and vortices |
| island | An island is a piece of land that is surrounded by water. |
| free ground water | water in interconnected pore spaces in the zone of saturation down to the first impervious barrier, moving under the control of the water table slope. |
| range unfolding | Process of removing range ambiguity in apparent range of a multitrip target on the radar. |
| calm | Atmospheric conditions devoid of wind or any other air motion |
| hydraulic action | lit |
| channel routing | The process of determining progressively timing and shape of the flood wave at successive points along a river. |
| flood stage | A gage height at which a watercourse overtops its banks and begins to cause damage to any portion of the defined reach |
| vapor pressure | The partial pressure of water vapor in the atmosphere. |
| area forecast discussion | This National Weather Service product is almost identical to the State Forecast Discussion; however, it deals with a much smaller area (just the county warning area of the NWFO), and it may or may not have the non-convective watches listed at the end of the product. Eventually, this product will replace the State Forecast Discussion. |
| bottom land hardwoods | Forested freshwater Wetlands adjacent to rivers in the southeastern United States, especially valuable for wildlife breeding, nesting, and habitat. |
| live moisture maps | These maps portray experimental live vegetation moisture with values ranging from 50 to 250 percent of dry weight. |
| mass extinction | A catastrophic, widespread perturbation where major groups of species become extinct in a relatively short time compared to normal background extinctions. |
| trend | (1) A statistical term referring to the direction or rate of increase or decrease in magnitude of the individual members of a time series of data when random fluctuations of individual members are disregarded |
| filtrate | A liquid that has passed through the filter medium. |
| sectorized hybrid scan | A single reflectivity scan composed of data from the lowest four elevation scans |
| site-specific | Term used in conjunction with "forecast" or "warning" to convey the fact that a hydrologic (stream) forecast is produced for an individual stream gage location as opposed to a general area (e.g., a city, zone, or county) as is commonly done in many types of weather forecasts. |
| saltation | Particle movement in water or wind where particles skip or bounce along the stream bed or soil surface. |
| watershed | land area from which water drains toward a common watercourse in a natural basin. |
| monsoon | A regional scale wind system that predictably change direction with the passing of the seasons |
| bioaccumulation | uptake and retention of substances by an organism from its surrounding medium (usually water) and from food. |
| hod | The Hydrologist on Duty at an RFC. |
| vertical visibility | The distance an observer can see vertically into an undefined ceiling, or the height corresponding to the top of a ceiling light projector beam, or the height at which a ceiling balloon disappears during the presence of an indefinite ceiling. |
| polar air mass | An air mass that forms over a high latitude region |
| ice-wedge casts | A vertical structure that results from cracks in frozen ground (by means of ice wedging) which are later filled by sediment |
| magnetic poles | Either of the two points on the earth's surface where the magnetic meridians converge |
| prey | Organism that is consumed by a predator. |
| effluent | (1) Something that flows out or forth, especially a stream flowing out of a body of water |
| rising sludge | (Water Quality) The rising of previously settled solids in the settling tank of an activated sludge system |
| crustal subsidence | The downwarping of Earth's crust due to the immense mass of continental ice sheets. |
| overturn | (1) The sinking of surface water and rise of bottom water in a lake or sea that results from changes in temperature that commonly occur in spring and fall |
| electrophoresis-2 | Electrophoresis refers to the movement of charged particles in an electric field |
| auroraphobia | The fear of the Northern Lights. |
| long wave trough | A wave in the prevailing westerly flow aloft which is characterized by a large length and amplitude |
| photosphere | Visible surface of Sun from which radiant energy is release. |
| pan | (1) A basin or depression in the earth, often containing mud or water |
| declared underground water basin | An area of the state proclaimed by the State Engineer to be underlain by a ground water source having reasonably ascertainable boundaries |
| bank-caving | Collapse of stream bank material into a stream channel. |
| wettability | the degree to which a fluid will spread into or coat a solid surface in the presence of other fluids into which it will not dissolve. |
| sma | The Soil Moisture Accounting Model. |
| current meter | An instrument for measuring the velocity of water flowing in a stream, open channel, or conduit by ascertaining the speed at which elements of the flowing water rotate a vane or series of cups. |
| aquiclude | A formation which contains water but cannot transmit it rapidly enough to furnish a significant supply to a well |
| soil erodibility | An indicator of a soil's susceptibility to raindrop impact, runoff, and other erosive processes. |
| crystallization | The process of a substance going directly from a vapor form (water vapor) to a solid (ice) at the same temperature, without going through the liquid phase (water) |
| catch rate | The time spent to catch fish expressed as catch in numbers or pounds per unit of effort. |
| oxbow lake | Is portion of abandoned stream channel filled with stagnant water and cut off from the rest of the stream |
| north pole | Surface location defined by the intersection of the polar axis with Earth's surface in the Northern Hemisphere |
| contour trenching | Development of water storage Detention or Retention Facilities along the contour by excavation and placement of soils as an embankment along the downstream side |
| throughflow | The roughly horizontal flow of water through soil or regolith. |
| tornado alley | Region in North America which receives a extraordinary high number of tornadoes |
| contributing area | That portion of a watershed which contributes to measured runoff under normal conditions. |
| primary wave | See P-wave. |
| liana | Species of plant that uses the support of wood plants to elevate its leaves above the forest canopy. |
| warmwater fish | A broad classification on non-salmonid fish that generally have at least one spiny ray, have pelvic and pectoral fins located behind the gills, and are usually suited for water that consistently exceeds 70 degrees F. |
| emergent | Rising above a surrounding medium, especially a fluid |
| interstitial | Referring to the Interstices or pore spaces in rock, soil, or other material subject to filling by water. |
| ecosystem management | (Environmental) An approach to managing the nation's lands and natural resources which recognizes that plant and animal communities are interdependent and interact with their physical environment (i.e., soil, water, and air) to form distinct ecological units called Ecosystems |
| dust dome | Dome of air that surrounds a city created from the urban heat island effect that traps pollutants like particulate matter. |
| kaolinite | A type of clay that is widespread in tropical and subtropical regions |
| unconfined groundwater | Groundwater that is not restricted by impervious layers of rock. |
| limnology | scientific study of physical, chemical, and biological conditions in lakes, ponds, and streams. |
| lahar | A very rapid type of downslope mass movement that involving mudflows from volcanic ash. |
| monomictic | lakes and reservoirs that are relatively deep, do not freeze over during winter, and undergo a single stratification and mixing cycle during the year (usually in the fall). |
| medial moraine | A moraine formed when two adjacent glaciers flow into each other and their lateral moraines are caught in the middle of the joined glacier. |
| floodway | (1) A part of the flood plain, otherwise leveed, reserved for emergency diversion of water during floods |
| podsol | soil type found in cold, wet climatic areas in high latitudes |
| latent heat flux | Latent heat flux is the global movement of latent heat energy through circulations of air and water |
| storage ratio | The net available storage divided by the mean flow for one year. |
| weir basin | (Irrigation) The wide, basinlike approach to the upstream side of a weir, being constructed so as to reduce to a minimum the effect of the momentum of the approaching water on the flow over the weir. |
| mitochondria | (see prokaryotic). |
| particulate loading | The mass of particulates per unit volume of water. |
| photosynthesis | The process of conversion of water and carbon dioxide to carbohydrates |
| cisk | An acronym for Conditional Instability of the Second Kind. |
| conditional fishing mortality rate | The fraction of an initial stock which would be caught during the year (or season) if no other causes of mortality operated |
| boundary water | A river or lake that is part of the boundary between two or more countries or provinces that have rights to the water. |
| light industry | an industry in which the physical mass of raw materials used is relatively low |
| fishing effort | 1 |
| pool | A deep reach of a stream |
| hail | a form of precipitation which forms into balls or lumps of ice over 0.2 inch in diameter |
| indigenous | Existing naturally in a region, state, country, etc. |
| zonal wind | Large-scale atmospheric flow in which the east-west component (i.e., latitudinal) is dominant |
| coastal flood watch | This National Weather Service product alerts residents along the Atlantic, Pacific, and Gulf Coasts to the possibility of coastal flooding. |
| microscale | The smallest scale of meteorological phenomena that range in size from a few centimeters to a few kilometers |
| millibar | The standard unit of measurement for atmospheric pressure used by the National Weather Service |
| infiltration | flow of water from the land surface into the subsurface. |
| bernoulli effect | The phenomenon of internal pressure reduction with increased stream velocity in a fluid |
| polar stratospheric clouds | High altitude clouds found in the stratosphere where the temperature is less than -85° Celsius |
| paleozoic | Geologic era that occurred from 570 to 245 million years ago. |
| improved irrigated acreage | Refers to farm acreage which has been leveled, planed and serviced by improved conveyance and control structures. |
| cooperative observer | An individual (or institution) who takes precipitation and temperature observations-and in some cases other observations such as river stage, soil temperature, and evaporation-at or near their home, or place of business |
| scotophobia | The fear of the darkness. See Achluophobia. |
| effusive eruption | Volcanic eruption where low-viscosity basaltic magma is released |
| zone of saturation | Groundwater zone within the Earth's bedrock where all available pores spaces are filled by water |
| sesquioxide | the oxides of iron and aluminium that occur in soils. |
| coast | a zone of interaction of the land and the sea at the margins where the two meet. |
| epidemic | widespread occurrence of a disease in a particular area or population. |
| tornado warning | A warning issued to the public that a tornado has been observed by an individual in a specified region |
| neutron | Atomic sub-particle found in the nucleus of an atom |
| aquifer | A body of rock that is sufficiently permeable to conduct groundwater and to yield economically significant quantities of water to wells and springs. |
| stoss | Side of a slope that faces the direction of flow of ice, wind, or water |
| rill | a small channel eroded into the soil by surface runoff; can be easily smoothed out or obliterated by normal tillage. |
| malnutrition | the body response to a lack of food in terms of the calorific energy intake or a lack of the right food in terms of the proportions of energy, minerals, protein, and vitamins |
| sheet flow | Flow that occurs overland in places where there are no defined channels, the flood water spreads out over a large area at a uniform depth |
| phytoplankton | free-floating, mostly microscopic aquatic plants. |
| continental shelf | The zone bordering a continent and extending to a depth, usually around 100 fathoms (600 feet), from which there is a steep descent toward greater depth. |
| ogives * | A series of ice waves or bands of lighter and darker material formed below ice falls in some glaciers |
| planned economy | see command economy. |
| initial loss | In hydrology, rainfall preceding the beginning of surface runoff |
| recharge basin | A surface facility, often a large pond, used to increase the infiltration of surface water into a ground water basin. |
| mesotrophic | reservoirs and lakes that contain moderate quantities of nutrients and are moderately productive in terms of aquatic animal and plant life. |
| interflow | (1) That movement of water of a given density in a reservoir or lake between layers of water of different density, usually caused by the inflow of water either at a different temperature, or with different silt or salt contents |
| appropriation | The right to take water from a natural stream or aquifer for beneficial use at a specified rate of flow, either for immediate use or to store for later use |
| hydraulic jump | The rapid change in the depth of flow from a low stage to a high stage, resulting in an abrupt rise of water surface. |
| habitat fragmentation | The breaking up of habitat into discrete islands through modification or conversion of habitat by management activities. |
| excessive heat warning | This product is issued by the National Weather Service when excessive heat is life threatening. The criteria for this warning varies from state to state. In Michigan, the criteria is a heat index of 115 degree F or higher for a period of 3 hours or more. |
| gravity | The force of attraction of the earth on an object |
| gene | The chemical unit of hereditary information that can be passed on from generation to generation. |
| radial velocity | The component of motion toward or away from a given location |
| constant pressure chart | A chart of a constant pressure surface in which atmospheric pressure is uniform everywhere at any given moment |
| paleoclimate | Climatic conditions in the geological past reconstructed from a direct or indirect data source. |
| boulder | A large substrate particle that is larger than cobble, 256 mm in diameter. |
| stream | A general term for a body of flowing water; natural water course containing water at least part of the year |
| population density | Number of individuals of a species per unit of area. |
| biological amplification | Increase in concentration of toxic fat-soluble chemicals in organisms at successively higher trophic levels of a grazing food chain or food web because of the consumption of organisms at lower trophic levels. |
| limnetic | Referring to a standing water Ecosystem (ponds or lakes). |
| blue ice | Water molecules reflect blue wavelengths of light. |
| meridional flow | Large-scale atmospheric flow in which the north-south component (i.e., longitudinal, or along a meridian) is pronounced |
| table | water beneath the surface of the ground, consisting largely of surface water that has seeped down, water beneath the earth's surface, occurring in aquifers at one or more depth levels, (see surface water). |
| national flood summary | This NWS daily product contains nationwide information on current flood conditions. It is issued by the Hydrometeorological Information Center of the Office of Hydrology. |
| pilot balloon | A small balloon whose ascent is used to determine the direction and speed of low level atmospheric winds |
| brackish | Having a somewhat salty taste, especially from containing a mixture of seawater and fresh water. |
| outburst flood | See Jokulhlaup. |
| tropics | Areas of the Earth within 20o North and South of the Equator. |
| tipping-bucket rain gage | A precipitation gage where collected water is funneled into a two compartment bucket; 0.01, 0.1 mm, or some other designed quantity of rain will fill one compartment and overbalance the bucket so that it tips, emptying into a reservoir and moving the second compartment into place beneath the funnel |
| convective outlook | A forecast containing the area(s) of expected thunderstorm occurrence and expected severity over the |
| through talik | Is a form of localized unfrozen ground (talik) in an area of permafrost |
| depth of runoff | The total runoff from a drainage basin, divided by its area |
| flood duration curve | A cumulative frequency curve that shows the percentage of time that specified discharges are equaled or exceeded. |
| first draw | The water that comes out when a tap is first opened |
| atmosphere | The gaseous or air portion of the physical environment that encircles a planet |
| mermaid | a fabled marine creature usually represented as having the head, trunk, and arms of a woman and a lower part like the tail of a fish. |
| indirect discharge | The introduction of pollutants from a non-domestic source into a publicly owned waste-treatment system |
| culvert | A buried pipe that allows flows to pass under a road. |
| overflow rate | One of the guidelines for design of the settling tanks and clarifiers in a treatment plant to determine if tanks and clarifiers are used enough. |
| soil science | The study of soils from an interdisciplinary perspective. |
| productivity | A measure of the capacity of a biological system |
| ecosphere | See biosphere. |
| growing season | (1) The period and/or number of days between the last freeze in the spring and the first frost in the fall for the freeze threshold temperature of the crop or other designated temperature threshold |
| fissure | Opening or crack in the Earth's crust. |
| outfall | The place where effluent is discharged into receiving waters. |
| separate sewer | A sewer system that carries only sanitary sewage; no storm-water runoff |
| hatch box | A device used to incubate relatively small numbers of fish eggs |
| ventifact | A loose piece of rock that has been polished smooth by wind transported particles |
| estuary | area of a lower river valley or mouth influenced by tidal change. |
| main lobe | The envelope of electromagnetic energy along the main axis of the radar beam. |
| incised river | A river that erodes its channel by a process of degradation to a lower base level than existed previously or is consistent with the current hydrology. |
| cbod | Carbonaceous Biochemical Oxygen Demand. A BOD test in which a nitrification inhibitor is added, so that only the carbonaceous oxygen demanding compounds are measured. |
| soft water | Water that contains low concentrations of metal ions such as calcium and magnesium |
| long-term potential catch | The largest annual harvest in weight that could be removed from a fish stock year after year, under existing environmental conditions |
| schedule of compliance | Description of remedial actions to be accomplished by the permit holder (type of facility to be installed or alternative control measures to be established) and a sequence of actions leading to compliance with applicable standards. |
| flocculation | the clustering of clay particles when river load meets sea water |
| throughfall | Describes the process of precipitation passing through the plant canopy |
| megawatt | A unit of electricity equivalent to 1 million watts or 1,000 kilowatts (KW). |
| surface wave | Type of seismic wave that travels across the Earth's surface |
| alkaline | sometimes water or soils contain an amount of alkali (strongly basic) substances sufficient to raise the pH value above 7.0 and be harmful to the growth of crops. |
| river regime | the variation in discharge over a year. |
| impoundment | A body of water formed behind a dam. |
| current canal | The current caused by an influent (inlet) or effluent (outlet) stream may effectively limit the growth of aquatic plants and create canal-like openings through weed beds. |
| organic chemicals | chemicals containing carbon. |
| watershed | Land area from which water drains toward a common watercourse in a natural basin. |
| specific humidity | In a system of moist air, the ratio of the mass of water vapor to the total mass of the system. |
| climax | The culminating stage in plant succession for a given site where the vegetation has reached a highly stable condition. |
| protons | Positively charged building blocks of an atom that are centered in the nucleus. |
| mammal | Group of warm blooded vertebrate animals |
| dissolved solids | Very small pieces of organic and inorganic material contained in water |
| sub-aerial processes | all physical processes occurring at the surface. |
| water balance | (1) A measure of the amount of water entering and the amount of water leaving a system |
| eutrophication | Enrichment of water, which causes excessive growth of aquatic plants and increasing activity of anaerobic microrganisms |
| cultural eutrophication | Decline of the oxygen rate in water, which has serious consequences for aquatic life, caused by humans. |
| return flow | (1) That part of a diverted flow that is not consumptively used and returned to its original source or another body of water |
| precipitable water | It measures the depth of liquid water at the surface that would result after precipitating all of the water vapor in a vertical column usually extending from the surface to 300 mb. |
| low-lying | Lying close to water or ground level as low-lying coastal areas. |
| gross water requirement | The Farm Delivery Requirement plus the seepage losses in the canal system from the headworks to the farm unit plus the waste of water due to poor operation. |
| splitting storm | A thunderstorm which splits into two storms which follow diverging paths (a left mover and a right mover) |
| kame | a short ridge, hill, or mound of stratified drift deposited by glacial meltwater. |
| cod | Chemical Oxygen Demand. A measure of the oxygen equivalent of the organic matter content of a sample that is susceptible to oxidation by a strong chemical oxidation. Differs from the BOD test in that COD uses oxygen derived from chemicals, while BOD uses oxygen derived from air dissolved in water. |
| contact metamorphism | Is the small scale metamorphic alteration of rock due to localized heating |
| mesa | A flat topped hill that rises sharply above the surrounding landscape |
| fallow | Cropland, either tilled or untilled, allowed to lie idle, during the whole or the greater part of the growing season. |
| free-flowing well | An artesian well in which the potentiometric surface is above the land surface |
| depressed stock | A stock of fish whose production is below expected levels based on available habitat and natural variations in survival levels, but above the level where permanent damage to the stock is likely. |
| free ground water | Water in interconnected pore spaces in the Zone of Saturation down to the first impervious barrier, moving under the control of the water table slope. |
| isohyet | The line drawn through geographic points recording equal amounts of rainfall during a given time or for a given of storm. |
| hydroelectric power water use | The use of water in the generation of electricity at plants where the turbine generators are driven by falling water |
| enzyme | Are types of proteins that are used to facilitate and regulate chemical reactions within cells. |
| vertical wind profile | A series of wind direction and wind speed measurements taken at various levels in the atmosphere that show the wind structure of the atmosphere over a specific location |
| eye | Area in the center of a hurricane that is devoid of clouds. |
| savanna | A tropical or sub-tropical plant community characterized by trees and shrubs scattered among a cover of grasses, herbs and forbs |
| suspension | Erosional movement of sediment continually held in the transport medium of air, water or ice. |
| sectoral change | the general trend for the percentage of a workforce in agriculture to decline over time and for the secondary and then tertiary sectors to become increasingly important. |
| infiltration gallery | A sub-surface groundwater collection system, typically shallow in depth, constructed with open-jointed or perforated pipes that discharge collected water into a watertight chamber from which the water is pumped to treatment facilities and into the distribution system |
| rock step | The step-like mountainside profile (in the postglacial landscape) often created as an eroding alpine glacier moved downslope. |
| pds watch | Slang for a tornado watch with enhanced wording (Particularly Dangerous Situation). |
| trellised drainage pattern | where the pattern of streams is such that the tributaries (or subsequent streams) to the main (or consequent stream) join at right-angles to it |
| critical stock | A stock of fish experiencing production levels that are so low that permanent damage to the stock is likely or has already occurred. |
| benthos | All the plant and animals living on or closely associated with the bottom of a body of water. |
| marina | A water-based facility used for storage, service, launching, operation, or maintenance of watercraft. |
| natural mortality | Deaths in a fish stock caused by predation, pollution, senility, etc., but not fishing. |
| flora | plant life. |
| overproduction | usually applied to food yields exceeding the needs of the area in which they are produced |
| impermeable | Not easily penetrated by water. |
| process water | Any water that comes in contact with a new material or product |
| virtual population | Utilized stock. |
| isotope | some elements have more than one form |
| synoptic track | Weather reconnaissance mission flown to provide vital meteorological information in data sparse ocean areas as a supplement to existing surface, radar, and satellite data |
| nowcast | A short-term weather forecast, generally out to six hours or less. This is also called a Short Term Forecast. |
| median | (Statistics) In a set of observations, the middle-most value with an equal number of observations lying above and below the median value. |
| categorical | A National Weather Service precipitation descriptor for a 80, 90, or 100 percent chance of measurable precipitation (0.01 inch). See Precipitation Probability (PoP). |
| arid | An adjunctive applied to regions where precipitation is so deficient in quantity, or occurs at such times, that agriculture is impracticable without irrigation. |
| wastage area | On a glacier, the terminal end where ablation results in deposition of till and removal of water. |
| heat | A form of energy transferred between two systems by virtue of a difference in temperature |
| quaternary | a period of geologic time lasting from 1.6m years ago to the present. |
| half-life | Time required for one half of the nuclei in a radioisotope to emit its radiation |
| meltwater | water that comes from the melting ice of a glacier or a snowbank. |
| glacier | a huge mass of land ice that consists of recrystallized snow and moves slowly downslope or outward. |
| flood plane | The position occupied by the water surface of a stream during a particular flood |
| hatchery production | The spawning, incubation, hatching, or rearing of fish in a hatchery or other artificial production facility. |
| drip irrigation | See Irrigation. |
| rheology | The study of flow behavior and characteristics. |
| targeted fishery | A harvest strategy designed to catch a specific groups of fish. |
| tsunami | a large wave, or series of waves, caused when an earthquake causes massive undersea crust movements and/or collapses which displace the water above. |
| u.s. geological survey | The Federal Agency chartered in 1879 by congress to classify public lands, and to examine the geologic structure, mineral resources, and products of the national domain |
| ice fog | Occurs when the temperature is much below freezing and water vapor condenses directly as ice crystals (sublimation) |
| intercepting drain | A drain constructed at the upper end of the area to be drained, to intercept surface or ground water flowing toward the protected area from higher ground, and carry it away from the area |
| particle size | the diameter, in millimeters, of suspended sediment or bed material |
| relocated | A term used in an advisory to indicate that a vector drawn from the preceding advisory position to the latest know position is not necessarily a reasonable representation of the cyclone's movement. |
| vermiculations | Irregular lines or impressions like worm tracks. |
| channel | An area that contains continuously or periodically flowing water that is confined by banks and a streambed. |
| flat-water | Of or on a level or slow-moving watercourse. |
| ocean trench | Deep depression found at the edge of the ocean floor |
| runoff | the water that falls as precipitation in a watershed and runs off into rivers and streams. May be stored in lakes and reservoirs and contributes to recharge where it infiltrates into the soil. In Phoenix, runoff enters sewers to wastewater plants for treatment and further use as reclaimed water. |
| passive remote sensing | Form of remote sensing where the sensor passively captures electromagnetic radiation reflected or emitted by an object. |
| barrage | a dam or barrier with adjustable gates and sluices built across an estuary in order to harness tidal energy. |
| methane | Methane is very strong greenhouse gas found in the atmosphere |
| flash flood | when flooding is very sudden and high volume compared to the channel involved. |
| troposphere | The lowest layer of the atmosphere located between the earth's surface to approximately 11 miles (17 kilometers) into the atmosphere |
| esu | "Evolutionarily Significant Unit; a ""distinct"" population of Pacific salmon, and hence a species, under the Endangered Species Act." |
| aliasing | The process by which frequencies too high to be analyzed with the given sampling interval appear at a frequency less than the Nyquist frequency. |
| gage height | (G.H.) is the water-surface elevation referred to some arbitrary gage datum |
| brackish | a slightly saline environment where sea water inputs are moderated by an inflow of freshwater. |
| bergschrund | A deep crevasse commonly found at the head of an alpine glacier |
| bioassay | a test to determine the relative strength of a substance by comparing its effect on a test organism with that of a standard preparation. |
| latitude | Latitude is the angular distance north or south from the equator to a particular location |
| millstream | The rapid stream of water flowing in a Millrace. |
| centrifugal force | The apparent force in a rotating system that deflects masses radially outward from the axis of rotation |
| snow advisory | A statement or advisory issued when snow is expected to create hazardous travel conditions |
| biosphere | the earth and all its ecosystems. |
| counter-radiation | Redirection of the Earth's longwave radiation back to the surface because of the greenhouse effect. |
| conservation | The continuing protection and management of natural resources in accordance with principles that assure their optimum long-term economic and social benefits. |
| entisols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| anabranch | A diverging branch of a river that re-enters the main stream. |
| human environment | Natural and physical environment and the relationship of people with that environment including physical, biological, cultural, social, and economic factors in a given area. |
| infrared satellite imagery | This satellite imagery senses surface and cloud top temperatures by measuring the wavelength of electromagnetic radiation emitted from these objects |
| tropical depression | Cyclones that have maximum sustained winds of surface wind speed (using the U.S |
| biodiversity | the variety of plant, animal, and microorganism species present in the ecosystem and the community structures the form. |
| segregation | the location of particular groups of people into distinct areas separate from the general population, usually based on race, religion or economic circumstances. |
| municipal discharge | The discharge of effluent from waste water treatment plants which receive waste water from households, commercial establishment, and industries |
| reaeration | Renewing air supplies in the lower layers of a reservoir in order to raise oxygen levels. |
| saturated adiabatic lapse rate | the rate of fall in air temperature by adiabatic change as saturated air gains altitude |
| riparian water right | the legal right held by an owner of land contiguous to or bordering on a natural stream or lake, to take water from the source for use on the contiguous land. |
| brandt report | produced in 1980 by a commission headed by Willy Brandt, former West German Chancellor |
| hydraulic grade line | A line whose plotted ordinate position represents the sum of pressure head plus elevation head for the various positions along a given fluid flow path, such as a pipeline or ground-water streamline. |
| arid | A term describing a climate or region in which precipitation is so deficient in quantity or occurs so infrequently that intensive agricultural production is not possible without irrigation. |
| striations | Grooves or channels in cloud formations, arranged parallel to the flow of air and therefore depicting the airflow relative to the parent cloud |
| boulder | Large fragment of rock that has a diameter greater than 256 millimeters (200 millimeters in the United Kingdom). |
| forward flank downdraft | The main region of downdraft in the forward, or leading, part of a supercell, where most of the heavy precipitation is. Compare with rear flank downdraft. See pseudo-warm front and supercell. |
| bar | an accumulation of alluvium (usually gravel or sand) caused by a decrease in sediment transport capacity on the inside of meander bends or in the center of an overwide channel. |
| convergence | Wind movement that results in a horizontal net inflow of air into a particular region |
| barrier beach | A long and narrow beach of sand and/or gravel that runs parallel to the coastline and is not submerged by the tide. |
| temperature | Temperature is defined as the measure of the average speed of atoms and molecules |
| pitch | Used to refer to angle or gradient |
| urban land-use | the spatial differences and similarities in certain types of land-use in urban areas which allow tracking of the history of their development and thus can be useful for future planning. |
| brn | An acronym for Bulk Richardson Number. See Bulk Richardson Number. |
| doppler frequency shift | f = 2 * V / l, where V is radial velocity of the target, l is the wavelength |
| groundwater recharge | the inflow to a ground water reservoir. |
| urban heat island | Observed condition that urban areas tend to be warmer than surrounding rural areas. |
| felsenmeers | A large area blanketed with angular debris from outcrops which have suffered repeated cycles of freezing and thawing. |
| tornado family | A series of tornadoes produced by a single supercell, resulting in damage path segments along the same general line. |
| waterspout | A small, weak tornado, which is not formed by a storm-scale rotation |
| gneiss | A metamorphosed coarse grained igneous rock |
| impervious | A term denoting the resistance to penetration by water or plant roots; incapable of being penetrated by water; non-porous. |
| fiber optics | It is used between 400 feet and 11 miles. |
| genetic diversity | The array of genetic traits that exists within a population which enables it to adapt to changing conditions. |
| initial detention | The volume of water on the ground, either in depressions or in transit, at the time active runoff begins |
| transpiration | Process by which water absorbed by plants, usually through the roots |
| hydrodynamics | The branch of science that deals with the dynamics of fluids, especially incompressible fluids, in motion. |
| salinization | The accumulation of salts in soil to the extent that plant growth is inhibited |
| toxic hot spot | location in enclosed bay, estuary, or any adjacent waters that has toxic pollution problems in the water or sediment in excess of applicable standards. |
| water | clear, colorless, odorless, tasteless liquid comprised of atoms of hydrogen (one atom) and oxygen (two atoms) = H20; essential for plant and animal life on Earth. The "universal solvent". |
| funnel cloud | A violent, rotating column of air visibly extending from the base of a towering cumulus or cumulonimbus toward the ground, but not in contact with it |
| pioneer community | Community dominated by pioneer species of plants. |
| reuse | Water that is discharged by one user and is used by other users |
| noctilucent clouds | Wavy, thin, bluish-white clouds that are best seen at twilight in polar latitudes |
| continental ice sheet | See continental glacier. |
| permeameter | A laboratory instrument for determining permeability by measuring the discharge through a sample of the material when a known hydraulic head is applied. |
| duplicates | two separate samples with separate containers taken at the same time at the same place. |
| discharge permit | a permit issued by a state or the federal government to discharge effluent into waters of the state or the United States |
| legume | Angiosperm plant species that is a member of the Fabaceae (Pea or Bean) family |
| cartography | Field of knowledge that studies map construction |
| ion | (1) An atom or molecule that carries a net charge (either positive or negative) because of an imbalance between the number of protons and the number of electrons present |
| sea-floor spreading | the widening of an ocean basin by the creation of new crust at a divergent margin. |
| channel inflow | Water, which at any instant, is flowing into the channel system form surface flow, subsurface flow, base flow, and rainfall that has directly fallen onto the channel. |
| instream use | The use of water that does not require withdrawal or diversion from its natural watercourse; for example, the use of water for navigation, recreation, and support of fish and wildlife. |
| ground water mining | The withdrawal of water from an aquifer in excess of recharge which, if continued over time, would eventually cause the underground supply to be exhausted or the water table could drop below economically feasible pumping lifts. |
| phase shift | The angular difference of two periodic functions. |
| water monitoring | The process of constant control of a body of water by means of sampling and analyses. |
| opaque | A condition where a material, such as a cloud, blocks the passage of radiant energy, especially light |
| flood problems | Problems and damages that occur during a flood as a result of human development and actions |
| tpc | An acronym for the Tropical Prediction Center. See Tropical Prediction Center (TPC). |
| hydropower | Power (e.g., electrical energy) produced by falling water; the utilization of the energy available in falling water for the generation of electricity. |
| non-potable water | Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals, or infective agents. |
| riparian | the land and habitat, plants and animals adjoining a stream or river. |
| cascade | A short, steep drop in stream bed elevation often marked by boulders and agitated white water. |
| snow water equivalent | The water content obtained from melting accumulated snow. |
| specific yield | The ratio of the water which will drain freely from the material to the total volume of the aquifer formation |
| vapor pressure | Pressure exerted by water vapor molecules in a given quantity of atmosphere. |
| indicator tests | Tests for a specific contaminant, group of contaminants, or constituent which signals the presence of something else. |
| soil conservation service | The former name of a branch of the United States Department of Agriculture, renamed the Natural Resources |
| sublimation | transformation between solid and gas, and vice versa, without being in a liquid stage. |
| flood capacity | The flow carried by a stream or floodway at bankfull water level |
| swallow hole | the point at which a river channel may disappear underground |
| safe yield | The rate at which water can be withdrawn from supply, source, or an aquifer over a period of years without causing eventual depletion or contamination of the supply. |
| isohel | A line on a weather map connecting points receiving equal sunlight. |
| solid | A state of matter where molecules where the mass of the substance does not have the property of flow. |
| offshore | Situated off the shore but within waters under a country's control, as offshore fisheries. |
| snag | Any standing dead, partially dead, or defective (cull) tree at least 10 inches in diameter at breast height and at least 6 feet tall. |
| mean high water | The average height of the high water over 19 years. |
| tertiary consumer | Organisms that occupy the fourth trophic level in the grazing food chain |
| windfall | Trees or parts of trees felled by high winds. |
| thermometer | Device used to measure temperature. |
| emissivity | The ratio of total radiative output from a body per unit time per unit area at a specific temperature and wavelength to that of a black body under the same environmental conditions. |
| organelle | Is a specialized structure found in cells that carry out distinct cellular functions. |
| herbicide | a chemical used to kill nuisance plants |
| niche specialization | Process where evolution, through natural selection, adapts a species to a particular set of abiotic and biotic characteristics within a habitat. |
| velocity cross section | This WSR-88D radar product displays a vertical cross section of velocity on a grid with heights up to 70,000 feet on the vertical axis and distance up to 124 nm on the horizontal axis. The two end points to create cross section are radar operator selected along a radial or from one AZRAN to another AZRAN within 124 nm of the radar that are less than 124 nm apart. It is used to: 1) Examine storm structure features such as location of updrafts/downdrafts, strength of storm top divergence, and the depth of mesocyclones; 2) Locate areas of convergence/divergence (when generated along a radial; and 3) Analyze areas of rotation (when generated from one AZRAN to another). |
| blocked areas | Areas in the Columbia River Basin where hydroelectric projects have created permanent barriers to anadromous fish runs |
| deflector screens/diversion screens | Wire mesh screens placed at the point where water is diverted from a stream or river |
| maximum contaminant level | The maximum level of a contaminant allowed in water by federal law |
| tdwr | An acronym for Terminal Doppler Weather Radar. |
| barometer | Instrument that measures atmospheric pressure. |
| deflation | Process where wind erosion creates blowout depressions or deflation hollows by removing and transporting sediment and soil. |
| hydrogen sulfide | A gas emitted during organic decomposition by a select group of bacteria, which strongly smells like rotten eggs. |
| cleavage | the line of weakness in a rock along which it will break when put under stress. |
| nitrite | Form of nitrogen commonly found in the soil |
| radar product generator | It generates the various WSR-88D radar products that are used by the radar operator |
| caldera | A large circular depression in a volcano. |
| ice pellets | A type of precipitation |
| carbamates | a class of new-age pesticides that attack the nervous system of organisms. |
| ground water law | The common law doctrine of Riparian Rights and the doctrine of prior appropriation (Appropriative Rights) as applied to ground water |
| water table | the top of the water surface in the saturated part of an aquifer. |
| basalt | A dark colored fine grained igneous rock formed from mafic magma. |
| onshore-offshore transport | The up and down movement of sediment roughly perpendicular to a shoreline because of wave action. |
| canopy | A layer of foliage in a forest stand |
| peat | a type of soil formed in cold wet conditions which inhibit full and proper decomposition of the litter layer |
| central vent | The main passage way by which volcanic magma travels to the Earth's surface. |
| irrigated area | The gross farm area upon which water is artificially applied for the production of crops, with no reduction for access roads, canals, or farm buildings. |
| sanitary water | Water discharged from sinks, showers, kitchens, or other nonindustrial operations, but not from commodes. |
| divide | The high ground that forms the boundary of a watershed |
| canal automation | The implementation of a control system that upgrades the conventional method of canal system operation. |
| relative potency factor | The ratio of the toxic potency of a given chemical to that of an index chemical in the CAG |
| primary sludge | The Sludge produced by primary treatment in a wastewater treatment plant. |
| potentiometric surface | the surface to which water in an aquifer can rise by hydrostatic pressure |
| rayleigh scattering | Changes in directions of electromagnetic energy by particles whose diameters are 1/16 wavelength or less |
| rapid drawdown | Lowering the elevation of water against a bank faster than the bank can drain, leaving a pressure imbalance that may cause the bank to fail. |
| irrigation | the controlled application of water for agricultural purposes through manmade systems to supply water requirements not satisfied by rainfall |
| wettable powder | dry formulation that must be mixed with water or other liquid before it is applied. |
| evaporimeter | An instrument which measures the evaporation rate of water into the atmosphere. |
| qualitative analysis | (Data Analysis) The examination or analysis of a phenomenon to determine its qualitative characteristics versus its quantitative characteristics, i.e., characteristics for which precise numerical identification are not appropriate. |
| stability index | The overall stability or instability of a sounding is sometimes conveniently expressed in the form of a single numerical value |
| draft | The depth below the water level, usually sea level, to whichthe base (or keel) of an iceberg penetrates is called its draft. |
| evergreen vegetation | Vegetation that keeps a majority of their leaves or needles throughout the year |
| rain | water drops which fall to the earth from the air. |
| pervious | Allowing passage through, as a material to water. |
| boiling point | The temperature at which the vapour pressure of a liquid equals the pressure of its surface |
| classification | Process of grouping things into categories. |
| influent stream | Any watercourse in which all, or a portion of the surface water flows back into the ground namely the, vadose zone, or zone of aeration. |
| adret slope | a south-facing slope. |
| game fish | a species such as trout, salmon, or bass, caught for sport. |
| recycling | the re-use of materials that would otherwise be deemed rubbish. |
| ice gorge | The gorge or opening left in a jam after it has broken. |
| intrazonal soil | one whose main characteristics are controlled by a single local factor |
| ecosystem | A system formed by the interaction of a group of organisms and their environment. |
| zenith | The point which is elevated 90 degrees from all points on a given observer's astronomical horizon |
| ventral fins | See pelvic fins. |
| algicide | substance or chemical used specifically to kill or control algae. |
| magnetic declination | The horizontal angle between true north and magnetic north or true south and magnetic south. |
| drainage divide | The boundary line, along a topographic ridge or along a subsurface formation, separating two adjacent drainage basins. |
| mixed-stock fishery | A harvest management technique by which different species, strains, races or stocks are harvested together. |
| sand dune | a mound of sand deposited by wind in desert areas and along shore lines. |
| perfected water right | A water right which indicates that the uses anticipated by an applicant, and made under permit, were made for Beneficial Use |
| polarization | the disparate development of wealth around a core leaving a much poorer peripheral area. |
| water meter | An instrument for recording the quantity of water passing through a particular outlet. |
| psammosere | succession of plants in a sandy environment such as coastal dunes. |
| approaching severe levels | A thunderstorm which contains winds of 35 to 49 knots (40 to 57 mph), or hail 1/2 inch or larger but less than 3/4 inch in diameter |
| chelation | Chemical weathering process that involves the extraction or metallic cations from rocks and minerals by chelates. |
| activated carbon | Substance used in the water treatment process to remove dissolved organic matter from raw drinking water. |
| leisure industry | the goods and services provided for consumption during leisure |
| bioindicator | A living organism that denotes the presence of a specific environmental condition |
| overshooting | The failure of the radar to detect a target due to the radar beam passing above the target. |
| influent stream | Any watercourse in which all, or a portion of the surface water flows back into the ground namely the, vadose zone, or zone of aeration. |
| lake-effect snow warning | This product is issued by the National Weather Service when pure lake effect snow (this is where the snow is a direct result of lake effect snow and not because of a low pressure system) may pose a hazard or it is life threatening. The criteria for this warning varies from area to area |
| wave refraction | The re-orientation of a wave so that it approaches a shoreline at a more perpendicular angle |
| occlusion | the coming together of the cold sectors of air in a depression as the warm sector is lifted from the surface altogether |
| firm annual yield | The yearly amount of water that can be dependably supplied from the raw water sources of a given water supply system. |
| cold pool | A region of relatively cold air, represented on a weather map analysis as a relative minimum in temperature surrounded by closed isotherms. Cold pools aloft represent regions of relatively low stability, while surface-based cold pools are regions of relatively stable air. |
| migrant | Life stage of anadromous and resident fish species which moves from one locale, habitat or system (river or ocean) to another. |
| method blank | laboratory grade water taken through the entire analytical procedure to determine if samples are being accidentally contaminated by chemicals in the lab |
| kaf | One thousand acre-feet. |
| pebble | A rounded piece of rock that is larger than gravel. |
| setback | Denotes the positioning of a levee or structure in relationship to a stream bank |
| detrital rock | Sedimentary rock that is composed of particles transported to their place of deposition by erosional processes |
| gravity model | a formula to calculate the likely interaction between two places given their distance apart, size and barriers (or lack of connectivity) between them. |
| seepage | The interstitial movement of water that may take place through a dam, its foundation, or abutments. |
| loess | Deposits of silt laid down by aeolian processes over extensive areas of the mid-latitudes during glacial and postglacial times. |
| distribution | two uses: |
| water waste | The non-beneficial use of water |
| natural selection | Differential survival and reproduction among members of a population or species in nature; due to variation in the possession of adaptive genetic traits. |
| harvest management | The process of setting regulations for the commercial, recreational and tribal fish harvest to achieve a specified goal within the fishery. |
| strong breeze | Large branches in motion; whistling heard in overhead wires; umbrellas used with difficulty; large waves begin to form; the white foam crest are more extensive everywhere (probably some spray). |
| least-cost location | the place where raw material and transport costs are minimized for a particular business, according to Weber. |
| texas hooker | Low pressure systems that originate in the panhandle region of Texas and Oklahoma |
| caudal peduncle | The tapering portion of a fish's body between the posterior edge of the anal fin base and the base of the caudal fin. |
| lfws | A generic term for any type of Local Flood Warning System. |
| hydraulic gradient pivot point | A location along the water surface in a canal reach where the water level remains essentially constant during changes in flow. |
| cryophobia | Fear of extreme cold, ice, or frost. |
| fixed ground water | Water held in saturated material within pore spaces so small that it is permanently attached to the walls, or moves so slowly that it is usually not available as a source of water for pumping. |
| astraphobia | The fear of thunder and lightning. See Astrapophobia, Brontophobia, Ceraunophobia, Keraunophobia, and Tonitrophobia |
| non-tariff barrier | a covert restriction to imported goods |
| network | points (vertices) joined by links |
| sea ice | At temperatures of -2° C (28.5° F), freezes directly from ocean water to a thickness of five meters (15 feet) |
| temperature inversion | Situation where a layer of warmer air exists above the Earth's surface in a normal atmosphere where air temperature decreases with altitude |
| water supplier | one who owns or operates a public water system. |
| nutrient sink | an ecosystem which has a tendency to store organic matter and thus the nutrients within it |
| natural fish | A fish that is produced by parents spawning in a stream or lake bed, as opposed to a controlled environment such as a hatchery. |
| hurricane watch | An announcement of specific coastal areas that a hurricane or an incipient hurricane condition poses a possible threat, generally within 36 hours |
| salinity | amount of salt in solution. |
| esker | Long twisting ridges of sand and gravel found on the Earth's surface |
| flash flood guidance | An internal product produced by the RFC's containing rainfall threshold values which must be exceeded in order for flooding to occur |
| returnflow | irrigation water that is applied to an area and which is not consumed in evaporation or transpiration and returns to a surface stream or aquifer. |
| water table | The level below the earth's surface at which the ground becomes saturated with water |
| oxidation | A chemical reaction in which ions are transferring electrons, to increase positive valence. |
| sublimation | Process where ice changes into water vapor without first becoming liquid |
| cell | Convection in the form of a single updraft, downdraft, or updraft/downdraft couplet, typically seen as a vertical dome or tower as in a cumulus or |
| dew point | The temperature to which air must be cooled at a constant pressure to become saturated. |
| pressure gradient force | A three-dimensional force vector operating in the atmosphere that accelerates air parcels away from regions of high pressure and toward regions of low pressure in response to an air pressure gradient. Usually resolved into vertical and horizontal components. |
| backwash | The return water flow of swash |
| irrigation pit | A small storage reservoir constructed to regulate or store the supply of water available to the irrigator. |
| cavitation | creation of pot holes in a stream bed due to the blasting effect of particles thrown against it by the formation and collapse of air bubbles |
| nitrogen fixation | Biological or chemical process where gaseous nitrogen is converted into solid forms of nitrogen |
| trickling filter | A wastewater treatment unit that contains medium material with bacteria |
| pump lift | The distance between the ground water table and the overlying land surface. |
| introgression | Introduction of genes from one population or species into another. |
| stratigraphy | Subdiscipline of geology that studies sequence, spacing, composition, and spatial distribution of sedimentary deposits and rocks. |
| selective fishery | A fishery that allows the unharmed release of non-target fish stocks/runs. |
| floodplain | Land that gets covered with water as a result of the flooding of a nearby stream |
| running water | Water distributed through pipes and fixtures as a house with hot and cold running water. |
| oil | Hydrocarbon based liquid commonly found in the pores of sedimentary rocks of marine origin. |
| eon | Longest geologic time unit. |
| range | Distance from the radar antenna. The WSR-88D radar has a range for velocity products out to 124 nm and reflectivity products out to 248 nm. |
| peak flow | The maximum instantaneous discharge of a stream or river at a given location |
| infrared | The long wave, electromagnetic radiation of radiant heat emitted by all hot objects |
| storm total precipitation | This WSR-88D radar product displays the total precipitation (in inches) as a graphical image. It displays hourly precipitation total (in inches) as a graphical image. Currently , this product is done in a polar format with resolution 1.1 nm by 1 degree. It will reset after one hour of no precipitation. It is used to monitor total precipitation accumulation; observe short term trends of precipitation tracks with time lapse of this product; and estimate total basin runoff and ground saturation. |
| giardia lamblia | a protozoa found in the feces of infected humans and animals that can cause severe gastrointestinal ailments |
| ravine | deep, steep-sided valley, gorge or cleft cut into a rocky landscape. |
| ozone | A nearly colorless gas and a form of oxygen (O2) |
| dry flood proofing | A dry flood proofed building is sealed against floodwaters |
| carbonates | the collective term for the natural inorganic chemical compounds related to carbon dioxide that exist in natural waterways. |
| water plan | A document of issues, policies, strategies and action plans intended to effectively and economically execute a Water Planning process. |
| riparian habitat | The aquatic and terrestrial habitat adjacent to streams, lakes, estuaries, or other waterways. |
| even-numbered properties | Properties whose official address ends in an even number, excluding city parks and golf courses |
| mass curve | A graph of the cumulative values of a hydrologic quantity (such as precipitation or runoff), generally as ordinate, plotted against time or date. |
| clean water act | federal legislation enacted in 1972 to restore and maintain the chemical, physical and biological integrity of the surface waters of the United States |
| salt lake | inland body of water with a high salinity |
| flow | the rate of water discharged from a source expressed in volume with respect to time. |
| hydrogeology | The science of chemistry and movement of groundwater. |
| rotation | See Earth rotation. |
| seepage bed | A trench or bed more than 36 inches (0.91 meter) wide containing at least 12 inches (30.5 centimeters) of clean, coarse aggregate and a system of distribution piping through which treated sewage may seep into the surrounding soil. |
| registration | Formal listing with EPA of a new pesticide before sale or distribution |
| infiltration | the penetration of water through the ground surface into sub-surface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls. |
| vent | The connection and piping through which gases enter and exit a piece of equipment. |
| backwater flooding | Upstream flooding caused by downstream conditions such as channel restriction and/ or high flow in a downstream confluence stream. |
| latent heat of condensation | The amount of heat energy release to the environment when a gas changes its state to a liquid |
| sidereal day | Time it takes to complete one Earth rotation relative to the position of a fixed star |
| anal fin | The fin located on the ventral median line and behind the anus. |
| sand | Loose particles of hard, broken rock or minerals |
| terminal moraine | A moraine found near the terminus of a glacier; also known as an end moraine. |
| control points | Horizontal and Vertical: Small monuments securely embedded in the surface of the dam |
| frost point | Dew point below freezing. |
| nuclear energy | Energy released when the nucleus of an atom experiences a nuclear reaction like the spontaneous emission of radioactivity, nuclear fission, or nuclear fusion. |
| daily flood peak | The maximum mean daily discharge occurring in a stream during a given flood event. |
| hydroelectricity | The production of electric power through use of the gravitational force of falling water. |
| snow garland | Snow appearing as a beautiful long thick rope draped on trees, fences and other objects |
| earth sciences tradition | Academic tradition in modern Geography that investigates natural phenomena from a spatial perspective. |
| potential evapotranspiration | (1) The maximum quantity of water capable of being evaporated from the soil and transpired from the vegetation of a specified region in a given time interval under existing climatic conditions, expressed as depth of water |
| scale | in general use refers to the size of an area or time period |
| active storage capacity | The total amount of reservoir capacity normally available for release from a reservoir below the maximum storage level |
| rainshadow | the area on the leeward side of a mountain range which experiences drier conditions than the windward side |
| radial drainage | a pattern of streams radiating from a central point or area e.g |
| advanced wastewater treatment | any treatment of sewage that goes beyond the secondary or biological water treatment stage and includes the removal of nutrients such as phosphorus and nitrogen and a high percentage of suspended solids. |
| gaging station | A particular site on a river, stream, canal, or body of water where systematic observations of stage and/or flow are measured. |
| altimeter | An instrument used to determine the altitude of an object with respect to a fixed level |
| south magnetic pole | Location in the Southern Hemisphere where the lines of force from Earth's magnetic field are vertical |
| billow | A large wave or swell of water. |
| unit hydrograph | (1) The Hydrograph of direct runoff from a storm uniformly distributed over the drainage basin during a specified unit of time; the hydrograph is reduced in vertical scale to correspond to a volume of runoff from the drainage basin of one inch |
| confined ground water | Ground water held under an aquiclude or an aquifuge called artesian if the pressure is positive. |
| eddy viscosity | a model parameter that reproduces the effects of turbulent mixing in fluid flow. |
| capillary potential | The work required to move a unit mass of water from the reference plane to any point in the soil column. |
| valley train | Outwash confined between two rock walls, moraines or by unmelted ice, ice blocks or calving ablation fields. |
| discontinuous permafrost | between 50˚N and the Arctic Circle where mean annual temperature is -1˚ to -5˚ there will be patches of permanent permafrost perhaps 50 metres deep, separated by areas of little or no permafrost which are kept warmer by local conditions such as rivers. |
| water management | the attempt to provide the right quality of water for a variety of uses in the places where it is required |
| frequency curve | A curve that expresses the relation between the frequency distribution plot, with the magnitude of the variables as abscissas and the number of occurrences of each magnitude in a given period as ordinates |
| hydrologic region | A study area, consisting of one or more planning subareas, used to analyze water use and hydrologic conditions |
| saturation mixing ratio | Mass of water vapor that a kilogram of dry air can hold at saturation |
| blackwater | wastewater from toilet, latrine, and agua privy flushing and sinks used for food preparation or disposal of chemical or chemical-biological ingredients. |
| steady-state mass balance | the mathematical concept that the sum of upstream pollutant loads, each determined by the product of their concentration times flow, equals a resultant downstream load after mixing. |
| chlorinated solvent | An organic solvent containing chlorine atoms that is often used as aerosol spray container, in highway paint, and dry cleaning fluids. |
| braided stream | Shallow stream channel that is subdivided into a number of continually shifting smaller channels that are separated by bar deposits. |
| solar constant | the amount of energy received per unit area from the sun over a given period of time. |
| potentiation | The ability of one chemical to increase the effect of another chemical. |
| biological diversity | The variety of different species, the genetic variability of each species, and the variety of different ecosystems that they form. |
| oligotrophic | having a low supply of plant nutrients |
| artificial control | A weir or other man-made structure which serves as the control for a stream-gaging station. |
| debris flow | A rapidly moving mass of rock fragments, soil, and mud, with more than half of the particles being larger than sand size. |
| usda | U.S |
| equilibrium time | The time when flow conditions become substantially equal to those corresponding to equilibrium discharge or equilibrium drawdown.. |
| littoral zone | The region of land bordering a body of water. |
| pandemic | disease spread over a wide geographical area. |
| bureau of reclamation | An agency that administers some parts of the federal program for water resource development and use in western states |
| caution stage | Same as alert stage. |
| multiple doppler analysis | The use of more than one radar (and hence more than one look angle) to reconstruct spatial distributions of the 2D or 3D wind field, which cannot be measured from a single radar alone |
| death rate | number of deaths per thousand people per year. |
| public notice | Notification by a regulatory agency (such as EPA or EPD) informing the public of agency actions such as the issuance of a draft permit or scheduling of a hearing |
| permafrost | frozen ground |
| partial pressure | That pressure of a gas in a liquid, which is in equilibrium with the solution |
| conduction | Conduction consists of energy transfer directly from atom to atom and represents the flow of energy along a temperature gradient. |
| soil texture | the ratio of sand, silt and clay within a soil. |
| shear | Variation in wind speed (speed shear) and/or direction (directional shear) over a short distance |
| sludge digester | tank in which complex organic substances like sewage sludge are biologically dredged |
| reservoir area | The surface area of a reservoir when filled to controlled retention water level. |
| xeric | Dry. |
| vapor blanket | The layer of air which overlies a body of water and, due to its proximity to the water, has a water vapor content higher than that of the surrounding atmosphere. |
| reverse fault | This vertical fault develops when compressional force causes the displacement of one block of rock over another. |
| dry adiabat | A line of constant potential temperature on a thermodynamic chart. |
| adult fish counts | A fish-viewing window is at the upstream end of most fish ladders |
| storage equation | The equation for the conservation of mass. |
| prior appropriation | a doctrine of water law that allocates the rights to use water on a first in time, first in right, basis. |
| mesohigh | A relatively small area of high atmospheric pressure that forms beneath a thunderstorm. It is usually associated with MCSs or their remnants. |
| wild populations | Fish that have maintained successful natural reproduction with little or no supplementation from hatcheries. |
| indicator | (Water Quality) An organism, species, or community that shows the presence of certain environmental conditions. |
| 10-hr | 1/4 to 1" diameters |
| suspended solids | Solid organic or inorganic particles that are held in suspension in a solution. |
| zone of fracture | The upper 50 meters of glacial ice is brittle and is carried by the ice below it. |
| aromatics | A type of hydrocarbon that contains a ring structure, such as benzene and toluene |
| evaporation | Process by which liquid water is converted into water vapor. |
| total sediment load | The sum of the bedload and the suspended sediment load. |
| backscattering | Portion of solar radiation directed back into space as a result of particle scattering in the atmosphere. |
| light year | Distance that light travels in the vacuum of space in one year |
| intermittent stream | A stream that flows periodically |
| static water depth | (Hydraulics) For a water well, the vertical distance from the centerline of the pump discharge down to the surface level of the free pool while no water is being drawn from the pool or water table. |
| aeration | the mixing or turbulent exposure of water to air and oxygen to dissipate volatile contaminants and other pollutants into the air. |
| polar coordinates | A coordinate system in which the two directions are distance from the origin and angle (sweeping around the origin like a clock) |
| specific energy | The sum of the piezometric head and the velocity head; total energy, with respect to the bottom of a conduit or channel as a datum. |
| hatch box | A device used to incubate relatively small numbers of eggs |
| gene frequency | Frequency of alleles at an individual or population level. |
| resource | A person, thing, or action needed for living or to improve the quality of life. |
| reference mark | A relatively permanent point of known elevation which is tied to a benchmark. |
| slipway | (Nautical) A sloping surface leading down to the water, on which ships are built or repaired and then more readily moved back into the water. |
| minor flooding | Flooding resulting in minimal or no property damage but some public inconvenience. |
| sub-synoptic low | Essentially the same as mesolow. |
| nimbostratus | This cloud exhibits a combination of rain or snow, and sometimes the base of the cloud cannot be seen because of the heaviness of precipitation |
| bioaccumulantion | The increase in concentration of a substance in living organisms, as they take in contaminated air, water, or food, due to slow metabolization and excretion. |
| plvi | see peak land value intersection (point). |
| levee | a natural or manmade earthen barrier along the edge of a stream, lake, or river |
| pondage | (1) The holding back of water for later release for power development above the dam of a hydroelectric plant to: (a) equalize daily or weekly fluctuations of streamflow, or (b) to permit irregular hourly use of water by the wheels to take care of fluctuations in the load demand |
| cone of depression | natural depression in the water table around a well during pumping. |
| commodity resources | Goods or products of economic use or value. |
| recharge rate | the quantity of water per unit of time that replenishes or refills an aquifer. |
| frazil slush | An agglomerate of loosely packed frazil which floats or accumulates under the ice cover. |
| canceled water right | A water right that is invalidated due to the failure of the water right holder to comply with the terms and conditions of the permit. |
| biodiversity | the range of species in a particular area. |
| diurnal | Pertaining to actions or events that occur during a twenty-four hour cycle or recurs every twenty-four hours |
| hadean | Geologic eon that occurred from 3800 to 4600 million years ago |
| ditch | A long narrow trench or furrow dug in the ground, as for irrigation, drainage, or a boundary line. |
| channel | U shaped section of the pipe within the manhole, where sewage flows through a hand formed pipe on the bottom half of a pipe |
| piezometric head | Synonymous with Hydraulic Head, which is now commonly used. |
| airmet | This NWS aviation product advises of weather that maybe hazardous, other than convective activity, to single engine, other light aircraft, and Visual Flight Rule (VFR) pilots |
| ww | Severe Thunderstorm Watch or Tornado Watch |
| water audit | A procedure that combines flow measurements and listening surveys (leak detection) in an attempt to give a reasonably accurate accounting of all water entering and leaving a system. |
| environmental water | The water for wetlands, the instream flow for a major river (based on the largest fish flow specified in an entire reach of that river) or, for wild and scenic rivers, the amount of water based on unimpaired natural flow. |
| zone of accumulation | The snowfields or cirques of mountain glaciers and the snowfields of continental glaciers are called the zone of accumulation because it is here than new snow falls to nourish the glacier. |
| hydraulic head | 1) The height of the free surface of a body of water above a given point beneath the surface. 2) The height of the water level at the headworks, or an upstream point, of a waterway, and the water surface at a given point downstream. 3) The height of a hydraulic grade line above the center line of a pressure pipe, at a given point. |
| isothermal | Of equal or constant temperature with respect to either space or time. |
| flanking line | A line of cumulus or towering cumulus clouds connected to and extending outward from the most active part of a supercell, normally on the southwest side |
| water column | an imaginary column extending through a water body from its floor to its surface |
| discharge | In the simplest form, discharge means outflow of water |
| contaminate | To make impure or unclean by contact or mixture. |
| biochemical oxygen demand | The quantity of oxygen utilized primarily in the biochemical oxidation of organic matter in a specified time and at a specified temperature. |
| aquaculture | farming of plants and animals that live in water, such as fish, shellfish, and algae. |
| disdrometer | Equipment that measures and records the size distribution of raindrops. |
| ozone generator | A device that generates ozone by passing a voltage through a chamber that contains oxygen |
| electrofishing | a biological collection method that uses electric current to facilitate capturing fishes. |
| brunisol soil | Soil order (type) of the Canadian System of Soil Classification |
| laboratory water | Purified water used in the laboratory as a basis to create solutions or making dilutions |
| compression | One of the three forces (see tension and shear), compression applied to an object causes deformation parallel and perpendicular to the constricting force. |
| stone | Rock or rock fragments used for construction. |
| scattering | The process by which small particles suspended in the air diffuse a portion of the incident radiation in all directions |
| gyre | A circular or spiral motion, primarily referring to water currents. |
| chelation | a form of chemical weathering |
| foreset beds | in a delta, the deposits of silts and clays found to the seaward side of the feature beyond the topset beds but above and before the bottomset beds |
| temperate grasslands | extensive natural grasslands in the continental interiors of temperate regions. |
| sulfur dioxide | A gas produced from volcanic eruptions, ocean spray, organic decomposition and the burning of fossil fuels |
| confining bed | A rock formation that will not readily transmit water and which retards or stops the free movement of water underground |
| interquartile range | statistical measure of the spread of values around the median |
| parasitism | Biological interaction between species where a parasite species feeds on a host species. |
| non-government organisation | any charity or volunteer association which takes on responsibility for a particular cause |
| intangible flood damage | Estimated damage done by disruption of business, danger to public health, shock, loss of life, and other factors not directly measurable. |
| firn | partially packed snow which lasts through at least one summer |
| green belt | in the UK, an area of land surrounding an urban area in which planning restrictions severely curb new housing, commercial and industrial developments |
| htc | The Hydrometeorological Training Council |
| rendzina | a thin soil developed on limestone or chalk bedrock. |
| bora | Term used to describe a katabatic wind in Yugoslavia. |
| average yearly supply | The average annual supply of a water development system over a whole hydrologic system. |
| limestone | Sedimentary rock composed of carbonate minerals, especially calcium carbonate |
| appropriate | To take the legal actions necessary to create a right to take water from a natural stream or aquifer for application to beneficial use. |
| taxonomic classification | Classification of organisms based on structural and physiological connections between other species. |
| f scale | See Fujita Scale. |
| altitude | In meteorology, the measure of a height of an airborne object in respect to a constant pressure surface or above mean sea level. |
| oxygen demand | the need for molecular oxygen to meet the needs of biological and chemical processes in water |
| eddy diffusion | Mixing of the atmosphere by chaotic air currents. |
| one-hour rainfall rate | This WSR-88D radar product displays hourly precipitation total (in inches) as a graphical image. This product is done in polar format with resolution 1.1 nm by 1 degree and it requires 54 minutes of precipitation for initial product. The product is then updated every volume scan for the most recent hourly precipitation accumulation. It is used to: 1) Assess rainfall intensities and amounts and 2) Aid in forecast procedures for flash flood watches and warnings, various statements, and river forecasts. |
| dew | Condensation of water on the Earth's surface because of atmospheric cooling. |
| crepuscular rays | Contrasting, alternating bright and dark rays in the sky |
| gamma radiation | A type of ionizing, electromagnetic radiation that readily penetrates the body tissues of organisms |
| lagoon | a shallow pond where sunlight, bacterial action, and oxygen work to purify wastewater |
| condensation funnel | A funnel-shaped cloud consisting of condensed water drops that has possible rotation. |
| narrowband communications | This is the narrowband (9600 Baud Rate) communication lines that distribute the WSR-88D radar products to the various users. |
| 100-hr | 1 to 3" diameter |
| flow meter | a gauge indicating the velocity and/or volume of a flowing liquid. |
| orphan anvil | Slang for an anvil from a dissipated thunderstorm, below which no other clouds remain. |
| osmosis | the movement of water molecules through a thin membrane |
| nssfc | National Severe Storms Forecast Center, in Norman, OK; now known as SPC. |
| edwards outcrop | where the Edwards and associated limestone formations are found at the surface |
| tail water | (1) In Hydraulics, water, in a river or channel, immediately downstream from a structure |
| jet streak | A region of accelerated wind speed along the axis of a jet stream. |
| digester | in wastewater treatment, a unit in which anaerobic bacterial action is induced and accelerated in order to break down and stabilize organic matter removed from the treatment process. |
| siltation | the deposition of finely divided soil and rock particles upon the bottom of stream and river beds and reservoirs. |
| litre | The basic unit of measurement for volume in the metric system; equal to 61.025 cubic inches or 1.0567 liquid quarts. |
| trickle | To flow or fall in drops or in a thin stream. |
| vapor trail | A cloudlike streamer or trail often seen behind aircraft flying in clear, cold, humid air |
| subtropical | The region between the tropical and temperate regions, an area between 35° and 40° North and South latitude |
| buttress dam | A dam consisting of a watertight upstream face supported at intervals on the downstream side by a series of buttresses. |
| demiwater | Demineralised water |
| base flood | The national standard for flood plain management is the base, or one percent chance flood |
| cryosol soil | Soil order (type) of the Canadian System of Soil Classification |
| farm irrigation efficiency | An expression comparing the amount of water actually required for growing a crop to the amount of irrigation water that is diverted at the farm headgate |
| sky | The vault-like apparent surface against which all aerial objects are seen from the earth. |
| lag time | time that passes between the point when precipitation is at its highest over a particular drainage basin during a particular precipitation event, and the point when discharge in the river channel is at its highest in that drainage basin for that precipitation event. |
| alpine glacier | A relatively small glacier that forms in high elevations near the tops of mountains. |
| tundra | A tundra is a cold, treeless area; it is the coldest biome. |
| inflow | Water that flows into a reservoir or forebay during a specified period. |
| escapement | The portion of a fish population that survives sources of natural mortality and harvest to reach its natal spawning grounds. |
| water disposal system | The complete system for removing excess water from land with minimum erosion |
| water supply outlook | A seasonal volume forecast, generally for a period centered around the time of spring snowmelt (e.g., April-July) |
| helicity | A property of a moving fluid, such as air, representing the potential for helical flow (flow that follows a corkscrew pattern) |
| algal bloom | a phenomenon whereby excessive nutrients within a river, stream or lake cause an explosion of plant life which results in the depletion of the oxygen in the water needed by fish and other aquatic life |
| micronutrient | Nutritional element required by an organism in relatively very small quantities. |
| collector sewers | Pipes to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility. |
| pressure filtration | (Water Quality) A process by which liquid is removed from a sludge by using external pressure to force it through a filter. |
| confluence | (1) The act of flowing together; the meeting or junction of two or more streams or rivers; also, the place where these streams meet |
| standard atmospheric pressure | A pressure of 101.32 kilopascals or 1013.2 millibars. |
| mulch | Any material such as leaves, bark, straw, or other materials applied to the soil surface to reduce evaporation. |
| scatter-graph | a graph which plots values by the use of dots |
| artificial recharge | water is put back into ground water storage from surface water through man made means. |
| ground water flow model | (1) A digital computer model that calculates a hydraulic head field for the modeling domain using numerical methods to arrive at an approximate solution to the differential equation of ground-water flow |
| mitochondria | Organelle in a cell that oxidizes organic (see respiration) energy for use in cellular metabolism. |
| irrigated acreage | The land area that is irrigated, which is equivalent to total irrigated crop acreage minus the amount of acreage that was double cropped. |
| confined aquifer | A water-bearing subsurface stratum that is bounded above and below by formations of impermeable soil or rock. |
| emigration | movement of people away from an area, region or country. |
| manning's equation | an empirical equation used to estimate the average hydraulic conditions of flow within a channel cross section. |
| surplus water | Developed water supplies in excess of contract entitlement or apportioned water. |
| capillary action | the means by which liquid moves through the porous spaces in a solid, such as soil, plant roots, and the capillary blood vessels in our bodies due to the forces of adhesion, cohesion, and surface tension |
| shear | It is the rate of change over a short duration |
| aquifer | A geologic formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs. |
| neve | The upper area of accumulation in a glacier where firn is found. |
| discharge | In glaciers, the total volume of ice passing through a specified cross section of the glacier during a particular unit of time. |
| invertebrate | Animal that does not have a backbone |
| rafs | An acronym for Regional Analysis and Forecasting System. |
| lightning channel | The irregular path through the air along which a lightning discharge occurs |
| brash ice | Accumulation of floating ice made up of fragments not more than 2 meters across; the wreckage of other forms of |
| diversion | The transfer of water from a stream, lake, aquifer, or other conduit to another watercourse or to the land, as in the case of an irrigation system. |
| genetic diversity | Genetic variability found in a population of a species or all of the populations of a species |
| effluent | any substance, particularly a liquid, that enters the environment from a point source |
| brackish | mixed fresh and salt water. |
| retention | That part of the precipitation falling on a drainage area that does not escape as a surface streamflow, during a given period. |
| average winter consumption | The amount of water used on average by a customer during the winter; provides a good indication of indoor water use. |
| river profile | see long profile. |
| ground frost | Frost that penetrates the soil surface in response to freezing temperatures. |
| magnetic reversal | A change in the polarity of the Earth's magnetic field |
| monthly climatological report | This climatological product is issued once a month by each National Weather Service office. It is a mix of tabular and narrative information. It is organized so that similar items are grouped together (i.e., temperature, precipitation, wind, heating/cooling degree information, etc.). |
| valley glacier | A stream of ice flowing down gradient. |
| red flag warning | A term used by fire-weather forecasters to call attention to limited weather conditions of particular importance that may result in extreme burning conditions. It is issued when it is an on-going event or the fire weather forecaster has a high degree of confidence that Red Flag criteria will occur within 24 hours of issuance. Red Flag criteria occurs whenever a geographical area has been in a dry spell for a week or two, or for a shorter period , if before spring green-up or after fall color, and the National Fire Danger Rating System (NFDRS) is high to extreme and the following forecast weather parameters are forecasted to met: 1) a sustained wind average 15 mph or greater 2) relative humidity less than or equal to 25 percent and 3) a temperature of greater than 75 degrees F. In some states, dry lightning and unstable air are criteria. A Fire Weather Watch may be issued prior to the Red Flag Warning. See Fire Weather Watch. |
| farm pond | A water impoundment made by constructing a dam or embankment or by excavating a pit or "dug out". |
| labour mobility | two kinds: |
| genetic conservation refuge | Reserve area whose goal is to protect genetic diversity and natural evolutionary processes within and among natural populations, while allowing varying degrees of exploitation and modification. |
| phanerozoic | Geologic eon that occurs from 2500 million years ago to today |
| hdi | see human development index. |
| water table | The upper surface of zone of saturation |
| mineralization | Decomposition of organic matter into its inorganic elemental components. |
| solfatara | a minor extrusive volcanic feature where gases escape from surface cracks and vents. |
| atad | An acronym for Automated Telephone Answering Device. A recorded telephone message giving current and forecast weather information. |
| composite reflectivity | This WSR-88D radar product displays the maximum reflectivities for each resolution grid box for all elevation angles in a volume scan. Available with combined attribute table which provides valuable information concerning storm characteristics, such as storm tops, maximum radial velocity and reflectivity, and possible existence of hail and mesocyclones. It is used to observe the highest reflectivities in a storm from any scanned elevation angle; determine intensity trends; and generate cross section through maximum reflectivity. |
| soil texture | The relative quantities of the different types and sizes of mineral particles in a soil. |
| infiltration | Water entering sewers and manholes via defective joints and connections, broken pipes, fractured manholes, etc. |
| station elevation | The vertical distance above mean sea level that is the reference level for all current measurements of atmospheric pressure at that station. |
| radioisotope snow gage | A snow water equivalent gage based on the absorption of gamma radiation by snow; this gage can measure up to 55 inches water equivalent with a 2 to 5 percent error. |
| surface impoundment | An indented area in the land's surface, such as a pit, pond, or lagoon. |
| altitude | How high a place is above sea level. |
| electrolyte | Substance that dissociates into ions when it dissolves in water. |
| leaching | The process by which soluble materials in the soil, such as salts, nutrients, pesticide chemicals or contaminants, are washed into a lower layer of soil or are dissolved and carried away by water. |
| cyanobacteria | Bacteria that have the ability to photosynthesize. |
| flood plain | Land bordering a stream |
| bank storage | Water absorbed and stored in the void in the soil cover in the bed and banks of a stream, lake, or reservoir, and returned in whole or in part as the level of water body surface falls. |
| organism abundance and condition | that portion of an Index of Biotic Integrity that is a metric measuring species abundance and condition, including proportion of individuals as hybrids and proportion of individuals with disease, tumors, physical damage, or physical anomalies. |
| blizzard warning | This product is issued by the National Weather Service when blizzard conditions are life threatening. The criteria for this warning varies from state to state. In Michigan, the criteria is a sustained wind or frequent wind gusts to 35 mph or more and considerable falling and/or blowing slow reducing visibility frequently to less than 1/4 mile for a duration of 3 hours or longer. |
| water budget | (1) (Hydrology) An accounting of the inflows to, the outflows from, and the storage changes of water in a hydrologic unit or system |
| sand | Mineral particle with a size between 0.06 and 2.0 millimeters in diameter |
| phreatic surface | A term equivalent to the Groundwater Surface or the Water Table; the free surface of ground water at atmospheric pressure. |
| wave-cut platform | at a coast, where wave action erodes into a cliff, causing it to collapse and retreat, a rock platform is left behind between the low and high water marks. |
| coastal zone | Lands and waters near the coast, whose uses and ecology are affected by the sea. |
| crp | The Probability that a given rainfall will cause a river, or stream to rise above flood stage. |
| depletion | Loss of water from surface water reservoirs or groundwater aquifers at a rate greater than that of recharge. |
| infiltration capacity | The maximum rate at which water can enter the soil at a particular point under a given set of conditions. |
| crp | Critical Rainfall Probability |
| rejuvenation | the increased erosional activity of a river brought about by a relative fall in sea-level which means the river must flow further and at increased gradient thus giving it more energy. |
| barber pole | Slang for a thunderstorm updraft with a visual appearance including cloud striations that are curved in a manner similar to the stripes of a barber pole |
| cretaceous | in geologic time, a period lasting from 144m to 65m years ago. |
| 1000-hr | 3 to 6 " diameter |
| tombolo | a sand deposit which joins an island with a nearby land mass. |
| crevasse | Elongated open cracks in glacial ice, usually nearly vertical, and subject to change at any moment |
| soil moisture | Water contained in the upper part of the soil mantle |
| river flooding | The rise of a river to an elevation such that the river overflows its natural banks causing or threatening damage. |
| leachate | water containing contaminants which leaks from a disposal site such as a landfill or dump. |
| gravel | A term used to describe unconsolidated sediments composed of rock fragments |
| return flow | Irrigation water applied to an area which is not consumed in evaporation or transpiration and returns to a surface stream or ground water aquifer. |
| routing | The methods of predicting the attenuation of a flood wave as it moves down the course of a river. |
| continental drift | theory that the land mass of the earth was once held as a single continent which has since split into segments which have drifted apart and into the modern configuration of the continents |
| peak flow | the highest discharge found in a river channel in response to a particular rainfall or snowmelt event. |
| density | The number or size of a population in relation to some unit of space. |
| rock cycle | General model describing the geomorphic and geologic processes involved in the creation, modification and recycling of rocks. |
| rain shadow | Areas of the leeward side of a mountain or mountain range which often receive much less rain than the windward side. |
| dry adiabatic rate | The rate of change of temperature in rising or descending unsaturated air parcel |
| flow augmentation | the addition of water to meet flow needs. |
| chemical weathering | attack and dissolving of parent rock by exposure to rainwater, surface water, oxygen, and other gases in the atmosphere, and compounds secreted by organisms |
| photometer | Any of a number of atmospheric phenomena which appear as luminous patterns in the sky |
| tectonic plate | An extensive layer of lithosphere that moves as a discrete unit on the surface of the Earth's asthenosphere. |
| base runoff | Sustained or fair weather runoff |
| acre-foot | the volume of water required to cover 1 acre of land (43,560 square feet) to a depth of 1 foot |
| sunny | When there are no opaque (not transparent) clouds. Same as Clear. |
| waterlogged | see saturated. |
| percolation | Vertical movement or infiltration of water from the Earth's surface to its subsurface |
| energy dissipation | The loss of kinetic energy of moving water due to internal turbulence, bottom friction, large rocks, debris, or other obstacles that impede flow. |
| genetic integrity | The ability of a breeding population or group of breeding populations to remain adapted to its natural environment. |
| safe yield | the annual amount of water that can be taken from a source of supply over a period of years without depleting that source beyond its ability to be replenished naturally in "wet years." |
| fire weather watch | A NWS Fire Weather Forecaster will issue this product whenever a geographical area has been in a dry spell for a week or two, or for a shorter period , if before spring green-up or after fall color, and the National Fire Danger Rating System (NFDRS) is high to extreme and the following forecast weather parameters within the next 48 hours are: 1) a sustained wind average 15 mph or greater 2) relative humidity less than or equal to 25 percent and 3) a temperature of greater than 75 degrees F. See Red Flag Warning. |
| melting level | The altitude which ice crystals and snowflakes melt as they descend through the atmosphere. |
| aquiclude | a formation which, although porous and capable of absorbing water slowly, will not transmit water fast enough to furnish an appreciable supply for a well or a spring. |
| box | Slang for a severe thunderstorm or tornado watch. See blue box and red box. |
| cold wave | A rapid fall in temperature within twenty-four hours to temperatures requiring substantially increased protection to agriculture, industry, commerce, and social activities |
| self sustaining population | A population of salmonids that exists in sufficient numbers to maintain its levels through time without supplementation with hatchery fish. |
| secondary wastewater treatment | treatment (following primary wastewater treatment) involving the biological process of reducing suspended, colloidal, and dissolved organic matter in effluent from primary treatment systems and which generally removes 80 to 95 percent of the Biochemical Oxygen Demand (BOD) and suspended matter |
| upstream control | Control structure adjustments based on information from upstream |
| backwater valve | A backwater valve is a backflow prevention valve designed to prevent sanitary sewage from backing up through your floor drain from the sanitary system into a building. |
| consumptive irrigation requirement | The quantity of irrigation water, exclusive of precipitation, stored soil moisture, or ground water, that is required consumptively for crop production. |
| cretaceous | Geologic period that occurred roughly 65 to 144 million years ago |
| squall | A strong wind characterized by a sudden onset in which the wind speed increases at least 16 knots and is sustained more than 22 knots or more for at least one minute. |
| population dynamics | The aggregate of changes that occur during the life of a population. |
| stone | Rock fragments larger than 25.4 cm (10 inches) but less than 60.4 cm (24 inches). |
| anvil dome | A large overshooting top or penetrating top on the top of a Cumulonimbus Cloud (Cb). |
| geostrophic wind | A steady horizontal motion of air along straight, parallel isobars or contours in an unchanging pressure or contour field |
| organic wastes | a quantitative measure of the degree to which organic compounds consume oxygen in water, based on a five-day test in which loss of oxygen in a sample results from bacterial respiration and chemical processes, a traditional water quality measurement applied to wastewater such as treated sewage. |
| ppt | See parts per thousand. |
| meter | A unit of length which constitutes the basis of the Metric System, was intended to be, and is very nearly, one ten-millionth part of the distance measured on a meridian of the earth from the equator to the pole, being equal to 39.37 U.S |
| reforestation | The natural or artificial restocking of an area with forest trees. |
| minor tidal overflow | Minor flooding caused by high tides that results in little if any damage. |
| water purveyor | a public utility, mutual water company, county water district, or municipality that delivers drinking water to customers. |
| vsb | An acronym for visible satellite imagery. |
| headland | at the coast, land utting out-further into the sea and separating bays. see also discordant coast . |
| afforestation | planting of trees on previously un-wooded land. |
| pumped storage project | A hydroelectric power plant and reservoir system using an arrangement whereby water released for generating energy during peak load periods is stored and pumped back into the upper reservoir, usually during periods of reduced power demand. |
| viscosity | The amount of the resistance to flow in a fluid due to intermolecular friction. |
| primary treatment | mechanical treatment in which large solids are screened out and suspended solids in the sewage settle out as sludge |
| service hydrologist | The designated expert of the hydrology program at a WFO. |
| stable | An atmospheric state with warm air above cold air which inhibits the vertical movement of air. |
| laboratory water | purified water used in the laboratory as a basis for making up solutions or making dilutions |
| esker fan | A small plain of sand and gravel built at the mouth of a subglacial stream and associated with an esker formed simultaneously. |
| conifer | A tree belonging to the order Gymnospermae, comprising a wide range of trees that are mostly evergreens |
| environmental impact statement | A formal document to be filed with the Environmental Protection Agency that considers significant environmental impacts expected from implementation of a major federal action. |
| settlement | a location where people have built structures to use as a base for their existence. |
| k-index | It is a measure of the thunderstorm potential based on vertical temperature lapse rate, moisture content of the lower atmosphere, and the vertical extent of the moist layer |
| lotic waters | flowing waters, as in streams and rivers. |
| dam | a large wall or earth barrier used to block a river valley |
| wildfire prevention advisory | This product is issued through the National Weather Service whenever either the Department of Natural Resources (DNR) or United State Forest Service (USFS) requests one due to a high fire danger. In the state of Michigan, this product will be issued by NWFO Gaylord and NWFO Marquette. |
| calorie intake | a measure of the amount of energy derived from food |
| discharge table | (1) A table showing the relation between two mutually dependant quantities or variable over a given range of magnitude |
| mlli | Lifted Index (LI) calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level. See Lifted Index. |
| critical flow | (1) The flow conditions at which the discharge is a maximum for a given specific energy, or at which the specific energy is a minimum for a given discharge |
| grout curtain | A barrier produced by injecting grout into a vertical zone, usually narrow (horizontally), and in the foundation to reduce seepage under a dam. |
| hygrometer | An instrument which measures the humidity of the air. |
| normalized demand | The process of adjusting actual water use in a given year to account for unusual events such as dry weather conditions, government interventions for agriculture, rationing programs, or other anomalies. |
| eluviation | removal of material from a soil horizon, usually downward. |
| dissolved organic compounds | Carbon substances dissolved in water. |
| heterogeneity | State of being dissimilar or diverse. |
| storm tide | The actual sea level resulting from astronomical tide combined with the storm surge |
| old-growth forest | A forest stand usually at least 180-220 years old with moderate to high canopy closure; a multilayered, multispecies canopy dominated by large overstory trees; high incidence of large trees; some with broken tops and other indicators of old and decaying wood (decadence); numerous large snags; and heavy accumulations of wood, including large logs on the ground. |
| berm | a low ridge towards the rear of a beach marking the uppermost level that waves reached during the previous high tide. |
| normal year | A year during which the precipitation or stream flow approximates the average for a long period of record. |
| plucking | Erosive process of particle detachment by moving glacial ice |
| biomonitoring | a test used to evaluate the relative potency of a chemical by comparing its effect on a living organism with the effect of a standard population on the same type of organism. |
| cascade flow | Regulated flow through a series of flow control structures. |
| snow pillow | An instrument used to measure snow water equivalents |
| wave period | The time elapsed for a wave to travel the distance of one wavelength. |
| point source | source of pollution that involves discharge of wastes from an identifiable point, such as a smokestack or sewage treatment plant |
| laissez-faire | the belief that markets should be left to run free from government intervention as business and consumer needs will find their balance in the market place. |
| return flow | surface water that returns to the natural environment after diversion for beneficial uses, such as for irrigation. |
| fixed drawdown period | The late summer and fall when the volume of the next spring runoff is not yet known, and reservoir operations are guided by fixed rule curve based on historical streamflow patterns. |
| cation exchange capacity | ability of the soil to retain cations and thus be fertile. |
| critical dry period | As a general definition, describes a series of water-deficient years, usually a historical period, in which a full reservoir storage system at the beginning is drawn down to minimum storage at the end without any spill. |
| impermeable | a rock which cannot absorb water and does not allow it to pass through. |
| ocean | An ocean is a large body of salt water that surrounds a continent |
| runoff cycle | That portion of the Hydrologic Cycle between incident precipitation over land areas and its subsequent discharge through stream channels or Evapotranspiration. |
| river basin | Drainage area of a river and its tributaries. |
| channel inflow | Water, which at any instant, is flowing into the channel system form surface flow, subsurface flow, base flow, and rainfall that has directly fallen onto the channel. |
| weathering landform | Is a landform created by the physical or chemical decomposition of rock through weathering |
| erratic | A large rock boulder that has been transported by glaciers away from its origin and deposited in a region of dissimilar rock. |
| stream gaging | The quantitative determination of stream flow using Gages, Current Meters, Weirs, or other measuring instruments at selected locations. |
| willy-willy | A tropical cyclone of hurricane strength near Australia. |
| urban runoff | storm water from city streets and adjacent domestic or commercial properties that carries pollutants of various kinds into the sewer systems and receiving waters. |
| vertebrate | Animal that does have a backbone |
| seiche | A standing wave oscillation in any enclosed lake which continues after the forcing mechanism has ceased |
| evaporation | The process by which a liquid changes to a vapour. |
| residential area | an area where the dominant land-use is for homes. |
| head loss | (1) The decrease in total head caused by friction |
| hanging wall | The topmost surface of an inclined fault. |
| stoplogs | Large logs, timbers or steel beams placed on top of each other with their ends held in guides on each side of a |
| dipolar structure | The dominate accumulations of + and - charges in a thunderstorm cell (+ charge in the upper part of the cloud and - charge in the bottom part of the cloud). |
| national response team | representatives of 13 federal agencies that, as a team, coordinate federal responses to nationally significant incidents of pollution and provide advice and technical assistance to the responding agencies. |
| artificial discharge | Addition of surface water to a groundwater reservoir by human activity, such as putting surface water into spreading basins |
| gallon | A unit of volume |
| cumulative causation | the idea that one factor can trigger a sequence of events which reinforce and amplify the entire process concerned |
| ice core | two types: |
| meander belt | The area between lines drawn tangential to the extreme limits of fully developed meanders. |
| evapotranspiration | total moisture lost through evaporation and transpiration. |
| comminution | the reduction in size of particles through attrition. |
| humus | the decomposed organic element of the soil |
| anaerobic | A process that takes place in the absence of oxygen, such as the digestion of organic matter by bacteria in a UASB-reactor. |
| t.s. | An abbreviation for Tropical Storm. See Tropical Storm. |
| selective breeding | The intentional selection of individual spawners in artificial production programs to produce particular traits in subsequent generations. |
| overdraft | pumping water from a groundwater basin or aquifer in excess of the supply flowing into the basin; results in a depletion or "mining" of the groundwater in the basin. |
| off-line reservoir | A reservoir constructed to the side of the main canal, usually in a natural drainage channel used to store surplus water runoff during the winter season for use during the irrigation season. |
| soil water | Water present in the soil pores. |
| outfall sewer | A sewer that receives wastewater from a collection system or from a treatment plant and conveys it to the point of final discharge. |
| thermocline | A vertical negative temperature gradient in some layer of a body of water which is appreciably greater than the gradients above and below it |
| groundwater storage | the storage of water in groundwater reservoirs. |
| meteoric water | Water derived from precipitation. |
| butte | A butte is a flat-topped rock or hill formation with steep sides. |
| basin | An area having a common outlet for its surface runoff. |
| z dr | See differential reflectivity. |
| groundwater prime supply | Long-term average annual percolation into major groundwater basins from percolation into major groundwater basins from precipitation falling on the land and from flows in rivers and streams. |
| absolute zero | Considered to be the point at which theoretically no molecular activity exists or the temperature at which the volume of a perfect gas vanishes |
| water flow | The rate of flow of water measured in volume and time (e.g., cubic feet per second, or cfs). |
| gradient wind | Horizontal wind in the upper atmosphere that moves parallel to curved isobars |
| standard length | The straight distance between the tip of the snout and the base of the caudal fin rays. |
| pressure regulating valve | A device that takes pressure from a high zone through a valve and regulates it to a zone of lower pressure. |
| ecosphere | total of all the ecosystems on the planet, along with their interactions; the sphere of air, water, and land in which all life is found. |
| ground fog | See radiation fog. |
| central pressure | The atmospheric pressure at the center of a high or low |
| fire danger rating | A fire control management system that integrates the effects of selected fire danger factors into one or more qualitative or numerical indices from which ease of ignition and probable fire behavior may be estimated. This is also called a Burn Index. |
| cold vapor | method to test water for the presence of mercury. |
| landsat | a remote-sensing satellite program run by NASA and the U.S |
| index of biotic integrity | a multi-metric measure of biological condition developed from collection of data for fish or other organisms |
| fringe water | Water occurring in the Capillary Fringe. |
| twister | A slang term used in the United States for a tornado. |
| transport | One of three distinct processes involved in erosion |
| baroclinity | The state of stratification in a fluid in which surfaces of constant pressure intersect surfaces of constant density |
| product water | Output water of a desalting or water treatment plant. |
| diffuse ice | Poorly defined ice edge limiting an area of dispersed ice; usually on the leeward side of an area of floating ice. |
| cambrian | in geologic time, a period lasting from 570m to 505m years ago. |
| dredging | The scooping, or suction of underwater material from a harbor, or waterway |
| perennial crops | Those plants that live and evapotranspire throughout the year (365 days). |
| critical habitat | Under the Endangered Species Act, critical habitat is defined as(1) the specific areas within a geographic area occupied by a federally listed species on which are found physical and biological features essential to the conservation of the species, and that may require special management considerations or protections; and (2) specific areas outside the geographic area occupied by a listed species, when it is determined that such areas are essential for the conservation of the species. |
| gravity dam | A concrete structure proportioned so that its own weight provides the major resistance to the forces exerted on it. |
| expanded town | a town deliberately tagged for expansion to try and alleviate population pressure on a nearby, larger urban area |
| infrastructure | the collective name for all the communication links and basic utility links that get built across a country to facilitate movements |
| hurricane model | The Geophysical and Fluid Dynamics Laboratory(GFDL) developed the hurricane model in order to improve hurricane landfall forecasts |
| hydrometeorological prediction center | This is one of 9 centers that comprises the National Centers for Environmental Prediction (NCEP, formerly the National Meteorological Center) |
| cumulonimbus cloud | A well developed vertical cloud that often has top shaped like an anvil |
| forebay reservoir | A reservoir used to regulate the flow of water to a hydroelectric plant; it may also serve other purposes such as recreation. |
| mortality | The number of fish lost or the rate of loss. |
| exempt land | Irrigation land in a district to which the acreage limitation and pricing provisions of reclamation law do not apply. |
| hydrologic cycle | The natural cycle of water passing through the environment, including evaporation, condensation, retention and run-off. |
| land use planning | The process of inventorying and assessing the status, potentials, and limitations of a particular geographic area and its resources, interacting with the populations associated and/or concerned with the area to determine their needs, wants, and aspirations for the future. |
| hydraulic permeability | The flow of water through a unit cross-sectional area of soil normal to the direction of flow when the hydraulic gradient is unity. |
| dispersal | An organism leaving its place or birth or activity for another location. |
| geohydrology | That branch of hydrology relating to subsurface, or subterranean waters. |
| river flooding | Inundation of a normally dry area along a river (usually the mainstem) due to increased water level or discharge |
| gnp | see gross national product. |
| critical low-flow | Low flow conditions below which some standards (Criteria) do not apply |
| negative feedback | Change in the state of a system that counteracts the measured effect of the initial alteration. |
| turning point | A temporary point whose elevation is determined by additions and subtractions of backsights and foresights respectively. |
| energy dissipator | A structure which slows fast-moving spillway flows in order to prevent erosion of the stream channel. |
| weathering | The process of physical and chemical decomposition which changes earth and rock materials in color, texture, composition, firmness or form |
| recession constant | Constant used to reduce the API value daily in the API method of estimating runoff. |
| stream reach | An individual first order stream or a segment of another stream that has beginning and ending points at a stream confluence |
| waterfall | A sudden, nearly vertical drop in a stream, as it flows over rock. |
| concentric rings | These are common in the most intense hurricanes |
| frost wedging | A process of physical weathering in which water freezes in a crack and exerts force on the rock causing further rupture. |
| gross sediment transport | The total amount of sediment transported along a shoreline in a specific time period. |
| freezing rain | A type of precipitation |
| mixing zone | a limited volume of receiving water that is allocated for diluting a wastewater discharge without causing adverse effects to the overall water body. |
| cirrocumulus clouds | Patchy white high altitude cloud composed of ice crystals |
| dcp | An electronic device that connects to a river or rainfall gage that records data from the gage and at pre-determined times transmits that data through a satellite to a remote computer. |
| sparger | A device that introduces compressed air into a liquid. |
| water exports | The artificial transfer (pipes, canals, aqueducts, etc.) of water to one region or subregion from another region. |
| impermeable | rock, sediment or soil incapable of transmitting fluids under pressure. A clay layer is generally impermeable to water. |
| bod5 | The amount of dissolved oxygen consumed in five days by bacteria that perform biological degradation of organic matter. |
| on-site sewage treatment | any individual residential sewage treatment and wastewater dispersal system, such as a septic system. |
| gene locus | The site on a chromosome where a gene is found. |
| mixed liquor | a mixture of activated sludge and water containing organic matter undergoing treatment in an aeration tank. |
| devonian | in geologic time, a period lasting from 408m to 360m years ago. |
| wild rivers | Rivers or sections of rivers that are free of impoundments and generally inaccessible except by trail, with watersheds or shorelines essentially primitive and waters unpolluted. |
| locus | The site on a chromosome where a gene is found |
| river gage | A device for measuring the river stage. |
| urban runoff | Water from an urban area that neither infiltrates the soil nor is consumed, but flows into a storm sewer or open waterway. |
| watt | A metric unit of measurement of the intensity of radiation in Watts over a square meter surface (W/m2 or W m-2). |
| non-consumptive use | Water drawn for use that is not consumed, such as water diverted for hydroelectric generation |
| ephemeral stream | A stream or portion of a stream, which flows only in direct response to precipitation |
| fossil water | Limited subterranean water deposits laid down in past ages but drawn on by modern man. |
| healthy stock | A stock of fish experiencing production levels consistent with its available habitat and within the natural variations in survival for the stock. |
| hydrologic equation | The water inventory equation: Inflow = [Outflow + Change in Storage], which balances the Hydrologic Budget and expresses the basic principle that during a given time interval the total inflow to an area must equal the total outflow plus the net change in storage. |
| solar noon | Point of time during the day when the Sun is aligned with True North and True South. |
| bottom fauna | see benthos. |
| stock origin | The genetic history of a stock. |
| melting | The physical process of a solid becoming a liquid |
| teleconnections | Information used by forecasters to determine what the weather might be elsewhere when compared with past weather conditions at the same degree of longitude. |
| spread effect | the transfer of resources away from a core area to a peripheral area due to diseconomies of scale. |
| power peaking | The generation of electricity to meet maximum instantaneous power requirements; usually refers to daily peaks. |
| water quality criteria | scientifically derived ambient limits developed and updated by EPA, under section 304(a)(1) of the Clean Water Act, for specific pollutants of concern |
| bernoulli's theorem | A statement of the conservation of energy for a steady, nonviscous, incompressible level flow |
| irrigation requirement | The quantity of water, exclusive of precipitation, that is required for crop production |
| pluvial | wet period during the Pleistocene evidenced by fluvial features In currently arid areas. |
| economic man | assumption used in many models of economic geography that human decision-making and subsequent behaviour is based on rational economic motives |
| gley | Dark gray to black, massive and dense sediment which accumulated slowly in low, wet, poorly drained areas. |
| independent variable | Variable in a statistical test that is thought to be controlling through cause and effect the value of observations in another dependent variable modeled in the test. |
| equivalent radar reflectivity | The concentration of uniformly distributed small (diameter 1/16 wavelength or less) water particles which would return the amount of power received |
| leeward | the downwind area from a slope. |
| corridor | A defined tract of land, usually linear, through which a species must travel to reach habitat suitable for reproduction and other life-sustaining needs. |
| erode | Wind, water, and movement of glaciers remove material from (erode) the surface of the earth. |
| polishing | (Water Quality) The removal of low concentrations of dissolved, recalcitrant organic compounds from either water intended for human consumption or wastewater that has been subjected to Primary and Secondary Wastewater Treatment |
| genetic adaptation | Changes in the genetic makeup of organisms of a species due to mutations that allow the species to reproduce and gain a competitive advantage under changed environmental conditions. |
| soil permeability | The rate at which water and air move vertically through a soil. |
| age specific survival rate | The average proportion of individuals in a particular are group that survive for a given period. |
| catch basin | A catch basin is also known as a storm drain inlet |
| rock knob | Carved by the forward advance of the glacier, these knobs have a smooth side and a plucked side |
| natural control | A stream-gaging control which is natural to the stream channel, in contrast to an artificial control constructed by man. |
| reregulating project | A dam and reservoir, located downstream from a hydroelectric peaking plant, with sufficient storage capacity to store the widely fluctuating discharges from the peaking plant and to release them in a relatively uniform manner downstream. |
| municipal sludge | semi-liquid residue remaining from the treatment of municipal water and wastewater. |
| pyroclastic cloud | the cloud of gas, ash, dust, stones and rocks emitted during a highly explosive volcanic eruption. |
| choropleth map | a map using different densities of shading to indicate the distribution of different classes of data by administrative unit across an area. |
| cross-connection | any actual or potential connection between a drinking water system and an unapproved water supply or other source of contamination. |
| desire line | a line on a map relating information on the movement of people by joining their point of origin with their destination |
| garden city | in the UK, a planned settlement with low housing density |
| beta index | a measurement of connectivity using the formula |
| hydraulic transient | (1) Interim stage when a flow changes from one steady-state condition to another steady-state condition because of a sudden acceleration or deceleration of flow |
| primacy | when the primate city is overly large compared to the size expected according to the rank-size rule. |
| dust whirl | A rotating column of air rendered visible by dust |
| bed | (1) An underwater or intertidal area in which a particular organism is established in large numbers |
| moss | About 9,500 species of plants that belong to the division bryophyta |
| one hundred-year flood | Having the same meaning as Base Flood, 1 percent Flood, or Hundred-Year Flood. |
| composite volcano | one in which the cone is made up of alternating layers of lavas and ashes. |
| potential energy | Is the energy that a body possesses by virtue of its position and that is potentially transformable into another form of energy. |
| rainbow | An arc that exhibits in concentric bands the colors of the spectrum and is formed opposite the sun by refraction and reflection of the sun's rays in rain drops. |
| mountain breeze | Local thermal circulation pattern found in areas of topographic relief |
| monophyletic | Relating to, descended from, or derived from one stock or source. |
| surge | A large, destructive ocean wave caused by very low atmospheric pressure and strong winds |
| tornado | A violently rotating column of air in contact with the ground and extending from the base of a thunderstorm |
| ground water overdraft | Pumpage of ground water in excess of safe yield. |
| ogee | A reverse curve shaped like an elongated letter S |
| old field | Cropland that is no longer used to produce an agricultural crop and that has been allowed to revert to natural plant cover. |
| inorganic | non-living things |
| state industry | one which is owned and operated by the government. |
| orographic lifting | Occurs when air is forced to rise and cool due to terrain features such as hills or mountains |
| reclaimed water | domestic wastewater that is under the direct control of a treatment plant owner/operator which has been treated to a quality suitable for a beneficial use. |
| system state | Current value of a system's elements, attributes, and/or relationships. |
| river | A natural stream of water of considerable volume, larger than a brook or creek. |
| stage i precipitation processing | The first level of precipitation processing, occurring within the WSR-88D computer and performance for each |
| check dam | A structure placed bank-to-bank downhill from a headcut on a hillslope to help revegetate a gully. |
| cross-sectional area | Area perpendicular to the direction of flow. |
| polar jet stream | A jet stream that is associated with the polar front in the middle and high latitudes |
| water availability model | a numerical surface water flow model used to determine the availability of surface water for water right permitting. |
| condensation | Exothermic physical process by which water vapor becomes liquid water (100C at 1atm) |
| saline water | water that contains significant amounts of dissolved solids. |
| thermosphere | A thermal classification, it is the layer of the atmosphere located between the mesosphere and outer space |
| supply | a schedule that shows the various quantities of things offered for sale at various prices at a point in time |
| community | Refers to all the populations of interacting species found in a specific area or region at a certain time. |
| breccia | Coarse grained sedimentary rock composed of cemented angular rock fragments. |
| mass movement | the downslope movement en masse of rock, earth or water |
| small circle | A circle on the globe's surface that does not bisect the center of the Earth |
| indicator organisms | Microrganisms, such as coliforms, whose presence is indicative for pollution or for the presence more harmful microrganisms. |
| meander | The winding of a stream channel. |
| gravity feed system | A system that provides flow in a channel or conduit through the use of gravity. |
| rating curve | A drawn curve showing the relation between gage height and discharge of a stream at a given gaging station. |
| adipose fin | A small fleshy fin with no rays, located between the dorsal and caudal fins. |
| succession | Directional cumulative change in the types plant species that occupy a given area, through time. |
| succession | A series of dynamic changes by which one group of organisms succeeds another through stages leading to potential natural community or climax. |
| carbon dioxide | Common gas found in the atmosphere |
| continental slope | The area of descent from the edge of the continental shelf into greater depth. |
| venturi | A channel that serves the measurement of water flows. |
| flood | An overflow of water onto lands that are used or usable by man and not normally covered by water |
| seamount | A volcanic mountain found on an ocean basin that has an origin not related to a mid-oceanic ridge or a tectonic subduction zone. |
| warm | To have or give out heat to a moderate or adequate degree |
| flooding | Temporary inundation of all or part of the floodplain along a well-defined channel or temporary localized inundation occurring when surface water runoff moves via surface flow, swales, channels, and sewers toward well-defined channels |
| in-lieu energy | Energy provided by a reservoir owner instead of water to which a downstream party is entitled. |
| lindane | a pesticide that causes adverse health effects when present in domestic water supplies and is toxic to freshwater fish and aquatic life. |
| peak discharge | Rate of discharge of a volume of water passing a given location |
| conservation | the maintenance of a landscape (natural or man-made) in its current state. |
| production | the conversion of raw materials into usable products. |
| critical velocity | Velocity at which a given discharge changes from tranquil to rapid flow; that velocity in open channels for which the specific energy (the sum of the depth and velocity head) is a minimum for a given discharge. |
| island arc | a chain, often arc-shaped, of volcanic islands |
| outfall | the place where a wastewater treatment plant discharges treated water into the environment. |
| biennial plant | Plant species that completes its life in two growing seasons. |
| doubling time | number of years taken for a population to double in size (number). |
| effluent seepage | Diffuse discharge of ground water to the ground surface. |
| watershed restoration | Improving current conditions of watersheds to restore degraded fish habitat and provide long-term protection to aquatic and riparian resources. |
| rapids | A reach of stream that is characterized by small falls and turbulent high velocity water. |
| heterosphere | The upper layer in a two part classification of the atmosphere based on the general homogeneity of chemical composition |
| salinity control | The physical control, management, and use of water and related land resources in such a way as to maintain or reduce salt loading and concentrations of salt in water supplies. |
| rift | Zone between two diverging tectonic plates |
| frost | The covering of ice crystals that forms by direct sublimation on exposed surfaces whose temperature is below freezing. |
| biomonitoring | surveillance of an ecosystem to monitor and record change. |
| deranged drainage | Drainage pattern that is highly irregular |
| tropical cyclone | Another name for hurricane. |
| air quality statement | This National Weather Service product is issued to relay air pollution information and issue Ozone Action Days. |
| ecological risk assessment | The application of a formal framework, analytical process, or model to estimate the effects of human actions on a natural resource and to interpret the significance of those effects in light of the uncertainties identified in each component of the assessment process |
| osmosis | the passage of a liquid from a weak solution to a more concentrated solution across a semi-permeable membrane that allows passage of the solvent (water) but not the dissolved solids. |
| surface runoff | water flowing along the ground into rivers, lakes, and oceans surface water - all water, fresh and salty, on the Earth's surface suspended - the state of floating in water rather than being dissolved in it suspension - a method of sediment transport in which air or water turbulence supports the weight of the sediment particles, thereby keeping them from settling out or being deposited |
| stream | a water course with flowing water, the smaller relative of a river. (Intermittent streams flow for only part of the year, as after the spring snow melt or rains.) |
| aquifer | a geologic formation that will yield water to a well in sufficient quantities to make the production of water from this formation feasible for beneficial use; permeable layers of underground rock or sand that hold or transmit groundwater below the water table. |
| river forecast | An internal product issued by RFCs to other NWS offices |
| hydrograph | A graph showing the stage, flow, velocity, or other property of water with respect to the passage of time |
| plagioclase feldspar | A type of feldspar that is rich in sodium and calcium |
| outcrop | Area of exposed bedrock at the Earth's surface with no overlying deposits of soil or regolith. |
| cso | Combined Sewer Overflows occurs when heavy rain or melting snow causes sanitary sewers to overflow into stormwater drainpipes |
| isolate | A population that is isolated. |
| haze | A suspension of fine dust and/or smoke particles in the air |
| salt marsh | Saltwater wetlands that occur along many coasts. |
| heat budget | see energy budget. |
| till | A random mixture of finely crushed rock, sand, pebbles, and boulders deposited by a glacier. |
| instream cover | overhanging or instream structure, such as tree roots, undercut streambanks, boulders, or aquatic vegetation that offer protection for aquatic organisms. |
| range resolution | The ability of the radar to distinguish two targets along the same radial, it is approximately � the pulse length. |
| infiltration capacity curve | A graph showing the time-variation of infiltration capacity |
| supercooled | Supercooled water remains in the liquid state even though the its temperature is below its freezing point. |
| flood irrigation | The application of irrigation water where the entire surface of the soil is covered by a sheet of water, called Controlled Flooding when water is impounded or the flow directed by border dikes, ridges, or ditches. |
| moisture stress | A condition of physiological stress in a plant caused by a lack of water. |
| urban flooding | Nuisance flooding of streets, underpasses, basements and other low-lying urban areas |
| downstream slope | The slope or face of the dam away from the reservoir water |
| swamp | A swamp is a type of freshwater wetland that has spongy, muddly land and a lot of water |
| rock flour | Fine-grained rock material produced when a glacier abrades or scrapes rock beneath it. |
| coastal flood statement | This National Weather Service product keeps the public and cooperating agencies informed of the status of existing coastal flood watches and warnings as well as provides an update on local conditions. It is also used to cancel a Coastal Flood Watch or a Coastal Flood Warning. |
| wire weight gage | A river gage comprised of a weight which is lowered to the water level |
| land pan | An evaporation pan located on land. |
| dipole pattern | The systematic polarity pattern or spatial distribution of concentrated + and - strike points of lightning flashes on the ground |
| winds and temperatures aloft | This NWS aviation product contains winds aloft which are computer prepared and contain forecast wind direction and speed as well at forecast temperatures |
| gene pool | Sum total of all the genes found in the individuals of the population of a particular species. |
| inflow | The entry of extraneous rainwater into a sewer system from sources other than infiltration, such as basement drains, sewer holes, storm drains, and street washing. |
| hydrologic region | A study area, consisting of one or more planning subareas, that has a common hydrologic character. |
| coe | An acronym for Corps of Engineers |
| leeside low | Extratropical cyclones that form on the downwind (lee) side of a mountain chain |
| ions | positive ions go through one membrane, while the negative ions flow through a different membrane, leaving the fresh water behind. |
| headwater | (1) the source and upper reaches of a stream; also the upper reaches of a reservoir |
| human-land tradition | Academic tradition in modern Geography that investigates human interactions with the environment. |
| erosion | used in mining some placer deposits to wash the unconsolidated deposits into sluice boxes. |
| transmissivity | The ability of an aquifer to transmit water. |
| acidification | the increase in acidity in an environment due to the development of a particular biome or due to human pollution causing unnaturally high levels of acid rain. |
| normal daily temperature | The average daily mean temperature for a given date, computed for a specific 30-year period. |
| dripstone | deposits of calcium carbonate that include stalactites, stalagmites, columns, and cave pearls. |
| ecotone | a transition zone between two distinctly different ecosystems or communities. |
| forecast crest | The highest elevation of river level, or stage, expected during a specified storm event. |
| d-value | The deviation of actual altitude along a constant pressure surface from the standard atmosphere altitude of that surface. |
| colonization | Movement of individuals or propagules of a species to a new territory. |
| la niña | Condition opposite of an El Ni隳 |
| hydrometeorological technicians | Individuals whose duties include data collection, quality control, gage network maintenance, as well as the gathering and disseminating of data and products at NWS Forecast Offices. |
| groundwater hydrology | the branch of hydrology that deals with groundwater; its occurrence and movements, its replenishment and depletion, the properties of rocks that control groundwater movement and storage, and the methods of investigation and utilization of ground water. |
| slope stability | The resistance of a natural or artificial slope or other inclined surface to failure by mass movement. |
| estuarine waters | Deepwater tidal habitats and tidal wetlands that are usually enclosed by land but have access to the ocean and are at least occasionally diluted by freshwater runoff from the land (such as bays, mouths of rivers, salt marshes, lagoons, etc.). |
| truncate caudal | Said of the margin of the caudal fin when it is squared off as in some catfish. |
| bed load | Sand, silt, gravel, or soil and rock detritus carried by a stream on or immediately above its bed |
| mechanical turbulence | The erratic movement of air or water influenced by local obstructions. |
| rotation | (Irrigation) Water delivery where a relatively constant supply flow is rotated to different users at varying times. |
| sand | Small substrate particles, generally referring to particles less than 2 mm in diameter |
| gust front | A boundary found ahead of a thunderstorm that separates cold storm downdrafts from warm humid surface air |
| analytical watershed | For planning purposes, a drainage basin subdivision used for analyzing cumulative impacts on resources. |
| gravitation | The mutual attraction between two masses of matter |
| alkalinity | Alkalinity means the buffering capacity of water; the capacity of the water to neutralize itself |
| colorado low | A low pressure disturbance that forms in the lee of the Rocky Mountains, usually in southeastern Colorado. |
| secondary substance | Organic chemical produced by a plant that has no direct function in its metabolism |
| diversification | a strategy for spreading business risk whereby a business branches into new industries or markets to protect against potential, unpredictable problems in their core business. |
| mining | extraction of minerals from the crust for industrial use. |
| caliche | an alkaline salt deposit (crust) created by salinisation. |
| tides | They are the periodic (occurring at regular intervals) variations in the surface water level of the oceans, bays, gulfs, and inlets. Tides are the result of the gravitiational attraction of the sun and the moon on the earth |
| boiling point | The temperature at which a liquid changes to a vaporous state |
| gross water yield | The available water runoff, both surface and subsurface, prior to use by man's activities, use by phreatophytes, or evaporation from free water surfaces. |
| reverse osmosis | a water treatment method whereby water is forced through a semipermeable membrane which filters out impurities. |
| species | A group of closely related individuals that can interbreed and produce fertile offspring. |
| storm hydrograph | A hydrograph representing the flow or discharge of water past a point on a river. |
| herbivore | Heterotrophic organism that consumes plants for nutrition |
| landlocked | (1) Enclosed or nearly enclosed by land, as a landlocked country without access to the sea or ocean |
| watch redefining statement | This product tells the public which counties/parishes are included in the watch. This is done not only by writing them all out, but by using the county FIPS codes in the Header of the product. It is issued by the local National Weather Service Forecast Office (NWFO). |
| permeability | The capability of soil or other geologic formations to transmit water. |
| transport capacity | the capacity of a river to carry sediment in suspension or to move sediment along the riverbed. |
| convergent plate margin | see destructive plate margin. |
| paleosol | An ancient or buried soil, often used as a stratigraphic marker for interglacial periods. |
| ephemeral streams | Streams that flow only in direct response to precipitation and whose channel is at all times above the water table. |
| unsaturated zone | the zone immediately below the land surface where the pores contain both water and air, but are not totally saturated with water |
| coefficient of determination | Statistic that measures the proportion of the variation in the dependent variable that is associated with the statistical regression of an independent variable |
| broken | An official sky cover classification for aviation weather observations, descriptive of a sky cover of 5/8 to 7/8. This is applied only when obscuring phenomenon aloft are present--that is, not when obscuring phenomenon are surface-based, such as fog. |
| friction | In meteorology, it is the turbulent resistance of the earth on the atmosphere |
| route of exposure | The way a chemical enters an organism after contact (e.g., ingestion, inhalation, or dermal absorption). |
| clarification | the clearing action that occurs during wastewater treatment when solids settle out |
| spin-up | Slang for a small-scale vortex initiation, such as what may be seen when a gustnado, landspout, or suction vortex forms. |
| meteorology | The science that deals with the phenomenon of the atmosphere, especially weather and weather conditions. |
| fluid drag | Reduction in the flow velocity of a fluid by the frictional effects of a surface. |
| public water use | from a public water supply, used for firefighting, municipal parks and pools, and landscaping and other public city uses. |
| economies of scale | lower per unit costs achieved by large-scale output |
| moisture equivalent | The ratio of: (1) the weight of water which the soil, after saturation, will retain against a centrifugal force 1,000 times the force of gravity, to (2) the weight of the soil when dry |
| longshore drift | the net movement of sediment along a coast |
| equilibrium surface discharge | The steady rate of surface discharge which results from a long-continued, steady rate of net rainfall, with discharge rate equal to net rainfall rate. |
| reregulation | Storing erratic discharges of water from an upstream hydroelectric plant and releasing them uniformly from a downstream plant. |
| variable wind direction | A condition when (1) the wind direction fluctuates by 60o or more during the 2-minute evaluation period and the wind speed is greater than 6 knots; or (2) the direction is variable and the wind speed is less than 6 knots. |
| intermittent stream | A stream which flows for only a part of the time |
| production | 1 |
| trough | An elongated area of low pressure in the atmosphere. |
| storage reservoir | A reservoir in which storage is help over from the annual high water period to the following low water period. |
| freezing point/freeze | The process of changing a liquid to a solid |
| mandibular | Pertaining to the lower jaw. |
| butt end | The bottom end of a cutting taken from a riparian plant that will root if planted in soil (it is opposite the budding tip's end of the cutting). |
| inundation | The covering by water of lands not normally so covered. |
| bog | A type of wetland that accumulates appreciable peat deposits |
| v notch | A radar reflectivity signature seen as a V-shaped notch in the downwind part of a thunderstorm echo |
| heavy industry | those secondary industries using bulk raw materials for both energy (e.g |
| anabranch | a secondary channel of a stream which leaves and then rejoins the main channel |
| lightning | Visible discharge of electricity created by thunderstorms. |
| fresh water | water containing less than 1,000 parts per million (ppm) of dissolved solids of any type |
| permanent control | A stream-gaging control which is substantially unchanging and is not appreciably affected by scour, fill, or backwater. |
| pulse width | The time occupied by an individual pulse broadcast from a radar. |
| precipitate | An insoluble reaction product in an aqueous chemical reaction. |
| peak flow | Refers to a specific period of time when the discharge of a stream or river is at its highest point. |
| cave | A natural cavity or recess that is roughly positioned horizontally to the surface of the Earth. |
| isostatic depression | the sinking of a landmass due to the overlying weight of ice. |
| strong gale | Slight structural damage occurs; high waves; dense streaks of foam on water surface along wind; crest of waves begin to roll over; spray may affect visibility. |
| piezometer | a nonpumping well, generally of small diameter, for measuring the elevation of a water table. |
| medium range | In forecasting, (generally) three to seven days in advance. |
| stair stepping | The process of continually updating river forecasts for the purpose of incorporating the effects rain that has |
| electrodialysis | a process which uses an electrical current and an arrangement of permeable membranes to separate soluble minerals from water |
| target | Precipitation or other phenomena which produces echoes on a radar display. |
| unconfined aquifer | an aquifer containing water that is not under pressure; the water level in a well is the same as the water table outside the well |
| normal fault | Vertical fault where one slab of the rock is displaced up and the other slab down |
| assessment level | Categories of the level of complexity of and data available for each assessment included in this document; index of abundance (INDEX), yield-per-recruit analysis (YIELD), analysis of the age structure of the catch (AGE STRUCTURE), analysis including the relationship between recruitment and spawning stock size (SPAWNING STOCK) and assessment that allows prediction of future (one or two years ahead) stock sizes and catches (predictive) |
| geographic information system | A computer information system that can input, store, manipulate, analyze, and display geographically referenced data to support the decision-making processes of an organization |
| anvil clouds | rapidly rising column of air in a convectional thunderstorm will soon reach the tropopause and be forced to spread in its upper portion to form an anvil shape. |
| katafront | A front where the warm air descends the frontal surface, except in the low layers of the atmosphere. |
| hydrosphere | The region that includes all the earth's liquid water, frozen water, floating ice, frozen upper layer of soil, and the small amounts of water vapor in the earth's atmosphere. |
| phylogenic classification | Classification of organisms based on genetic connections between other species. |
| tropical storm | A tropical cyclone in which the maximum sustained surface winds are from 39 miles per hour (34 knots) to 73 miles per hour (63 knots) |
| effective radar reflectivity factor | See Equivalent Radar Reflectivity Factor. |
| net rain | The portion of rainfall during a storm which reaches a stream as direct surface flow. |
| buffer strip | A barrier of permanent vegetation, either forest or other vegetation, between waterways and land uses such as agriculture or urban development, designed to interrupt and filter out pollution before it reaches the surface water resource. |
| allochthonous sediment | one in which the major components have formed in situ. |
| first amended consent decree | A second Consent Decree agreement, signed in 1999, that addresses Sanitary Sewer Overflows (SSOs) and operation of the City's wastewater treatment plants. |
| hemisphere | lit |
| anastomising | see braiding. |
| crustal plate | see crust. |
| dna | DNA is a complex molecule that carries an organism s heritable information |
| river kilometer | Distance, in kilometers, from the mouth of the indicated river |
| nitrate | a nutrient essential to plant growth. |
| grass/forb | An early forest successional stage where grasses and forbs are the dominant vegetation. |
| ripple | (1) To form or display little undulations or waves on the surface, as disturbed water does |
| excess rain | Effective rainfall in excess of infiltration capacity. |
| nonporous | something which does not allow water to pass through it |
| mid-oceanic ridge | an elongated range of undersea mountains formed by the extrusion of lava, combined with the upward pressure of a convection plume, at a divergent plate margin. |
| mpca | Minnesota Pollution Control Agency |
| stadial | a short-term advance of ice during a more general interglacial period. |
| percolation | (1) The movement, under hydrostatic pressure, of water through the interstices of a rock or soil |
| transform fault | Massive strike-slip fault continental in size |
| invisible trade | import and export of services in industry sectors such as banking, tourism and education |
| fogbow | A whitish semicircular arc seen opposite the sun in fog |
| leakage | (1) (Hydrology) The flow of water from one Hydrogeologic Unit to another |
| industrial location theory | any theory attempting to explain why industries are found to have located in the places they are found |
| synthetic organic chemicals | man-made organic chemicals |
| epoch | geological time period |
| water quality | The condition of water with respect to the amount of impurities in it. |
| milt | The sperm of fishes. |
| fundamental niche | Describes the total range of environmental conditions that are suitable for a species existence without the effects of interspecific competition and predation from other species. |
| reference map | Map that shows natural and human-made objects from the geographical environment with an emphasis on location |
| bottom-up | ideas, initiatives or developments originating in and flowing from the lower levels of a hierarchy further up the hierarchy. |
| conjunctive operation | The operation of a ground water basin in combination with a surface water storage and conveyance system |
| mdc | See more developed country. |
| partly sunny | When the predominant/average sky condition is covered 3/8 to 4/8 with opaque (not transparent) clouds. Same as Partly Cloudy. |
| enrichment | When the addition of nutrients, such as nitrogen and phosphorus, from sewage effluent or agricultural runoff to surface water, greatly increases algal growth. |
| minimum pool | A term used to describe the lowest level of reservoir capacity safe for maintaining fish and aquatic life or for some other designated beneficial purpose |
| flood | an overflow or inundation that comes from a river or other body of water and causes or threatens damage |
| inferior mouth | The type of mouth that opens on the ventral surface (like sturgeon). |
| groundwater | The supply of fresh water found beneath the earth's surface (usually in aquifers) that is often used for supplying wells and springs. |
| hydrograph | A graph describing stream discharge over time. |
| paleolake | An ancient lake that existed in the past when hydrological conditions were different. |
| boundary layer | The layer of reduced velocity in fluids, such as air and water, that is immediately adjacent to the surface of a solid past which the fluid is flowing. |
| braiding | when a river is forced to divide into multiple channels which interlink with each other |
| lichen | an organism created by the joining of fungus and algae. |
| evaporation rate | The quantity of water, expressed in terms of depth of liquid water, which is evaporated from a given surface per unit of time |
| drainage | An area (basin) mostly bounded by ridges or other similar topographic features, encompassing part, most, or all of a watershed and enclosing some 5,000 acres. |
| photochemical smog | a heavy, brown coloured, air pollution formed by the reaction of vehicle and factory emissions with sunlight to produce ozone which is harmful to humans, animals and plants. |
| natural replacement | The ordinary replacement of older, less efficient water fixtures (toilets, faucets, etc.) with new, more efficient fixtures as the older fixtures wear out, break or are replaced. |
| water delivery system | Reservoirs, canals, ditches, pumps, and other facilities to move water. |
| conservation area | Designated land where conservation strategies are applied for the purpose of attaining a viable plant or animal population. |
| aquaculture | Art and science of farming organisms that live in water, such as fish, shellfish, and algae. |
| hydrocarbons | chemical compounds that consist entirely of carbon and hydrogen; also referred to as volatile organic compound. |
| flocculation | The accumulation of destabilized particles and micro flakes, and subsequently the formation of sizeable flakes |
| soft water | Any water that does not contain large concentrations of the dissolved minerals calcium or magnesium. |
| streambank erosion | The wearing away of streambanks by flowing water. |
| fog | Fog exists if the atmospheric visibility near the Earth's surface is reduced to 1 kilometer or less |
| leave strips | Generally narrow bands of forest trees that are left along streams and rivers to buffer aquatic habitats from upslope forest management activities. |
| exfoliation | the 'peeling' away of outer layers of rock in a process of physical weathering found where diurnal temperature range is very wide |
| vadose zone | The subsurface zone between the water table (Zone of Saturation) and the land surface where some of the spaces between the soil particles are filled with air |
| aid | transfer of resources from a donor to a recipient |
| rfc | Centers that serve groups of Weather Forecast Offices, in providing hydrologic guidance and is the first echelon office for the preparation of river and flood forecasts and warnings. |
| lobe | A tongue-like extension of some material |
| cheimaphobia | The fear of cold. |
| conventional water | A natural freshwater supply as opposed to desalted or brackish water. |
| organism | any form of animal or plant life. |
| key species | species that are targeted for instream flow assessment or more generally taxa of interest; may include lotic-adapted species, imperiled species, sport fishes, or other species related to study objectives. |
| irrigation water requirement | The total quantity of water, exclusive of effective precipitation, that is required for crop production, to include crop consumptive use, leaching requirements, and on-farm conveyance losses. |
| aqueous | something made up of water. |
| basin lag | The time it takes from the centroid of rainfall for the hydrograph to peak. |
| effluent stream | Any watercourse in which all, or a portion of the water volume came from the Phreatic zone, or zone of saturation by way of groundwater flow, or baseflow. |
| runoff rate | The volume of water running off in a unit of time from a surface, expressed as inches of rainfall per hour, cubic feet per second, or other units. |
| continental shelf | Shallow submerged margin of the continents that lies between the edge of the shoreline and the continental slope |
| offset | (Irrigation) The difference between the controlled variable and the referenced input, for example, in a canal system, the difference between the actual water level in the canal and the water level at design flow. |
| winter | Season between fall and spring |
| tarn | A small lake that fills the central depression in a cirque. |
| ferruginous | a soil in which a hard layer of laterite forms due to alternating periods of leaching and capillary action |
| stock transfer | Transfer of fish from one location to another |
| phytoplankton | Free-floating, mostly microscopic aquatic plants. |
| small stream flooding | Flooding of small creeks, streams, or runs. |
| altocumulus standing leticular | These clouds are formed on the crests of waves crested by barriers in the wind flow |
| hydrogeology | The part of geology concerned with the functions of water in modifying the earth, especially by erosion and deposition; geology of ground water, with particular emphasis on the chemistry and movement of water. |
| lysimeter | A device to measure the quantity or rate of downward water movement through a block of soil usually undisturbed, or to collect such percolated water for analysis as to quality. |
| forest | Ecosystem dominated by trees |
| soil moisture | the water contained in the pore space of the unsaturated zone. |
| blinding | A build-up of particles in a filter medium, that prevents fluids from flowing through. |
| rolled filled dam | An embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment |
| subsurface water | Water below the surface of the ground, including soil moisture, intermediate zone water, capillary fringe water, and ground water. |
| alluvium | Sediments deposited by erosional processes, usual by streams. |
| chromosome | A thread-like structure containing many genes. |
| tailwater runoff | Refers to unused irrigation water or rain water that is collected at the base or at the end of an irrigation system or field in a ditch or other impoundment |
| phreatic divide | an underground watershed |
| income | money received |
| cumuliform | Descriptive of all clouds with vertical development in the form of rising mounds, domes, or towers. |
| gene diversity analysis | A hierarchical analysis of the genetic variation observed at polymorphic loci (see allele) in a set of samples that partitions this variation into several, typically geographic, components |
| flood stage | The level of a river or stream where overflow onto surrounding areas can occur. |
| hydrologic cycle | The constant circulation of water from the sea, through the atmosphere, to the land, and back to the sea by over-land, underground, and atmospheric routes. |
| noaa weather radio | It is the voice of the National Weather Service. NOAA Weather Radio broadcasts National Weather Service warnings, watches, forecasts and other hazard information 24 hours a day. It is provided as a public service by the Department of Commerce's National Oceanic and Atmospheric Administration. The NOAA Weather Radio network has more than 480 stations in the 50 states and near adjacent coastal waters, Puerto Rico, the U.S |
| gross domestic product | the total summed value of the output in a country for a year |
| debris | Obstructions in a sewer line, such as tree roots and trash that reduce the capacity of the sewer and contribute to blockage and overflows. |
| system boundary | Outer edge of system |
| freezing | the change of a liquid into a solid as temperature decreases |
| correlation coefficient | Statistic that measures the degree of linear association between two variables |
| pressure head | The relative pressure (excess over atmospheric pressure) divided by the unit weight of water; expressed in units of height. |
| ocean take | The portion of the total harvest for a species or stock that occurs in marine areas. |
| watershed | An area of land thats total surface drainage flows to a single point in a stream. |
| ngvd of 1929 | National Geodetic Vertical Datum of 1929 |
| minimum moisture content | The amount of water in soil during the driest time of the year. |
| subtropical storm | A subtropical cyclone in which the maximum sustained surface wind speed (using the U.S |
| speciation | The process by which new species originate through mutations, natural selection, and evolution. |
| weather surveillance radar | The newest generation of Doppler radars, the 1988 Doppler weather radar |
| terminus | End or snout of a glacier. |
| floodway | The channel of a river or stream and the parts of the floodplain adjoining the channel that are reasonably required to efficiently carry and discharge the flood water or flood flow of a river or stream. |
| lee | Side of a slope that is opposite to the direction of flow of ice, wind, or water |
| rodenticide | A pesticide or other agent used to kill rats and other rodents or to prevent them from damaging food, crops, or forage. |
| echo tops | This WSR-88D radar product displays echo top heights (thousands of feet) based on the highest elevation angle at which greater than or equal to 18 dBZ reflectivities are determined. The heights are referenced to Mean Sea Level (MSL). A circular stair-step appearance often occurs due to echo beam top limitations. It is used to gain a quick estimation of the most intense convection (highest tops); detect mid-level echoes before low level echoes are detected; and assist in differentiating non-precipitation echoes from real storms. |
| eddy | A localized chaotic movement of air or liquid in a generally uniform larger flow. |
| permanent monument | Fixed monuments placed away from the dam which allow movements in horizontal and vertical control points on the dam to be monitored by using accurate survey procedures. |
| spearman rank correlation coefficient | a statistical measure of the degree to which two sets of data are correlated according to the formula: |
| snowburn | A burn of the skin, like a sunburn, but caused by the sun's rays reflected off the snow surface. |
| confidence level | the degree of confidence that a statistical result is the correct one rather than one produced by chance. |
| cumulonimbus mammatus cloud | It is associated with a cumulonimbus cloud |
| artificial production | (or Artificial propagation) Spawning, incubating, hatching or rearing fish in a hatchery or other facility constructed for fish production. |
| user agency | A public fire service or wildlands management agency, Federal or non-Federal, which regularly requires and uses NWS fire and forestry meteorological services. |
| flash flood watch | This product is issued by the local National Weather Service office (NWFO) for events that have the potential for short duration (usually less than 6 hours) intense flooding of counties, communities, streams or areas for which the occurrence is neither certain nor imminent |
| photon | A discrete unit of radiant energy. |
| phreatic zone | The locus of points below the water table where soil pores are filled with water |
| maximum depth | The greatest depth of the body of water measured in feet and 10ths of feet. |
| spring | An issue of water from the earth; a natural fountain; a source of a reservoir of water. |
| biological contaminants | Living organisms such as viruses, bacteria, fungi, and mammal and bird antigens that can cause harmful health effects to humans. |
| shear stress | the frictional force per unit area exerted on a streambed by flowing water |
| the south | see economically less developed countries. |
| recycled water | water that is used more than one time before it passes back into the natural hydrologic system. |
| wave spectrum | The distribution of wave energy with respect to wave frequency or period. Wave spectra assist in differentiating between wind waves and swells. |
| heat lightning | Lightning that appears as a glowing flash on the horizon |
| flocculation | large scale treatment process involving gentle stirring whereby small particles in flocs are collected into larger particles so their weight causes them to settle to the bottom of the treatment tank. |
| outflow channel | A natural stream channel which transports reservoir releases. |
| waterfall | a sudden vertical or near vertical fall of water where a river course is interrupted by a drop away in the land over which it is flowing. |
| rural | lit |
| dryland farming | Practice of crop production without irrigation in semiarid regions usually by using moisture-conserving farming techniques. |
| hanging valley | A secondary valley that enters a main valley at an elevation well above the main valley's floor |
| projected savings | An estimate of the amount of water that will not be used because both suppliers and customers are implementing certain efficiency practices. |
| hydrologic basin | The complete drainage area upstream from a given point on a stream. |
| mass balance | The relative balance between the input and output of material within a system. |
| kettle | A shallow, bowl-shaped depression formed when a large block of glacial ice breaks away from the main glacier and is buried beneath glacial till, then melts |
| slate | A fine grained metamorphic rock with well developed bedding planes derived from the slight recrystrallization of shale. |
| hydrophobic | Having an aversion for water. |
| rain gauge | An instrument used to measure the amount of rain that has fallen |
| nitrification | A biological process, during which nitrifying bacteria convert toxic ammonia to less harmful nitrate |
| canal pool | Canal section between check structures |
| kirchoff's law | This law suggests that good emitters of radiation are also good absorbers of radiation at specific electromagnetic radiation wavelength bands |
| predominant wind | It is the wind that in the forecasters judgment generates (or is expected to generate) the local component of the significant sea conditions across the forecast area. |
| spatial tradition | Academic tradition in modern Geography that investigates geographic phenomena from a strictly spatial perspective. |
| jig | An apparatus for cleaning or separating crushed ore by agitation in water. |
| hot spot | A volcanic area on the surface of the Earth created by a rising plume of magma. |
| albedo | The portion of incoming radiation which is reflected by a surface. |
| rolled filled dam | An embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment. |
| initial water deficiency | The quantity, usually expressed in depth of water in inches on a unit area, by which the actual water content of a given soil zone (usually the Root Zone) is exceeded by the field capacity of that zone at the beginning of the rainy season. |
| swell | Ocean waves that have traveled out of their generating area |
| caldera volcano | Explosive type of volcano that leaves a large circular depression |
| divergent plate margin | see constructive plate margin. |
| ice jam | An accumulation of broken river ice caught in a narrow channel, frequently producing local flooding |
| solution | the taking of minerals into water and removing them through flow. |
| phase | A particular angular stage or point of advancement in a cycle; the fractional part of the angular period through which the wave has advanced, measured from the phase reference. |
| kingdom | Top most level of the common system used to classify life |
| pedestrianisation | the temporary or permanent blocking of streets to vehicular traffic. |
| drawdown | a lowering of the ground-water surface caused by pumping. |
| effluent guidelines | Technical EPA documents which set effluent limitations for given industries and pollutants. |
| altimeter | An instrument that indicates the altitude of an object above a fixed level |
| hydraulic roughness | an estimate of the resistance to flow due to energy loss caused by friction between the channel and the water |
| capillary zone | The soil area just above the water table where water can rise up slightly through the cohesive force of capillary action |
| fishing mortality | Deaths in a fish stock caused by fishing. |
| kalema | a violent surf that occurs on the coast of the Guinea region, West Africa. |
| permissible velocity | (Hydraulics) The highest velocity at which water may be carried safely in a channel or other conduit |
| flood control storage | Storage of water in reservoirs to abate flood damage. |
| trap | To catch or take in fish from a stream, or a device which does so. |
| surges | Periods of extremely rapid movements in glacial flow. |
| resource | Anything obtained from the environment to meet the needs of a species. |
| concrete-gravity structure | A type of concrete structure in which resistance to overturning is provided only by its own weight. |
| bubble high | A mesoscale area of high pressure, typically associated with cooler air from the rainy downdraft area of a thunderstorm or a complex of thunderstorms |
| sewage | The waste and wastewater produced by residential and commercial sources and discharged into sewers. |
| lakeshore warning | The local National Weather Service Offices with Great Lakes responsibility will issue this product to alert the public when there is either a potential or actual reports of major Great Lakes lakeshore flooding and erosion. If precautions are not taken, this could pose a considerable threat to life and property. |
| slope | The side of a hill or mountain, the inclined face of a cutting, canal or embankment or an inclination from the horizontal |
| breakthrough | Crack or break in a filter bed that allows the passage of floc or particulate matter through a filter. |
| random variable | A variable characterized by random behavior in assuming its different possible values |
| biological control | use of natural organisms to fight weeds and pests in agriculture. |
| striations | The long, parallel scratches and grooves produced in rocks underneath a glacier as it moves over them. |
| jar test | a laboratory procedure that simulates a water treatment plant's coagulation/flocculation units with differing chemical doses, mix speeds, and settling times to estimate the minimum or ideal coagulant dose required to achieve certain water quality goals. |
| non-cohesive soil | Soil particles that have no natural resistance to being pulled apart at their point of contact, for example, silt, sand, gravel. |
| raindrop impact | Force exerted by a falling raindrop on a rock, sediment, or soil surface. |
| completion | sealing off access of undesireable water to the well bore by proper casing and/or cementing procedures. |
| water allocation | In a hydrologic system in which there are multiple uses or demands for water, the process of measuring a specific amount of water devoted to a given purpose or use. |
| back pressure | Pressure that can cause water to backflow into the water supply when a user's waste water system is at a higher pressure than the public system. |
| streamline | (1) A line that is parallel to the direction of flow of a fluid at a given instant |
| considerable cloudiness | When the predominant/average sky condition is covered by more than half, but not completely covered by opaque (not transparent) clouds. In other words, 5/8 to 7/8 of the sky is covered by opaque clouds. Same as Considerable Cloudiness. |
| cyclone | An area of closed pressure circulation with rotating and converging winds, the center of which is a relative pressure minimum |
| harris-ullman | model of urban land-use based on multiple nuclei i.e |
| demineralisation | Processes to remove minerals from water, usually the term is restricted to ion exchange processes. |
| reservoir | A man-made facility for the storage, regulation and controlled release of water. |
| river gage datum | The arbitrary zero datum elevation which all stage measurements are made from. |
| keetch-byram drought index | A soil/duff drought index that ranges from 0 (no drought) to 800 (extreme drought) and is based on a soil capacity of 8 inches of water |
| membrane filter method | A procedure used to recover and count bacteria in samples of liquid substances, such as water |
| river basin | Drainage area of a river and its tributaries. |
| turbulent flow | A flow that contains may rapid fluctuations. |
| exploitation rate | The proportion of a population at the beginning of a given time period that is caught during that time period (usually expressed on a yearly basis) |
| collector sewers | Pipes used to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility. |
| pull factor | an attractive quality of a place which pulls migrants to it. |
| diffraction | The result of light waves interfering with other after passing through a narrow aperture, causing them to bend or spread. |
| snow advisory | This product is issued by the National Weather Service when a low pressure system produces snow that may cause significant inconveniences, but do not meet warning criteria and if caution is not exercised could lead to life threatening situations. The advisory criteria varies from area to area. In Michigan, the criteria for its issuance is a snow event that is forecasted to produce snow (average of forecast range) greater than 3 inches, but less than warning criteria (6 inches in Lower Michigan and 8 inches in Upper Michigan) in 12 hours. If the forecaster feels that it is warranted, he or she can issued it for amounts less than the minimum criteria. For example, it may be issued for the first snow of the season or when snow has not fallen in long while. |
| upper level system | A general term for any large-scale or mesoscale disturbance capable of producing upward motion (lift) in the middle or upper parts |
| fermentation | The conversion of organic matter to methane, carbon dioxide and other molecules by anaerobic bacteria. |
| background level | the concentration of a substance in an environmental media (water or soil) that occurs naturally or is not the result of human activities. |
| kilowatthour | a power demand of 1,000 watts for one hour |
| dew | Water droplets that form upon surfaces on or near the ground when air is cooled toward its dew point. |
| dcp | An electronic device that connects to a river or rainfall gage that records data from the gage and at pre-determined times transmits that data through a satellite to a remote computer. |
| channel modification | The modification of the flow characteristics of a channel by clearing, excavation, realignment, lining, or other means to increase its capacity |
| straight-line winds | Any surface wind that is not associated with rotation |
| aquatic ecosystem | Any body of water, such as a stream, lake, or estuary, and all organisms and nonliving components within it, functioning as a natural system. |
| photochemical smog | Photochemical smog is a condition that develops when primary pollutants (oxides of nitrogen and volatile organic compounds created from fossil fuel combustion) interact under the influence of sunlight to produce a mixture of hundreds of different and hazardous chemicals known as secondary pollutants |
| monitoring | Sampling and analysis of air, water, soil, wildlife, and other conditions, to determine the concentrations of contaminants. |
| recovery/restoration | The reestablishment of a threatened or endangered species to a self-sustaining level in its natural ecosystem (i.e., to the point where the protective measures of the Endangered Species Act are no longer necessary). |
| tropopause | The tropopause is a relatively thin atmospheric transition layer found between the troposphere and the stratosphere |
| vicious circle | a downward spiral of negative feedback where a trigger event starts a sequence of effects which continue to make the situation worse. |
| permeability | The ability of a material to transmit fluid through its pores when subjected to a difference in head. |
| tolerance | 1)The ability of a living thing to withstand adverse conditions, such as pest attacks, weather extremes, or pesticides |
| deionized water | water free of inorganic chemicals. |
| closed lakes | Those that do not have an effluent in contrast to drainage lakes or open lakes which do have outlet streams |
| reflection | Process of returning sound or light waves back to their source. |
| bank-full discharge | The stream discharge corresponding to the water stage that first overtops the natural banks |
| water pollution | Generally, the presence in water of enough harmful or objectionable material to damage the water's quality. |
| development | The construction, erection, or emplacement of one or more buildings, structures, or surface improvements on land which is a premises in order to establish or expand a principal residential or nonresidential use. |
| meander line | A line delineated by government survey for the purpose of defining the bends or windings of the banks of a stream or the shore of a body of water, and as a means for ascertaining the quantity of land embraced by the survey. |
| sop | Standard Operating Procedure |
| unravel | The lose material from the edges of a revetment. |
| ice storm | It is usually used to describe occasions when damaging accumulations of ice are expected during freezing rain situations |
| decomposable waste | waste that under suitable natural conditions can be transformed through biological and chemical processes into compounds that do not impair water quality. |
| kinetic energy | lit |
| mud slide | Fast moving soil, rocks and water that flow down mountain slopes and canyons during a heavy a downpour of rain. |
| vapor pressure | The pressure exerted by the molecules of a given vapor |
| sea breeze front | A coastal phenomena, it is restricted to large bodies of water and their immediate coast lines |
| bog | A habitat that consists of waterlogged spongy ground |
| gage height | The water-surface elevation referred to some arbitrary gage datum |
| transverse bands | Bands of clouds oriented perpendicular to the flow in which they are embedded |
| recharge | water added to an aquifer |
| sausage dam | A dam composed of loose rock that has been wrapped with wire into cylindrical bundles and laid in a horizontal or vertical position. |
| independent variable | one which is not affected by another e.g |
| flooding problem | The disruption to community affairs, damage to property and facilities, and the danger to human life and health that occurs when land use is incompatible with the hydrologic-hydraulic system. |
| theta-e ridge | An axis of relatively high values of theta-e |
| manhole | Vertical openings that serve as access holes for maintenance in sanitary or storm drain infrastructure |
| recurrence interval | The average time period that separates natural events of a specific magnitude |
| cation | An ion carrying a positive atomic charge. |
| bromeliad | Plants of the bromeliad family (Bromeliaceae) |
| roche mouton | lit |
| weather vane | Originally used as a wind vane, it is an instrument that indicates the wind direction |
| condensation nuclei | A particle upon which condensation of water vapor occurs |
| threshold limit value | The concentration of an airborne substance that a healthy person can be exposed to for a 40-hour work week without adverse effect; a workplace exposure standard. |
| interceptor sewer | very large sewer lines that collect the flow from main and trunk lines and carry them to treatment plants. |
| flood plain | relatively flat and normally dry land alongside water that is covered during a flood. |
| mineralization | The process whereby concentrations of minerals, such as salts, increase in water, often a natural process resulting from water dissolving minerals found in rocks and soils through which it flows. |
| doppler shift | The change in observed frequency of wave energy due to the relative motion of the observer and wave source |
| primary consumer | Organisms that occupy the second trophic level in the grazing food chain |
| surface tension | The elastic-like force in a body, especially a liquid, tending to minimize, or constrict, the area of the surface. |
| reach | The distance between two specific points outlining that portion of the stream, or river for which the forecast applies |
| piedmont glacier | A glacier occurring on the piedmont, the gradually sloping area leading down from a mountain to the plains or to the sea |
| density current | A flow of water maintained by gravity through a large body of water, such as a reservoir or lake, and retaining its unmixed identity because of a difference in density. |
| blocking high | The development of a warm ridge or cutoff high aloft at high latitudes which becomes associated with a cold high at the surface, causing a split in the westerly winds |
| siltstone | Fine grained sedimentary rock composed of lithified silt particles. |
| note | MPH equals approximately 1.15 x Knots |
| natural resource | A material source of wealth, such as timber, fresh water, or a mineral deposit, that occurs in a natural state and has economic value |
| instream aeration | The addition of air to a flowing stream to maintain the dissolved oxygen content of the water at an acceptable level. |
| southern oscillation | Reversal of atmospheric circulation in tropical Pacific Ocean that triggers the development of an El Ni隳. |
| infiltration index | An average rate of infiltration, in inches per hour, equal to the average rate of rainfall such as that the volume of rainfall at greater rates equals the total direct runoff. |
| physical weathering | breaking down of parent rock into bits and pieces by exposure to temperature and changes and the physical action of moving ice and water, growing roots, and human activities such as farming and construction |
| lotic system | A flowing body of fresh water, such as a river or stream |
| inorganic | Matter other than plant or animal and not containing a combination of carbon, hydrogen, and oxygen, as in living things. |
| direct flood damage | The damage done to property, structures, goods, etc., by a flood as measured by the cost of replacement and repairs. |
| fuelwood | as it suggests, the use of wood as a fuel |
| piping | The progressive development of erosion of a dam structure by seepage, appearing downstream of the dam as a hole or seam discharging water that contains soil particles. |
| flowline | (1) The general path that a particle of water follows under laminar flow conditions |
| seismic | lit |
| flume | a small, U-shaped channel built into a river to aid the measurement of discharge. |
| lifted index | It is a stability index used to determine thunderstorm potential |
| hydrocarbon | Organic compound composed primarily of hydrogen and carbon atoms |
| hydrosphere | Considered as the water portion of the earth's surface |
| hydrometeorology | The science of the application of meteorology to hydrologic problems; the branch of meteorology that deals with the occurrence, motion, and changes of the state of atmospheric water |
| subcritical flow | flow characterized by low velocity and a Froude number less than 1 |
| pedogenesis | lit |
| flora | (1) A term used to describe the entire plant species of a specified region or time |
| grade | The vertical alignment of a sewer. |
| water main | A principal pipe in a system of pipes for conveying water, especially one installed underground. |
| time | Measurable period in which cause and effect occurs and systems function. |
| geostrophic wind | Horizontal wind in the upper atmosphere that moves parallel to isobars |
| eolian landform | Is a landform formed from the erosion or deposition of weathered surface materials by wind |
| freeboard | the vertical distance between the lowest point along the top of a surface impoundment dike, berm, levee, treatment works or other similar feature and the surface of the liquid contained therein. |
| river summary | A NWS summary of river and/ or crest stages for selected forecast points along the river. |
| tropical storm warning | A warning for tropical storm conditions including sustained winds within the range of 34 to 63 kt (39 to 73 mph or 63 to 118 kph) that are expected in a specified coastal area within 24 hours or less. |
| precipitation rate | The amount of water applied per unit of time, usually expressed in inches per hour. |
| stormwater discharge | Precipitation that does not infiltrate into the ground or evaporate due to impervious land surfaces, but instead flows onto adjacent land or water areas and is routed into drain/sewer systems. |
| piping | The progressive development of internal erosion by seepage, appearing downstream as a hole or seam discharging water that contains soil particles. |
| angular area of sphere | Equals 4*pi steradians. |
| troll fishery | A type of commercial salmon fishery taking place in marine waters where gear is limited to multiple lures or baits trolled behind the boat, attached to lines suspended from long poles or outriggers. |
| hydrologic unit | is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature. |
| retrogression | In meteorology, it is the movement of a weather system in a direction opposite to the direction of the basic flow in which it is embedded |
| bathymetry | (1) The measurement of the depth of large bodies of water (oceans, seas, ponds and lakes) |
| subsistence flows | the component of an instream flow regime that represents infrequent, naturally occurring low flow events that occur for a seasonal period of time |
| pavement | A rock surface, often eroded or striated, which underlies glacial till and is exposed in sufficient quantity to resemble a sidewalk or open plaza. |
| tropopause | The upper boundary of the troposphere, usually characterized by an abrupt change in lapse rate from positive (decreasing temperature with height) to neutral or negative (temperature constant or increasing with height). It is also the boundary between the troposphere and the stratosphere. |
| indirect flood damage | Expenditures made as a result of the flood (other than repair) such as relief and rescue work, removing silt and debris, etc. |
| klystron | An electron tube used as a low-power oscillator or a high-power amplifier at ultrahigh frequencies |
| esturine waters | Deepwater tidal habitats and tidal wetlands that are usually enclosed by land but have access to the ocean and are at least occasionally diluted by freshwater runoff from the land (such as bays, mouths of rivers, salt marshes, lagoons). |
| cross section | See radar cross section. |
| backing winds | Winds which shift in a counterclockwise direction with time at a given location (e.g |
| bernoulli's equation | Under conditions of steady flow of water, the sum of the velocity head, the pressure head, and the head due to elevation at any given point is equal to the sum of these heads at any other point plus or minus the head losses between the points due to friction or other causes. |
| ecosystem | the interacting system of a biological community and its non-living environmental surroundings; a complex system composed of a community of fauna and flora, taking into account the chemical and physical environment with which the system is interrelated. |
| solubility | the amount of mass of a compound that will dissolve in a unit volume of solution. |
| conveyance loss | water loss in pipes, channels, conduits, and ditches by leakage or evaporation. |
| intermittent stream | A stream that flows only for short periods over a year |
| remote sensor | Mechanical devices used to remotely sense an object or phenomenon. |
| ph | "The negative logarithm of the molar concentration of hydrogen ion |
| lag time | the time from the center of a unit storm to the peak discharge or center of volume of the corresponding unit hydrograph. |
| towering cumulus | It signifies a relatively deep layer of unstable air |
| greenhouse effect | The overall warming of the earth's lower atmosphere primarily due to carbon dioxide and water vapor which permit the sun's rays to heat the earth, but then restrict some heat-energy from escaping back into space. |
| toxic | Harmful to living organisms. |
| advanced wastewater treatment | Any treatment of sewage water that includes the removal of nutrients such as phosphorus and nitrogen and a high percentage of suspended solids. |
| subirrigation | (1) Irrigation below the surface (as by a periodic rise of the water table or by a system of underground porous pipes) |
| nimbostratus clouds | Dark, gray low altitude cloud that produces continuous precipitation in the form of rain or snow |
| lotic | Meaning or regarding things in running water. |
| artesian well | A well drilled into a confined aquifer. |
| effluent | The sewage or industrial liquid waste that is released into natural water by sewage treatment plants, industry, or septic tanks. |
| commuting | movement of people between place of residence and place of work and vice versa |
| comparison goods | those goods which are highly priced and which are bought infrequently |
| beach drift | The lateral movement of sediments on a beach when the angles of swash and backwash differ. |
| eluviation | (1) The removal of soil material in suspension (or in solution) from a layer or layers of a soil |
| hygrometer | An instrument for measuring atmospheric humidity. |
| initial storage | That portion of precipitation required to satisfy interception by vegetation, the wetting of the soil surface, and Depression Storage. |
| ocean | A body of saline water found occupying all or part of the Earth's ocean basins |
| mushroom | Slang for a thunderstorm with a well-defined anvil rollover, and thus having a visual appearance resembling a mushroom. |
| noncontact recreation | recreational pursuits not involving a significant risk of water ingestion, including fishing, commercial and recreational boating, and limited body contact incidental to shoreline activity |
| primary consumers | the herbivores which feed on plants and are available as food to carnivores. |
| ppine | Plan Position Indicates No Echoes, referring to the fact that a radar detects no precipitation within its range. An intensity-modulated display on which echo signals are shown in plan view with range and azimuth angle displayed in polar coordinates, forming a map-like display |
| pesticide | any chemical sprayed on crops to prevent disease or to kill pests which attack the plants |
| treatment | process of converting the raw water from the SRP canals through sedimentation, filtering, disinfection and testing at TIQ Valley water treatment plants to produce finished water of pure quality at your tap. |
| bathymetric map | A map showing the depth (bottom contours) of water in lakes, streams, or oceans |
| shaping | The scheduling and operation of generating resources to meet seasonal and hourly load variations. |
| pressure characteristic | The pattern of the pressure change during the specified period of time, usually the three hour period preceding an observation |
| lifted index | A measure of atmospheric instability that is obtained by computing the temperature that the air near the ground would have if it were lifted to a higher level and comparing it to the actual temperature at that altitude |
| head race | A channel which directs water to a water wheel; a forebay. |
| appropriate | To authorize the use of a quantity of water to an individual requesting it. |
| surface water | Water that flows in streams and rivers and in natural lakes, in wetlands, and in reservoirs constructed by humans. |
| subsurface storm flow | The lateral motion of water through the upper layers until it enters a stream channel |
| reuse water | Water used repeatedly. |
| point precipitation | Precipitation at a particular site, in contrast to the mean precipitation over an area. |
| self-supplied water | water withdrawn from a surface- or ground-water source by a user rather than being obtained from a public supply |
| assimilation | the ability of a water body to purify itself of pollutants. |
| mesocyclone | A area of rotation of storm size that may often be found on the southwest part of a supercell |
| noctiphobia | The fear of the night. |
| specialization | at different scales, the concentration of effort into particular areas so that the efficiency and quality are maximized. |
| medium water use plants | Plants which require some supplemental watering throughout the life of the plant. |
| herb | A nonwoody angiosperm whose above ground vegetation dies off seasonally. |
| flood irrigation | See Irrigation. |
| cooling tower | Large tower used to transfer the heat in cooling water from a power or industrial plant to the atmosphere either by direct evaporation or by convection and conduction. |
| navigation methods | Three basic methods of providing and managing inland waterways - 1) Run-of-the-River: no provision of upstream storage; 2) Slack-Water: locks and dams provide slack water or pools with adequate depth for the draft of heavy barges and area to prevent excessive velocities; 3) Canalization: in lieu of a series of dams on the river a canal with locks adjoins the river. |
| fertility | two kinds: |
| preferred use | A use given some sort of preference not given other uses |
| autocorrelation | A measure of similarity between displaced and undisplaced (in time, space, etc.) versions of the same function. |
| settleable solids | in sewage, suspended solids that will settle when the sewage is brought to a quiet state for a reasonable length of time, usually two hours. |
| granitic magma | Felsic magma that generates mainly granitic rocks. |
| national meteorological center | Now incorporated into the National Centers for Environmental Prediction, it was the division of the National Weather Service that produced, processed, handled, and distributed meteorological and oceanographic information to users throughout the Northern Hemisphere, specifically U.S |
| garden festival | in the UK, a large scale renovation of derelict inner-city land by designating it for the planting of specially designed gardens |
| conduction | The transfer of energy due to actual contact of two materials, not their movement relative to each other. |
| host | Organism that develops disease from a pathogen or is being feed on by a parasite. |
| non-potable | Water that is unsafe or unpalatable to drink because it contains pollutants, contaminants, minerals or infective agents. |
| firewhirl | A tornado-like rotating column of fire and smoke created by intense heat from a forest fire or volcanic eruption. |
| shield volcano | Volcano created from alternate layers of lava flows |
| drainage area | of a stream at a specified location is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from precipitation normally drains by gravity into the stream above the specified point. |
| pingo | A large conical mound that contains an ice core |
| gravitational water | Water that moves into, through, or out of a soil or rock mass under the influence of gravity. |
| european model | One of medium-range (3 to 7 days) forecast models that forecasters use to write their extended forecasts. It has a resolution of 75 kilometers and covers the entire northern hemisphere. References to it can be found in NMC (National Meteorological Center) and area forecast discussions. This model comes from European Centre for Medium-Range Weather Forecasts (ECMWF) which is an international organization supported by 18 European Member States |
| parts per billion | the number of "parts" by weight of a substance per billion parts of water |
| perfection | The process of meeting terms and conditions of a water right permitting process which results in a Perfected Water Right. |
| depth hoar | In snow, relatively large (1 to several mm diameter), cohesionless, coarse, faceted snow crystals resulting from the presence of steep temperature gradients within the snowpack. |
| rotational slip | Form of mass movement where material moves suddenly along a curvilinear plane |
| polar cell | one of the cells of atmospheric circulation in the tri-cellular model. |
| clastic sedimentary rock | Sedimentary rocks that are formed by the lithification of weathered rock debris that has been physically transported and deposited. |
| fetch | 1) An area from which waves are generated by a wind that is nearly constant in direction and speed. |
| aeration tank | A chamber used to inject air into water. |
| ebb current | A tidal current that is receding or declining. |
| environment | two meanings: |
| capillarity | (1) The property of tubes or earth-like particles with hair-like openings which, when immersed in fluid, raise (or depress) the fluid in the tubes above (or below) the surface of the fluid in which they are immersed |
| net reservoir evaporation | The difference between the total evaporation from the reservoir water surface and the Evapotranspiration from the reservoir area under pre-reservoir conditions, with identical precipitation considered for both conditions. |
| siltation | the deposition or accumulation of fine soil particles. |
| tropical storm | An organized group of thunderstorms often found over a tropical ocean that generates a cyclonic flow of between 64 and 118 kilometers per hour |
| polar vortex | High pressure system located in the upper atmosphere at the polar regions |
| flash flood table | A table of pre-computed forecast crest stage values for small streams for a variety of antecedent moisture conditions and rain amounts |
| sediment storage capacity | The volume of a reservoir planned for the deposition of sediment. |
| second world | outdated term for the old communist bloc of the USSR and Eastern Europe. |
| vip levels | Categorized intervals of reflectivity which are computer processed by a Digital Video Integrator Processor (D/VIP) |
| overdraft | That quantity of water pumped in excess of the safe yield; the act of overdrawing a water supply or aquifer in amounts greater than replenishment |
| chemical pollution | Introduction of chemical contaminants into a water body. |
| tide | Cyclical rise and fall of the surface of the oceans |
| gust | A rapid fluctuation of wind speed with variations of 10 knots or more between peaks and lulls. |
| ecological health | The state of an ecosystem in which processes and functions are adequate to maintain diversity of biotic communities commensurate with those initially found there. |
| crust | solid, outer layer of the earth |
| button-up fry | A salmonid fry that has not completely absorbed its yolk sac and has emerged from its spawning gravel. |
| vapor dispersion | The movement of vapor clouds or plumes in the air due to wind, gravity, spreading, and mixing. |
| unsaturated zone | the area above the water table where soil pores are not fully saturated, although some water may be present. |
| ambient medium | material surrounding or contacting an organism (e.g., outdoor air, indoor air, water, or soil through which chemicals or pollutants can reach the organism. |
| plankton | Minute plant (phytoplankton) and animal organisms (zooplankton) that are found in aquatic ecosystems. |
| blowdown | Trees felled by high winds. |
| threshold runoff | The runoff in inches from a rain of specified duration that causes a small stream to slightly exceed bankfull |
| total soil water potential | The work per unit quantity of pure water that has to be done to change its energy status to that of soil water at the point under consideration |
| jokulhlaup | An Icelandic term meaning glacier dammed lake outburst flood. |
| convectional precipitation | Is the formation of precipitation due to surface heating of the air at the ground surface |
| prognostic discussion | This Hydrometeorological Prediction Center (HPC) discussion may include analysis of numerical and statistical models, meteorological circulation patterns and trends, and confidence factors. Reference is usually made to the manually produced 6- to 10-day Northern Hemisphere prognoses for mean 500 millibar heights and mean 500 millibar height anomalies. Discussions may also refer to the method of operational ensemble predictions. |
| reconnaissance code | An aircraft weather reconnaissance code that has come to refer primarily to in-flight tropical weather observations, but actually signifies any detailed weather observation or investigation from an aircraft in flight. |
| mathematical model | A representation of physical laws or processes expressed in terms of mathematical symbols and expressions (i.e., equations) |
| sensible heat | Heat that can be measured by a thermometer and thus sensed by humans. |
| concentration process | The process of increasing the number of particles per unit volume of a solution, usually by evaporating the liquid. |
| ecosystem management | A strategy or plan to manage ecosystems to provide for all associated organisms, as opposed to a strategy or plan for managing individual species. |
| glaciology | The study of the physical and chemical propeties of snow and ice. |
| irrigated land | Land receiving water by controlled artificial means for agricultural purposes from surface or subsurface sources. |
| dredging | The removal of material from the bottom of water bodies using a scooping machine |
| glacial surge | The rapid forward movement of a glacier. |
| contour flooding | Irrigation method resulting in flooding fields from Contour Ditches. |
| terrestrial radiation | Long wave radiation that is emitted by the earth back into the atmosphere |
| stream terrace | A surface representing remnants of a stream's channel or flood plain when the stream was flowing at a higher level |
| habitat | The native environment where a plant or animal naturally grows or lives. |
| ice wedge | when temperature fall below -15蚓, ice in soil contracts |
| moisture equivalent | The ratio of (1) the weight of water which the soil, after saturation, will retain against a centrifugal force 1,000 times the force of gravity, to (2) the weight of the soil when dry |
| hummocked ice | Ice piled haphazardly one piece over another to form an uneven surface. |
| seasonal wetlands | Wetland areas flooded or taking on the characteristics of a wetland only during specific periods of the year or seasons. |
| active storage capacity | The total usable storage capacity available for seasonal or cyclic water storage |
| psychrometer | An instrument used to measure water vapor content of the atmosphere |
| thermocline | fairly thin zone in a lake that separates an upper warmer zone (epilimnion) from a lower colder zone (hypolimnion). |
| albedo | The portion of incoming radiation which is reflected by a surface. |
| foliation | Process where once randomly distributed platy minerals in a rock become reoriented, because of metamorphism, in a parallel manner. |
| federal disaster area | Before a community is eligible for disaster assistance from the federal government, it must be declared a Federal Disaster Area |
| interim solution | Actions to be taken in a 2- to 4-year period. |
| water rights | "Priority claims to water |
| background | Value for a parameter that represents the conditions in a system prior to a given influence in space or time. |
| eutrophication | The process of enrichment of water bodies by nutrients. |
| effluent | Wastewater--treated or untreated--that flows out of a treatment plant, sewer, or industrial outfall |
| hygrograph | An instrument that records the hygrometer's measure of water vapor. |
| raw materials | unprocessed inputs to an industrial process. |
| thermosphere | the upper layer of the atmosphere above 80km from the earth surface |
| look angle | A given radar's "perspective" on a storm; i.e., the angle at which its antenna beam hits it |
| river summary | A NWS summary of river and/or crest stages for selected forecast points along the river. |
| outlet discharge structure | Protects the downstream end of the outlet pipe from erosion and is often designed to slow down the velocity of released water to prevent erosion of the stream channel. |
| land breeze | a wind blowing from the land towards the sea |
| storage | (1) Water artificially impounded in surface or underground reservoirs for future use |
| foundation | The natural material on which the dam structure is placed. |
| gross primary productivity | the addition, through photosynthesis, of organic matter in plants measured in dry grammes per square metre per year. |
| developed | an out of date term for economically more developed countries |
| pressure head | Energy contained by fluid because of its pressure, usually expressed in feet of fluid (foot pounds per pound). |
| hydrologic unit | A distinct watershed or river basin defined by an 8-digit code. |
| navigational telex | One part of Global Maritime Distress and Safety System (GMDSS) for automatically disseminating safety information, including weather warnings and forecasts, in text form via medium frequency radio to mariners within 200 nautical miles of shore. |
| granular activated carbon | pure carbon heated to promote "active" sites which can adsorb pollutants |
| issue | A matter of controversy or dispute over resource management activities that is well defined or topically discrete. |
| saddle | A depression or sag on the ice sheet between domes. |
| popcorn convection | Slang for showers and thunderstorms that form on a scattered basis with little or no apparent organization, usually during the afternoon in response to diurnal heating |
| achluophobia | The fear of darkness. |
| product suite | Support for transoceanic, fishing, and recreational marine users, coastal communities, marine navigation, and other marine interests. |
| biofuel | fuel derived from biomass |
| floodgate | (1) A gate used to control the flow of a body of water |
| conduit | (1) A natural or artificial channel through which fluids may be conveyed |
| geostationary orbit | an orbit path that keeps a satellite over the exact same point on the earth surface at all times. |
| ion | An atom, molecule or compound that carries either a positive (cation) or negative (anion) electrical charge. |
| phase change | Reorganization of a substance at the atomic or molecular level resulting in a change of the physical state of matter |
| reclaimed wastewater | treated wastewater that can be used for beneficial purposes, such as irrigating certain plants. |
| sial | crustal material made mainly of silica and aluminium. |
| genetic risk | The probability of an action or inaction having a negative impact of the genetic character of a population or species. |
| bog | waterlogged, spongy ground forming in cooler, high-rainfall areas |
| sunset | Moment of time when the Sun's edge completely disappears below the Earth's horizon. |
| radial drainage | An arrangement of stream courses in which the streams radiate outward in all directions from a central zone or inward from all directions to a central area. |
| non-point sources | Diffuse water pollution sources without a specific point of origin |
| venturi | A short tube with a constricted throat used to determine fluid pressures and velocities by measurement of differential pressures generated at the throat as a fluid traverses the tube. |
| electrical conductivity | A measure of the salt content of water. |
| igneous | a rock formed through the cooling of magma or lava |
| instream flows | See flows. |
| barchan dune | Crescent shaped sand dune that has its long axis transverse to the wind and its crescent tips pointed downwind. |
| hydromechanics | The branch of physics having to do with the laws governing the motion and equilibrium of fluids. |
| accessory cloud | A cloud which is dependent on a larger cloud system for development and continuance |
| phreatic surface | The free surface of ground water at atmospheric pressure. |
| ephemeral streams | Streams which flow only in direct response to precipitation and whose channel is at all times above the water table. |
| obsidian | Glassy dark colored volcanic rock |
| newton | The unit of force giving a mass of about one kilogram (2.205 pounds) an acceleration of about one meter (1 yard) per second per second. |
| kilowatt-hour | A basic unit of electrical energy that equals one kilowatt of power applied for one hour. |
| holocene | the current geological period, currently about 10,000 years long. |
| well | an artificial excavation put down by any method for the purposes of withdrawing water from the underground aquifers |
| meltwater | The water from melted snow or ice. |
| pulse storm | A thunderstorm within which a brief period (pulse) of strong updraft occurs, during and immediately after which the storm produces a short episode of severe weather |
| tissue | A group of similar cells that are organized into a structure with a specific purpose. |
| atm | One unit of atmospheric pressure is equal to the total weight of the air on the earth's surface at sea level (14.70 pounds per square inch). |
| northing | Second measurement of a grid reference used to specific the location of a point on a rectangular coordinate system |
| uplift | (Hydraulics) The upward pressure of water on the base of a structure or the upward pressure in the pores of a material, i.e., Interstitial Pressure. |
| multi-cropping | The practice of producing two or more crops consecutively on the same parcel of land during a 12-month period |
| horizontal integration | the merging of firms at the same stage of production. |
| soil conservation service | The former name of a branch of the United States Department of Agriculture, renamed the Natural Resources Conservation Service (NRCS) |
| manning n | after Robert Manning |
| microclimate | the local climate conditions that show variations to the general climate conditions of the wider environment. |
| mean monthly temperature | The average of the mean monthly maximum and minimum temperatures. |
| backpressure | a pressure that can cause water to backflow into the water supply when a user's wastewater system is at a higher pressure than the public system. |
| true north | Direction of the North Pole from an observer on the Earth. |
| containerization | the development of standardized metal containers for cargo which can be transshipped between train, lorry and ship carriers |
| zone of saturation | The layer beneath the surface of the land in which all openings are filled with water. |
| riparian areas | Land areas directly influenced by a body of water |
| circle of illumination | A line that bisects areas on the Earth receiving sunlight and those areas in darkness |
| average annual recharge | amount of water entering the aquifer on an average annual basis |
| remediation | methods used to remove or contain a toxic spill or hazardous materials from a Superfund site; a generic term used to describe cleanup activities. |
| point source pollution | Pollutants discharged from an identifiable, stationary location or fixed facility, such as a pipe. |
| backwash | used in both physical and human geography |
| continent | one of the seven largest pieces of land on earth. |
| long wave | A large wave in the polar jet stream and the westerlies that extends from the middle to the upper troposphere |
| gross reservoir capacity | The total amount of storage capacity available in a reservoir for all purposes, from the streambed to the normal maximum operating level |
| finished water | Treated potable water that is considered safe and suitable for delivery to consumers. |
| surface supply | Water supply from streams, lakes, and reservoirs. |
| capillary fringe | The soil area just above the water table where water can rise up slightly through the cohesive force of capillary action |
| albedo | The percent reflectivity of a surface |
| eutrophic lake | Shallow, murky bodies of water that have excessive concentrations of plant nutrients causing excessive algal production. |
| sun | Luminous star around which the Earth and other planets revolve around |
| elements | The distinctive building blocks of matter that make up every material substance. |
| crest width | The thickness or width of a dam at the level of the crest (top) of the dam |
| monitoring | specific testing that all public water systems must perform on a frequent and regular basis for detection and safety purposes |
| base | accept an unshared pair of electrons from a base or react with a base to form a salt, a substance that has more free hydrogen ions, H+, than hydroxyl ions, OH-, (see alkaline). |
| avulsion | A change in channel course that occurs when a stream suddenly breaks through its banks. |
| chemigation | Application of pesticides or fertilizers to farmlands through irrigation systems. |
| tornado | a localized, anti-clockwise spiral of wind with extremely violent wind speed and uplift. |
| point source | The source of pollution discharged from any identifiable point, including ditches, channels, sewers, tunnels and containers of various types. |
| "right of free capture" | The idea or concept that the water under a person's land belongs to that person and they are free to capture and use as much as they want |
| channelization | The modification of a natural river channel; may include deepening, widening, or straightening. |
| diversion | The taking of water from a stream or other body of water into a canal, pipe, or other conduit. |
| bag of waters | The double-walled fluid-filled sac that encloses and protects the fetus in the womb and that breaks releasing its fluid during the birth process |
| floc | A cluster of frazil particles |
| hail | Hail is a solid form of precipitation that has a diameter greater than 5 millimeters |
| flash flood | A flood which follows within a few hours (usually less than 6 hours) of heavy or excessive rainfall, dam or levee failure, or the sudden release of water impounded by an ice jam |
| rain forest | A forest which grows in a region of heavy annual precipitation |
| rock flour | Very finely ground rock fragments that form between the base of a glacier and the underlying bedrock surface. |
| absorption | The process in which incident radiant energy is retained by a substance |
| inflow | entry of rainwater into a sewer system from sources other than infiltration, such as basement drains, manholes, storm drains, and street washing. |
| check irrigation | A method of irrigation in which an area is practically or entirely surrounded by earth ridges. |
| radiation inversion | It is a thermally produced, surface-based inversion formed by rapid radiational cooling of the Earth's surface at night |
| seep | a spot where water contained in the ground oozes slowly to the surface and often forms a pool; a small spring. |
| streambed | The channel through which a natural stream of water runs or used to run, as a dry streambed. |
| initial dilution | the process that results in the rapid and irreversible turbulent mixing of effluent and receiving water around the point of discharge. |
| hydrologic service area | A geographical area assigned to Weather Service Forecast Office's/Weather Forecast Office's that embraces one or more rivers. |
| sand | Small substrate particles, generally from 0.6 to 2.0 mm in diameter |
| enteric viruses | a category of viruses related to human excreta found in waterways. |
| sclerophyllous vegetation | Term used to describe drought resistant vegetation common in Mediterranean climates |
| mixed precipitation | Any of the following combinations of freezing and frozen precipitation: snow and sleet, snow and freezing rain, or sleet alone |
| keystone species | Species that interacts with a large number of other species in a community |
| manhole | A subsurface structure in which two or more pipes meet, with person access from the ground surface. |
| organism | Any form of life. |
| water quality standard | The combination of a designated use and the maximum concentration of a pollutant which will protect that use for any given body of water |
| organic | (1) Referring to or derived from living organisms |
| storm | Any disturbed state of the atmosphere, especially affecting the Earth's surface, and strongly implying destructive and otherwise unpleasant weather. Storms range in scale from tornadoes and thunderstorms through tropical cyclones to widespread extratropical cyclones. |
| streambank erosion | The removal of soil from streambanks by flowing water. |
| water recycling | the treatment of urban wastewater to a level rendering it suitable for a specific, direct, beneficial use. |
| environmental analysis | An analysis of alternative actions and their predictable short-term and long-term environmental effects, incorporating physical, biological, economic, and social considerations. |
| partial-duration flood series | A list of all flood peaks that exceed a chosen base stage or discharge, regardless of the number of peaks occurring in a year |
| estuarine zone | area near the coastline that consists of estuaries and coastal saltwater wetlands. |
| water quality | term used to describe the chemical, physical and biological characteristics of water, usually in respect to its suitability for a particular purpose. Drinking water must meet the highest water quality standards. |
| abdominal pelvics | Pelvic fins located on the abdomen far behind the pectoral fins; pelvic bones do not attach to pectoral girdle. |
| daily flood peak | The maximum mean daily discharge occurring in a stream during a given flood event. |
| risk assessment | A methodology used to examine all possible risks involved with a particular product or organism |
| hardpan | a shallow layer of earth material which has become relatively hard and impermeable, usually through the deposition of minerals |
| latent heat transfer | The removal or addition of heat when a substance changes state |
| ice gorge | The gorge or opening left in a jam after it has broken. |
| roches moutonnée ** | An Alpine term for a rock knob with one smooth side and one steep side, produced by glacial plucking |
| stage-discharge relation | is the relation between gage height (stage) and the volume of water per unit of time (discharge) flowing in a channel. |
| watch cancellation | This product will be issued to let the public know when either a Tornado Watch or Severe Thunderstorm Watch has been canceled early. It is issued by the Storm Prediction Center (SPC) in Norman, Oklahoma. In the text of the statement it will specify the severe weather watch number and the area which the watch covered. |
| shifting cultivation | a farming system in which a small tribal group cuts and burns the natural vegetation before cultivating the land |
| fjords | Steep-sided inlets of the sea which occur in flooded glacial troughs. |
| 90th percentile | (Water Quality) Term used in conjunction with water sampling standards as required under the Safe Drinking Water Act (SDWA) and amendments thereto |
| drainage basin | Land surface region drained by a length of stream channel. |
| plug flow | type of flow that occurs in tanks, basins, or reactors when a slug of water moves through without ever dispersing or mixing with the rest of the water flowing through. |
| sand bar | a long strip of deposited sand lying offshore, usually only exposed at low tide, if at all. |
| contour furrows | Furrows plowed approximately on the contour on pasture and rangeland to prevent runoff and increase infiltration; also, furrows laid out approximately on the contour for irrigation purposes. |
| climatic cycle | the periodic changes climate displays, such as a series of dry years following a series of years with heavy rainfall. |
| municipal water | Municipal water may come from either ground water or surface water sources |
| zone of aeration | The locus of points just above the water table where soil pores may either contain air or water |
| saturate | To treat or charge something to the point where no more can be absorbed, dissolved, or retained |
| rill erosion | Removal of soil particles from a bank slope by surface runoff moving through relatively small channels |
| gleization | A soil formation process that occurs in poorly drained environments |
| constructive plate margin | in plate tectonics, a plate boundary where the relative movement of the crustal plates is apart from each other allowing magma to rise from the mantle and solidify to construct new crust. |
| nitric oxide | A gas produced by bacterial action in the soil and by high temperature combustion |
| niche | Adaptive role that a species has in a habitat |
| piedmont | where a mountain range abruptly falls into a lowland area. |
| headwaters | Streams at the source of a river. |
| environmental audit | (1) An internal investigation of company compliance with environmental regulations |
| dealiasing | Process of correcting for aliases in the velocity measurement |
| tropic of cancer | The most northern point on the earth where the sun is directly overhead, located at approximately 23.5 degrees North latitude. |
| reclamation withdrawal | A withdrawal of public lands in connection with a reclamation project. |
| narrow | (1) A body of water with little width that connects two larger bodies of water |
| stratosphere | layer of the atmosphere from approximately 12 to 50km |
| proxy data | Data that measures the cause and effect relationship between two variables indirectly. |
| comma cloud | A feature seen on satellite images with a distinctive comma-shape |
| cold air advection | Transport of cold air into a region by horizontal winds. |
| coliform bacteria | non-pathogenic microorganisms used in testing water to indicate the presence of pathogenic bacteria. |
| natal stream | Stream of birth. |
| abutment seepage | Reservoir water that moves through seams or pores in the natural abutment material and exits as seepage. |
| backwater flooding | Upstream flooding caused by downstream conditions such as channel restriction and/or high flow in a downstream confluence stream. |
| surface tension | Tension of a liquid's surface |
| irrigated area | The area upon which water is artificially applied |
| channel | A channel is a body of water that connects two larger bodies of water (like the English Channel) |
| cultivation | the preparation and use of land for crop growing. |
| chattermarks | Striations or marks left on the postglacial exposed bedrock caused by the striking of englacial debris against the bedrock surface during glacial movement. |
| aeration | Any active or passive process by which intimate contact between air and liquid is assured, generally by spraying liquid in the air, bubbling air through water, or mechanical agitation of the liquid to promote surface absorption of air. |
| control dam | A dam or structure with gates to control the discharge from the upstream reservoir or lake. |
| cfc | see chloroflurocarbon |
| brine | highly salty and heavily mineralized water containing heavy metal and organic contaminants. |
| scour | the erosive action of running water in streams, which excavates and carries away material from the bed and banks |
| watershed | A watershed, also known as drainage area or catchment, is the specific land area that drains water into a lake, river or other body of water. |
| consent decree | A negotiated agreement by the City to implement a court-ordered directive to evaluate and implement short and long-term plans for eliminating water quality violations |
| fish passage managers | Located at the Fish Passage Center, the two fish passage managers are responsible for the specific planning, implementation and monitoring activities of the Center aimed at helping fish on their migratory routes in the Columbia River Basin |
| parametric data | Data such as rating curves, unit hydrographs, and rainfall/runoff curves which define hydrologic variables in models. |
| hanging valley | A shallow glacial trough that leads into the side of a larger, main glacial trough. |
| virus | Is a fragment of DNA or RNA that depends on the infection of host cells for their reproduction |
| swash | A thin sheet of water that moves up the beach face after a wave of water breaks on the shore. |
| pollarding | in forest/woodland management, the technique of cutting tree growth back to the main trunk and thereby encouraging new growth from the top of the main trunk. |
| hardwood bottomland | hardwood forested lowlands adjacent to some rivers, especially valuable for wildlife breeding, nesting, and habitat. |
| barometric pressure | The actual pressure value indicated by a pressure sensor. |
| acidic | the condition of water or soil that contains a sufficient amount of acid substances to lower the pH below 7.0. |
| state forecast product | This National Weather Service product is intended to give a good general picture of what weather may be expected in the state during the next 5 days. The first 2 days of the forecast is much more specific than the last 3 days. In comparison with the Zone Forecast Product, this product will be much more general. |
| torrent | (1) A turbulent, swift-flowing stream |
| density | The ratio of the mass of a substance to the volume it occupies |
| macroburst | One of 2 categories of downbursts (the other category is called a microburst) |
| fair | It is usually used at night to describe less than 3/8 opaque clouds, no precipitation, no extremes of visibility, temperature or winds. It describes generally pleasant weather conditions. |
| hydrograph | A curve showing stream discharge over time. |
| undulating | To move in waves |
| updraft | Current(s) of air with marked vertical upward motion. If the air is sufficiently moist, then the moisture condenses to become a cumulus cloud or an individual tower of |
| location quotient | a statistical measure of concentration |
| fungus | a non-photosynthetic organism which feeds on organic matter e.g |
| sloughing | Movement of a mass of soil down a bank into the channel (also called slumping) |
| divide | The high ground that forms the boundary of a watershed. A divide is also called a ridge. |
| specific yield | The ratio of the water which will drain freely from the material to the total volume of the aquifer formation |
| coastal wetland | Wetland habitat found along a coastline and is covered with ocean salt water for all or part of the year |
| residue | the dry solids remaining after the evaporation of a sample of water or sludge. |
| symmetric double eye | A concentrated ring of convection that develops outside the eye wall in symmetric, mature hurricanes |
| dalton's law | States that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the gases |
| perspiration | The fluid, consisting of water with small amounts of urea and salts, that is excreted through the pores of the skin by the sweat glands; sweat. |
| hydrolysis | The decomposition of organic compounds by interaction with water. |
| wind wave | An ocean or lake wave resulting from the action of wind on the water's surface |
| futile call | A situation in which a junior (more recent) priority is allowed to continue to divert in spite of a downstream senior call when curtailing the junior would not produce any additional water for the senior. |
| recharge rate | The quantity of water per unit of time that replenishes or refills an aquifer. |
| flow-sensitive habitats | habitats that show hydraulic response to relatively small changes in streamflow |
| backwater effect | The effect which a dam or other obstruction has in raising the surface of the water upstream from it. |
| absorb | to take in. |
| insect | Relatively small and simple animals that have a rigid external skeleton, three body sections, three pairs of legs, and antennae |
| michigan travel advisory | This is a product issued by the Michigan State Police. It summarizes road conditions as related to weather factors. |
| precipitable water | Amount of water potentially available in the atmosphere for precipitation |
| cenozoic | Geologic era that occurred from 65 million years ago to today. |
| silt | Mineral particle with a size between 0.004 and 0.06 millimeters in diameter |
| food chain | Organisms that are interrelated in their feeding habits, each feeding upon organisms that are lower in the chain and in turn being fed on by organisms higher in the chain. |
| supramaxilla | A small bone attached to the posterior end of the maxilla, dorsally. |
| major flooding | Flood conditions resulting in extensive inundation and property damage |
| hydro | The prefix denoting water or hydrogen. |
| watt | A unit of power or the rate of energy use or conversion when one joule of energy (0.0238 calories) is used or converted per second. |
| influent water | Water that flows into sink holes, open cavities, and porous materials and disappears into the ground. |
| ice storm | A severe weather condition characterized by falling freezing precipitation |
| condensation | The change of state from a gas to a liquid. |
| sleet | precipitation which is a mixture of rain and ice. |
| chlorophyll | Green pigment found in plants and some bacteria used to capture the energy in light through photosynthesis. |
| air stagnation advisory | This National Weather Service product is issued when major buildups of air pollution, smoke, dust, or industrial gases are expected near the ground for a period of time. This usually results from a stagnant high pressure system with weak winds being unable to bring in fresh air. |
| headwall | The steep rock at the top edge of the cirque. |
| free moisture | Liquid that will drain freely from solid waste by the action of gravity only. |
| nomad | a wanderer, a person or animal which moves from place to place non-economic benefit - a gain resulting from a trade-off that cannot be measured in dollars nonpoint source pollution - pollution which comes from diffuse sources such as urban and agricultural runoff NPDES (National Pollutant Discharge Elimination System) permits - permits issued to point sources for the purpose of limiting pollution in discharges |
| rainwash | The erosion of soil by overland flow |
| molecules | Combinations of two or more atoms of the same or different elements held together by chemical bonds. |
| transport wind | The average wind over a specified period of time within a mixed layer near the surface of the earth. |
| supercooling | The reduction of the temperature of any liquid below the melting point of that substance's solid phase |
| irrigated area | The gross area upon which water is artificially applied. |
| reflectivity | The measure of the efficiency of a radar target in intercepting and returning Electro Magnetic Energy |
| inches of runoff | The volume of water from runoff of a given depth over the entire drainage. |
| land reconstruction | (Mining) (1) Restoring land and water areas adversely affected by past mining practices and increasing the productivity of the areas for a beneficial use |
| insolation | Incoming solar radiation |
| sandstone | A type of sedimentary rock that contains a large quantity of weathered quartz grains. |
| vad | It is a WSR 88-D product which shows the radar derived wind speeds at various heights |
| anabranch | A diverging branch of a river which re-enters the main stream. |
| beam filling | The measure of variation of hydrometeor density throughout the radar sampling volume |
| jeopardy | A finding made through consultation under the Endangered Species Act that the action of a federal agency is likely to jeopardize the continued existence of a threatened or endangered species. |
| embeddedness | a measure of the degree that gravel and larger substrates are surrounded by fine particles (silt and sand). |
| titration | An analytical technique to determine how much of a substance is present in a water sample by adding another substance and measuring how much of that substance must be added to produce a reaction. |
| flood watch | This watch is issued by a local National Weather Service Office (NWFO) to indicate that there ia a potential of flooding in or close to the watch area. Those in the affected area are urged to be ready to take action if a flood warning is issued or flooding is observed. In flooding, the onset of flooding take place much slower (usually greater than 6 hours) than a flash flood. This type of flooding usually occurs in Michigan during the convective season with "train echoes" or slow moving thunderstorms, and can also occur with synoptic scale systems that last a relatively long period of time and encompass a large area. They are usually issued up to 12 hours prior to the possible flood event. These watches can vary in size depending on the size of the meteorological event. |
| flood frequency curve | (1) A graph showing the number of times per year on the average, plotted as abscissa, that floods of magnitude, indicated by the ordinate, are equaled or exceeded |
| surface based convection | Convection occurring within a surface-based layer, i.e., a layer in which the lowest portion is based at or very near the earth's surface |
| lime | Common water treatment chemical |
| river gage | A device for measuring the river stage. |
| grilse | Salmon less than 22 inches (56cm) Fork Length (FL). |
| immigration | inward movement of people to a country. |
| resident population | The number of persons who live within a state or other political subdivision (county, city, etc.) who consider it their permanent place of residence |
| flood tide | Time during the tidal period when the tide is rising |
| rationalization | the reorganization of a company to increase efficiency, usually by cutting costs especially labour costs. |
| cusps | small hollows on beach fronts, a few metres across, which look like mini bays within the beach itself. |
| flood of record | The highest observed river stage or discharge at a given location during the period of record keeping |
| farm diversification scheme | in UK, grants available to farmers to develop supplementary income from alternative, non-farming activities on their land |
| sea mile | A unit of length distinguished from a nautical mile |
| geopressured reservoir | a geothermal reservoir consisting of porous sands containing water or brine at high temperature or pressure. |
| core punch | Slang for a penetration by a vehicle into the heavy precipitation core of a thunderstorm. |
| rural depopulation | the net movement of people to urban areas. |
| threshold pollutant | substance that is harmful to a particular organism only above a certain concentration, or threshold level. |
| spray irrigation | Any irrigation by means of nozzles along a pipe or from perforated overhead pipes. |
| normal lapse rate | Average rate of air temperature change with altitude in the troposphere |
| mean low water | The average height of the low water over 19 years. |
| subtropical cyclone | A low pressure system that develops over subtropical waters that initially has a non-tropical circulation, but in which some elements of tropical cyclone cloud structure are present |
| dorsal | Pertaining to the back, or situated near to or on the back. |
| sea | ocean or lake by a relatively narrow opening or channel. |
| polarization | In the context of particles in an electric field, it is the displacement of charged centers within a particle in response to the electrical forces acting thereon. |
| drainage reuse | reuse of agricultural drainage on salt-tolerant crops. |
| sewage treatment plant | a facility designed to receive the wastewater from domestic sources and to remove materials that damage water quality and threaten public health and safety when discharged into receiving streams or bodies of water |
| fecundity | The total number of eggs produced by a female fish. |
| condensation | The change in state of matter from vapor to liquid that occurs with cooling |
| tropic of capricorn | The most southern point on the earth where the sun is directly overhead, located at approximately 23.5 degrees South latitude. |
| calibration | to check, adjust, or determine by comparison that a computer model will produce results that meet or exceed some defined criteria within a specified degree of confidence. |
| cellular | Composed of cells |
| harvest rate | The proportion of a returning run or total population of salmonids that is taken by fisheries, usually expressed as a catch to escapement ratio. |
| solubility | The amount of mass of a compound that will dissolve in a unit volume of water. |
| suncup | A melted bowl-shaped depression in ice due to insolation. |
| injection | Generally refers to a system of artificially introducing surface water into the ground water system as a means of storage or recharge |
| silt | a particle of rock/mineral with a diameter between 0.01 and 0.1mm. |
| rainfall rate | The amount of precipitation occurring in a unit of time; generally expressed in inches per hour. |
| high water mark | A mark indicating the highest level reached by a body of water. |
| bajada | Consecutive series of alluvial fans forming along the edge of a linear mountain range |
| desalination | the process of salt removal from sea or brackish water. |
| hydropneumatic | a water delivery system, usually small, that maintains water pressure in the distribution system by means of pressure in a compressed air tank. |
| yield | the quantity of water expressed either as a continuous rate of flow (cubic feet per second, etc.) or as a volume per unit of time |
| sssi | see Site of Special Scientific Interest. |
| stream order | The relative position, or rank, of a stream channel segment in a drainage network. |
| lentic system | A nonflowing or standing body of fresh water, such as a lake or pond |
| source water | in its natural state, before any treatment for drinking. |
| surface water | water that flows in streams and rivers and in natural lakes, in wetlands, and in reservoirs constructed by humans. |
| slip-face | the lee side of a sand dune so called because material often slides or rolls down it. |
| dryline bulge | A bulge in the dry line, representing the area where dry air is advancing most strongly at lower levels (i.e., a surface dry punch). Severe weather potential is increased near and ahead of a feature. |
| gavelkind | see fragmentation. |
| turbidity | A measure of non-transparency of water due to the presence of suspended matter. |
| consumable water supply | That amount of river water available for consumption at a given point on the river after existing prior water rights have been met. |
| mississippian | Geologic period that occurred roughly 320 to 360 million years ago |
| long profile | the side view of a river course from source to mouth which shows how the gradient of the river changes as it flows. |
| snow stick | A portable rod used to measure snow depth. |
| emergent plant | A plant that grows in shallow water with the root system submerged under the water and the upper vegetation rising above the water surface. |
| tailwater recovery | The process of collecting irrigation water runoff for reuse in the system. |
| cyclogenesis | The process that creates a new low pressure system or cyclone, or intensifies a pre-existing one |
| seas | This term is used in National Weather Service Marine Forecasts to describe the combination or interaction of wind waves and swells (combined seas) in which the spearate components are not distinguished. This includes the case when swells are negligible or are not considered in describing sea state. |
| dam failure | Catastrophic event characterized by the sudden, rapid, and uncontrolled release of impounded water. |
| stream order | classification of streams within a drainage basin so that it can be compared with another |
| backswamp | Marshy low lying area in a stream's floodplain |
| friction head | The decrease in total head caused by friction. |
| subsurface flow | Water which infiltrates the soil surface and moves laterally through the upper soil layers until it enters a channel. |
| maximum probable flood | The largest flood for which there is any reasonable expectancy. |
| concentration | the measure is useful because it corrects for temperature, salinity, and atmospheric pressure which influence the saturation level, a high deficit can be an indicator of a water quality problem. |
| correlative rights | Certain rights of land owners over a common ground water basin are coequal, or correlative, so that any one owner cannot take more than his share even if the rights of others are impaired |
| spillway | The channel or passageway around or over a dam through which excess water is diverted |
| hydrologic equation | The water inventory equation (Inflow = Outflow + Change in Storage) which expresses the basic principle that during a given time interval the total inflow to an area must equal the total outflow plus the net change in storage. |
| wet bulb thermometer | A thermometer used to measure the lowest temperature in the ambient atmosphere in its natural state by evaporating water from a wet muslin-covered bulb of a thermometer |
| deciduous | Trees and plants that shed their leaves at the end of the growing season. |
| radiation | The process by which energy is propagated through any medium by virtue of the wave motion of that medium |
| esturine zone | The area near the coastline that consists of estuaries and coastal saltwater wetlands. |
| runnel | (1) A rivulet; a brook |
| bistatic radar | A radar which uses separate antennas for transmission and reception; usually the transmitter and receiver are at different locations |
| deposition | the laying down of material by erosion or transport by water or air. |
| tertiary treatment | In sewage, the additional treatment of effluent beyond that of secondary treatment to obtain a very high quality of effluent for reuse. |
| specific yield | The ratio of the volume of water that a rock will yield by gravity, after being saturated, to its own volume, expressed as a percentage. |
| dynamic metamorphism | Form of metamorphism that causes only the structural alteration of rock through pressure |
| profile | A graph showing variation of elevation with distance along a traverse. |
| volcanic neck | See volcanic pipe. |
| commercial thinning | The removal of generally merchantable trees from an even-ages stand, usually to encourage growth of the remaining trees. |
| marine-based ice sheet | A large mass of ice with its base grounded below sea level. |
| delta | An alluvial deposit, often in the shape of the Greek letter "delta", which is formed where a stream drops its debris load on entering a body of quieter water. |
| adaptation | Changes in an organism's structure or habits that allow it to adjust to its surroundings. |
| mean annual discharge | Daily mean discharge averaged over a period of years |
| prevailing visibility | The visibility that is considered representative of conditions at the station; the greatest distance that can be seen throughout at least half the horizon circle, not necessarily continuous. |
| preservative | a chemical added to a water sample to keep it stable and prevent compounds in it from changing to other forms or to prevent microorganism densities from changing prior to analysis. |
| downward spiral | decline occurring in a vicious circle or negative cumulative causation. |
| conjunctive use | The operation of a groundwater basin in combination with a surface water storage and conveyance system |
| net consumptive use | The Consumptive Use decreased by the estimated contribution by rainfall toward the production of irrigated crops |
| groundwater | the store of water that has moved by percolation into the lower layers of the soil or the bedrock. |
| typhoon | A tropical cyclone of hurricane strength in the Eastern Hemisphere. |
| index model | A hydrologic computer model based on empirical, statistical relationships. |
| elr | see environmental lapse rate. |
| wave crest | The curved tops or ridges of an oscillating wave. |
| turbidity | a cloudy condition in water due to suspended silt or organic matter. |
| growth overfishing | The rate of fishing, as indicated by an equilibrium yield-per-recruit curve, greater than which the losses in weight from total mortality exceed the gain in weight due to growth |
| tailings pond | An excavated or diked area that is intended to contain liquid and solid wastes from mining and milling operations. |
| isthmus | An isthmus is a narrow strip of land connecting two larger landmasses |
| member agency | one of 27 member public water providers associated with the Metropolitan Water District of Southern California, from which it purchases water and on whose board it is represented microorganism - an organism of microscopic size, such as bacterium migratory - moving from one area to another on a seasonal basis mitigation - a way in which an agency may offset negative environmental impacts of a project or make the impacts less serious mulch - material spread on the ground to reduce soil erosion and evaporation of water; include hay, plastic sheeting and wood chips municipal water district - a public water provider, owned and operated by more than one city government, which supplies water to its member cities |
| supercooled liquid water | In the atmosphere, liquid water can survive at temperatures colder than 0 degrees Celsius; many vigorous storms contain large amounts of supercooled liquid water at cold temperatures |
| nipdwr | National Interim Primary Drinking Water Regulations. |
| cerunophobia | The fear of thunder. See Astraphobia, Astrapophobia, Brontophobia, Keraunophobia, and Tonitrophobia |
| hydrogeologic unit | Any soil or rock unit or zone that because of its hydraulic properties has a distinct influence on the storage or movement of ground water. |
| demography | The study of characteristics of human populations, especially size, density, growth, distribution, migration and vital statistics and the effect of these on social and economic conditions. |
| shefpars | A software decoder for SHEF Data. |
| lateral | Building or house service connection to sewer or sewer-to-sewer connection. |
| fill | (Geology) Any sediment deposited by any agent such as water so as to fill or partly fill a channel, valley, sink, or other depression. |
| receiving waters | A river, ocean, stream, or other watercourse into which wastewater or treated effluent is discharged. |
| brackish | Environment that is influenced by seawater with a salinity less than 35 parts per thousand (usually caused by the presence of an inflow of fresh water). |
| anion | A negatively charged ion that results from the dissociation of salts, acids or alkali's in solution. |
| hydraulic grade line | A line whose plotted ordinate position represents the sum of pressure head plus elevation head for the various positions along a given fluid flow path, such as along a pipeline or a ground water streamline |
| laminar flow | Movement of water within a stream that occurs as uninterrupted parallel flows |
| masonry dam | A dam constructed mainly of stone, brick, or concrete blocks that may or may not be joined with mortar |
| nitrogen | a plant nutrient that can cause an overabundance of bacteria and algae when high amounts are present, leading to a depletion of oxygen and fish kills |
| vortex | Any circular or rotary flow in the atmosphere that possesses vorticity. |
| moisture stress | A condition of physiological stress in a plant caused by lack of water. |
| zone of engineering control | The area occupied by a hazardous waste treatment, storage, or disposal facility which the owner or operator can readily decontaminate if a leak is detected, thus preventing hazardous waste or its constituents from entering groundwater of surface water. |
| communication | the movement and/or exchange of information, goods and people over time and space. |
| adsorption | physical or chemical bonding of solid particles with liquids or gases. |
| wall cloud | An abrupt lowering of a cloud from its parent cloud base, a cumulonimbus or supercell, with no visible precipitation underneath |
| ldc | See less developed country. |
| plantation | a large-scale form of agriculture in which a tree or bush species is planted from which a fruit, leaf or sap is harvested |
| spit | an embankment of sand which juts out from the land, often across a river mouth |
| stratiform snow | Same as for stratiform rain except precipitation is in the form of snow. |
| stability | when the DALR and SALR are both higher than the ELR then an air mass will be cooler than its surroundings and will sink back to its original position once the upward forces on it have ceased e.g |
| craton | see shield area. |
| streamflow | Water flowing in the stream channel |
| infiltration rate | the quantity of water that can enter the soil in a specified time interval. |
| miners' inch | A rate of discharge through an orifice one inch square under a specific head. |
| sludge | solid matter that settles to the bottom of sedimentation tanks in a sewage treatment plant and must be disposed of by digestion or other methods or recycled to the land. |
| subpolar lows | Surface zone of atmospheric low pressure located at about 60° North and South latitude |
| mesotrophic | Reservoirs and lakes which contain moderate quantities of nutrients and are moderately productive in terms of aquatic animal and plant life. |
| dissolve | The process during which solid particles mix molecule by molecule with a liquid and appear to become part of the liquid. |
| high seas | The major oceans of the world including, for National Weather Service purposes, the coastal and offshore areas. Areas of responsibility for the United States are determined by international agreements under the auspices of the World Meteorological Organization (WMO). |
| lagoon | calm, protected area of water between a barrier beach or coral reef and a coastline, or in the centre of an atoll. |
| acidity | The quantitative capacity of water to neutralize a base, expressed in ppm or mg/L calcium carbonate equivalent |
| stream power | a measure of energy available to move sediment, or any other particle in a stream channel |
| water budget | An accounting of the inflow to, outflow from, and storage changes of water in a hydrologic unit. |
| deep percolation loss | Water that percolates downward through the soil beyond the reach of plant roots. |
| evaporite | Type of sedimentary rock that is formed from the concentration of dissolved salts through evaporation. |
| stage ii precipitation processing | The second level of precipitation processing, occurring within the WFO Advanced Weather Interactive |
| latitude | Latitude is a north-south measurement of position on the Earth |
| geographic information system | A computer system capable of storing and manipulating spatial data. |
| staple food crop | the main crop which forms the basis of calorific content of the diet for a particular area |
| dds | Data Distribution System. |
| dioxin | Any of a family of compounds known chemically as dibenzo-p-dioxins |
| developing gale | Used in the National Weather Service High Seas Forecast. It refers to an extratropical low or an area in which gale force winds of 34 knots (39 mph) to 47 knots (54 mph) are "expected" by a certain time period |
| border irrigation | A surface method of irrigation by flooding between two confining border levees or dikes |
| soil water | The water found occupying the pore spaces between soil particles. |
| ensemble hydrologic forecasting | A process whereby a continuous hydrologic model is successively executed several times for the same forecast period by use of varied data input scenarios, or a perturbation of a key variable state for each model run |
| heredity | The transmission of behavioral, physiological and morphological characteristics from parent to offspring. |
| charles' law | States that when the pressure is held constant, the volume of a gas varies directly with the temperature |
| sulfuric acid | Acid with the chemical formula H2SO4. |
| demand forecast | A prediction of future water use |
| rating table | (1) A table showing the relation between two mutually dependent quantities or variables over a given range of magnitude |
| buried drain | A covered drain usually made of clay, concrete, or plastic pipe installed beneath the ground surface at a planned grade and depth for conveyance of excess groundwater. |
| gradient | Vertical drop per unit of horizontal distance. |
| flood frequency curve | (1) A graph showing the average interval of time within which a flood of a given magnitude will be equaled or exceeded once |
| fresh water | Water that generally contains less than 1000 milligrams per litre of dissolved solids such as salts, metals, nutrients, etc. |
| radar coded message | This is an alphanumeric coded message which will be used in preparation of a national radar summary chart. It is automatically produced by the WSR-88D's Radar Product Generator (RPG) in 3 parts (reflectivities, storm motion, and echo tops). |
| elevation | height above sea-level. |
| alternative | One of several policies, plans, or projects proposed for making decisions. |
| inflow jets | Local jets of air near the ground flowing inward toward the base of a tornado. |
| cross seas | Steep waves with short, sharp wave crests. They form when two or more wave trains moving in different directions run together. |
| lessivage | downward movement of clay particles through a soil in suspension as water passes through. |
| cambrian | Geologic period that occurred from 570 to 505 million years ago |
| leachate | Solution containing material leached from a soil. |
| spring | water flowing naturally from the Earth; volume of water can vary from a seep or trickle to a huge flow, i.e |
| cnif | Calibration Network Information Files |
| quench tank | A water-filled tank used to cool incinerator residues or hot materials during industrial processing. |
| expansion | Undeveloped areas adjacent to the boundaries of existing distributor contract areas that those distributors would logically be expected to serve in the future and that have been included in the Combined Service Area. |
| false origin | Location of the starting coordinates picked to the south and west of the true origin of a rectangular coordinate system |
| effluent limitation | Restrictions established by a state or EPA on quantities, rates, and concentrations in wastewater discharges. |
| mainstem survival | The proportion of anadromous fish that survive passage through the dams and reservoirs while migrating in the Columbia and Snake rivers. |
| ground water reservoir | An aquifer or aquifer system in which ground water is stored |
| limnophobia | The fear of lakes. |
| flowing artesian well | A well drilled into a confined aquifer with enough hydraulic pressure for the water to flow to the surface without pumping. |
| retrofit | An umbrella term that refers to the modification of something for more efficiency |
| wind chill advisory | The National Weather Service issues this product when the wind chill could be life threatening if action is not taken |
| phreatophytes | plants that send their roots into or below the capillary zone to use ground water. |
| wave | A moving swell or ridge on the surface of a solid or liquid or within the medium of a gas |
| rockfill dam | An embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment |
| crop subsidy | A price support paid to farmers by the government. |
| coastal convergence | The convergence or running together of land and se winds, creating a stronger band of windnear the shore. Factors such as the shape of the shoreline and the angle between the wind and the shore determine the severity of this effect. |
| low tide | the lowest point to which the sea falls against the land in its daily vertical movement. |
| rotor cloud | An altocumulus cloud formation that can be found in the lee of a mountain or similar barrier |
| sandstone aquifer | The type of aquifer supplying groundwater to large parts of the United States upper Middle West, Appalachia, and Texas |
| filling | Used in describing the history of a low pressure system or an area of cyclonic circulation, it means an increase in the central pressure of the system |
| ocean | The intercommunicating body of salt water occupying the depressions of the earth's surface, or one of its major primary subdivisions, bounded by the continents, or the equator, and other imaginary lines |
| hydraulic radius | The cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter. |
| perennial stream | one that flows all year round |
| mid-level cooling | Local cooling of the air in middle levels of the atmosphere (roughly 8 to 25 thousand feet), which can lead to destabilization of the entire atmosphere if all other factors are equal |
| backwater effect | The effect which a dam or other obstruction or construction has in raising the surface of the water upstream from it. |
| calving ** | Ice sheets calve by breaking off flat pieces when the walls of crevasses give way or chunks fall off the front of an ice sheet |
| condensation | the process of water vapor in the air turning into liquid water |
| adsorption | Separation of liquids, gases, colloids or suspended matter from a medium by adherence to the surface or pores of a solid. |
| headwater | Referring to the source of a stream or river |
| nowcast | A short-term weather forecast for expected conditions in the next few hours. |
| extensive agriculture | cultivation of a large land area producing a relatively low per unit yield. |
| snow blindness | Temporary blindness or impaired vision that results from bright sunlight reflected off the snow surface |
| fragmentation | The process of reducing size and connectivity of stands that compose a forest. |
| pesticide | Any chemical agent used for the control of specific organisms, for example, Insecticides, Herbicides, Fungicides, etc. |
| sedimentation tanks | Wastewater tanks in which floating wastes are skimmed off and settled solids are removed for disposal. |
| indigenous | originating in a particular area, region or nation |
| ipm | Integrated Pest Management |
| multiple use | Harmonious and coordinated management of the various surface and subsurface resources, without impairment of the land, that will best meet the present and future needs of the people |
| fishway | A device made up of a series of stepped pools, similar to a staircase, that enables adult fish to migrate up the river past dams. |
| electrons | Negatively charged building blocks of an atom that circle around the nucleus. |
| snowfield | The zone of accumulation sometimes a cirque, cwm or corrie; or a large open collecting point between mountains. |
| forest land | Land which is at least 10 percent occupied by forest trees of any size or formerly having had such tree cover and not currently developed for non-forest use |
| channelization | The modification of a natural river channel; may include deepening, widening, or straightening. |
| leachate collection system | a system that gathers leachate and pumps it to the surface for treatment. |
| synergism | The cooperative action of two or more organisms producing a greater total result than the sum of their independent effects; chemicals or muscles in synergy enhance the effectiveness of one another beyond what an individual could have produced. |
| acidic | The condition of water or soil that contains a sufficient amount of acid substances to lower the pH below 7.0. |
| duration of ice cover | The time from freeze-up to break-up of an ice cover. |
| oxidation-reduction potential | The electric potential required to transfer electrons from the oxidant to the reductant, used as a qualitative measure of the state of oxidation in water treatment systems. |
| upper mantle | Layer of the Earth's interior extending from the base of the crust to 670 kilometers below the surface |
| dorsal fin ray | Refers to one of the cartilaginous rays (stiff rods) located in the membrane of a dorsal fin. |
| volatility | the tendency of a liquid to evaporate. |
| evaportranspiration | The process by which water is returned to the air through direct evaporation or by transpiration of vegetation. |
| separate sewer system | A two-pipe sewer system in which one pipe collects sewage and sends it to a wastewater treatment plant and the other pipe collects stormwater, which is typically discharged to a stream. |
| vertical temperature profile | A series of temperature measurements taken at various levels in the atmosphere that show the thermal structure of the atmosphere over a specific location |
| ph | a measure of the relative acidity or alkalinity of water |
| thermodynamic equilibrium | This type of equilibrium describes a condition in a system where the distribution of mass and energy moves towards maximum entropy. |
| erg desert | A region in a desert where sand is very abundant. |
| state of matter | Form of matter |
| flood wave | A rise in streamflow to a crest and its subsequent recession caused by precipitation, snow melt, dam failure, or reservoir releases. |
| poe-treatment | Point-Of-Entry treatment |
| pressure head | Energy contained by fluid because of its pressure, usually expressed in feet of fluid (foot pounds per pound). |
| net water demand | The amount of water needed in an irrigation or water service area to meet all requirements |
| toxicity | The capacity of a chemical to do harm to an organism by other than mechanical means. |
| filter | a device used to remove solids from a mixture or to separate materials |
| artificial flood | deliberate release of water from dam reservoirs to create downstream flooding that is beneficial to farmland or wetland areas. |
| rain forest | A tropical woodland that has an annual rainfall of at least 100 inches (254 centimeters) and often much more, typically restricted to certain lowland areas. |
| granite | Medium to coarse grained igneous rock that is rich in quartz and potassium feldspar |
| ocean basin | Part of the Earth's outer surface that is comprised of the ocean floor, mid-oceanic ridges, continental rise, and continental slope |
| peak use rate | The maximum periodic rate of consumptive use (Evapotranspiration) of water by plants. |
| contents | The volume of water in a reservoir |
| river forecast | An internal product issued by RFCs to other NWS offices |
| mouth | End of a stream |
| humidity | A general term used to describe the amount of water vapor found in the atmosphere. |
| business cycle | regular pattern of 'boom and bust'upturns and downturns in economic demand and output repeating every 5-7 years. |
| weir | A vertical structure in an open channel with a calibrated opening that measures water's rate of flow |
| incidental recharge | Ground water recharge (infiltration) that occurs as a result of human activities unrelated to a recharge project, for example, irrigation and water diversion (unlined canals) |
| subsidence | The downwarping of Earth's crust due to additional weight (such as a glacier or a transgressing sea) being applied to it. |
| ion exchange | The replacement of undesirable ions with a certain charge by desirable ions of the same charge in a solution, by an ion-permeable absorbent. |
| mass movement | General term that describes the downslope movement of sediment, soil, and rock material. |
| radar beam | The straight line that a radar pulse travels along |
| dental fluorosis | disorder caused by excessive absorption of fluorine and characterized by brown staining of teeth. |
| histosols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| lee | sheltered side of a slope. |
| plastic solid | A perfectly plastic solid yields after a critical threshold of stress has been exceeded |
| antenna reflector | The portion of an antenna system which reflects the energy from the radiating element into a focused beam; generally circular parabolas for weather radars. |
| evaporation | The process of the passage of water from liquid to vapour. |
| cumulus congestus | Same as towering cumulus. Sometimes referred to just as congestus. |
| litter layer | dead organic matter lying on the surface and waiting for/in the process of decomposition. |
| solum | Part of the soil that is capable of supporting life. |
| detention basins | Structures which are built upstream from a populated area so that precipitation flows do not flood and cause the loss of life or property |
| asap | AHOS SHEF Automatic Processing System |
| industrial waste | Unwanted materials from an industrial operation; may be liquid, sludge, or hazardous waste. |
| chromosomes | they unite to cause fertilization and a diploid zygote. |
| stream | a general term for a body of flowing water; natural water course containing water at least part of the year |
| tailwater height | Height of water immediately downstream of the dam |
| anticyclone | a stable, generally subsiding air mass producing high pressure, warming conditions |
| navier-stokes equations | a set of equations that describe the physics governing the motion of a fluid |
| detention storage | The volume of water, other than depression storage, existing on the land surface as flowing water which has not yet reached the channel. |
| pump | a device which moves, compresses, or alters the pressure of a fluid, such as water or air, being conveyed through a natural or artificial channel. |
| incubation channel | A man-made channel in the streambed used for hatching fish eggs. |
| breakpoint chlorination | Addition of chlorine to water until there is enough chlorine present for disinfection of water. |
| kilogram | one thousand grams. |
| zodiac | The position of the sun during the course of the year as it appears to move though successive constellations |
| pumping test | a test conducted to determine aquifer or well characteristics. |
| groundwater | Water that occupies the pore spaces found in some types of bedrock. |
| monopoly | control of supply of a product or service to a particular market |
| condensation | the formation of water droplets or ice crystals from water vapour when it is cooled to the dew point. |
| iteroparous | Species that reproduce repeatedly during their lifetime. |
| inverted siphon | A closed pipeline with its end sections above the middle section, used for crossing under drainage channels, roadways, depressions, or other structures |
| hod | The Hydrologic Operations Division of the Office of Hydrology (OH). |
| transmissibility | The rate at which water at the prevailing water temperature is transmitted through a unit width of the aquifer under a unit hydraulic gradient |
| mangrove | Treed wetlands located on the coastlines in warm tropical climates. |
| ecosystem | An ecosystem is a system where populations of species group together into communities and interact with each other and the abiotic environment. |
| geohydrology | A term which denotes the branch of Hydrology relating to subsurface or subterranean waters; that is, to all waters below the surface. |
| earthen dam | An embankment dam in which more than 50% of the total volume is formed of compacted fine-grained material |
| break of bulk | a site where cargo is broken down from a large, bulk carrying unit, to smaller scale units, usually involving a change in the mode of transport. |
| intermittent stream | A stream that flows periodically |
| growing season | Considered the period of the year during which the temperature of cultivated vegetation remains sufficiently high enough to allow plant growth |
| marble | Metamorphic rock created by the recrystallization of calcite and/or dolomite. |
| asaptran | The software component of ASAP. |
| thunder | The sound emitted by the rapidly expanding gases along the channel of a lightning discharge |
| hard water | Water that contains a great number of positive ions |
| corrasion | see abrasion. |
| conservation | to protect from loss and waste |
| gale warning | The National Weather Service will issue these marine warnings for 1-minute sustained winds between 34 (39 mph or 63 kph) and 47 knots (54 mph or 87 kph) are expected at end of downwind fetch (nearshore or open waters). This warning will be headlined in the Open Great Lakes Forecast (Product Header CCCGLFXX) and the Nearshore Marine Forecast (Product Header CCCNSHXXX) when conditions are expected to occur within 24 hours following the forecast issuance time. The headline will be "...GALE WARNING IN EFFECT...". When the hazard has ended, the last forecast will indicate this in the headline by replacing the "IN EFFECT" phrase with "DISCONTINUED". |
| endangered species act | The federal law that sets forth how the United States will protect and recover animal and plant species whose populations are in dangerous decline or close to extinction |
| barogram | A graphic record of air pressure produced by a barograph. |
| gravity irrigation | See Irrigation. |
| lfc | An acronym for Level of Free Convection. See Level of Free Convection. |
| skew t-log p diagram | A thermodynamic diagram, using the temperature and the logarithm of pressure as coordinates |
| watthour | an electrical energy unit of measure equal to one watt of power supplied to, or taken from, an electrical circuit steadily for one hour. |
| instantaneous unit hydrograph | The theoretical, ideal, unit hydrograph that has a infinitesimal duration. |
| internal flow | The movement of ice inside a glacier through the deformation and realignment of ice crystals; also known as creep. |
| wellhead protection area | A protected surface and subsurface zone surrounding a well or well field that supplies a public water system and through which contaminants could likely reach well water. |
| hydrophyte | any plant which has adapted to moist environments. |
| hydroelectricity | Electric energy produced by water-powered turbine generators. |
| flood | The inundation of a normally dry area caused by high flow, or overflow of water in an established watercourse, |
| s-wave | a seismic wave which moves material in a motion perpendicular to the direction in which the energy of the wave itself is travelling. |
| ground water mining | Pumping ground water from a basin where the safe yield is very small, thereby extracting ground water which had accumulated over a long period of time. |
| toxic substance | A chemical or mixture that can cause illness, death, disease, or birth defects |
| wind waves | Local, short period waves generated from the action of wind on the water surface (as opposed to swell). Commonly referred to as waves. In a National Weather Service Coastal Marine Forecast or Offshore Forecast, wind waves are used when swells are described in the forecast. |
| chemical | One of the millions of different elements and compounds found naturally and synthesized by humans. |
| effective precipitation | 1) That part of the precipitation that produces runoff. 2) A weighted average of current and antecedent precipitation that is "effective" in correlating with runoff. 3) That part of the precipitation falling on an irrigated area that is effective in meeting the consumptive use requirements. |
| spawn | The act of reproduction of fishes |
| heavy metals | Metals having a specific gravity of 5.0 or greater; generally toxic in relatively low concentrations to plant and animal life and tend to accumulate in the food chain |
| cardinal points | The four main navigational directions (North, East, South, and West) found on a compass or a map. |
| enclosure | in the UK 1450-1820, the move from an agricultural system based on open, or shared, crop fields with common land for grazing and resource collection (e.g |
| gaussian | Refers to the normal distribution; phenomena whose events are "normally" distributed are "Gaussian" distributed |
| raptor | A bird of prey, adapted for seizing and tearing prey. |
| vaporization | The change of a substance from a liquid or solid state to the gaseous state. |
| senescence | the aging process |
| aerophobia | The fear of drafts, air swallowing, or air bourne noxious substances. |
| hygroscopic water | Water held within 0.0002 millimeters of the surface of a soil particle |
| ensemble hydrologic forecasting | A process whereby a continuous hydrologic model is successively executed several times for the same forecast period by use of varied data input scenarios, or a perturbation of a key variable state for each model run |
| immigrant species | Species that migrate into an ecosystem or that are deliberately or accidentally introduced into an ecosystem by humans |
| estuary | thin zone along a coastline where freshwater system(s) and river(s) meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon). |
| perennial streams | Streams which flow continuously. |
| sole-source aquifer | an aquifer that supplies 50 percent or more of the drinking water of an area. |
| monitoring | Periodic or continuous surveillance or testing to determine the level of compliance with statutory requirements and/or pollutant levels in various media or in humans, plants, and animals. |
| eukaryota | All the organisms with a eukaryote cell type |
| acid | a substance that has a pH of less than 7, which is neutral |
| subrefraction | The bending of the radar beam in the vertical which is less than under standard refractive conditions |
| seal | the impermeable material, such as cement grout bentonite, or puddling clay placed in the annular space between the borehole wall and the casing of a water well to prevent the downhole movement of surface water or the vertical mixing of artestian waters. |
| pioneer | used to define a species or community of plant(s) that is first to colonise a previously barren area. |
| stream bank | The side slopes of an active channel between which the streamflow is normally confined. |
| ozone hole | Is a sharp seasonal decrease in stratospheric ozone concentration that occurs over Antarctica in the spring |
| lateral sewers | Pipes that run under city streets and receive the sewage from homes and businesses, as opposed to domestic feeders and main trunk lines. |
| cliff | A cliff is a steep face of rock and soil. |
| hydraulic radius | The right cross-sectional area of a stream of water divided by the length of that part of its periphery in contact with its containing conduit; the ratio of area to wetted perimeter |
| circulation cells | Large areas of air movement created by the rotation of the earth and the transfer of heat from the equator toward the poles |
| positive vorticity advection | A region of positive vorticity usually several hundred of kilometers wide on a upper level chart that moves with the general wind flow |
| thunderstorm | A storm several kilometers in diameter created by the rapid lifting of moist warm air which creates a cumulonimbus cloud |
| hinge crack | Crack caused by significant changes in water level. |
| slurry | A pumpable mixture of solids and fluid. |
| snow crust | The crisp, almost icy, surface on fallen snow, usually formed by the slight melting and refreezing of the surface snow. |
| meridian | a line tracing a circle that passes through both poles. |
| moist adiabats | They show how the air temperature would change inside a rising parcel of saturated air. |
| scenic waterway | Rivers or river segments chosen for scenic and recreation qualities to be preserved in their natural state. |
| annual operating plan | A yearly plan for operating reservoirs on the Columbia River |
| map | An abstraction of the real world that is used to depict, analyze, store, and communicate spatially organized information about physical and cultural phenomena. |
| grade control structure | A weir, dam, sill, drop structure, or other structure used to control erosion in stream channels with steep grades or where the slope has been destabilized. |
| lithosphere | That part of the earth which is composed predominantly of rocks (either coherent or incoherent, and including the disintegrated rock materials known as soils and subsoils), together with everything in this rocky crust. |
| heat island | The dome of relatively warm air which develops over the center of urbanized areas. |
| anticyclonic rotation | Rotation in the opposite sense as the Earth's rotation. In the Northern Hemisphere, this would be clockwise as would be seen from above. |
| location | A term used in geography that deals with the relative and absolution spatial position of natural and human-made phenomena. |
| foot wall | The bottommost surface of an inclined fault. |
| serial derecho | It consists of an extensive squall line which is oriented such that the angle between the mean wind direction and the squall line axis is small |
| augmentation | Increasing stream flow under normal conditions, by releasing storage water from reservoirs. |
| sustained harvest | A harvest volume that can be maintained through time without decline. |
| waterlogging | saturation of soil with irrigation water so the water table rises close to the surface. |
| channel realignment | The construction of a new channel or a new alignment which may include the clearing, snagging, widening, and/or deepening of the existing channel. |
| latent heat of condensation | The amount of heat released by a unit mass of substance, without change in temperature, while passing from the vapor to the liquid state. |
| xbt | Abbreviation for expendable bathythermograph. |
| receiving waters | a river, ocean, stream, or other watercourse into which wastewater or treated effluent is discharged. |
| combined seas | Generally referred to as "SEAS". It is used to describe the combination or interaction of wind waves and swells. In some prediction techniques, its height is the square root of the sum of the squares of the wind wave and swell heights. It is generally equal to the height of the swell plus 1/3 the height of the wind waves. |
| dew point | Dew point is the temperature at which water vapor saturates from an air mass into liquid or solid usually forming rain, snow, frost or dew |
| hydroelectricity | Electric energy production by water powered turbine generators. |
| isotherm | line that connects points of equal temperature. |
| outcrop | exposed at the surface |
| flood statement | A statement issued by the NWS to inform the public of flooding along major streams in which there is not a serious threat to life or property |
| hinge crack | Crack caused by significant changes in water level. |
| per-capita water use | The water produced by or introduced into the system of a water supplier divided by the total residential population; normally expressed in gallons per-capita per day (gpcd). |
| triassic | a period of geologic time lasting from 245m to 208m years ago. |
| backwash | A backward flow or water, also referred to as Backrush |
| head | The difference between the pool height and tailwater height |
| pharyngeal teeth | Teeth located behind the gills and before the esophagus, and anchored in bone. |
| jokulhlaup | An Icelandic term meaning glacier dammed lake outburst flood. |
| reliction | A recession of the sea or other water body leaving land uncovered |
| sun pointing | Alignment of the radar antenna by locating the position of the sun in the sky, which has an exactly known position given the radar's location and the present time |
| brackish water | Generally, water containing dissolved minerals in amounts that exceed normally acceptable standards for municipal, domestic, and irrigation uses |
| zone of saturation | the space below the water table in which all the interstices (pore spaces) are filled with water |
| dip-net fishery | A traditional tribal fishery for salmon and steelhead where fish are captured using long-handled dip nets, usually at waterfalls or other obstructions, which congregate the fish and make them more vulnerable to harvest. |
| watch | A forecast issued well in advance of a severe weather event to alert the public of the possibility of a particular hazard, such as tornadoes, severe thunderstorms, flash and river floods, winter storms, or heavy snows. |
| soil fertility | The ability of a soil to provide nutrients for plant growth. |
| severe weather | Generally, any destructive weather event, but usually applies to localized storms, such as blizzards, intense thunderstorms, or tornadoes. |
| runoff plots | Areas of land, usually small, arranged so the portion of rainfall or other precipitation flowing off and perhaps carrying soluble materials and soil may be measured. |
| primogeniture | inheritance of an estate to the eldest son, or eldest child, only. |
| groundwater storage capacity | The space or voids contained in a given volume of soil and rock deposits. |
| bragg scattering | Scatter from small-scale fluctuations (i.e., turbulence) in the refractive index of the atmosphere |
| special marine warning | This is issued by the National Weather Service for hazardous weather conditions (thunderstorms over water, thunderstorms that will move over water, cold air funnels over water, or waterspouts) usually of short duration (2 hours or less) and producing sustained winds or frequent gusts of 34 knots or more that is not covered by existing marine warnings. These are tone alerted on NOAA Weather Radio. Boaters will also be able to get this information by tuning into Coast Guard and commercial radio stations that transmit marine weather information. |
| pleistocene | first epoch of the Quaternary, 2 m |
| geomorphology | the science of understanding landform formation. |
| pasteurisation | The elimination of microrganisms by heat applies for a certain period of time. |
| perched water table | The water table of a relatively small ground-water body supported above the general ground water body. |
| demand | the number of units of something that will be purchased at various prices at a point in time |
| intercepting drain | A drain constructed at the upper end of the area to be drained, to intercept surface or ground water flowing toward the protected area from higher ground, and carry it away from the area |
| usable storage capacity | The available storage capacity plus the remaining ground water storage within a reasonable pump lift |
| landspout | A small, weak tornado, which is not formed by a storm-scale rotation |
| consumptive waste | Water that returns to the atmosphere without providing benefit to humans. |
| sawrs-ii | Indicates automated observations taken by a commissioned Automated Surface Observing System |
| molecule | Minute particle that consists of connected atoms of one or many elements. |
| ground water overdraft | The condition of a ground water basin in which the amount of water withdrawn by pumping exceeds the amount of water that recharges the basin over a period of years during which water supply conditions approximate average |
| monocline | A fold in layered rock that creates a slight bend. |
| gondwanaland | a supercontinent proposed by Alfred Wegener after the breakup of Pangaea (the single continent) into two |
| glacial uplift | Upward movement of the Earth's crust following isostatic depression from the weight of the continental glaciers. |
| surface water withdrawals | Includes all waters taken from streams, rivers, ponds, lakes, reservoirs, springs and all effluent and other waste water. |
| coriolis force | the effect of drag from the earth rotation on airflow. |
| indicator parameters | measurable physical or chemical characteristics or attributes of water or soil-pore moisture used to indicate the possible presence of waste constituents, or the effects of waste constituents on waters. |
| hydrodynamic dispersion | (1) Spreading (at the macroscopic level) of the solute front during transport resulting from both mechanical dispersion and molecular diffusion |
| marep | An acronym for the Marine Reporting Program. These are recreation craft equipped with VHF radio to assist Environment Canada, Ontario Region and the National Weather Service in preparing reliable marine forecasts for vessels operating in near-shore waters around The Great Lakes. |
| phreatic zone | the area in an aquifer in which relatively all pores and fractures are saturated with water |
| building sewer | The sewer line that connects building wastewater sources to the public or street sewer, including lines serving homes, public buildings, commercial establishments and industry structures |
| friction | Resistance between the contact surfaces of two bodies in motion. |
| tributary drainage | The area from which water drains by gravity into a water course. |
| control scheme | The collection of methods and algorithms brought together to accomplish control of a canal system. |
| short term forecast | This National Weather Service narrative summary describes the weather in the local area and includes a short-range forecast (usually not more than 6 hours). This product will be updated more frequently when it is used during active weather. This product is also sometimes referred to as a "NOWcast". |
| environmental impact statement | Detailed analysis of the impacts of a project on all aspects of the natural environment required by federal National Environmental Policy Act for federal permitting or use of federal funds. |
| headwaters | Streams at the source of a river. |
| dissolved solids | inorganic material contained in water or wastes |
| outfall | The mouth or outlet of a river, stream, lake, drain or sewer. |
| water hammer | (1) Very rapid pressure wave in a conduit due to a sudden change in flow; the potentially damaging slam, bang, or shudder that occurs in a pipe when a sudden change in water velocity (usually as a result of too-rapidly starting a pump or operating a valve) creates a great change in water pressure |
| celestial equator | The projection of the plane of the geographical equator upon the celestial sphere. |
| flash flood statement | This product is issued after either a Flash Flood Watch or a Flash Flood Warning has been issued by a local National Weather Service Forecast Office (NWFO). It will provide the latest information on the flash flooding situation or event. It will also be used to remove parts of the geographical area covered by the original watch or warning when the flash flooding event is no longer a threat or has ended in a certain area. It cannot be used to add a geographical area to either a watch or a warning. A new watch or warning is required to do this. Finally, this statement can be used to terminate the original watch or warning when it is no longer valid. This is usually optional when either a watch or warning expires. |
| stratified drift | Layered and sorted sediments deposited by meltwater streams or bodies of water adjacent to the ice. |
| irrigation | Applying water or wastewater to land areas to supply the water and nutrient needs of plants. |
| moisture holding capacity | the amount of liquid that can be held against gravity, by waste materials or soil, without generating free liquid. |
| fermentation | Decomposition and breakdown of organic matter by anaerobic means. |
| photovoltaic cells | a unit, usually of silicon, which is able to collect and store, temporarily, energy from the sun to produce electricity. |
| impermeability | Characteristic of geologic materials that limit their ability to transmit significant quantities of water under the pressure differences normally found in the subsurface environment. |
| maximum | The greatest value attained by a function, for example, temperature, pressure, or wind speed |
| threshold | in human geography, the minimum number of people required to support a good or service |
| purgeable organics | volatile organic chemicals which can be forced out of the water sample with relative ease through purging. |
| waa | An acronym for Warm Air Advection. See Warm Air Advection. |
| distribution channel | the route a product takes from producer to consumer |
| eye wall | It is an organized band of cumuliform clouds that immediately surrounds the center (eye) of a hurricane |
| bank | The margins of a channel |
| blending | The mixing or combination of one water source with another, typically a finished source of water with raw water to reuse water while still satisfying water quality standards, for example, mixing of product water from a desalting plant with conventional water to obtain a desired dissolved solids content, or mixing brine effluents with sewage treatment plant effluents in order to reduce evaporation pond size. |
| high pressure | An area of atmospheric pressure within the Earth's atmosphere that is above average |
| obliquity | Tilt of the Earth's polar axis as measured from the perpendicular to the plane of the Earth's orbit around the Sun |
| stream capture | The process whereby a stream rapidly eroding headward cuts into the divide separating it from another drainage basin, and provides an outlet for a section of a stream in the adjoining valley |
| hep | see hydro-electric power. |
| biochemical oxygen demand | The amount of oxygen (measured in mg/L) that is required for the decomposition of organic matter by single-cell organisms, under test conditions |
| high flow pulses | the component of an instream flow regime that represents short-duration, in-channel, high flow events following storm events |
| b-run steelhead | Summer steelhead crossing Bonneville Dam after August 25. |
| biogeochemical cycling | the flow of chemical substances to and from the major environmental reservoirs (atmosphere, hydrosphere, lithosphere, and biosphere). |
| manometer | An instrument for measuring pressure which usually consists of a U-shaped tube containing a liquid, the surface of which in one end of the tube moves proportionally with changes in pressure on the liquid in the other end |
| input | in systems theory, any element introduced to the system from outside. |
| managerial controls | (Irrigation) Methods of nonpoint source pollution control based on decisions about managing agricultural wastes or application times or rates for agrochemicals. |
| rawinsonde | An upper air observation that evaluates the winds, temperature, relative humidity, and pressure aloft by means of a balloon-attached radiosonde that is tracked by a radar or radio direction-finder |
| concordant flows | Flows at different points in a river system that have the same Recurrence Interval, or the same frequency of occurrence |
| slough | A shallow backwater inlet that is commonly exposed at low flow or tide. |
| veering | A clockwise shift in the wind direction in the Northern Hemisphere at a certain location |
| moderate flooding | Flood conditions characterized by the inundation of secondary roads, transfer of property to higher elevations, and some evacuations of people and livestock |
| moveable bed streams | These are most common in the arid West, where steep slopes and lack of vegetation result in a lot of erosion |
| field moisture deficiency | The quantity of water, which would be required to restore the soil moisture to field moisture capacity. |
| bacteria | Simple single celled prokaryotic organisms |
| entrance head | The Head required to cause flow into a conduit or other structure, including both entrance loss and Velocity Head. |
| phenolphthalein alkalinity | the alkalinity in a water sample measured by the amount of standard acid needed to lower the pH to a level of 8.3 as indicated by the change of color of the phenolphthalein from pink to clear. |
| bandpass filter | A filter whose frequencies are between given upper and lower cutoff values, while substantially attenuating all frequencies outside these values (this band). |
| pumping head | Energy given to a fluid by a pump, usually expressed in feet of fluid (foot pounds per pound). |
| project | Run-of-river or storage dam and related facilities; also a diversion facility. |
| agglomerate | An ice cover of floe formed by the freezing together of various forms of ice. |
| soil management | The basis of all scientific agriculture, which involves six essential practices: (1) proper tillage; (2) maintenance of a proper supply of organic matter in the soil; (3) maintenance of a proper nutrient supply, including water; (4) control of soil pollution; (5) maintenance of the correct soil acidity; and (6) control of erosion. |
| weathering | breakdown of rock in situ by physical and chemical processes due to the presence of water, plants and animals |
| horst fault | A fault that is produced when two reverse faults cause a block of rock to be push up. |
| local flooding | Flooding conditions over a relatively limited (localized) area. |
| scree | An accumulation of weathered rock fragments at the base of a steep rock slope or cliff. |
| deforestation | Removal of trees from a habitat dominated by forest. |
| intrabasin transfer | The diversion of water within a drainage basin. |
| mechanical bypass systems | See bypass system. |
| grid south | The direction south as measured on the Universal Transverse Mercator grid system. |
| hydraulic head | (1) The height of the free surface of a body of water above a given point beneath the surface |
| drainage wind | A wind common to mountainous regions that involves heavy cold air flowing along the ground from high to low elevations because of gravity |
| recharge | The addition of water to an aquifer by infiltration, either directly into the aquifer or indirectly by way of another rock formation |
| saturation | Atmospheric condition where water is changing its phase to liquid or solid |
| immature soil | one which has not had time to develop |
| derelict land grant | in the UK, government funding for the improvement of derelict land. |
| curtain drain | A drain constructed at the upper end of the area to be drained, to intercept surface or ground water flowing toward the protected area from higher ground, and carry it away from the area |
| swamp | A type of wetland that is dominated by woody vegetation and does not accumulate appreciable peat deposits |
| talus | the accumulation of weathered material on a slope. |
| chute spillway | the overall structure which allows water to drop rapidly through an open channel without causing erosion |
| strip farming | the splitting of a larger field into smaller strips which are looked after by individual farmers. |
| surplus production | Production of new weight by a fishable stock, plus recruits added to it, less what is removed by natural mortality |
| low water | (1) The lowest level of water in a body of water, such as a river, lake, or reservoir |
| hydrologic study approach | The study of a project's water distribution based upon a hydrological balance, where inflow (diversion into project) is balanced with outflow (precautionary drawdowns, crop consumptive use, deep seepage, surface return flows, and undefined "losses"). |
| ground water plume | A volume of contaminated groundwater that extends downward and outward from a specific source; the shape and movement of the mass of the contaminated water is affected by the local geology, materials present in the plume, and the flow characteristics of the area groundwater. |
| thaw | A warm spell of weather when ice and snow melt |
| pitot tube | An instrument used to measure the velocity of flowing water, with the velocity head of the stream an index of velocity |
| channel-forming discharge | See dominant discharge. |
| jetty | A structure extending into a sea, lake, or river to influence the current or tide, in order to protect harbors, shores, and banks. |
| re-regulating reservoir | A reservoir for reducing diurnal (daily) fluctuations resulting from the operation of an upstream reservoir for power production. |
| semelparous | Species that reproduce only once during their lifetime. |
| pyramidal peak | the classic, pyramid-shape of a mountain-top formed when three or four corries form on different sides of the mountain and erode backwards towards each other. |
| ozone layer | Atmospheric concentration of ozone found at an altitude of 10 to 50 kilometers above the Earth's surface |
| litter | Accumulation of leaves, twigs and other forms of organic matter on the soil surface |
| river terrace | remnants of previous floodplains left higher than the existing river channel by increased erosion due to rejuvenation. |
| brown snow | Snow intermixed with dust particles. A not uncommon phenomenon in many parts of the world. Snows of other colors, such as yellow snow, are similarly explainable. |
| water quality | the chemical, physical, biological, radiological, and thermal condition of water. |
| clarity | The clearness of a liquid. |
| divergent evolution | Creation of two or more unique species from one ancestral species through the differential evolution of isolated populations. |
| gross secondary productivity | Total amount of chemical energy assimilated by consumer organisms. |
| spenes | An acronym for NESDIS Satellite Precipitation Estimates. |
| polar substance | A substance that carries a positive or negative charge, for instance water. |
| land use | The primary or primary and secondary uses of land, such as cropland, woodland, pastureland, etc |
| sanitary landfill | (Water Quality) A disposal site employing methods of disposing of solid wastes in a manner that minimizes environmental hazards by spreading, compacting to the smallest practical volume and applying cover material over all exposed wastes at the end of each operating day. |
| growing season | the length of time in the year available for crop growth |
| maritime climate | the climate of land areas in coastal regions where the characteristics of the climate are clearly affected by the proximity to the water mass |
| intermittent stream | Any nonpermanent flowing drainage feature having a definable channel and evidence of scour or deposition |
| thermistor | An electrical resistance device used in the measurement of temperature. |
| ergs | 1 joule is about 0.7375 foot-pounds. |
| tidal anomaly | Actual water level minus the tide table predictions. |
| permanent control | A stream gaging control which is substantially unchanging and is not appreciably affected by scour, fill, or backwater. |
| accretion | growth of a natural feature by enlargement due to the addition of more of the same material. |
| gaging station | A particular site on a stream, canal, lake, or reservoir where systematic observations of Gage Height or discharge are obtained. |
| assay | a test for a specific chemical, microbe, or effect. |
| rime | Ice deposits formed when supercooled water droplets freeze on contact with an object (deposition). |
| crest of dam | The elevation of the uppermost surface of a dam excluding any parapet walls, railings, etc. |
| richter scale | A logarithmic measurement scale of earthquake magnitude |
| ahos-s | Automatic Hydrologic Observing System - Satellite |
| arête | A sharp-edged ridge of rock formed between adjacent cirque glaciers. |
| siberian express | A fierce, cold flow of air that originates in Siberia, then moves into Alaska and northern Canada before moving southward into the United States. |
| fouling | The deposition of organic matter on the membrane surface, which causes inefficiencies. |
| founder | To sink below the water. |
| diatomaceous | consisting of or abounding in diatoms, a class of unicellular or colonial algae having a silicified cell wall that persists as a skeleton after death. |
| overbank flow | Movement of flood waters outside a stream channel during period of high discharge. |
| canopy closure | The degree to which the canopy (forest layers above one's head) blocks sunlight or obscures the sky. |
| base width | The time duration of a unit hydrograph. |
| submergent features | those formed where a coastline experiences a relative rise in sea-level. |
| wildfall | Trees or parts of trees felled by high winds. |
| contact recreation | activities involving a significant risk of ingestion of water, such as wading by children, swimming, water skiing, diving and surfing |
| reduction | a chemical reaction involving the removal of oxygen. |
| turbine | a rotary motor driven by a flow of water, steam or wind to produce electrical energy. |
| band width | The number of cycles per second between the limits of a frequency band. |
| freeze-thaw weathering | a process of physical or mechanical weathering |
| deposit | something dropped or left behind by moving water, as sand or mud. |
| barometer | An instrument used for measuring air pressure |
| fire weather district | A fire weather district is the area of routine service responsibility as defined by the NWS. This area is usually defined by climatological factors, but may be modified somewhat to administrative boundaries of the User Agencies. |
| solifluction | a mass movement of soil in periglacial areas when upper layers thaw in summer and are lubricated in comparison to the permafrost below. |
| nimbostratus | A dark, gray cloud characterized by more or less continuously falling precipitation |
| collection site | A stream, lake, reservoir, or other body of water fed by water drained from a watershed. |
| tvs | An image of a tornado on the Doppler radar screen that shows up as a small region of rapidly changing wind speeds inside a mesocyclone |
| dendrogram | A branching diagram, sometimes resembling a tree, that provides one way of visualizing similarities between different groups or samples. |
| isotropic | physically uniform in all directions |
| joint-use capacity | That reservoir capacity which has been assigned to flood control purposes during certain periods of the year and to other purposes during other periods of the year. |
| indirect flood damage | Expenditures made as a result of the flood (other than repair) such as relief and rescue work, removing silt and debris, etc. |
| sere | a particular type of plant succession. |
| potential energy | The energy available in a substance because of position (e.g., water held behind a dam) or chemical composition (hydrocarbons) |
| conduction | the transmission of heat through a substance i.e |
| sill | Horizontal planes of igneous rock that run parallel to the grain of the original rock deposits.They form when magma enters and cools in bedding planes found within the crust |
| river basin development | A program to develop the use of the water and land resources of a river basin, so coordinated as to obtain a greater efficiency of use than would be possible if the resources were developed by uncoordinated, multiple-purpose projects. |
| conservation biology | Multidisciplinary science that deals with the conservation of genes, species, communities, and ecosystems that make up Earth's biodiversity |
| tropic | a line of latitude marking the most northerly and most southerly overhead paths of the sun |
| bridging point | a site factor |
| biosphere | The transition zone between the earth and the atmosphere within which most terrestrial life forms are found |
| equator | The geographic circle at 0 degrees latitude on the earth's surface |
| diversion | to remove water from a water body |
| bottom | (1) The deepest or lowest part, as the bottom of a well |
| neutral atmosphere | Condition in the atmosphere where isolated air parcels do not have a tendency to rise or sink |
| biological processes | Processes characteristic of, ore resulting from, the activities of living organisms. |
| invert | The internal elevation at the bottom of the sewer. |
| nocturnal inversion | see Radiational Inversion |
| physical weathering | Breaking down of rock into bits and pieces by exposure to temperature and changes and the physical action of moving ice and water, growing roots, and human activities such as farming and construction. |
| sewer separation | The practice of separating combined single pipe systems into separate sewers for sanitary and storm water flows. |
| distribution graph | A unit hydrograph of direct runoff modified to show the proportions of the volume of runoff that occur during successive equal units of time. |
| thin line echo | A narrow, elongated, non-precipitating echo |
| growth management program | A program comprised of several techniques to coordinate public and private decisions about the location and timing of development in order to best utilize environmental and physical resources. |
| optimum | The level of an abiotic factor or condition in the environment within the tolerance range at which a species or population can function most efficiently or with the greatest positive effect to its physiological or reproductive fitness. |
| residue | The dry solids remaining after the evaporation of a sample of water or sludge. |
| espinit | ESP Initialization Program |
| electron | A sub-particle of an atom that contains a negative atomic charge. |
| net economic benefits | Economic benefits minus economic costs. |
| wsr-74 | A NWS Weather Surveillance Radar designed in 1974. It used to be part of weather radar network. It was replaced by WSR-88D units. |
| effective precipitation | That portion of precipitation which remains on the foliage or in the soil that is available for Evapotranspiration, and reduces the withdrawal of soil water by a like amount |
| tropopause | The boundary zone or transition layer between the troposphere and the stratosphere |
| grit chamber | A concrete basin that allows larger grit particles (sand, dust, seeds, etc.) to settle out, while lighter materials pass through to the treatment process. |
| ucp | The WSR-88D radar operator uses this to control the entire radar system. One of the main things that the radar operator will do at the UCP is change volume scan strategies of the antenna. These volume scan strategies tell the radar how many elevation angles will be used during a single volume scan (a volume scan is the completion of a sequence of elevation angles), and the amount of time it will take to complete that sequence of elevation cuts, each one being a single rotation of the antenna's 1 degree beam at selected elevation angles. The WSR-88D uses 3 scan strategies. They are the following: 14 elevation angles in 5 minutes (this is used during severe weather situations), 9 elevation angles in 6 minutes (this is used when there is precipitation within 248 nautical miles of the radar), and 5 elevation angles in 10 minutes (this is used when there is no precipitation within 248 nautical miles). The radar operator at the UCP can also adjust the radar products and help the users out with their communication problems. |
| run-off | all water leaving a drainage basin. |
| moisture equivalent | The ratio of 1) the weight of water which the soil, after saturation, will retain against a centrifugal force 1,000 times the force of gravity, to 2) the weight of the soil when dry |
| gleying | in soils that are waterlogged, reduction of ferric iron to ferrous iron takes place changing the colour of the soil from reddish brown to blue-grey. |
| fragmentation | The subdivision of a solid in fragments |
| floodproofing | Any combination of structural and nonstructural additions, changes, or adjustments to structures that reduce or eliminate flood damage. |
| little climatic optimum | Time period from 900 - 1200 AD |
| crust | Earth's outer most layer of solid rock |
| disinfection | The decontamination of fluids and surfaces |
| ground clutter | A pattern of radar echoes from fixed ground targets (buildings, hills, etc.) near the radar |
| buttress dam | Buttress dams are comprised of reinforced masonry or stonework built against concrete |
| spectrum | Is a graph that describes the quantity of radiation that is emitted from a body at particular wavelengths. |
| stokes- law | the settling rate of a particle in water is proportional to the diameter of that particle i.e |
| pump station | mechanical device installed in sewer or water system or other liquidcarrying pipelines to move the liquids to a higher level. |
| calcite | Mineral formed from calcium carbonate |
| reservoir | a pond, lake, tank, or basin (natural or human made) where water is collected and used for storage |
| wavelength | The distance a wave will travel in the time required to generate one cycle |
| macronutrient | Nutritional element required by an organism in relatively large quantities. |
| mid-columbia dams | Dams owned by the mid-Columbia Public Utility Districts |
| confined aquifer | an aquifer that lies between two rock layers of very low permeability |
| cumulative effects | The combined environmental impacts that accrue over time and space from a series of similar or related individual actions, contaminants, or projects. |
| losses incidental to irrigation | The quantity of water depleted by irrigation in excess of the beneficial irrigation consumptive use. |
| stage | The level of the water surface above a given datum at a given location. |
| instability | Atmospheric condition where a parcel of air is warmer that the surrounding air in the immediate environment |
| normal year | A year during which the precipitation or stream flow approximates the average for a long period of record. |
| devonian | Geologic period that occurred roughly 360 to 408 million years ago |
| entrance region | The region upstream from a wind speed maximum in a jet stream (jet max), in which air is approaching (entering) the region of maximum winds, and therefore is accelerating |
| cliff | A very steep slope of rock or soil. |
| population density | number of people per unit area, usually people per square kilometre. |
| bank-full channel depth | the maximum depth of a channel within a rifle segment when flowing at a bank-full discharge. |
| geyser | A periodic thermal spring that results from the expansive force of super heated steam |
| phreatic water | Synonymous with the Zone of Saturation. |
| drainage basin | is a part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. |
| temperature inversion | a situation where temperature of air in the lower troposphere increases with height. |
| output | relates to activity and means the amount of goods and services produced |
| gorge | deep, narrow, steep (often vertical) -sided valley which usually has a river occupying its entire floor. |
| hydrologic model | Mathematical formulations that simulate hydrologic phenomenon considered as processes or as systems. |
| human development index | an attempt to make 'fairer' but still statistical measurements of development that became popular at the UN in the 1990s |
| hydrologic cycle | Often called the water cycle, it is the vertical and horizontal transport of water in all its states between the earth, the atmosphere, and the seas. |
| salinity | Concentration of dissolved salts found in a sample of water |
| lagoon | A lagoon is a shallow body of water that is located alongside a coast. |
| limnology | The study of the physical, chemical, hydrological, and biological aspects of fresh water. |
| floe | An accumulation of frazil flocs (also known as a "pan") or a single piece of broken ice. |
| parcel | A volume of air small enough to contain uniform distribution of its meteorological properties and large enough to remain relatively self-contained and respond to all meteorological processes. |
| share-cropping | a system of land rent where the farmer pays with a percentage of his yield rather than cash. |
| colloids | finely divided solids which will not settle but which may be removed by coagulation or biochemical action. |
| coral bleaching | Situation where coral lose their colorful symbiotic algae |
| solar radiation | Electromagnetic radiation that originates from the Sun |
| geyser | a periodic thermal spring that results from the expansive force of super heated steam. |
| volcano | A volcano is a mountainous vent in the Earth's crust |
| stream reach | An individual segment of stream that has beginning and ending points defined by identifiable features such as where a tributary confluence changes the channel character or order. |
| environmental impact | the positive or negative effect of any action upon a given area or source. |
| precambrian shield | Another term for shield. |
| meander amplitude | The distance between points of maximum curvature of successive meanders of opposite phase in a direction normal to the general course of the meander belt, measured between centerlines of channels. |
| absolute | The micron rating of a filter |
| rocketsonde | A type of radiosonde that is shot into the atmosphere by a rocket, allowing it to collect data during its parachute descent from a higher position in the atmosphere than a balloon could reach. |
| recharge | refers to water entering an underground aquifer through faults, fractures, or direct absorption. |
| nurp | National Urban Runoff Program |
| lake | an inland body of water, usually fresh water, formed by glaciers, river drainage etc |
| runoff | Water that flows over the ground and reaches a stream as a result of rainfall or snowmelt. |
| bivalve | any animal with a two-part, hinged shell. |
| pathogen | a disease-producing agent; usually applied to a living organism |
| landscape | A heterogenous land area with interacting ecosystems that are repeated in similar form throughout. |
| miller cylindrical projection | Map projection that mathematically projects the Earth's surface onto a cylinder that is tangent at the equator |
| runoff | Water from rainfall or snowmelt, which flows across the ground surface into drainage facilities, rivers, streams, ponds, lakes and wetlands or shallow groundwater. |
| infant mortality | the number of deaths of infants below one year of age as a proportion of every thousand live births in that population in that year. |
| dewater | The separation of water from sludge, to produce a solid cake. |
| control | designates a feature downstream from the gage that determines the stage-discharge relation at the gage |
| ocean trench | deep depressions in the ocean floor (up to 11km) formed at a subduction zone where the denser plate is forced below the less dense one. |
| terminal velocity | Maximum speed that can be achieve by a body falling through a fluid like water or air. |
| gallery | "(1) A passageway within the body of a dam or abutment; hence the terms ""grouting gallery,"" ""inspection gallery,"" and ""drainage gallery."" (2) A long and rather narrow hall; hence the following terms for a power plant: ""valve gallery,"" ""transformer gallery,"" and ""busbar gallery.""" |
| awips | An acronym for Advanced Weather Interactive Processing System |
| membrane filter | Filter made of plastic or modified cellulose and having a known pore diameter |
| cuspate foreland | Is a triangular accumulation of sand and/or gravel located along the coastline |
| playa | Flat-floored bottom of an undrained desert plains basin. |
| gage datum | The arbitrary zero datum elevation which all stage measurements are made from. |
| mesoscale convective complex | A large mesoscale convective system (MCS) which is about the size of the state of Ohio or Iowa and lasts at least 6 hours |
| englacial | All the glacial environments which occur within the ice itself are called englacial environments. |
| aurora | A glowing light display in the nighttime sky cause by excited gases in the upper atmosphere giving off light |
| interception storage requirements | Water caught by plants at the onset of a rainstorm |
| delta | an alluvial deposit made of rock particles (sediment, and debris) dropped by a stream as it enters a body of water. |
| visible satellite imagery | This type of satellite imagery uses reflected sunlight (this is actually reflected solar radiation) to see things in the atmosphere and on the Earth's surface |
| base flood | The flood having a 1 percent average probability of being equaled or exceeded in a given year at a designated location |
| capitalism | a social and economic system relying on market mechanisms to allocate factors of production which are privately rather than state owned. |
| unesco | the United Nations Educational, Scientific and Cultural Organisation |
| federalism | the combination of smaller states under a larger, national (federal) government to improve ability and efficiency in providing some administrative functions e.g |
| magma | Molten rock originating from the Earth's interior. |
| kolkhoz | a collective farm in the USSR. |
| multicell storm | A thunderstorm made up of two or more single-cell storms. |
| ball lightning | A relatively rare form of lightning consisting of a luminous ball, often reddish in color, which moves rapidly along solid objects or remains floating in mid-air |
| sea ice | Ice that is formed by the freezing of sea water |
| basal sliding | The sliding of a glacier over the ground on a layer of water. |
| inch-degrees | The product of inches of rainfall multiplied the temperature in degrees above freezing (Fahrenheit Scale), used as a measure of the snowmelting capacity of rainfall.. |
| tarn | A small mountain lake that occurs inside a cirque basin. |
| seed bank | Collection of seeds available for germination in the soil. |
| central place theory | the idea that all settlements influence the area surrounding them in the provision of goods and services -the sphere of influence |
| ice floes | Areas of broken pack ice, chaotically fractured and floating on the near-frozen sea |
| dependent variable | Variable in a statistical test whose observation's values are thought to be controlled through cause and effect by another independent variable modeled in the test. |
| blowdown | The water drawn from boiler systems and cold water basins of cooling towers to prevent the buildup of solids. |
| transpiration | An essential physiological process in which plant tissues give off water vapor to the atmosphere. |
| net rainfall | The portion of rainfall which reaches a stream channel or the concentration point as direct surface flow. |
| trace | 1) A rainfall amount less than 0.01 of an inch |
| mean sea level | The average height of the surface of the sea at a particular location for all stages of the tide over a 19-year period |
| hydrodynamic loads | Forces imposed on structures by floodwaters due other impacts of moving water on the upstream side of the structure, drag along its sides, and eddies or negative pressures on its downstream side. |
| soil structure | General term that describes how mineral and particles organic matter of are organized and clumped together in a soil. |
| operable unit | a term used by the Superfund program to describe a discrete action that comprises an incremental step toward comprehensively addressing site problems |
| inversely proportional | Cause and effect relationship between two variables where a positive or negative change in the quantity of one causes a predictable opposite change in quantity in the other. |
| inset | An inflow, as of water; a channel. |
| entrainment | (Streams) The incidental trapping of fish and other aquatic organisms in the water, for example, used for cooling electrical power plants or in waters being diverted for irrigation or similar purposes. |
| contiguous habitat | Habitat suitable to support the life needs of a species that is distributed continuously across the landscape. |
| wfo | A National Weather Service Weather Forecast Office. |
| fujita tornado intensity scale | Tornado classification system developed by T |
| urban | built-up area |
| municipal watershed | The watershed from which the runoff is used for drinking purposes in a city. |
| vortex | A rapid spiraling motion of air or liquid around a center of rotation. |
| barrage | Any artificial obstruction placed in water to increase water level or divert it |
| pirep | An acronym for pilot report. |
| solute | a substance that is dissolved in another substance, thus forming a solution. |
| analog | Class of devices in which the output varies continuously as a function of the input. |
| frost | sublimation of water vapour directly onto surfaces such as plants, cars and pavements when very rapid heat loss occurs during an anticyclone during winter when temperatures allow the formation of ice crystals. |
| nuclear energy | uranium is processed into uranium dioxide, which undergoes nuclear fission |
| threatened species | Under the Federal Endangered Species Act, animal populations may be determined to be either threatened or endangered |
| truncated spurs | Triangular hillside features due to glacial erosion of the headlands between two former streams. |
| key watershed | As defined by National Forest and Bureau of Land Management District fish biologists, a watershed containing (1) habitat for potentially threatened species or stocks of anadromus salmonids or other potentially threatened fish, or (2) greater than six square miles with high-quality water and fish habitat. |
| limited water-soluble substances | (Water Quality) Water pollution chemicals that are soluble in water at less than one milligram of substance per liter of water. |
| drainage basin | A part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water |
| breaker | The quick collapse of an overextended water wave as it approaches the shoreline |
| limestone pavement | a lagstone-pattern appearing on exposed, flat upper surfaces of a mass of limestone |
| chott | the name given to depressions found along and within the northern border zone of the Sahara which fill with water from the overland flow during flash floods |
| glacial trough | A deep U-shaped valley with steep valley walls that was formed from glacial erosion |
| product distribution | Direct support for all national and international marine users |
| watershed | (1) All lands enclosed by a continuous hydrologic drainage divide and lying upslope from a specified point on a stream |
| miscibility | The ability of two liquids to mix. |
| ferralitic | a soil in which the heavy leaching of silica leaves a higher concentration of iron giving the soil a rich red colour |
| notch | The opening in a dam or spillway for the passage of water. |
| bergeron-findeison process | a theory of raindrop formation |
| field | (1) A broad, level, open expanse of land; a meadow |
| cleavage | The tendency of some minerals or rocks to break along planes of weakness |
| haploid | Cell that contains only one set of chromosomes |
| fecal coliform | the portion of the coliform bacteria group which is present in the intestinal tracts and feces of warm-blooded animals |
| rain area | (1) The area indicated on a weather map over which rain fell within a certain period of time |
| population | The number of people living in a certain area. |
| storm tracks | The path or tracks generally followed by a cyclonic disturbance. |
| perfected water right | a water right which indicates that the uses anticipated by an applicant, and made under permit, were made for beneficial use |
| land reform | imposed redistribution of land and/or changes in land ownership designed to increase agricultural productivity under the philosophy that owner-occupiers make more of an effort therefore as much agricultural land as possible should be owner-occupied. |
| meander | The winding of a stream channel. |
| brackish water | Water that is neither falls in the category of salt water, nor in the category of fresh water |
| forest hydrology | The study of hydrologic processes as influenced by forest and associated vegetation. |
| dissolved oxygen | The amount of free (not chemically combined) oxygen in water |
| indigenous | Existing, growing, or produced naturally in a region. |
| ribbon lightning | Appears to be a broad stream of fire |
| invof | An acronym for "in vicinity of". |
| juvenile | Fish from one year of age until sexual maturity. |
| land retirement | (Agriculture) Taking land out of agriculture production by leaving it fallow or letting it return to a natural state. |
| size | Area of cloud top -32 degrees C or less: 100,000 square kilometers or more (slightly smaller than the state of Ohio), and area of cloud top -52 degrees C or less: 50,000 square kilometers or |
| persistence | The length of time during which a signal is visible on a radar display. |
| surcharge capacity | The volume of a reservoir between the maximum water surface elevation for which the dam is designed and the crest of an uncontrolled spillway, or the normal full-pool elevation of the reservoir with the crest gates in the normal closed position. |
| suspension | the transport of load in the body of the water in a river i.e being carried along in the flow. |
| nitrogen supersaturation | A condition of water in which the concentration of dissolved nitrogen exceeds the saturation level of water |
| river statement | A product issued to communicate notable hydrologic conditions which do not involve flooding, i.e., within river bank rises, minor ice jams, etc. |
| head | The difference between the pool height and tailwater height |
| headrace | A channel that carries water to a water wheel or turbine; a forebay. |
| ultraviolet radiation | Electromagnetic radiation with a wavelength between 0.1 and 0.4 micrometers (µm). |
| latent heat | release of heat during a change of state |
| acid rain | the acidic rainfall which results when rain combines with sulfur oxides emissions from combustion of fossil fuels. |
| scute | An extendal bony plate, usually keeled. |
| facilitation | Modification of a system that makes subsequent modifications easier. |
| uncorrelated shear | It is a sufficiently strong circulation detected on only one elevation angle within a thunderstorm. |
| fcst | NWSRFS Forecast Program to produce operational forecasts. |
| litterfall | Movement of leaves, twigs and other forms of organic matter from the biosphere to the litter layer found in soil. |
| cold low | A low pressure system that has its coldest temperatures at or near the center of circulation, and is thermally barotropic with respect to a horizontal plane |
| soil porosity | The volume of water that can be held in a soil |
| protozoa | Heterotrophic eukaryotic unicellular organisms that belong to the kingdom protista. |
| synoptic chart | a weather map. |
| sub-basin | in general, a portion of a river basin. |
| environmental impact | The positive or negative effect of any action upon a give area or resource. |
| pulse repetition time | The time elapsed between pulses by the radar |
| lagoon system | (Water Quality) A system of scientifically construction Lagoons or ponds in which sunlight, algae, and oxygen interact to restore water to a quality equal to effluent from a Secondary Treatment Plant. |
| drainage density | The relative density of natural drainage channels in a given area |
| ecmwf | An acronym for European Centre for Medium-Range Weather Forecasting model. See European Model. |
| water contamination | Impairment of water quality to a degree which reduces the usability of the water for ordinary purposes, or which creates a hazard to public health through poisoning or spread of disease. |
| pyramid of biomass | Graphic model describing the distribution of biomass in an ecosystem or community at the trophic level |
| opisometer | Mechanical device for measuring non-linear distances on maps. |
| storm sewer | a sewer that carries only surface runoff, street wash, and snow melt from the land |
| tarn lake | After melting, the central depression of a former cirque may hold a tarn lake. |
| river basin plan | A plan for the development of water and related land resources to make the best use of such resources to meet the basin needs and make the greatest long-term contribution to the economic growth and social well-being of the people of the basin and the nation. |
| pelagic | Of or in the open ocean or open water. |
| lysimeter | Meteorological instrument used to measure potential and actual evapotranspiration. |
| spillway crest | The elevation of the highest point of a spillway. |
| water quality | A term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose. |
| sunspot | Dark colored region on the Sun that represents an area of cooler temperatures and extremely high magnetic fields. |
| free-flowing weir | A weir that in use has the tailwater lower than the crest of the weir. |
| full-sib family | A group of individuals that shares the same two parents (i.e., brothers and sisters) |
| rural-urban migration | the movement of people from rural areas to urban areas. |
| seasonal application efficiency | The sum of evapotranspiration of applied water and leaching requirement divided by the total applied water, expressed as a percentage: SAE=(ETAW+LR)/AW. |
| summation layer amount | The amount of sky cover for each layer is given in eighths of sky cover attributable to clouds or obscurations |
| luvisol soil | Soil order (type) of the Canadian System of Soil Classification |
| recurrence interval | average amount of time between events of a given magnitude |
| frost | Deposition of ice at the Earth's surface because of atmospheric cooling. |
| coastline | The line that separates a land surface from an ocean or sea. |
| zonal soil | soils that have been under development for a very long period of time and therefore show characteristics clearly attributable to the biome in which they are found. |
| stream load | Refers to the material or sediment carried by a stream |
| thermosphere | Atmospheric layer above the mesosphere (above 80 kilometers) characterized by air temperatures rising rapidly with height |
| sand filter | (Water Quality) A device used to remove particles from drinking water prior to distribution to customers |
| conflicting uses | Uses that act to the detriment of other users |
| slack water | (1) The period at high or low tide when there is no visible flow of water |
| ctenoid scales | A type of fish scale that has spines or ctenii on the posterior or exposed portion, found on bass, walleye, and other fish. |
| enhancement | Emphasis on improving the value of particular aspects of water and related land resources. |
| project efficiency | The project efficiency is a general term referring to the efficiency relating to all aspects of a project's use of water. |
| biological oxidation | Decomposition of complex organic materials by microrganisms through oxidation. |
| ejector | A device used to inject a chemical solution into wastewater during water treatment. |
| mafic magma | Magma that is relative poor in silica but rich in calcium, magnesium, and iron content |
| land spreading | The disposal of solid effluents derived from wastewater treatment facilities on the surface of the ground for dilution or dispersal. |
| literacy | the ability to read and write |
| source | the start point of a stream or river. |
| alkaline | the condition of water or soil that contains a sufficient amount of alkali substance to raise the pH above 7.0. |
| stratified drift | A type of glacial drift that has been partially sorted by glaciofluvial meltwater. |
| marsh | A type of wetland that does not accumulate appreciable peat deposits and is dominated by herbaceous vegetation |
| immiscibility | the inability of two or more substances or liquids to readily dissolve into one another, such as soil and water. |
| period | Geologic time unit that is shorter than an era but longer than a epoch. |
| day-second feet | Often abbreviated as DSF |
| genotype | The complement of genes in an individual |
| minimum spanning tree | A means of depicting nearest genetic neighbors |
| storm tracking information | This WSR-88D radar product displays the previous, current, and projected locations of storm centroids (forecast and past positions are limited to one hour or less). Forecast tracks are based upon linear extrapolation of past storm centroid positions, and they are intended for application to individual thunderstorms not lines or clusters. It is used to provide storm movement: low track variance and/or 2 or more plotted past positions signify reliable thunderstorm movement. |
| wastewater | Water that contains dissolved or suspended solids as a result of human use. |
| confluence | where two river channels join. |
| biogeochemical cycling | Cycling of a single element, compound or chemicals by various abiotic and biotic processes through the various stores found in the biosphere, lithosphere, hydrosphere, and atmosphere. |
| stability | The capability of a system to tolerate or recover from disturbance or an environmental stress. |
| ecology | The study of the relationships between living organisms and their environment. |
| longwave radiation | See infrared radiation. |
| lightning discharge | The series of electrical processes by which charge is transferred along a channel of high ion density between electrical charge centers of opposite sign |
| neutral | Any substance with a pH around 7. |
| plastic deformation | Irreversible change in the shape of a material without fracture as the result of the force of compression or expansion. |
| climograph | Two dimensional graph that plots a location's air temperature and precipitation on times scales that range from a 24 hour period to a year. |
| scarp | the steep slope of an escarpment. |
| base flows | the component of a flow regime that represents normal flow conditions between precipitation events |
| oxygen depletion | The reduction of the dissolved oxygen level in a water body. |
| secondary sector | manufacturing industry. |
| short wave | A progressive wave of smaller amplitude, wave length, and duration than a long wave |
| contaminant | anything present in the environment that could be harmful to human health (including microorganisms, minerals, chemicals). |
| mechanical aeration | Use of mechanical energy to inject air into water to cause a waste stream to absorb oxygen. |
| latifundia | system of landholding found most commonly in Latin America |
| nitrogen fixation | a process carried out by certain algae and soil bacteria whereby atmospheric nitrogen is incorporated to form nitrogen-based organic compounds |
| reclaimed land | artificial land created in coastal areas. |
| siphon tubes | (Irrigation) Small curved pipes, typically 0.5-4.0 inches (1.3-10.2 centimeters) in diameter, that deliver water over the side of a head ditch or lateral to furrows, corrugations, or borders. |
| advection | horizontal transfer of heat by a horizontally moving air mass. |
| mudballs | round material that forms in filters and gradually grows when not removed by backwashing. |
| syzygy | The instance (new moon or full moon) when the earth, sun, and moon are all in a straight line. |
| pan handle hook | Low pressure systems that originate in the panhandle region of Texas and Oklahoma which initially move east and then "hook" or recurve more northeast toward the upper Midwest or Great Lakes region. In winter, these systems usually deposit heavy snows north of their surface track. Thunderstorms may be found south of the track. |
| urbanization | the increasing percentage of a population living in urban areas due to rural-urban migration and higher levels of natural increase in the urban areas. |
| overdraft | Withdrawals of ground water at rates perceived to be excessive |
| fluoridation | The addition of a chemical to increase the concentration of fluoride ions in drinking water |
| drainage area | An area having a common outlet for its surface runoff (also see Watershed and Catchment Area). |
| bubblers | Irrigation heads which deliver water to the soil adjacent to the heads. |
| fresh water | such as a river or stream, (see lentic). |
| survival rate | Number of fish alive after a specified time interval, divided by the initial number |
| waste utilization | Using an agricultural or other waste on land in an environmentally acceptable manner while maintaining or improving soil and plant resources. |
| fathom | A unit of length equal to six feet which is used to measure the depth of water. |
| ph | numeric value that describes the intensity of the acid or basic (alkaline) conditions of a solution |
| irrigation efficiency | The percentage of water applied that can be accounted for in soil moisture increase for consumptive use. |
| map projection | the system of representing the three-dimensional surface of the world into the two-dimensional surface of a piece of paper. |
| capillary action | (1) The action by which water is drawn around soil particles because there is a stronger attraction between the soil particles and the water molecules themselves |
| aquifer | Permeable layers of underground rock, or sand that hold or transmit groundwater below the water table that will |
| closed basin | A basin draining to some depression or pond within its area, from which water is lost only by evaporation or percolation |
| solar radiation | see insolation. |
| aquatic | although many are planktonic, some species are extremely large. |
| cites | Convention on International Trade in Endangered Species of Wild Flora and Fauna -an international agreement designed to limit the harmful impacts of removal of plants and animals from their natural habitats, especially those whose population numbers decline to critical levels |
| gravity irrigation | (1) Irrigation in which the water is not pumped but flows and is distributed by gravity, includes sprinkler systems when gravity furnishes the desired head (pressure) |
| kcfs | A measurement of water flow equivalent to 1,000 cubic feet of water passing a given point for an entire second. |
| catchment | (1) the catching or collecting of water, especially rainfall |
| spawning stock biomass | The total weight of all sexually mature fish in the population |
| plucking | a form of glacial erosion in which ice freezes on to rock and pulls it away when the glacier moves on. |
| sedimentation | the accumulation of sediment. |
| tropical wave | Another name for an easterly wave, it is an area of relatively low pressure moving westward through the trade wind easterlies |
| riverine habitat | The aquatic habitat within streams and rivers. |
| intercepting drain | A drain constructed at the upper end of an area to intercept and carry away surface or ground water flowing toward the area from higher ground. |
| subbasin | Major tributaries to and segments of the Columbia and Snake rivers. |
| biotechnology | use of biological knowledge and research to developing technologies especially in pharmaceutical areas. |
| duststorm | A severe weather condition characterized by strong winds and dust-filled air over a large area |
| system loss | An amount of water, expressed as a percentage, lost to leaks, seepage and unauthorized use. |
| dike | (1) (Engineering) An embankment to confine or control water, especially one built along the banks of a river to prevent overflow of lowlands; a levee |
| regulation reservoir | A reservoir used in canal and irrigation systems to reduce the mismatch between downstream demands and upstream water supplies in order to maintain a balanced operation. |
| rating curve | a graph showing the relationship between water surface elevation and discharge of a stream or river at a given location |
| microburst | One of 2 categories of downbursts (the other category is called a macroburst) |
| stream discharge | A river or stream's rate of flow over a particular period of time |
| dam | Any artificial barrier which impounds or diverts water |
| ctenoid | Having a comb-like margin. |
| light absorption | The amount of light a certain amount of water can absorb over time. |
| nomad | a person without a permanent home who moves from place to place throughout the year seeking subsistence |
| impermeable | Not capable of transmitting fluids or gases in appreciable quantities |
| stratiform rings and bands | These occur between the active convective bands of a hurricane outside of the eye wall |
| spheroidal weathering | A type of below ground chemical weathering where the corners of jointed rocks become rounded over time |
| mechanisation | the replacement of human and/or animal labour with machines. |
| pathogens | Any virus, bacteria, or fungi that cause disease. |
| exotic species | one found in an area to which it is not native. |
| virga | It is a patch of precipitation that evaporates before it reaches the ground |
| lightning ignition efficiency | Ignition efficiency is calculated by algorithm, using the National Fire Danger Rating System (NFDRS) 100 hour fuel moisture and specialized fuel type maps for the western United States to indicate probability of ignition, given occurrence of lightning. |
| microbarograph | A instrument designed to continuously record a barometer's reading of very small changes in atmospheric pressure. |
| coniferous woodland | woodland or forest made up of softwood trees having common characteristics such as an evergreen appearance, waxy needle-like leaves and usually producing seeds within cones which open to allow dispersal by wind. |
| positive feedback | Change in the state of a system that enhances the measured effect of the initial alteration. |
| distribution system | the network of pipes leading from a treatment plant to customers' plumbing systems. |
| automated event-reporting gage | (see Tipping Bucket Rain Gage); for river stage gages, IFLOWS pressure transducer type gages can be programmed to report if water surface rises or falls by a predetermined amount. |
| surface runoff | The portion of rainfall that moves over the ground toward a lower elevation and does not infiltrate into the soil. |
| fluid | Substance, gas or liquid, that has the property of flow. |
| potential natural water loss | The water loss during years when the annual precipitation greatly exceeds the average water loss |
| hydrograph separation | The process where the storm hydrograph is separated into baseflow components and surface runoff components. |
| headward erosion | Erosion which occurs in the upstream end of the valley of a stream, causing it to lengthen its course in such a direction. |
| positive area | The area on a sounding representing the layer in which a lifted parcel would be warmer than the environment; thus, the area between the environmental temperature profile and the path of the lifted parcel |
| glacial retreat | The backwards movement of the snout of a glacier. |
| fog bow | A nebulous arc or circle of white or yellowish light sometimes seen in fog. |
| vadose zone | The locus of points just above the water table where soil pores may either contain air or water |
| microhabitat | zones of similar physical characteristics within a mesohabitat unit, differentiated by aspects such as substrate type, water velocity, and water depth. |
| toxic release inventory | A database of annual toxic releases from certain manufacturers compiled from EPCRA Section 313 reports |
| anerobic | Characterizing organisms able to live and grow only where there is no air or free oxygen, and conditions that exist only in the absence of air or free oxygen. |
| recharge | The introduction of surface or ground water to groundwater storage such as an aquifer |
| recurrence interval | The average amount of time between events of a given magnitude |
| solvent | Substance (usually liquid) capable of dissolving one or more other substances. |
| carbon cycle | Storage and cyclic movement of organic and inorganic forms of carbon between the biosphere, lithosphere, hydrosphere, and atmosphere. |
| cyclonic rainfall | see depressions. |
| hydric | Wet. |
| ultisols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| supercritical water | a type of thermal treatment using moderate temperatures and high pressures to enhance the ability of water to break down large organic molecules into smaller, less toxic ones |
| zooplankton | animal species of plankton. |
| aquifer | An underground geological formation, or group of formations, containing water |
| reference mark | A relatively permanent point of known elevation which is tied to a benchmark. |
| infiltration | Movement of water through the soil surface into the soil. |
| water yield | The quantity of water derived from a unit area of watershed. |
| holocene epoch | Period of time from about 10,000 years ago to today |
| water right | Legal rights to use a specific quantity of water, on a specific time schedule, at a specific place, and for a specific purpose. |
| icicle | Ice that forms in the shape of a narrow cone hanging point down |
| competitive exclusion | Situation where no two competitively interacting species can occupy exactly the same fundamental niche indefinitely because of resource limitations |
| capillary fringe | The soil area just above the water table where water can rise up slightly through the cohesive force of capillary action |
| swe | Snow Water Equivalent |
| eutrophic lake | Lake that has an excessive supply of nutrients, mostly in the form of nitrates and phosphates |
| odd-numbered properties | Properties whose official address ends in an odd number, excluding city parks and golf courses |
| nutrient | Any food, chemical element or compound an organism requires to live, grow, or reproduce. |
| eukaryotic organelles | they may have photosynthetic pigments but lack chloroplasts, the specialized photosynthetic organelles in higher plants, and mitochondria. |
| european parliament | the elected body of representatives who draft legislation appropriate to the pan-European members of the EU |
| base width | (1) The time interval between the beginning and end of the direct runoff produced by a storm |
| aurora | It is created by the radiant energy emission from the sun and its interaction with the earth's upper atmosphere over the middle and high latitudes |
| wsr-57 | A NWS Weather Surveillance Radar designed in 1957. It used to be part of weather radar network. It was replaced by WSR-88D units. |
| catastrophism | General theory that suggests that certain phenomena on the Earth are the result of catastrophic events |
| flood stage | A gage height at which a watercouse overtops its banks and begins to cause damage to any portion of the defined |
| greenhouse effect | The heating effect caused by gases in the atmosphere absorbing heat (solar radiation) instead of letting it escape back into space |
| partly cloudy | When the predominant/average sky condition is covered 3/8 to 4/8 with opaque (not transparent) clouds. Same as Partly Sunny. |
| raceway | A rectangular fish rearing unit that has a continuous flow of freshwater to maintain suitable oxygen, temperature, and cleanliness for intensive production. |
| direct flood damage | The damage done to property, structures, goods, etc., by a flood as measured by the cost of replacement and repairs. |
| rain foot | Slang for a horizontal bulging near the surface in a precipitation shaft, forming a foot-shaped prominence |
| irrigation requirement | The quantity of water, exclusive of precipitation, that is required for production of a specific crop. |
| non-tributary groundwater | Underground water in an aquifer that neither draws from nor contributes to a natural surface stream in any measurable degree. |
| ice rafted debris | Material carried by floating ice that eventually melts and is deposited on the floor of the sea or a lake. |
| base | a substance that has a pH of more than 7, which is neutral |
| in-situ oxidation | technology that oxidizes contaminants dissolved in groundwater, converting them into insoluble compounds. |
| viscosity | The syrupiness of water and it determines the mobility of the water |
| clay | Substrate particles that are smaller than silt and generally less than 0.004 mm in diameter. |
| spawning surveys | Spawning surveys utilize counts of redds and fish carcasses to estimate spawner escapement and identify habitat being used by spawning fish |
| wfo | A National Weather Service Weather Forecast Office. |
| field capacity | The amount of water held in soil against the pull of gravity. |
| shortwave radiation | Electromagnetic radiation with a wavelength between 0.1 and 0.7 micrometers (µm) |
| relative humidity | A dimensionless ratio, expressed in percent, of the amount of atmospheric moisture present relative to the amount that would be present if the air were saturated |
| birth control programme | a systematic approach to controlling the birth rate in a particular area, usually at the national or sub-national level in an ELDC. |
| deepening | Used in describing the history of a low pressure system or an area of cyclonic circulation, it means a decrease in the central pressure of the system |
| bacterial water contamination | The introduction of unwanted bacteria into a water body. |
| bed material | The sediment mixture that a streambed is composed of. |
| zeta potential | An electrokinetic measurement which can be used for the control of coagulation processes. |
| valley wall | The side slope of a stream or glacial valley. |
| lithification | the cementing of sediments to form rock. |
| wind speed | The rate at which air is moving horizontally past a given point |
| deflation hollow | A surface depression or hollow commonly found in arid and semiarid regions caused by wind erosion |
| great circle | An imaginary circle drawn on the Earth's surface that has its center synchronize to the center of the planet |
| surface irrigation | application of water by means other than spraying such that contact between the edible portion of any food crop and the irrigation water is prevented. |
| pathogen | Microscopic parasite organism that causes disease in a host |
| fiscal policy | those government policies relating to raising revenue (through taxation and other measures) and government spending (on what it should spend and to what level). |
| hydraulic fracturing | Any technique involving the pumping of fluid under high pressure into an oil or gas formation to create fissures and openings in the reservoir rock and increase the flow of oil or gas. |
| convection | Motions in a fluid that transport and mix the properties of the fluid |
| kame | A steep-sided, conical mound or hill formed of glacial drift that is created when sediment is washed into a depression on the top surface of a glacier and then deposited on the ground below when the glacier melts away. |
| breach | The failed opening in a dam. |
| volcanic cone | see volcano. |
| santa ana wind | A strong, hot, dry foehn-like wind that blows from the north, northeast, or east into southern California. |
| arch | when a cave in the side of a headland is eroded right through to the other side forming a bridge-shaped landform. |
| quarry | open-air works where rock is removed for commercial use. |
| boiling point | the temperature at which a liquid boils |
| floodplain | Any normally dry land area that is susceptible to being inundated by water from any natural source |
| wet meadow | Areas where grass predominate |
| market | can be seen in two ways: |
| graded stream | A stream that has a long profile that is in equilibrium with the general slope of the landscape |
| riparian rights | Water rights that are acquired together with title to the land bordering a source of surface water; the right to put to beneficial use surface water adjacent to one's land |
| hydrostatic head | A measure of pressure at a given point in a liquid in terms of the vertical height of a column of the same liquid which would produce the same pressure. |
| degree day | It gauges the amount of heating or cooling needed for a building using 65 degrees as a baseline |
| frazil ice | Disorganized, slushy ice crystals in the water column, usually near the water surface |
| frost creep | Slow mass movement of soil downslope that is initiated by freeze-thaw action |
| global warming | the warming of the atmosphere, or more properly the increase over time in average annual global temperature |
| field capacity | The capacity of soil to hold water |
| disturbance | This has several applications |
| resident species | Species of fish which spend their entire lives in freshwater. |
| nucleated settlement | the arrangement of buildings in a settlement in a tight cluster as a result of the landscape e.g |
| interglacial | Period of time during an ice age when glaciers retreated because of milder temperatures. |
| beam width | The angular width of the radar beam. |
| kilowatt-hour | A unit of electrical energy equal to 1,000 watt-hours or a power demand of 1,000 watts for one hour |
| rain | Precipitation, either in the form of drops larger than 0.02 inch (0.5 mm), or smaller drops, which in contrast to drizzle, are widely separated |
| soft water | Water that contains low concentrations of multivalent cations, such as calcium and magnesium |
| meltwater | Water produced from the melting of snow and/or glacial ice. |
| northing | the horizontal gridlines on a map so called because their numeric value increases from south to north. |
| aquifer | one that does not deliver drinking water, an unused aquifer or below the levels of fresh water. |
| breakup | The time when a river whose surface has been frozen from bank to bank for a significant portion of its length begins to change to an open water flow condition |
| cold | A condition marked by low or decidedly subnormal temperature |
| phytoplankton | Usually microscopic aquatic plants, sometimes consisting of only one cell. |
| preopercle | The large membrane bone lying in front of and parallel to the opercle. |
| certificate of water right | An official document which serves as evidence of a Perfected Water Right. |
| mesotrophic lake | Lake with a moderate nutrient supply |
| effective precipitation | (1) That part of the precipitation that produces runoff |
| vacuum filtration | (Water Quality) A process by which liquid is extracted from a sludge |
| recharge zone | A land area into which water can infiltrate into an Aquifer relatively easily |
| forminifera | a protozoan, microscopic shellfish which proliferates in warm marine environments and whose sedimentation leads eventually to the formation of chalk. |
| natural production | See Naturally spawning populations. |
| desert | A desert is a very dry area. |
| nccf | An acronym for the NOAA Central Computer Facility. |
| snow stake | A 1-3/4 inch square, semi-permanent stake, marked in inch increments to measure snow depth. |
| braided stream | Characterized by successive division and rejoining of streamflow with accompanying islands |
| jennie salmon | A young female salmon that matures precociously(earlier than other fish in its age-class). |
| hydraulic gradient | In general, the direction of groundwater flow due to changes in the depth of the water table. |
| metamorphic rock | A rock that forms from the recrystallization of igneous, sedimentary or other metamorphic rocks through pressure increase, temperature rise, or chemical alteration. |
| forfeiture | The invalidation of a water right because of five or more consecutive years of nonuse. |
| groundwater law | the common law doctrine of riparian rights and the doctrine of prior appropriation as applied to ground water. |
| dry valley | valley, usually found in upland areas of limestone or chalk, demonstrating the characteristics of a typical upper course river, but containing no river. |
| tail-end charlie | Slang for the thunderstorm at the southernmost end of a squall line or other line or band of thunderstorms |
| sediment dam | A structure used specifically to trap sediment in water and prevent its transport further downstream. |
| morphology | the form, shape, or structure of a stream or organism. |
| climatic year | a period used in meteorological measurements |
| troposphere | lower layer of the atmosphere, from the surface to the tropopause |
| pluvial | In hydrology, anything that is brought about directly by precipitation. |
| artesian | Water held under pressure in porous rock or soil confined by impermeable geological formations. |
| separate sewer | a sewer system that carries only sanitary sewage, not stormwater runoff |
| map scale | The relationship between the actual size of a place and its size as shown on a map. |
| floodplain | The flat or nearly flat land along a river or stream or in a tidal area that is covered by water during a flood. |
| genus | A group in the classification of organisms |
| fission | Reproduction of microrganisms by means of cell division. |
| immigration | Referring to the movement of organisms into an area |
| chemical reaction | Reaction between chemicals where there is a change in the chemical composition of the elements or compounds concerned. |
| fema | Federal Emergency Management Agency |
| chlorination | the adding of chlorine to water or sewage for the purpose of disinfection or other biological or chemical results. |
| diversion channel | (1) An artificial channel constructed around a town or other point of high potential flood damages to divert floodwater from the main channel to minimize flood damages |
| deciduous woodland | woodland or forest made up of trees which have broad, flat leaves and which shed them annually during autumn, or fall |
| hydroelectric plant | A hydroelectric power plant which utilizes streamflow only once as the water passes downstream; electric power plant in which the energy of falling water is used to spin a turbine generator to produce electricity. |
| streamflow routing | A technique used to compute the effect of channel storage on the shape and movement of a flood wave. |
| blinds | water samples containing a chemical of known concentration given a fictitious company name and slipped into the sample flow of the lab to test the impartiality of the lab staff. |
| balanced groundwater scenario | A term referring to the development of a scenario exploring changes in cropping patterns such that long-term ground water withdrawals do not exceed long-term groundwater recharge rates. |
| ulj | An acronym for Upper Level Jet. See Jet Stream. |
| rapids | A part of a stream where the current is moving with a greater swiftness than usual and where the water surface is broken by obstructions, but without a sufficient break in slope to form a water fall, as where the water descends over a series of small steps |
| mfs | Micro Filtration System, it serves full automatic solid/ liquid separation. |
| cull | A tree or snag that does not meet merchantable specifications. |
| frame | The metal ring that holds a manhole in place. |
| precambrian | Span of geologic time that dates from 4.6 billion to 570 million years ago |
| civil emergency message | These National Weather Service statements are issued when a local or state official wants a warning disseminated regarding nuclear accidents, spills of toxic material, and other similar situations. |
| perched groundwater | Local saturated zones above the water table which exist above an impervious layer of limited extent. |
| aeration | A process which promotes biological degradation of organic matter in water |
| space environment center | This center provides real-time monitoring and forecasting of solar and geophysical events, conducts research in solar-terrestrial physics, and develops techniques for forecasting solar and geophysical disturbances |
| cercla | Comprehensive Environment Response, Compensation and Liability Act |
| hsa | A geographical area assigned to Weather Service Forecast Office's/Weather Forecast Office's that embraces one or more rivers. |
| boulder wind | A local name referring to an extremely strong downslope wind in the Front Range of the Rocky Mountains near Boulder, Colorado. |
| tube settler | Device using bundles of tubes to let solids in water settle to the bottom for removal by sludge. |
| element | A molecule composed of one type of atom |
| septic tank | a tank used to detain domestic wastes to allow the settling of solids prior to distribution to a leach field for soil absorption |
| radiosonde | A balloon-borne instrument that measures and transmits pressure, temperature, and humidity to a ground-based receiving station |
| confining bed | A body of "impermeable" material stratigraphically adjacent to one or more aquifers |
| grooves/grooving | As the glacier moves forward, rocks imbedded in the ice scratch the underlying materials |
| bed material | The sediment mixture of which a streambed, lake, pond, reservoir, or estuary bottom is composed. |
| schengen agreement | an agreement by some members of the EU to remove all travel restrictions for their nationals across the borders of the members. |
| bedrock | General term for consolidated (solid) rock that underlies soils or other unconsolidated material. |
| reserve supply | Developed but presently unused surface water supply available to certain portions of a hydrologic study or planning area (as defined) to meet planned future water needs; the supply is not usually available to other areas needing additional water because of a lack of physical facilities and/or institutional arrangements. |
| particle size | The sizes of a particle, determined by the smallest dimension, for instance a diameter |
| infiltrometer | An instrument which determines the rate and amount of water percolating into the soil by measuring the difference between the amount of water applied and that which runs off |
| pollution | The alteration of the physical, chemical, or biological properties of water by the introduction of any substance into water that adversely affects any beneficial use of water. |
| moho discontinuity | The lower boundary of the crust |
| mariculture | cultivation of fish and shellfish in estuarine and coastal areas |
| horn | A high mountain peak that forms when the walls of three or more glacial cirques intersect. |
| pyroxene | A group of single chained inosilicate minerals whose basic chemical unit is the silica tetrahedron (SiO4) |
| satellite images | Images taken by a weather satellite that reveal information, such as the flow of water vapor, the movement of frontal system, and the development of a tropical system |
| pancake ice | Circular flat pieces of ice with a raised rim; the shape and rim are due to repeated collisions. |
| ecology | The study of interrelationships of living organisms to one another and to their surroundings. |
| downwelling current | Ocean current that travels downward into the ocean because of the convergence of opposing horizontal currents or because of an accumulation of seawater. |
| counterurbanisation | decentralisation of population from large urban areas to smaller ones or rural areas |
| mixing ratio | The ratio between the weight (mass) of water vapor (or some other gas) held in the atmosphere compared to the weight of the dry air in a given volume of air |
| sewage treatment return flow | Water returned to the hydrologic system by sewage treatment facilities. |
| snow stake | A 1-3/4 inch square, semi-permanent stake, marked in inch increments to measure snow depth. |
| hydrology | the science dealing with the properties, distribution, and circulation of water. |
| funnel cloud | A condensation funnel extending from the base of a towering cumulus or Cb, associated with a rotating column of air that is not in contact with the ground (and hence different from a tornado) |
| glacier table | A rock sitting on top of a pillar of ice shielded from insolation by the rock's mass. |
| land application | discharge of wastewater onto the ground for treatment or reuse. |
| inbreeding depression | A reduction in fitness resulting from mating between close relatives that occurs by chance in small populations or by assortative mating in large populations. |
| public right-of-way | The designated area that lies between private property lines on the side that parallels the street |
| time lag | The time necessary for a fuel particle to lose approximately 63 percent of the difference between its initial moisture content and its equilibrium moisture content. |
| marine inversion | A temperature inversion created by the cooling of a warm airmass from below by the cool lakes on spring and summer days. The same effect can occur along the oceans anytime of the year. |
| core area | The area of habitat essential in the breeding, nesting, and rearing of young, up to the point of dispersal of the young. |
| htc | The Hydrometeorological Training Council. |
| comma echo | - A thunderstorm radar echo which has a comma-like shape |
| kame terrace | A long flat ridge composed of glaciofluvial sediment |
| percolation deep | In irrigation or farming practice, the amount of water that passes below the root zone of the crop or vegetation. |
| pothole | two types: |
| sustainable development | Development that ensures that the use of resources and the environment today does not restrict their use by future generations. |
| troposphere | the layer of atmosphere closest to the Earth, extending seven to ten miles above the surface, containing most of the clouds and moisture. |
| combined shear contour | This WSR-88D radar product is a contoured version of Combined Shear (CS) that is displayable alone or as an overlay on reflectivity or velocity products. It is generated upon radar operator request for the same elevation angle selected as the Combined Shear (CS) product. It is used: 1) as an overlay to highlight shear zones on velocity products; and 2) to identify low-level wind shear associated with gust fronts, downbursts, and mesoscale rotational phenomena. Aviation interests and operational researchers primarily use this radar product. |
| infuse | To steep in liquid (as water) without boiling so as to extract the soluble constituents or principles. |
| polar easterlies | Winds that originate at the polar highs and blow to the subpolar lows in a east to west direction. |
| clean water act | The federal law, enacted in 1972 as the Federal Water Pollution Control Act Amendments of 1972, and amended in 1977 as the Clean Water Act, that established the basic structure for regulating discharges of pollutants into the waters of the United States |
| bottomset bed | Horizontal deltaic deposit of alluvial sediment composed of fine silt and clay. |
| transition period | A period of environmental change during which a population increases or decreased to a new stable equilibrium level. |
| sample | water analyzed for regulated testing purposes. Taken from source water, within and leaving the treatment facility. |
| dormitory settlement | a rural settlement that is increased in size due to the influx of new residents from a nearby urban area |
| lifts | Layers of loose soil |
| net precipitation | The potential for Leachate generation from a waste disposal site |
| generation | Act or process of producing electric energy from other forms of energy |
| endemism | the characteristic of being confined to or indigenous in, a certain area or region. |
| hummock | A hillock of broken ice which has been forced upward by pressure. |
| oceanography | The study of the ocean, embracing and integrating all knowledge pertaining to the ocean's physical boundaries, the chemistry and physics of sea water, and marine biology. |
| inflow stinger | A beaver tail cloud with a stinger-like shape. |
| complex index of refraction | m = n + i*k, where n is the normal index of refraction, i is sqrt(-1), and k is the absorption coefficient. |
| perspire | To produce sweat or salty water from glands in the skin |
| throughflow | the movement of water through a soil to a river channel. |
| stage ii precipitation processing | The second level of precipitation processing, occurring within the WFO Advanced Weather Interactive Processing System (AWIPS) and performed on an hourly basis |
| one-tailed statistical test | Is an inferential statistical test where the values for which one can reject the null hypothesis are located entirely in one side of the center of the probability distribution. |
| crown | The upper part of a tree or other woody plant that carries the main system of branches and the foliage. |
| connectivity | the extent to which points, or nodes, in a network may be interconnected and thus a measure of the network efficiency in allowing transfers in space or time |
| sensitive species | Those species that (1) have appeared in the Federal Register as proposed for classification and are under consideration for official listing as endangered or threatened species or (2) are on an official state list or (3) are recognized by the U.S |
| diamicton | Unsorted, unstratified rock debris composed of a wide range of particle sizes |
| bank | The margins of a channel |
| hydrologic unit | is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature as delineated by the Office of Water Data Coordination on State Hydrologic Unit Maps; each hydrologic unit is identified by an eight-digit number. |
| water pollution | Generally, the presence in water of enough harmful or objectionable material to damage the water quality. |
| dew point | A measure of atmospheric moisture. The temperature to which air must be cooled, at constant pressure and moisture content, in order for saturation to occur |
| secondary data | (Data Analysis) Typically, data acquired from published sources as opposed to data acquired from direct observation or measurement such as a survey |
| lag | 1) |
| loess | Windblown rock flour of the silt size class |
| solonetzic soil | Soil order (type) of the Canadian System of Soil Classification |
| soil taxonomy | The classification of a soil in a hierarchical system based on its various properties |
| experiment | A controlled investigation designed to evaluate the outcomes of causal manipulations on some system of interest. |
| sustained overdraft | long term withdrawal from the aquifer of more water than is being recharged. |
| current | A horizontal movement of water, such as the Gulf Stream off the east coast of North America, or air, such as the jet stream. |
| swell | Wind-generated waves that have travelled out of their generating area. Swells characteristically exhibit smoother, more regular and uniform crests and a longer period than wind waves. |
| scientific method | The approach science uses to gain knowledge |
| mean sea level | The level of the surface of the sea between mean high and mean low tide; used as a reference point for measuring elevations. |
| secondary carnivore | See tertiary consumer. |
| ice lense | Horizontal accumulation of permanently frozen ground ice. |
| fossil | Geologically preserved remains of an organism that lived in the past. |
| hydroelectric plant | A hydroelectric power plant which generates electric power during peak load periods by using water pumped into a storage reservoir during off-peak periods. |
| subduction | the movement of an oceanic plate beneath another crustal plate |
| gage rod | A measuring device that shows the water level in the reservoir. |
| permafrost | Perennially frozen layer in the soil, found in alpine, arctic, and antarctic regions. |
| mesoscale | Size scale referring to weather systems smaller than synoptic-scale systems but larger than storm-scale systems |
| environmentalism | the politicization of concern for the environment and demands for action to protect and conserve it. |
| slip-off slope bank | The bank of a meandering stream which is not eroded by stream action, and which may be built up gradually. |
| productivity | Rate of energy fixation or storage of biomass by plants |
| exosphere | The outermost zone in the Earth's atmosphere |
| derived products | Processed base data on the Doppler radar. |
| terminus | The end of the glacier |
| qpfhsd | NCEP Heavy Snow Discussion |
| high wind watch | This product is issued by the National Weather Service when there is the potential of high wind speeds developing that may pose a hazard or is life threatening. The criteria for this watch varies from state to state. In Michigan, the criteria is the potential for sustained non-convective (not related to thunderstorms) winds greater than or equal to 40 mph and/or gusts greater than or equal to 58 mph. |
| flood basalt | See plateau basalt. |
| locational factor | any factor which has an influence in an entrepreneurial decision to locate industry in a particular place. |
| response time | The amount of time in which it will take a watershed to react to a given rainfall event. |
| recruitment overfishing | The rate of fishing above which the recruitment to the exploitable stock becomes significantly reduced |
| marina | a man-made dock or mooring area, protected from the sea, particularly for the mooring of pleasure craft. |
| eosophobia | The fear of dawn or daylight. |
| ground moraine | A continuous layer of till deposited beneath a steadily retreating glacier. |
| flow augmentation | The addition of water to a stream, especially to meet instream flow needs. |
| critical dry year | A dry year in which the full commitments for a dependable water supply cannot be met and deficiencies are imposed on water deliveries. |
| convective rings and bands | Like "Stratiform Rings and Bands" they occur outside the eye wall of the hurricane |
| evaporative cooling | Cooling of a liquid, such as water, by allowing a portion to evaporate |
| home range | The area that an animal traverses in the scope of normal activities |
| hydrostatic head | A measure of pressure at a given point in a liquid in terms of the vertical height of a column of the same liquid which would produce the same pressure. |
| fresh water | Water found rivers, lakes, and rain, that is distinguished from salt water by its appreciable lack of salinity. |
| furrow irrigation | See Irrigation. |
| dynamic ice | Pressure due to a moving ice cover or drifting ice |
| sympatric | Occupying the same geographic area |
| infiltration rate | Rate of absorption and downward movement of water into the soil layer. |
| krill | Small abundant crustaceans that form an important part of the food chain in Antarctic waters. |
| trajectory | The curve that a body, such as a celestial object, describes in space |
| outfall | The place where a sewer, drain, or stream discharges; the outlet or structure through which reclaimed water or treated effluent is finally discharged to a receiving water body. |
| high wind warning | This product is issued by the National Weather Service when high wind speeds may pose a hazard or is life threatening. The criteria for this warning varies from state to state. In Michigan, the criteria is sustained non-convective (not related to thunderstorms) winds greater than or equal to 40 mph lasting for one hour or longer, or winds greater than or equal to 58 mph for any duration. |
| phreatic surface | The free surface of ground water at atmospheric pressure. |
| evaporation pan | Meteorological instrument that is used to measure evaporation rates. |
| sedimentary cycle | biogeochemical cycle in which materials primarily are moved from land to sea and back again. |
| negative vorticity advection | A region of negative vorticity usually several hundred of kilometers wide on a upper level chart that moves with the general wind flow |
| capillary action | movement of water through very small spaces due to molecular forces called capillary forces. |
| névé | Partially melted and compacted snow that has a density of at least 500 kilograms per cubic meter. |
| katabatic wind | Any wind blowing down the slope of a mountain. |
| sdm | an acronym for Station Duty Manual |
| climate | The historical record and description of average daily and in seasonal weather events that help describe a region |
| land breeze | A diurnal coastal breeze that blows offshore, from the land to the sea |
| trophic level | Level of organization in the grazing food chain. |
| lower mantle | Layer of the Earth's interior extending from 670 to 2,900 kilometers below the surface crust |
| rockfill dam | An embankment dam in which more than 50 percent of the total volume is comprised of compacted or dumped pervious natural or crushed rock. |
| drizzle | Slowly falling precipitation in the form of tiny water droplets with diameters less than 0.02 inches or 0.5 millimeters |
| chance | A National Weather Service precipitation descriptor for 30, 40, or 50 percent chance of measurable precipitation (0.01 inch). When the precipitation is convective in nature, the term scattered is used. See Precipitation Probability (PoP). |
| rain barrel | Rain barrels collect rainwater, which can be used in gardens and lawns, as well as preventing excessive runoff. |
| imperiled species | declining, rare, or uncommon species; species federally listed as threatened or endangered, or candidates for such; and species with limited distributions. |
| silt | Substrate particles smaller than sand and larger than clay. |
| water cycle | natural pathway water follows as it changes between liquid, solid, and gaseous states; biogeochemical cycle that moves and recycles water in various forms through the ecosphere |
| emergency action plan | A predetermined plan of action to be taken to reduce the potential for property damage and loss of life in an area affected by a dam break or excessive spillway release. |
| playa | A dry lake bed found in a desert. |
| point source | A stationary location from which pollutants are discharged |
| permit | a permit issued by a state or the federal government to discharge effluent into waters of the state or the United States |
| dam | Any artificial barrier which impounds or diverts water |
| obligate species | A plant or animal that occurs only in a narrowly defined habitat such as tree cavity, rock cave, or wet meadow. |
| sounding | A plot of the atmosphere, using data rom upper air or radiosonde observations |
| underemployment | when people have jobs that do not fully occupy them and so they do not earn sufficient wages to properly cover their needs. |
| dorsal fin | The fin located on the back of fishes, and in front of the adipose fin, if it is present. |
| precipitation | two types: |
| interception | The process of storing rain or snow on leaves and branches which eventually evaporates back to the air |
| natural increase | in population studies, when the birth rate is higher than the death rate. |
| extinction | The natural or human induced process by which a species, subspecies or population ceases to exist. |
| pumping-generating plant | A plant at which the turbine-driven generators can also be used as motor-driven pumps. |
| mine drainage | Water pumped or flowing from a mine. |
| initial detention | The volume of water on the ground, either in depressions or in transit, at the time active runoff begins. |
| water table | the upper boundary of the saturated portion of a soil or rock. |
| slump | see rotational movement. |
| bog | a type of wetland that accumulates appreciable peat deposits |
| photogrammetry | The science of using aerial photographs and other remote sensing imagery to obtain measurements of natural and human-made features on the Earth. |
| stilling well | a tube of wide diameter sunk into a river bank which thus allows an accurate and constant measurement of the still water surface level of the river itself. |
| ethnic | having one or all of the following: common national or cultural tradition; common language; commonality relating to race or descent thereof. |
| tephra | Fragmented rock material ejected by a volcanic explosion |
| segregated ice | A form of periglacial ground ice that consists of almost pure ice that often exists as an extensive horizontal layer |
| time zone | An area using the same standard of time. |
| gunge | Slang for anything in the atmosphere that restricts visibility for storm spotting, such as fog, haze, precipitation (steady rain or drizzle), widespread low clouds (stratus), etc. |
| evolutionarily significant unit | "A definition of ""species"" used by NMFS in administering the Endangered Species Act |
| snow | Frozen precipitation in the form of white or translucent ice crystals in complex branched hexagonal form |
| toxic water pollutants | Compounds that are not naturally found in water at the given concentrations and that cause death, disease, or birth defects in organisms that ingest or absorb them. |
| hawaiian high | See Pacific High. |
| mesozoic | an era of geologic time lasting from 245m to 65m years ago. |
| ph | The value that determines if a substance is acid, neutral or basic, calculated from the number of hydrogen ions present |
| rainshadow effect | Reduction of precipitation commonly found on the leeward side of a mountain |
| fire danger | The result of both constant factors (fuels) and variable factors (primarily weather), which affects the ignition, spread, and difficulty of control of fires and the damage they cause. |
| flood damage | The economic loss caused by floods, including damage by inundation, erosion, and/or sediment deposition |
| isopleth | A line on a weather map connecting constant thickness (layer of atmosphere). |
| base | (1) Any of various typically water-soluble and bitter tasting compounds that in solution have a pH greater than 7, are capable of reacting with an acid to form a salt, and are molecules or ions able to take up a proton from an acid or able to give up an unshared pair of electrons to an acid |
| emergency services | Services provided in order to minimize the impact of a flood that is already happening |
| quaternary sector | those types of economic activity involving high technology and information services which have appeared in the last thirty years and do not fit neatly into the secondary or tertiary sectors. |
| bed forms | three-dimensional configurations of bed material, which are formed in streambeds by the action of flowing water. |
| cottage industry | small-scale, home-based production. |
| environmental indicator | a measurement, statistic or value that provides evidence of the effects of environmental management programs or of the state or condition of the environment. |
| discharge | volume of water passing by a given location within a given time period. Usually expressed in either cubic feet per second (cfs) or gallons per minute (gpm). |
| folding | Aliasing; applied to both velocity and range aliasing. |
| industrial estate | planned area of integrated buildings and roads for industrial use, especially by modern industrial businesses |
| filtration | A treatment process, under the control of qualified operators, for removing solid (particulate) matter from water by means of porous media such as sand or a man-made filter; often used to remove particles that contain pathogens. |
| earth revolution | Refers to the orbit of the Earth around the Sun |
| displacement | distance by which portions of the same geological layer are offset from each other by a fault. |
| foodweb | a model structure used to represent the links between organisms within an environment, based upon the order in which various organisms consume one another. |
| backing | A counterclockwise shift in the wind direction in the Northern Hemisphere at a certain location |
| streamer | A channel of very high ion density which propagates through the air by the continual establishment of an electron avalanche ahead of its tip. |
| rdp | Rainleader Disconnect Program |
| profundal zone | a lake's deep-water region that is not penetrated by sunlight. |
| water solubility | The maximum possible concentration of a chemical compound dissolved in water. |
| gabion | A wire cage, usually rectangular, filled with cobbles and used as a component for water control structures or for channel and bank protection. |
| irrigation water | Water diverted or pumped for irrigation of crops or pasture |
| isolation | Absence of genetic crossing among populations because of distance or geographic barriers. |
| crack | A separation formed in an ice cover of floe that does not divide it into two or more pieces. |
| nominal catch | The sum of the catches that are landed (expressed as live weight or equivalents) |
| earthfill or earth dam | An embankment dam in which more than 50 percent of the total volume is formed of compacted fine-grained material obtained from a borrow area (i.e., excavation pit). |
| hygroscopic coefficient | Maximum limit of hygroscopic water around the surface of a soil particle. |
| hydraulics | (1) The study of liquids, particularly water, under all conditions of rest and motion |
| industrial smog | Form of air pollution that develops in urban areas |
| radioactive decay | Natural decay of the nucleus of an atom where alpha or beta particle and/or gamma rays are released at a fixed rate. |
| detachment | One of three distinct processes involved in erosion |
| maquis | scrub vegetation made up of plants such as heathers which can grow up to 3 metres in height |
| wedge | Primarily refers to an elongated area of shallow high pressure at the earth's surface |
| forest landscape | Land presently forested or formerly forested and not currently developed for nonforest use. |
| field capacity | The amount of water held in soil against the pull of gravity |
| glacier | a mass of ice formed through the accumulation of multiple years of snow input causing compaction and thus the expulsion of air from within the mass. |
| coastal flooding | Flooding that occurs from storms where water is driven onto land from an adjacent body of water |
| storage | The volume of water in a reservoir at a given time. |
| diploid | Cell that contains two sets of chromosomes |
| velocity | The speed of movement of an object in one direction. |
| granite | a massive, intrusive rock |
| snow density | New fallen snow density is near or less than 0.1 |
| sediment trapping efficiency | the ratio of sediment retained within the reservoir to the sediment inflow to the reservoir. |
| floodwall | A long, narrow concrete, or masonry embankment usually built to protect land from flooding |
| slope | The ratio of the change in elevation over distance. |
| thermal high | Area of high pressure in the atmosphere caused by the area having warmer temperatures relative to the air around it. |
| histogram | a bar chart where the vertical (y) axis is frequency and the horizontal (x) axis is the classes/values of data that have been measured for frequency. |
| gdp | see gross domestic product. |
| land breeze | Local thermal circulation pattern found at the interface between land and water |
| catotelm | the lower level or layer of a peat deposit. |
| allocation | Division of the fish resource among harvesters and needs for reproduction |
| upstream slope | The part of the dam which is in contact with the reservoir water |
| isotherm | A line on a weather map connecting points of equal temperature. |
| rainsplash | soil erosion caused by the force of impact of raindrops. |
| low-head dam | A dam at which the water in the reservoir is not high above the turbine units. |
| psychrometric table | Table of values that allows for the determination of relative humidity and dew point from dry-bulb and wet-bulb temperatures recorded on a psychrometer. |
| waterfall | a sudden, nearly vertical drop in a stream, as it flows over rock. |
| return flow | The part of a diverted flow which is not consumptively used and which returns to a water body. |
| dnr | Department of Natural Resources. |
| radio-telemetry | Automatic measurement and transmission of data from remote sources via radio to a receiving station for recording and analysis. |
| inert waste | waste that does not contain hazardous waste or soluble pollutants at concentrations in excess of applicable water quality objectives, and does not contain significant quantities of decomposable waste. |
| second-day feet | The volume of water represented by a flow of one cubic foot per second for 24 hours; equal to 84,000 cubic feet |
| absolute humidity | the amount of water vapour in the air in grams per cubic metre. |
| zooplankton | Small heterotrophic organisms found inhabiting aquatic ecosystems |
| continental glacier | A glacier that forms over large areas of continents close to the poles. |
| kansan | North American glaciation related to European Mindel glaciation. |
| basin lag | (1) The time from the centroid (centermost point in time based on total period rainfall) of rainfall to the hydrograph peak |
| tertiary treatment | removal from wastewater of traces or organic chemicals and dissolved solids that remain after primary treatment and secondary treatment. |
| seashore | (1) Land by the sea |
| phreatophyte | A plant that habitually obtains its water supply from the zone of saturation, either directly or through the capillary fringe. |
| pressure falling rapidly | A decrease in station pressure at a rate of 0.06 inch of mercury or more per hour which totals 0.02 inch or more. |
| continental shield | See shield. |
| lifting condensation level | It is the height at which a parcel of air becomes saturated when lifted dry-adiabatically. |
| seed dispersal | movement of seeds away from parent plants. |
| wildlife | Mammals and birds, game and non-game species that are not domesticated. |
| wellfield | area containing one or more wells that produce usable amounts of water or oil. |
| transboundary | Refers to U.S |
| no till farming | Planting crops without prior seedbed preparation, into an existing cover crop, sod, or crop residues, and eliminating subsequent tillage operations. |
| ridge | An elongated area of high atmospheric pressure that is associated with an area of maximum anticyclonic circulation |
| oxygen demanding waste | organic water pollutants that are usually degraded by bacteria if there is sufficient dissolved oxygen (DO) in the water. |
| pressure filter | (Water Quality) A device used to remove fine particulate matter from water |
| juvenile transportation | Collecting migrating juvenile fish and transporting them around the dams using barges or trucks. |
| stock a | part of a fish population usually with a particular migration pattern, specific spawning grounds, and subject to a distinct fishery |
| external cost | cost of production or consumption that must be borne by society; not by the producer. |
| diluting water | distilled water that has been stabilized, buffered, and aerated |
| food chain | Movement of energy through the trophic levels of organisms |
| lahar | mudflow associated with volcanic activity |
| bank stability | The properties of a stream bank that counteract erosion, for example, soil type, and vegetation cover. |
| habitat | The local environment in which a organism normally lives and grows. |
| freons | See chlorofluorocarbons. |
| evaporation pan | A pan used to hold water during observations for the determination of the quantity of evaporation at a given location |
| flow | The amount of water passing a particular point in a stream or river, usually expressed in cubic-feet per second (cfs). |
| pore ice | A form of periglacial ground ice that is found in the spaces that exist between particles of soil. |
| condensation | the change of state from a gas to a liquid |
| rock | A compact and consolidated mass of mineral matter |
| small stream flooding | Flooding of small creeks, streams, or runs. |
| oh | The Office of Hydrology, located in Silver Springs, MD. |
| pyloric caecum | A projection in the form of a blind sac attached to the intestine near the posterior end of the stomach. |
| parts per million | The number of "parts" by weight of a substance per million parts of water |
| stewardship | an approach to environmental management which advocates careful balance between development and protection of the environment. |
| longitudinal profile | A graphic presentation of elevation vs |
| rainfall intensity-duration curve | A curve showing the relationship between average rainfall or precipitation depth (or the rate) and storm duration in a given area. |
| fema designated flood zone | FEMA designates Flood Zones, which are zones where water overflows from a river or stream during extreme storm events |
| static water level | elevation or level of the water table in a well when the pump is not operating; the level or elevation to which water would rise in a tube connected to an artesian aquifer or basin in a conduit under pressure. |
| forminifera | Microscopic organisms of the group protozoa that are found living mainly in marine environments |
| riparian water rights | the rights of an owner whose land abuts water |
| drainage density | The relative density of natural drainage channels in a given area |
| food surplus | when food stores build up in certain areas |
| sporadic permafrost | Form of permafrost that exists as small islands of frozen ground in otherwise unfrozen soil and sediments. |
| combined sewage | Wastewater and storm drainage carried in the same pipe. |
| catchability | "The fraction of a fish stock which is caught by a defined unit of the fishing effort |
| permeable | a rock which can absorb water (porous) or allow water to pass through cracks and joints (pervious). |
| chelate | Organic substances that cause the chemical process of chelation. |
| sill | a sheet-like intrusion of magma between bedding planes. |
| riparian | Located on the banks or a stream or other body of water. |
| conventional method | Where operations personnel (ditchrider and watermaster) control the canal system onsite |
| ice age | see glacial. |
| kokanee | The self-perpetuating, nonanadromous form of O |
| sea-floor spreading | The process of oceanic crust creation and sea-floor movement that occurs at the mid-oceanic ridge. |
| river capture | when the headwaters of one river are able to generate headward erosion and then break into another river channel and divert the flow into the new channel. |
| static equilibrium | Static equilibrium occurs where force and reaction are balanced and the properties of the system remain unchanged over time. |
| riparian doctrine | The system for allocating water used in England and the eastern United States |
| ecosystem functions | Processes that are necessary for the self-maintenance of an Ecosystem such as primary production, nutrient cycling, decomposition, etc |
| recarbonization | process in which carbon dioxide is bubbled into water being treated to lower the pH. |
| channel | a natural or artificial watercourse that continuously or intermittently contains water, with definite bed and banks that confine all but overbanking streamflows. |
| dalr | see dry adiabatic lapse rate. |
| wettability | The relative degree to which a fluid will spread into solid surface in the presence of other immiscible fluids. |
| hydroelectric power water use | The use of water in the generation of electricity at plants where the turbine generators are driven by falling water. |
| tertiary treatment | Treatment of wastewater to a level beyond Secondary Treatment but below Potable |
| nebulaphobia | The fear of fog. See Homichlophobia. |
| twilight zone | in Burgess model of urban land use, the second zone, surrounding the CBD characterized by old factories and slum areas which may be in transition and experiencing some regeneration. |
| braided stream | Characterized by successive division and rejoining of streamflow with accompanying islands |
| water right | A legally protected right, granted by law, to take possession of water occurring in a water supply and to put it to Beneficial Use. |
| unsteady flow | Flow that is changing with respect to time. |
| marsh | an area periodically inundated and treeless and often characterized by grasses, cattails, and other monocotyledons |
| irrigation | The controlled application of water to arable lands to supply water requirements not satisfied by rainfall. |
| short circuiting | when some of the water in tanks or basins flows faster than the rest; shortcircuiting may result in shorter contact, reaction, or settling times than calculated or presumed. |
| right abutment | That part of the right-hand side of a valley side wall against which a dam is constructed |
| jet stream | A high-speed, meandering wind current, generally moving from a westerly direction at speeds often exceeding 400 kilometers (250 miles) per hour at altitudes of 15 to 25 kilometers (10 to 15 miles) |
| chemical energy | Energy consumed or produced in chemical reactions. |
| percolation | The movement of water, under hydrostatic pressure, through the interstices of a rock or soil, except the movement through large openings such as caves. |
| coefficient of runoff | Factor in the rational runoff formula expressing the ratio of peak runoff rate to rainfall intensity. |
| refractivity | N = (n-1)*10^6, where n is refractive index and N is a function of temperature, pressure and vapor pressure (in the atmosphere). |
| bank | the sloping land bordering a stream channel that forms the usual boundaries of a channel |
| north magnetic pole | Location in the Northern Hemisphere where the lines of force from Earth's magnetic field are vertical |
| overrunning | This occurs when a relatively warm air mass is forced above a cooler air mass of greater density |
| self-produced water | A water supply (usually from wells) developed and used by an individual or entity. |
| hydraulic radius | stream efficiency measured by dividing cross-sectional area of a stream by the wetted perimeter |
| illuviation | inward movement of clays, minerals and organic matter to a low soil horizon From one above. |
| wet floodproofing | An approach to floodproofing which usually is a last resort |
| geostrophic wind | The horizontal wind for which the coriolis acceleration (caused by the Earth's rotation) exactly balances the horizontal pressure force |
| record report | This nonroutine narrative product is issued by the National Weather Service to report meteorological and hydrological events that equal or exceed existing records. |
| ground clutter | A pattern of radar echoes reflecting off fixed ground targets such as buildings or hills near the radar |
| moderate flooding | The inundation of secondary roads; transfer to higher elevation necessary to save property -- some evacuation may be required. |
| scwmc | Shingle Creek Watershed Management Commission |
| transpiration | process by which water that is absorbed by plants (usually by the roots) is evaporated into the atmosphere from the plant surfaces, such as leaf pores. (See evapotranspiration and water cycle/hydrologic cycle.) |
| overland flow | The flow of rainwater or snowmelt over the land surface toward stream channels |
| hydrograph | a chart that measures the amount of water flowing past a point as a function of time. |
| channelization | The process of changing (usually straightening) the natural path of a waterway. |
| channel inflow | Water which at any instant is flowing into the channel system from surface flow, subsurface flow, base flow, and rainfall directly on the channel. |
| refugee | a person who flees their home country through a fear of persecution on the grounds of race or religion, or membership of some other group. |
| coromell | The prevailing evening land breeze which takes place from November to May in the vicinity of La Paz, at the southern tip of Baja California, Mexico. |
| harvested rainwater | The rain that falls on a roof or yard and is channeled by gutters or channels to a storage tank |
| urban heat island | The increased air temperatures in urban areas in contrast to cooler surrounding rural areas. |
| old growth forest | Climax forests dominated by late successional species of trees that are hundreds to thousands of years old |
| polluted | Something which contains foreign substances. |
| watershed | Land area from which water drains toward a common watercourse in a natural basin. They range in size from a few acres to large areas of the country. |
| flutes | Long grooves gouged by englacial debris on subglacial pavement parallel to the direction of glacial movement. |
| aquaculture | The controlled cultivation and harvest of aquatic plants or animals (e.g., edible marine algae, clams, oysters, and salmon). |
| activated coal | This is the most commonly used adsorption medium, produced by heating carbonaceous substances or cellulose bases in the absence of air |
| water pollution | The alteration of the constituents of a body of water by man to such a degree that the water loses its value as a natural resource. |
| differential reflectivity | A measure of the difference in reflectivity of a target when the transmitted waves are polarized horizontally or vertically. |
| natural decrease | in population studies, when the death rate is higher than the birth rate. |
| ngvd | National Geodetic Vertical Datum |
| reserves | amount of a particular resource in known locations that can be extracted at a profit with present technology and prices. |
| melting point | The temperature at which a solid substance undergoes fusion, changing from a solid to a liquid state |
| fetch | (1) The distance traveled by waves in open water, from their point of origin to the point where they break |
| turbidity | presence of very tiny particles in water that give it a cloudy appearance. Removal of particles in treatment results in clear water. |
| sediment-delivery ratio | The ratio of sediment yield to gross erosion, expressed in percent. |
| mass number | Total number of neutrons and protons in the nucleus of an atom |
| conventional sewer systems | Systems that were traditionally used to collect municipal wastewater in gravity sewers and convey it to a central primary or secondary treatment plant, before discharge on receiving surface waters. |
| secondary consumer | Organisms that occupy the third trophic level in the grazing food chain |
| meander amplitude | The distance between points of maximum curvature of successive meanders of opposite phase in a direction normal to the general course of the Meander Belt, measured between centerlines of channels. |
| water conservation | Reduction in applied water due to more efficient water use such as implementation of Urban Best Management Practices or Agricultural Efficient Water Management Practices |
| prior appropriation | The water law doctrine that confers priority to use water from natural streams based upon when the water rights were acquired |
| labour-intensive | an economic activity where labour is the largest input by value, as opposed to capital. |
| embryo | The early stages of development before an organism becomes self supporting. |
| echo tops contour | This WSR-88D radar product displays a line contour image of echo tops data. The contour interval and base contour value are selected at the WSR-88D's Principle User Processor (PUP). It is used to view a contour image of echo tops; gain a quick estimation of the most intense convection (highest tops); detect mid-level echoes before low level echoes are detected; and assist in differentiating non-precipitation echoes from real storms. |
| compounds | Two or more different elements held together in fixed proportions by attractive forces called chemical bonds. |
| cut bank | The outside bank of a bend, often eroding opposite a point bar. |
| cartesian coordinates | The familiar "x-y" coordinate system, in which the axes are at right angles to each other |
| water pollution | The alteration of the constituents of a body of water by man to such a degree that the water loses its value as a natural resource. |
| permeable | ability of a material to allow the passage of a liquid, such as water, through sands and gravels or rocks. Water moves more quickly through sands, whereas clay is impermeable. |
| perennial stream | A stream that normally has water in its channel at all times. |
| per capita use | the average amount of water used per person during a standard time period, generally per day. |
| orographic precipitation | rainfall that occurs as a result of warm, humid air being forced to rise by topographic features such as mountains |
| hatchery | Refers to facilities that incubate eggs and rear the young for release into streams and rivers. |
| pervious zone | A part of the cross section of an Embankment Dam comprising material of high permeability. |
| karyotype | The number, size, and morphology of the chromosome complement. |
| clear well | A reservoir containing potable water which has been previously treated before entering the distribution lines. |
| irrigation efficiency | The percentage of water applied that can be accounted for in soil moisture increase for consumptive use. |
| fungi | Group, at the kingdom level, in the classification of life |
| aquifer | An underground layer of rock or soil containing ground water. |
| mean column velocity | the average velocity of fluid flow measured in a column extending from the surface of the water to the bed of the channel |
| q' or quadrature | The component of the complex signal that is 90 degrees out of phase with the inphase component |
| classic old growth | Forest stands with unusually old and large trees that also meet criteria for old-growth forest. |
| refraction | the tendency for waves to become more parallel to the coastline as they approach it |
| water analysis | The determination of the physical, chemical, and biological characteristics of water |
| hard water | Water which forms a precipitate with soap due to the presence of calcium, magnesium, or ferrous ions in solution. |
| grike | the crack in a limestone pavement. |
| isobar | The line drawn on a weather map connecting points of equal barometric pressure. |
| weir | a wall or plate placed in an open channel to measure the flow of water; a wall or obstruction used to control flow from settling tanks and clarifiers to ensure a uniform flow rate and avoid short-circuiting. |
| shear | Force parallel to a surface as opposed to directly on the surface |
| mare nostrum | A navigable body of water, such as a sea, that is under the jurisdiction of one nation or that is shared by two or more nations. |
| environmental manipulation | Actions taken directly or indirectly by man to alter the natural characteristics and evolving patterns of an Ecosystem through alterations to plant or animal life, or habitat conditions. |
| gulf | A gulf is a part of the ocean (or sea) that is partly surrounded by land (it is usually larger than a bay). |
| conductor | Any substance or object which carries electricity. |
| blizzard | A winter storm which produces the following conditions for at least 3 hours: 1) sustained winds or frequent gusts to 35 miles per hour or greater 2) considerable falling and/or blowing snow reducing visibility to less than 1/4 mile. |
| abutment seepage | Reservoir water that moves through seams or pores in the natural abutment material and exits as seepage. |
| due diligence | The efforts necessary to bring an intent to appropriate water to fruition; actions that demonstrate a good faith intention to complete a diversion of water within reasonable time. |
| severe thunderstorm watch | This is issued by the National Weather Service when conditions are favorable for the development of severe thunderstorms in and close to the watch area. A severe thunderstorm by definition is a thunderstorm that produces 3/4 inch hail or larger in diameter and/or winds equal or exceed 58 miles an hour. The size of the watch can vary depending on the weather situation. They are usually issued for a duration of 4 to 8 hours. They are normally issued well in advance of the actual occurrence of severe weather. During the watch, people should review severe thunderstorm safety rules and be prepared to move a place of safety if threatening weather approaches. |
| solution | a mixture of a solvent and a solute |
| bloom | a proliferation of algae and/or higher aquatic plants in a body of water; often related to pollution or excessive nutrients, especially when they accelerate growth. |
| peak power | The amount of power transmitted by a radar during a given pulse |
| remembrement | the consolidation of fragmented land parcels, split by inheritance practices over many years, back into larger units. |
| stratus clouds | Low altitude gray colored cloud composed of water droplets |
| metabolism | Describes all of the enzymatic reactions performed by the cells of an organism. |
| incidental harvest | The take (or harvest) of species other than the target species in a fishery. |
| distortion | Change in a signal resulting in gross nonlinearities in signal processing or handling. |
| ocean floor | Flat plain found at the bottom of the ocean |
| habitat | the native environment or specific surroundings where a plant or animal naturally grows or lives |
| water right | A legally protected right to take possession of water occurring in a natural waterway and to divert that water for beneficial use. |
| mercury barometer | Type of barometer that measures changes in atmospheric pressure by the height of a column of mercury in a U-shaped tube which has one end sealed and the other end immersed in an open container of mercury |
| water discharge | The amount of water and sediment flowing in a channel, expressed as volume per unit of time |
| demography | the study of demographics. |
| estancia | a ranch in Spanish-speaking S |
| conditional natural mortality rate | The fraction of an initial stock that would die from causes other than fishing during a year (or season), if there were no fishing mortality |
| hydraulic loading | (Water Quality) For a sand filter wastewater treatment unit, the volume of wastewater applied to the surface of the filtering medium per time period |
| rotor cloud | A turbulent cloud formation found in the lee of some large mountain barriers |
| mineral soil | Soil composed of predominantly mineral rather than organic materials. |
| climate | Meteorological elements that characterize the average and extreme conditions of the atmosphere over a long period of time at any one place or region of the earth's surface. |
| evaporation | Process by which water is changed from the liquid state to the vapor state |
| reserve capacity | Extra treatment capacity built into wastewater treatment plants and sewers to be able to catch up with future flow increases due to population growth. |
| settling basin | An enlargement in the channel of a stream to permit the settling of materials carried in suspension. |
| production capacity | The capacity of a water body or production facility to produce fish. |
| application activities | Conducted to support the civilian maritime community and other government agencies in support of safety of life at sea , ie |
| public water use | Water supplied from a Public Water Supply System and used for such purposes as fire fighting, street washing, and municipal parks and swimming pools |
| biodegradable | Capable of being broken down by living organisms into inorganic compounds. |
| flood problems | Problems and damages that occur during a flood as a result of human development and actions |
| back pressure | a pressure that can cause water to Backflow into the water supply when a user's waste water system is at a higher pressure than the public system. |
| plug | cement, grout, or other material used to fill and seal a hole drilled for a water well. |
| genetics | The study of genes and gene pools. |
| anvil | The upper portion of a cumulonimbus cloud that becomes flat and spread-out, sometimes for hundreds of miles downstream from the parent cloud |
| water-soluble substance | a substance that can readily disperse through the environment. |
| transient water system | A non-community water system that does not serve 25 of the same nonresidents per day for more than six months per year. |
| hypothesis | A tentative assumption that is made for the purpose of empirical scientific testing |
| ecoregion | a geographic area over which the macroclimate is sufficiently uniform to permit development of similar ecosystems on sites with similar geophysical properties. |
| discharge | the volume of water that passes a given point within a given period of time |
| operating year | The 12 month period from August 1 through July 31. |
| heating degree day | see Degree Day |
| water use | used for a specific purpose, i.e., domestic, agricultural or industrial. |
| rearing habitat | Areas in rivers or streams where juvenile salmon and trout find food and shelter to live and grow. |
| pathogen | microorganisms which can cause disease. |
| topographical map | a map of surface feature, natural and human, drawn to scale. |
| water transfer | Artificial conveyance of water from one area to another across a political or hydrological boundary |
| drift | Early writers assumed that glacial deposits had drifted in with the Great Flood. |
| atmospheric particulates | solids present in the atmosphere |
| watershed | land area that drains to a particular stream, river or lake. Large watersheds (Colorado or Gila Rivers) contain many smaller watersheds.) |
| thematic mapper | Remote sensing device found on Landsat satellites that scans images in seven spectral bands from visible to thermal infrared. |
| lithosphere | That part of the earth which is composed predominantly of rocks (either coherent or incoherent, and including the disintegrated rock materials known as soils and subsoils), together with everything in this rocky crust. |
| reservoir surcharge | Water in a reservoir that resides above the spillway. |
| longshore transport | The transport of sediment in water parallel to a shoreline. |
| latent heat of vaporization | The amount of heat energy required from the environment to change the state of a liquid to a gas |
| riffle | A reach of stream that is characterized by shallow, fast moving water broken by the presence of rocks and boulders. |
| population policy | government interventions to try and control high population growth, stimulate low population growth or control the distribution of people within a country. |
| economic activity | work or industry undertaken for economic purposes |
| polynya | The open seawater between pack-ice and the land or the edge of a glacier. |
| redd | A nest of fish eggs covered with gravel. |
| raw water | Untreated water. |
| canopy | when the trees in a woodland or forest area are close enough together that the upper leaf layer of the trees form a more or less consistent cover. |
| river | a natural stream of water of considerable volume. |
| design criteria | The hypothetical flood used in the sizing of the dam and the associated structures to prevent dam failure by overtopping, especially for the spillway and outlet works. |
| radar reflectivity | The sum of all backscattering cross-sections (e.g., precipitation particles) in a pulse resolution volume divided by that volume |
| valve | A device fitted to a pipeline or orifice in which the closure member is either rotated or moved in some way as to control or stop flow. |
| meridional | Movement of wind or ocean waters in a direction that is roughly perpendicular to the lines of latitude. |
| fishery | the aquatic region in which a certain species of fish lives floc - clumps of impurities removed from water during the purification process; formed when alum is added to impure water flocculation - a step in water filtration in which alum is added to cause particles to clump together floodplain - area formed by fine sediments spreading out in the drainage basin on either side of the channel of a river as a result of the river's fluctuating water volume and velocity fog - clouds that form at the Earth's surface frost - the ice that forms on surfaces as a result of the temperature of that surface reaching freezing before the air becomes saturated with water |
| up-flow | An upward flow of water. |
| isobar | Lines on a map joining points of equal atmospheric pressure. |
| snowflake | A six-pointed cluster of ice crystals which fall from a cloud is called a snowflake. |
| secondary consumer | any animal which feeds on primary consumers or other secondary consumers. |
| fahrenheit scale | Scale for measuring temperature |
| age | The number of years of life completed, here indicated by an arabic numeral, followed by a plus sign if there is any possibility of ambiguity (age 5, age 5+)1. |
| movement | A term used in geography that deals with the migration, transport, communication, and interaction of natural and human-made phenomena across the spatial dimension. |
| conjunctive management | The integrated management and use of two or more water resources, such as a (ground water) aquifer and a surface water body. |
| squall | A sudden onset of strong winds with speeds increasing to at least 16 knots (18 miles per hour) and sustained at 22 or more knots (25 miles per hour) for at least one minute |
| forebay | The water behind a dam |
| landfill | a location for the disposal of human waste be it domestic, commercial or industrial |
| pollution indicator organism | (Water Quality) A plant or animal species that is not normally present in an aquatic environment unless the body of water has been subjected to damage by pollution |
| population structure | the ratio of age groups, by sex, within a population. |
| public water system | by law, a drinking water system that serves 15 or more connections or 25 or more people; must meet EPA standards for treatment and water quality. http://www.epa.gov/ebtpages/watedrinkingwater.html |
| north-south divide | the imaginary line separating the mostly EMDW of the North from the ELDW of the South. |
| wilting point | The point at which the rate of water leaving a plant's leaves is greater than the water uptake by the roots |
| lithosphere | Is the solid inorganic portion of the Earth (composed of rocks, minerals, and elements) |
| polychlorinated biphenyls | A group of chemicals found in industrial wastes. |
| lakeshore statement | The local National Weather Service Offices with Great Lakes responsibility will issue this product to alert the public when their is either a potential or actual reports of minor Great Lakes lakeshore flooding and erosion. This means that the lakeshore flooding or erosion would not cause too much damage to property, but it would be an inconvenience to living or driving in those areas. |
| combined sewer | a sewer system that carries both sanitary sewage and stormwater runoff |
| rock | See cobble. |
| meteoric water | groundwater which originates in the atmosphere and reaches the zone of saturation by infiltration and percolation. |
| sea arch | A coastal landform composed of rock that resembles an arch |
| cone of depression | Cone shaped depression occurring horizontally across a water table |
| left bank | The left-hand bank of a stream viewed when the observer faces downstream. |
| doppler dilemma | The interdependence of maximum unambiguous range and maximum unambiguous velocity on the pulse repetition frequency, PRF |
| wind | Air moving horizontally and/or vertically. |
| brood stock | Adult fish used to propagate the subsequent generation of hatchery fish. |
| unloading | The release of the contaminant that was captured by a filter medium. |
| depletion curve | That part of the hydrograph extending from the point of termination of the Recession Curve to the subsequent rise or alternation of inflow due to additional water becoming available for stream flow. |
| geographic information system | the creation of a database of geographic information from a variety of sources which allow the cross-referencing and compilation of different data sets so that relationships may be observed or postulated. |
| base flow | The sustained portion of stream discharge that is drawn from natural storage sources, and not effected by human activity or regulation. |
| maswma | Metropolitan Area Surface Water Management Act |
| duty of water | The amount of water that through careful management and use, without wastage, is reasonably required to be applied to a tract of land for a length of time that is adequate to produce the maximum amount of the crops that are ordinarily grown there. |
| lake | Any inland body of standing water, usually fresh water, larger than a pool or pond; a body of water filling a depression in the earth's surface. |
| surface water | Water that flows in streams and rivers and in natural lakes, in wetlands, and in reservoirs constructed by |
| hydroelectric | Having to do with production of electricity by water power from falling water. |
| overbank flow | Water flow over the top of the bankfull channel onto the floodplain. |
| acid rain | Rainfall with a pH of less than 7.0 |
| in-line filtration | A pre-treatment method in which chemicals are mixed by the flowing water; commonly used in pressure filtration installations |
| trace | Generally, an unmeasurable or insignificant quantity |
| advanced oxidation process | One of several combination oxidation processes |
| discharge | The volume of water passing through a channel during a given time, usually measured in cubic feet per second. |
| public water use | water supplied from a public-water supply and used for such purposes as firefighting, street washing, and municipal parks and swimming pools. |
| buys ballot | a Dutch scientist |
| illuviation | Deposition of humus, chemical substances, and fine mineral particles in the lower layers of a soil from upper layers because of the downward movement of water through the soil profile |
| recharge area | An area of land where there is a net annual transfer of water from the surface to ground water; where rainwater soaks through the earth to reach an aquifer. |
| impervious | The ability to repel water, or not let water infiltrate. |
| wrapping gust front | A gust front which wraps around a mesocyclone, cutting off the inflow of warm moist air to the mesocyclone circulation and resulting in an occluded mesocyclone. |
| elastic deformation | Change in the shape of a material as the result of the force of compression or expansion |
| mass wasting | General term that describes the downslope movement of sediment, soil, and rock material. |
| raw water | Intake water before any treatment or use. |
| flood warning | A release by the NWS to inform the public of flooding along larger streams in which there is a serious threat to life or property |
| nutrient | any chemical or compound which is used by an organism in order to survive and/or grow. |
| water pipe | (1) A pipe that is a conduit for water |
| filter feeder | An aquatic animal, such as a clam, barnacle, or sponge, that feeds by filtering particulate organic material from water. |
| origin | The arbitrary starting point on a graph or grid coordinate system |
| air quality standards | The maximum level which will be permitted for a given pollutant |
| internal drainage | (1) Movement of water down through soil to porous aquifers or to surface outlets at lower elevations |
| spawning escapement | The total number of adult fish returning to a hatchery or stream to spawn. |
| foresight | A sighting on a point of unknown elevation from an instrument of known elevation |
| mesopause | Thin boundary layer found between the mesosphere and the thermosphere |
| antlophobia | The fear of floods. |
| velocity zones | Areas within the floodplain subject to potential high damage from waves |
| threatened species | Species that is still plentiful in its natural range but is likely to become endangered because of declining population numbers. |
| snow telemetry | An automated network of snowpack data collection sites |
| roll cloud | A low, horizontal tube-shaped arcus cloud associated with a thunderstorm gust front (or sometimes with a cold front) |
| debris torrent | Rapid movement of a large quantity of materials (wood and sediment) down a stream channel during storms or floods |
| epa | Environmental Protection Agency |
| corrie glaciation | The development of ice fields between peaks, the growth and coalescence of mountain ice caps into regional ice caps, and the growth of these regional caps into ice sheets. |
| drought | Climatic condition where water loss due to evapotranspiration is greater than water inputs through precipitation. |
| polarization radar | A radar which takes advantage of ways in which the transmitted waves' polarization affect the backscattering |
| scud | Small, ragged, low cloud fragments that are unattached to a larger cloud base and often seen with and behind cold fronts and thunderstorm gust fronts |
| terminal mouth | Said of the location of the mouth when it opens at the end of the head, as in trout. |
| light | A humanly visible form of electromagnetic radiation |
| manning's roughness | a coefficient in Manning's equation that accounts for energy loss due to the friction between the channel and the water |
| sea-wave | at sea, waves represent a horizontal movement of energy but a vertical elliptical movement of water. |
| flow | Volume of water in a river or stream, passing a specific observation site, during a specific time period |
| harvest | Fish that are caught and retained in a fishery (consumptive harvest). |
| nwsh | The National Weather Service Headquarters. |
| strain | The result of a physical material to stress. |
| direct solar radiation | Solar radiation received by the Earth's atmosphere or surface which has not been modified by atmospheric scattering. |
| assimilative capacity | the capacity of a natural body of water to receive and dilute wastewaters or toxic materials without damage to aquatic life or humans who consume the water. |
| photosynthesis | The manufacture by plants of carbohydrates and oxygen from carbon dioxide and water in the presence of chlorophyll, using sunlight as an energy source. |
| infiltration capacity | The maximum rate at which the soil, when in a given condition, can absorb falling rain or melting snow. |
| climatology | The study of climate |
| isentropic lift | Lifting of air that is traveling along an upward-sloping isentropic surface |
| run-off | The part of precipitation water that runs off the land into streams or other surfacewater. |
| dredging | Removing material (usually sediments) from wetlands or waterways, usually to make them deeper and wider. |
| levee | Bank of sand and silt built by a river during floods, where the Suspended Load is deposited in greatest quantity close to the river |
| upwelling | The process by which water rises from a lower to a higher depth, usually as a result of divergence and offshore currents |
| muggy | A subjective term for warm and excessively humid weather. |
| law of stream number | Morphometric relationship observed in the number of stream segments of a particular classification order in stream channel branching |
| dynamic range | The ratio, usually expressed in decibels, of the maximum to the minimum signal that a system can handle |
| attenuation | the process whereby the magnitude of a flood event is reduced by slowing, modifying, or diverting the flow of water. |
| metasomatic metamorphism | Form of metamorphism that causes the chemical replacement of elements in rock minerals when gases and liquids permeate into bedrock. |
| cold front | A transition zone in the atmosphere where an advancing cold air mass displaces a warm air mass. |
| live capacity | The total amount of storage capacity available in a reservoir for all purposes, from the dead storage level to the normal water or normal pool level surface level |
| stemflow | Is the process that directs precipitation down plant branches and stems |
| emergent coast | a coast that has experienced net sea level fall and the characteristics particular to it as a result. |
| international date line | The line of longitude located at 180° East or West (with a few local deviations) where the date changes by a day |
| protectionism | the placing of barriers to trade used by a government to try and promote domestic products over imports. |
| toxaphene | chemical that causes adverse health effects in domestic water supplies and is toxic to fresh water and marine aquatic life. |
| hydraulic earthfill dam | An embankment built up from waterborne clay, sand, and gravel carried through a pipe or flume. |
| sprinkler head | A device that projects water through the air in the form of small particles or droplets. |
| brine disposal | Removing water that contains high concentrations of salt. |
| industrialisation | the move from an economy dominated by agricultural output and employment to one dominated by manufacturing. |
| cistern | a tank used to collect rainwater runoff from the roof of a house or building. |
| forecast point | A location that represents an area (reach of a river), where a forecast is made available to the public |
| buttress dam | Buttress dams are comprised of reinforced masonry or stonework built against concrete |
| environment | aggregate of external conditions that influence the life of an individual organism or population. |
| laminar flow | Streamline flow in which successive flow particles follow similar path lines and head loss varies with velocity to the first power. |
| instantaneous rate of recruitment | "Number of fish that grow to catchable size per short interval of time, divided by the number of catchable fish already present at that time |
| fishing intensity | 1 |
| specific humidity | Measurement of atmospheric humidity |
| swell | see sea-wave. |
| ecology | study of the ecosystem with particular reference to the relationships between plants and animals and the environment. |
| situation | the relationship of a settlement site to its surroundings and thus a factor in whether the settlement will grow or not. |
| translatory wave | (Hydraulics) A wave, such as a flood wave, whose water particles constantly progress in the direction of the wave movement; a characteristic of unsteady flow |
| fish passage facilities | Features of a dam that enable fish to move around, through, or over without harm |
| field sprinkler system | A system of closed conduits carrying irrigation water under pressure to orifices designed to distribute the water over a given area. |
| supersaturation | See dissolved gas concentrations. |
| freezing spray | An accumulation of supercooled water droplets on a vessel or object which are below the freezing point of water |
| vault | Same as BWER. |
| glaciology | Collectively, the branches of science concerned with the causes and modes of ice accumulation and with ice action, on the earth's surface |
| hydrometeorology | The interdisciplinary science involving the study and analysis of the interrelationalships between the atmospheric and land phases of water as it moves through the hydrologic cycle. |
| max | An abbreviation of maximum. |
| isoline | Lines on a map joining points of equal value. |
| cumulus humilis | Cumulus clouds with little or no vertical development characterized by a generally flat appearance |
| wild stock | A stock that is sustained by natural spawning and rearing in the natural habitat, regardless of parentage (includes native). |
| seepage losses | A measure of water losses in a conveyance system due to water being seeped into the surrounding soils |
| filtration | the mechanical process which removes particulate matter by separating water from solid material, usually by passing it through sand. |
| stock | A specific population of fish spawning in a particular stream during a particular season. |
| shower | Precipitation from a convective cloud that is characterized by its sudden beginning and ending, changes in intensity, and rapid changes in the appearance of the sky |
| standard solution | any solution in which the concentration is known. |
| geomorphology | Geomorphology is the scientific field that investigates how landforms are formed on the Earth (and other planets). |
| flow duration curve | A cumulative frequency curve that shows the percentage of time that specified discharges are equaled or exceeded. |
| habitat conservation plan | An agreement between the Secretary of the Interior and either a private entity or a state that specifies conservation measures that will be implemented in exchange for a permit that would allow taking of a threatened or endangered species. |
| population distribution | the variation in population densities over wide areas. |
| chart datum | A plane of reference, established by the National Ocean Survey (NOS), as a mean low water level for each of the Great Lakes |
| nutrient cycle | the cyclic conversions of nutrients from one form to another within biological communities |
| acre | A measure of area equal to 43,560 square feet (4,046.87 square meters) |
| canal reach | The segment of the main canal system consisting of a series of canal pools between major flow control structures. |
| polypedon | An identifiable soil with distinct characteristics found in a location or region |
| fully permanent sprinkler system | An irrigation system usually composed of buried enclosed conduits carrying water under pressure to fixed orifices to distribute water over a given area. |
| transmission lines | Pipelines that transport raw water from its source to a water treatment plant. |
| sun dog | Either of two colored luminous spots that appear at roughly 22° on both sides of the sun at the same elevation |
| jet stream | a long narrow meandering current of high-speed winds near the tropopause blowing from a generally westerly direction and often exceeding a speed of 250 miles per hour. |
| dispersion | the movement and spreading of contaminants out and down in an aquifer. |
| normal year | A year during which the precipitation or streamflow approximates the average for a long period of record. |
| focus | See earthquake focus. |
| backwater flooding | Flooding caused by a restriction or blocking of flow downstream |
| catchment | (1) The catching or collecting of water, especially rainfall |
| continental drift | Theory that suggests that the Earth's crust is composed of several continental plates that have the ability to move |
| uncontracted water | A volume of water in a storage reservoir that is not assigned for other purposes, such as irrigation. |
| migration | The movement of oil, gas, contaminants, water, or other liquids through porous and permeable rock. |
| salinity | The concentration of salt in a body of water |
| lignite | Low grade coal |
| quota | a limit to production or trade |
| flocculation | Chemical processes where salt causes the aggregation of minute clay particles into larger masses that are too heavy to remain suspended water. |
| aob | An acronym for "At or Below". |
| depletion curve | That part of the hydrograph extending from the point of termination of the Recession Curve to the subsequent rise or alternation of inflow due to additional water becoming available for stream flow. |
| lake effect snow | Snow showers that are created when cold dry air passes over a large warmer lake, such as one of the Great Lakes, and picks up moisture and heat. |
| aquifer | soil or rock below the land surface that is saturated with water |
| stable channel | A stream channel with the right balance of slope, planform, and cross section to transport both the water and sediment load without net long-term bed or bank sediment deposition or erosion throughout the stream segment. |
| wood treatment facility | An industrial facility which treats lumber and other wood products for outdoor use |
| potamophobia | The fear of rivers or running water. |
| balance of trade | the net sum of imports and exports of visible goods |
| drifting snow | Snow particles blown from the ground by the wind to a height of less than six feet. |
| base width | The time duration of a unit hydrograph. |
| dual economy | a country having one or two core areas which far outstrip the development of the surrounding peripheral area. |
| treaty tribes | Any Indian tribe recognized by the United States government, with usual and accustomed fishing grounds, whose fishing rights were reserved under a treaty and have been affirmed by a federal court. |
| odd-year run | A population of fish that returns to its natural spawning grounds in odd numbered years, such as the pink salmon. |
| correlation coefficient ® | A statistical expression that varies between -1 and +1 depending upon how close the variables measured in a population are related |
| even-year run | A population of fish that returns to its natural spawning grounds in even numbered years. |
| basin boundary | The topographic dividing line around the perimeter of a basin, beyond which overland flow (i.e.; runoff) drains away into another basin. |
| rivulet | A small stream or brook; a streamlet. |
| nutrient pollution | Contamination of water resources by excessive inputs of nutrients |
| tundra | A level to undulating treeless plain characteristic of Arctic and subarctic regions |
| easterly wave | Atmospheric disturbance in the tropical trade winds |
| sanitary landfill | landfill that is lined with plastic or concrete or located in clay-rich soils to prevent hazardous substances from leaking into the environment. |
| crop | (1) Plants, seeds, flowers and root tubers that are grown to be used as food or to be sold for profit |
| tropical depression | A tropical cyclone in which the maximum sustained surface winds are 38 miles per hour (33 knots) or less |
| wetland | An area that is saturated by surface water or groundwater, with vegetation adapted for life under those soil conditions. |
| mutualism | Interspecific interaction where both species experience and increase in their fitness after interacting with the other species |
| climate | aggregate weather conditions of an area over a long period of time which allow for the designation of seasonal patterns and expected future weather. |
| land reclamation | Making land capable of more intensive use by changing its general character, as by drainage of excessively wet land, irrigation of arid or semiarid land, or recovery of submerged land from seas, lakes, and rivers. |
| quota | A number of fish allocated for harvest to a particular fishing group or area. |
| strike | One of the directional properties of a geologic structure such as a fold or a fault |
| rossby waves | the wave-pattern of flow of the westerly winds which blow in the upper atmosphere |
| roll cloud | A relatively rare, low-level, horizontal, tube-shaped cloud |
| hjulstrّm curve | a graph showing critical stream velocities for the erosion, transport and deposition of different sizes of load. |
| old growth | Forests that either have never been cut or have not been cut for many decades |
| storm surge | A rise above the normal water level along a shore caused by strong onshore winds and/or reduced atmospheric pressure |
| zone of saturation | The space in the soil below the water table in which all the pores are filled with water |
| precipitation | The process by which crystals form from saturated solutions |
| algae | Microscopic plants that grow in sunlit water containing phosphates, nitrates, and other nutrients |
| volcano | An elevated area of land created from the release of lava and ejection of ash and rock fragments from and volcanic vent. |
| new town | the targeted and rapid expansion of a settlement (although they may also be built from scratch) to alleviate the pressure of overly high demand for housing in a region, especially on existing cities. |
| phloem | Food conducting tissue in vascular plants. |
| rapid deepening | A decrease in the minimum sea-level pressure of a tropical cyclone of 1.75 mb/hr or 42 mb for 24 hours. |
| employment sector | the broad types of economic activity within which jobs are provided: primary, secondary, tertiary and quaternary. |
| nutrient concentrations | (see anoxia, anaerobic). |
| crest gage | A gage used to obtain a record of flood crests at sites where recording gages are installed. |
| lotic-adapted species | species for which all or part of their life history is dependent on flowing water. |
| deflation | wind removal of small, grain-size rock particles such as sand. |
| constructive wave | a low height, low frequency wave where the net movement of material is up the beach as the swash is stronger than the backwash. |
| percolation test | A soil test to determine if soil will take sufficient water seepage for use of a septic tank. |
| integrated resource planning | A method for looking ahead using environmental, engineering, social, financial and economic considerations; includes using the same criteria to evaluate both supply and demand options while involving customers and other stakeholders in the process. |
| deposition nuclei | Six-sided microscopic particle that allows for deposition of water as ice crystals in the atmosphere |
| island model of migration | An equilibrium model of gene flow and genetic drift that is applied under the assumption that a species (or operational taxonomic unit or ESU) is subdivided into populations of equal size, all of which exchange migrants at a constant rate, with migrants coming with equal probability from all other populations. |
| gully reclamation | use of small dams of manure and straw; earth, stone,or concrete to collect silt and gradually fill in channels of eroded soil. |
| calm | smoke rises vertically; sea like a mirror |
| papilla | A small fleshy projection. |
| basin | A segment or portion of a larger watershed area, based on the natural water drainage pattern. |
| texture | Refers to relative proportions of clay, silt, and sand in soil. |
| lake | An inland body of standing water deeper than a pond, an expanded part of a river, a reservoir behind a dam. |
| bearing | A system that measures in reference to the cardinal points of a compass in 90 degree quadrants. |
| traction | Erosional movement of particles by rolling, sliding and shuffling along the eroded surface |
| ukmet | A medium-range (3 to 7 day) numerical weather prediction model operated by the United Kingdom METeorological Agency. It has a resolution of 75 kilometers and covers the entire northern hemisphere. Forecasters use this model along with the European and MRF in making their extended forecasts (3 to 7 days). |
| equinox | Two days during the year when the declination of the Sun is at the equator |
| volcano | An opening in the earth's crust through which steam and lava are forced out. |
| forecast | (Statistics) A forecast is a quantitative estimate (or set of estimates) about the likelihood of future events based on past and current information |
| geocoding | The conversion of features found on an analog map into a computer-digital form |
| food chain | generally, but not always, occurs due to a contaminant being soluble in fatty tissues and not in water, (see bioaccumulation, bioconcentration). |
| hydrometeorologists | Individuals who have the combined knowledge in the fields of both meteorology and hydrology which enables them to study and solve hydrologic problems where meteorology is a factor. |
| drainage basin | The area of land that drains water, sediment, and dissolved materials to a common outlet at some point along a stream channel. |
| infauna | Aquatic animals that live in the substrate of a body of water, especially in a soft sea bottom. |
| water yield | Runoff, including ground water outflow that appears in the stream, plus ground water outflow that leaves the basin underground |
| laboratory blank | An artificial sample, usually distilled water, introduced to a chemical analyzer to observe the response of the instrument to a sample that does not contain the material being measured |
| sheet erosion | The removal by surface runoff of a fairly uniform layer of soil from a bank slope from "sheet flow" or runoff that flows over the ground surface as a thin, even layer not concentrated in a channel. |
| remote sensing | The gathering of information from an object or surface without direct contact. |
| index contour | Contour line that is accentuated in thickness and is often labeled with the appropriate measure of elevation |
| pressure melting point | under a glacier, the pressure brought to bear by the mass of ice above can lower the freezing/meting point of water. |
| cuspate foreland | triangular beach form |
| economic demand | The consumer's willingness and ability to purchase some quantity of a commodity based on the price of that commodity. |
| rate control | Rate control refers to controlling the rate of runoff using structures to simulate pre-construction conditions. |
| salt | generally potassium or ammonium is the cation, used to coagulate particles in water treatment. |
| kilowatt | The electrical unit of power which equals 1,000 watts or 1.341 horsepower |
| inundation map | A map delineating the area that would be inundated in the event of a dam failure. |
| gametes | The sexual reproductive cells, eggs and sperm. |
| outfall | the place where a sewer, drain, or stream discharges; the outlet or structure through which reclaimed water or treated effluent is finally discharged to a receiving water body. |
| warm air advection | Transport of warm air into an area by horizontal winds. Low-level warm advection sometimes is referred to (erroneously) as overrunning |
| suspended solids | solids that are not in true solution and that can be removed by filtration |
| pilot tests | The testing of a cleanup technology under actual site conditions in a laboratory in order to identify potential problems before implementation. |
| snow depth | The actual depth of snow on the ground at any instant during a storm, or after any single snowstorm or series of storms. |
| cirque | A steep-walled semicircular basin in a mountain caused by glacial erosion |
| isohyet | A line that connects points of equal rainfall. |
| hail index | This WSR-88D radar product displays an indication of whether the thunderstorm structure of each identified by the storm series algorithm is conducive to the production of hail. A green triangle indicates areas where the algorithm thinks that there is hail. It will also display an estimated hail size. This does not mean that there is actually hail occurring or the hail is the size that the radar is indicating, but it does attract the radar operator's attention to check out the thunderstorm more closely. |
| collada | A strong, steady wind blowing from the north or northwest in the upper part of the Gulf of California and from the northeast in the lower part. |
| barrier island | Long, narrow islands of sand and/or gravel that are usually aligned parallel to the shore of some coasts. |
| gale | Breaks twigs off trees; impedes progress; moderately high waves of greater length; edges of crests begin to break into spindrift; foam on water surface is blown in well-marked streaks along wind. |
| sediment | usually applied to material in suspension in water or recently deposited from suspension |
| water crossing | A commonly used route for crossing a river or stream. |
| crest | the top of a dam, dike, or spillway, which water must reach before passing over the structure; the summit or highest point of a wave; the highest elevation reached by flood waters flowing in a channel. |
| truncated spur | steep cliff face at the side of a glacial trough where a valley glacier has removed an interlocking spur |
| nmc | National Meteorological Center, with headquarters near Washington D.C.; now known as NCEP. |
| bergy bit | A large chunk of glacial ice (or a very small iceberg) which floats in the sea. |
| yolk | The food part of an egg. |
| instantaneous discharge | is the discharge at a particular instant of time. |
| headwater basin | A basin at the headwaters of a river |
| phytoplankton | Small photosynthetic organisms, mostly algae and bacteria, found inhabiting aquatic ecosystems |
| tropical cyclone | It is a warm-core low pressure system which is non-frontal |
| ground water table | The upper surface of the Zone of Saturation for underground water |
| reduced-risk pesticides | These are pesticides which : (1) reduce pesticide risks to human health; (2) reduce pesticide risks to nontarget organisms; (3) reduce the potential for contamination of valued, environmental resources, or (4) broaden adoption of IPM or makes it more effective |
| upriver stocks | Salmon and steelhead stocks that spawn in the Columbia River or its tributaries above Bonneville Dam. |
| principal spillway | Allows discharge of water from a reservoir when the water level exceeds the top of the spillway |
| bust | - Slang for an inaccurate forecast or an unsuccessful storm chase; usually a situation in which thunderstorms or severe weather are expected, but do not occur. |
| precipitation gage | A device used to collect and measure precipitation. |
| detention time | the time required for a volume of water to pass through a tank at a given rate of flow; in storage reservoirs, the length of time water will be held before being used. |
| seed | Fertilized ovule of a plant that contains an embryo and food products for germination |
| pressure tendency | The pressure characteristic and amount of pressure change during a specified time period, usually the three hour period preceding the observation. |
| capillary zone | soil area above the water table where water can rise up slightly through the cohesive force of capillary action |
| podzolization | Soil forming process that produces a strongly leached soil with a distinctive iron hardpan layer in the B horizon |
| acquired immune deficiency syndrome | a fatal syndrome caused by HIV |
| inu or ins | An acronym for Inertial Navigation Unit or System: A highly accurate tool for measuring and keeping track of motions and accelerations |
| solution | generally from the decomposition of natural plant and animal tissues, but including some anthropogenic contaminants. |
| self-purification | The ability of a body of water to rid itself of pollutants |
| coriolis effect | The effect caused by the Earth's rotation which deflects air moving between two places |
| resurgence | the reappearance of a river at the surface after it has spent some time running underground |
| phreatic zone | The locus of points below the water table where soil pores are filled with water |
| low clouds | A term used to signify clouds with bases below 6,000 feet and are of a stratiform or a cumuliform variety |
| effluent limitation | restrictions established by a a regulating agency such as a State or the EPA in an NPDES permit on quantities, rates, and concentrations in wastewater discharges. |
| hard water | water containing a high level of calcium, magnesium, and other minerals |
| commercial fishery | A fishery, using various types of fishing gear, that is intended to harvest one or more species of fish for the purpose of selling them to fish buyers or directly to the public. |
| mb | An acronym for Millibars. See Millibars. |
| neap tide | A minimum tide occurring at the first and third quarters of the moon. |
| arctic | Of or relating to the area around the geographic North Pole, from 90° North to the Arctic Circle at approximately 66 1/2 North latitude. |
| hydrograph | A graph showing the water level (stage), discharge, or other property of a river with respect to time |
| laminar flow | A flow in which rapid fluctuations are absent. |
| caution stage | Same as alert stage. |
| reef | A ridge of rocks found in the tidal zone along a coastline |
| secchi disc | A circular plate, generally about 10-12 in (25.4-30.5 cm) in diameter, used to measure the transparency or clarity of water by noting the greatest depth at which it can be visually detected |
| intake traveling screens | See turbine intake screens. |
| littoral zone | (1) The shallow area near the shore of a non-flowing body of water; that portion of a body of fresh water extending from the shoreline lakeward to the limit of occupancy of rooted plants |
| gamete | A haploid reproductive cell. |
| algorithm | A computer program (or set of programs) which is designed to systematically solve a certain kind of problem |
| river basin | See watershed. |
| water table decline | the regional lowering of the water table due to over pumping of wells. |
| salts | minerals that cause salinity |
| stratus cloud | a layered cloud found below 2.5 km which produces light drizzle. |
| polar axis | Is a line drawn through the Earth around the planet rotates |
| sea level pressure | The pressure value obtained by the theoretical reduction or increase of barometric pressure to sea-level. |
| intake | The entrance to a turbine at a dam, diversion works, or pumping station. |
| muskeg | Poorly drained marshes or swamps found overlying permafrost. |
| base flow | Rate of discharge in a stream where only the throughflow and groundwater flow from subsurface aquifers contribute to the overall flow. |
| import controls | measures imposed by governments to restrict the import of particular goods or goods from a particular country |
| tropical advisories | Official information issued by the Tropical Prediction Centers describing all tropical cyclone watches and warnings in effect along with details concerning tropical cyclone locations, intensity and movement, and precautions that should be taken. Advisories are issued to describe (a) tropical cyclones prior to issuance of watches and warnings and (b) subtropica cyclones. |
| vadose water | Water occurring in the Unsaturated Zone (Vadose Zone) between the land surface and the water table. |
| head loss | The decrease in total head caused by friction, entrance and exit losses. |
| erratic | A boulder or other rock fragment transported by glacial ice from their place of origin (or a previous glacial resting point) to an area which has a different type of bedrock. |
| brine | Highly salty and heavily mineralised water, containing heavy metal and organic contaminants. |
| manhole structure | Reference to and all activities relevant to manhole structures throughout the text shall also be taken to include junction boxes, inspection chambers, drop shafts, sumps, and all other auxiliary structures appurtenant to the sewerage system. |
| soil creep | Slow mass movement of soil downslope |
| protein | Organic substances primarily composed of carbon, hydrogen, nitrogen, and some other minor elements which are arranged in about 20 different compounds known as amino acids |
| parent-material | rock or regolith from which the inorganic, mineral component of a soil is derived. |
| allele | An alternate form of a gene. |
| prediction | Forecast or extrapolation of the future state of a system from current or past states. |
| detention basins | Detention basins are normally dry, but are designed to detain surface water temporarily during, and immediately after a runoff event |
| float | (1) To remain suspended within or on the surface of a fluid without sinking |
| temperature | The degree of hotness or coldness. |
| bubbler gage | A water stage recording device that is capable of attaching to a LARC for data automation purposes. |
| glacial trough | see glacial valley. |
| subyearling | A developmental life stage of fish that are less than one year old. |
| outlook | It is used to indicate that a hazardous weather or hydrologic event may develop |
| tenure | the conditions of occupancy of a piece of land. |
| well | A deep hole with the purpose to reach underground water supplies. |
| drainage basin | A part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. |
| geomorphology | A branch of both physiography and geology that deals with the form of the earth, the general configuration of its surface, and the changes that take place due to erosion of the primary elements and the buildup of erosional debris. |
| laurasia | Northern section of Pangaea. |
| climatology | Scientific study of the Earth's climate over long time spans (greater than several days) |
| capillary action | Water that at some point rises higher than that portion of its surface, not in contact with the solid surface |
| certificate of water right | an official document which serves as court evidence of a perfected water right. |
| sanitary survey | An on-site review of the water sources, facilities, equipment, operation and maintenance of a public water system to evaluate the adequacy of those elements for producing and distributing safe drinking water. |
| flood frequency | A statistical expression or measure of how often a hydrologic event of a given size or magnitude should, on an average, be equaled or exceeded |
| net water yield | The available water runoff at a given location, both surface and subsurface, after the upstream uses by man's activities, use by Phreatophytes, and evaporation from upstream free water surfaces. |
| transpiration | the loss of water from plants through the stomata in the leaves. |
| log and safety boom | A net-like device installed in a reservoir, upstream of the principal spillway, to prevent logs, debris and boaters from entering a water discharge facility or spillway. |
| geothermal | heat from within the earth |
| virgin flow | the streamflow which exists or would exist if man had not modified the conditions on or along the stream or in the drainage basin. |
| spillway | A channel for reservoir overflow. |
| staccato lightning | A Cloud to Ground (CG) lightning discharge which appears as a single very bright, short-duration stroke, often with considerable branching. |
| hydroscope | An optical device used for viewing objects far below the surface of water. |
| bustee | the name for a shanty town in India. |
| slope protection | The protection of a Slope against wave action or erosion. |
| hydrologic services | A general term referring to the operations, products, verbal communications, and related forms of support provided by the NWS for the Nation's streams, reservoirs, and other areas affected by surface water. |
| direct runoff | The runoff entering stream channels promptly after rainfall or snow melt |
| dry-bulb thermometer | Thermometer on a psychrometer used to determine current air temperature |
| insolation | Direct or diffused shortwave solar radiation that is received in the Earth's atmosphere or at its surface. |
| observation well | A well used to monitor changes in water levels of an aquifer and to obtain samples for water quality analyses. |
| eruption | the escape of gases, steam and lava from within the crust to the surface or into the atmosphere |
| scale | The precipitate that forms on surfaces in contact with water as the result of a physical or chemical change. |
| muscovite | Rock forming mineral of the mica group. |
| progressive derecho | They are characterized by a short curved squall line oriented nearly perpendicular to the mean wind direction with a bulge in the general direction of the mean flow |
| ice crystals | A fall of unbranched (snow crystals are branched) ice crystals in the form of needles, columns, or plates |
| drumlin | a mound of glacial debris formed into a smooth, elongated feature whose apex is skewed towards the rear (in terms of the direction of movement) |
| thermal low | Also known as heat low, it is an area of low pressure due to the high temperatures caused by intensive heating at the surface |
| source | A source is the beginning of a river. |
| staff gage | A vertical staff graduated in appropriate units which is placed so that a portion of the gage is in the water at all times |
| age-class | A group of individuals of a certain species that have the same age. |
| travel time | The time required for a flood wave to travel from one location to a subsequent location downstream. |
| drainage basin | The total area of land from which water drains into a specific river. |
| sheetwash | The removal of loose surface materials by overland flow |
| fahrenheit | An older form of temperature measurement |
| spheroidal weathering | the chemical weathering of blocks of rock so that they take on a more rounded shape. |
| gini coefficient | G= ½ Σ(Xi -Yi) Xi and Yi are two sets of data expressed as a percentage |
| coastal marine forecasts | This National Weather Service marine product is designed to serve the needs of the widest variety of maritime activities in the coastal waters of Atlantic Ocean, Pacific Ocean, and Gulf of Mexico. Coastal water traffic ranges from numerous small and weather-sensitive craft, many of which do not venture far from land, to the largest ocean-going vessels. Another important activity is the offshore energy vessels that includes mobile drill ships and fixed platforms. |
| sediment | soil particles, sand, and minerals washed from the land into aquatic systems as a result of natural and human activities. |
| lotic environment | Characterizing aquatic communities found in running water. |
| soil moisture regime | The changes in the moisture content of soil during a year. |
| distribution main | See Water Main. |
| air pollution | The soiling of the atmosphere by contaminants to the point that may cause injury to health, property, plant, or animal life, or prevent the use and enjoyment of the outdoors. |
| rhyolite | A fine grained extrusive igneous rock that is rich in quartz and potassium feldspar |
| opercle | Refers to the largest bone in the operculum. |
| freezing rain advisory | This product is issued by the National Weather Service when freezing rain or freezing drizzle causes significant inconveniences, but does not meet warning criteria (normally an ice accumulation of 1/4 inch or greater) and if caution is not exercised, it could lead to life-threatening situations. |
| edaphic | lit |
| snow roller | The product of moist, cohesive snow that when initiated by wind rolls across the landscape, gathering snow until it can no longer move |
| run-by | Run-by occurs when a high magnitude storm occurs and the flow in the street is going too fast to enter the storm drain inlet, usually a catch basin, and ‘runs by’. |
| gleysol soil | Soil order (type) of the Canadian System of Soil Classification |
| hardpan | a thin crust of material within a soil as a result of the illuviation of iron and/or aluminium from layers above or the precipitation of calcium carbonates which cement sands together. |
| benefit-cost ratio | The relationship of the economic benefits of an action to its total costs. |
| cloud-cloud lightning | Streaks of lightning reaching from one cloud to another. |
| gradient | the steepness of a slope. |
| abrasion | Hydraulic wear or scour on the wall of a sewer, through-flow channel or manhole wall. |
| roe | The eggs of fishes. |
| profiler | An instrument designed to measure horizontal winds directly above its location, and thus measure the vertical wind profile |
| chelating agents | Organic compounds that have the ability to draw ion from their water solutions into soluble complexes. |
| palaeomagnetism | evidence of past differences in the alignment of the Earth magnetic field |
| backwater | (1) A small, generally shallow body of water attached to the main channel, with little or no current of its own, or (2) A condition in subcritical flow where the water surface elevation is raised by downstream flow impediments. |
| saturated zone | The zone in the earth's crust, extending from the water table downward, in which all open pore spaces in the soil or rock are filled with water at greater than atmospheric pressure |
| tributary | A stream that flows into another stream, river, or lake. |
| bioassessment | monitoring the aquatic environment to determine the health of a stream. |
| signal-to-noise ratio | A ratio that measures the comprehensibility of data, usually expressed as the signal power divided by the noise power, usually expressed in decibels (dB). |
| second law of thermodynamics | This law states that heat can never pass spontaneously from a colder to a hotter body |
| groundwater | water within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table. |
| maximum sustainable yield | The greatest amount of a renewable natural resource (e.g., forests or wildlife) that can be removed without diminishing the continuing production and supply of the resource. |
| backup sawrs | Indicates automated observations taken by a commissioned version 3 of an |
| resilience | the ability of an ecosystem to maintain or restore biodiversity, biotic integrity, and ecological structure and processes following disturbance. |
| severe weather statement | A National Weather Service product which provides follow up information on severe weather conditions (severe thunderstorm or tornadoes) which have occurred or are currently occurring. |
| wetland | Natural land-use type that is covered by salt water or fresh water for some time period |
| backwater effect | The rise in surface elevation of flowing water upstream from and as a result of an obstruction to flow |
| environmental analysis | (1) An analysis of alternative actions and their predictable short and long-term environmental effects, which may include physical, biological, economic, social and environmental design factors and their interaction |
| sector model | based on 149 US cities, an urban land-use model which accounts for transport routes within the city |
| soil horizon | Layer within a soil profile that differs physically, biologically or chemically from layers above and/or below it. |
| natural flow | The flow past a specified point on a natural stream that is unaffected by stream diversion, storage, import, export, return flow, or change in use caused by modifications in land use. |
| montreal protocol | Treaty signed in 1987 by 24 nations to cut the emissions of chlorofluorocarbons (CFCs) into the atmosphere |
| lithification | Process by which sediments are consolidated into sedimentary rock. |
| coliform index | A rating of the purity of water based on a count of coliform bacteria. |
| watershed area | The watershed area at a point in the stream refers to the area of the earth from which the water concentrates toward that point, through the drainage system. |
| usgs | United States Geological Survey |
| cryotic | Something that is frozen. |
| leaching | extraction or flushing out of dissolved or suspended materials from the soil, solid waste, or another medium by water or other liquids as they percolate down through the medium to groundwater. |
| pollutant | A substance that has a harmful effect on the health, survival, or activities of humans or other living organisms. |
| sargasso sea | An area of the North Atlantic Ocean between Bermuda and the Azores |
| emigration | Migration of an organism out of an area for the purpose of changing its residence permanently |
| land voiding | The process of damaging land by gully action causing this land to be unproductive for agricultural uses and relegating its use primarily to wildlife and recreation. |
| fcst | NWSRFS Forecast Program to produce operational forecasts |
| sewage treatment | The processing of wastewater for the removal or reduction of contained solids or other undesirable constituents. |
| soil erosion | the processes by which soil is removed from one place by forces such as wind, water, waves, glaciers, and construction activity and eventually deposited at some new place. |
| isolated | A National Weather Service convective precipitation descriptor for a 10 percent chance of measurable precipitation (0.01 inch). Isolated is used interchangeably with few. See Precipitation Probability (PoP). |
| confining bed or unit | a body of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers. |
| catchment area | An area having a common outlet for its surface runoff (also see Drainage Area or Basin, Watershed). |
| lewp | An acronym for Line Echo Wave Pattern. See Line Echo Wave Pattern. |
| moho | see Mohorovicic discontinuity. |
| major flooding | A general term including extensive inundation and property damage |
| upper-level disturbance | A disturbance in the upper atmospheric flow pattern which is usually associated with clouds and precipitation |
| pressure melting point | Temperature at which minerals deep within the Earth and ice below the surface of a glacier are caused to melt because of the introduction of pressure. |
| thunder snow | A wintertime thunderstorm from which falls snow instead of rain |
| sial layer | The part of the crust that forms the continents and is composed of relatively light, granitic rocks. |
| corrie | A steep-walled semicircular basin in a mountain caused by glacial erosion |
| intermountain high | An area of high pressure that occurs during the winter between the Rocky Mountains and the Sierra-Cascade ranges |
| land breeze | The land-to-sea surface wind that occurs in coastal areas at night |
| flocculation | Process by which clumps of solids in water or sewage aggregate through biological or chemical action so they can be separated from water or sewage. |
| wild rivers | Rivers or sections of rivers that are free of impoundments and generally inaccessible except by trail, with watersheds or shorelines essentially primitive and water unpolluted. |
| rfc | Centers that serve groups of Weather Service Forecast offices and Weather Forecast offices, in providing hydrologic guidance and is the first echelon office for the preparation of river and flood forecasts and warnings. |
| gravitational water | the water in the soil that is unavailable to plants and which flows out of the soil as throughflow to the river channel or percolates into the rock below. |
| mist | Liquid particles measuring 40 to 500 micrometers, are formed by condensation of vapour |
| atom | The smallest unit of matter that is unique to a particular element |
| evapotranspiration | The combined processes by which water is transferred from the earth surface to the atmosphere; evaporation of liquid or solid water plus transpiration from plants |
| continuous permafrost | Form of permafrost that exists across a landscape as an unbroken layer. |
| triple point | The point at which any three atmospheric boundaries meet |
| snow creep | A continuous, extremely slow, downhill movement of a layer of snow. |
| hypo chlorite | An anion that forms products such as calcium and sodium hypo chlorite |
| visibility | the distance from which an object can be seen |
| reptile | Group of terrestrial vertebrate animals that includes turtles, tortoises, snakes, lizards, crocodiles, and alligators. |
| fishery | The act, process, or occupation of attempting to catch fish, which may be retained or released. |
| crest | 1) The highest stage or level of a flood wave as it passes a point |
| overcast | The amount of sky cover for a cloud layer that is 8/8ths, based on the summation layer amount for that layer. |
| ice shove | On-shore ice push caused by wind, and currents, changes in temperature, etcetera. |
| footloose | industries that do not rely on the location of raw materials or the cost of transporting them for their own locational decision-making |
| hydraulic ram | A device which uses the energy of falling water to force a small portion of the water to a height greater than the source |
| thermal circulation | Atmospheric circulation caused by the heating and cooling of air. |
| heat lightning | Lightning that occurs at a distance such that thunder is no longer audible. |
| offshore/onshore flow | Offshore flow occurs when air moves from land to sea |
| capillary water | the water that moves around the soil and is available for plant use. |
| valve | A device fitted to a pipeline or orifice in which the closure member is either rotated or moved in some way as to control or stop flow. |
| rainleaders | Rooftop drains are also called rainleaders |
| subsoil | Soil material underlying the surface soil. |
| finished water | Water that has passed through all the processes in a water treatment plant and is ready to be delivered to consumers. |
| watermaster | An employee of a water department who distributes available water supply at the request of water right holders and collects hydrographic data. |
| paleozoic | an era of geologic time lasting from 570m to 245m years ago. |
| adiabatic process | A thermodynamic change of state in a system in which there is no transfer of heat or mass across the boundaries of the system |
| native species | A species of fish indigenous to a specific state. |
| sustainability | A decision-making concept describing development that meets the needs of the present without compromising the ability of future generations to meet their own needs. |
| streamflow | the water discharge that occurs in a natural channel |
| channelization | straightening and/or deepening of river channels to improve/maintain navigability and for flood control. |
| junior rights | Water rights that were obtained more recently and therefore are junior in priority to older or more senior rights |
| annular space | the space between two concentric cylindrical objects, one of which surrounds the other, such as the space between the walls of a drilled hole and a casing. |
| hierarchy | organisation by class of importance, status or authority |
| canopy | the overhanging cover formed by branches and foliage. |
| iflows | The Integrated Flood Observing and Warning System. |
| inch-degrees | The product of inches of rainfall times temperature in degrees above freezing (Fahrenheit), used as a measure of the snowmelting capacity of rainfall. |
| flash flood warning | This warning signifies a short duration of intense flooding of counties, communities, streams, or urban areas with high peak rate of flow. Flash floods may result from such things as torrential downpours, dam breaks, or ice jam breaks. |
| level of development | In a planning study, the practice of holding constant the population, irrigated acreage, industry, and wildlife so that hydrologic variability can be studied to determine adequacy of supplies. |
| shut-off nozzle | Device attached to end of hose that completely shuts off the flow even if left unattended. |
| storm relative | Measured relative to a moving thunderstorm, usually referring to winds, wind shear, or helicity. |
| temperature-gradient metamorphism | Process of firnification when large temperature gradients exist within the snowpack, such as within adjacent layers of snow |
| solute | chemical or pollutant in a specified volume or weight of solvent, air, water, soil or other medium, accumulating a level of some material over and above the level found in the ambient environment, generally applied to an organism. |
| subglacial | The area below the glacier |
| irrigation requirement | The quantity of water, exclusive of precipitation, that is required for crop production |
| lcl | An acronym for Lifted Condensation Level. See Lifted Condensation Level. |
| streamflow | the discharge that occurs in a natural channel. |
| satellite hydrology program | A NOHRSC program that uses satellite data to generate areal extent of snow cover data over large areas of the western United States. |
| pool height | The height of the water behind a dam |
| mesohabitat | basic structural elements of a river or stream such as pools, backwaters, runs, glides, and riffles. |
| urban climate | the climate of an urban area is distinct from the general conditions for the region in which it is located due to the energy released through human activity. |
| qualitative water assessment | Analyses of water used to discribe the visible or aestetic charcteristics of water. |
| deadman | A log, block of concrete, rebar, or other object buried in a stream bank that is used to tie in revetment with cable or chain. |
| ridge ice | Ice piled haphazardly one piece over another in the form of ridges or walls. |
| zone | (1) (Ecology) An area characterized by similar flora or fauna; a belt or area to which certain species are limited |
| potable | suitable, safe, or prepared for drinking |
| decomposition | The breakdown of matter by bacteria and fungi, changing the chemical makeup and physical appearance of materials. |
| sleet | Also known as ice pellets, it is winter precipitation in the form of small bits or pellets of ice that rebound after striking the ground or any other hard surface |
| cappi | An acronym for Constant Altitude PPI. A data product providing radar data at a fixed height or altitude, rather than at a fixed elevation angle. |
| mechanical weathering | see physical weathering. |
| ripple | Stream bed deposit found streams |
| nonpoint source pollution | Pollution that does not originate from a clear or discrete source. |
| aeration tank | a chamber used to inject air into water. |
| specific discharge | For ground water, the rate of discharge per unit area, measured at right angles to the direction of flow. |
| rain | Precipitation in the form of liquid water droplets greater than 0.5 mm |
| hydrograph | A graph showing the water level (stage), discharge, or other property of a river volume with respect to time. |
| latitude | The location north or south in reference to the equator, which is designated at zero (0) degrees |
| special avalanche warning | Issued by the National Weather Service when avalanches are imminent or occurring in the mountains. It is usually issued for a 24 hour period. |
| operculum | The gill cover. |
| maximum contaminant level | the designation given by the U.S |
| clear | The state of the sky when no clouds or obscurations are observed or detected from the point of observation. |
| live box | A container filled with water and often equipped with accessories such as aeration equipment that is used to hold and transport live fish. |
| parapet wall | A solid wall built along the top of the dam for ornament, safety, or to prevent overtopping. |
| viruses | The smallest life forms known, that are not cellular in nature |
| dry weather flow | Streamflow which results from precipitation that infiltrates into the soil and eventually moves through the soil to the stream channel |
| permafrost | Soil or rock at or near the ground in Arctic or subarctic regions that has been continuously frozen for a long time. |
| ped | a structured unit of soil created when particles become grouped and bound together |
| relative humidity | A type of humidity that considers the ratio of the actual vapor pressure of the air to the saturation vapor pressure |
| lateral line | A series of sensory pores opening to the exterior along the side of fish. |
| tailwater height | Height of water immediately downstream of the dam |
| numerous | A National Weather Service convective precipitation descriptor for a 60 or 70 percent chance of measurable precipitation (0.01 inch). See Precipitation Probability (PoP). |
| subabdominal pelvic fin | Said of pelvic fins when placed forward on abdomen but not attached internally to pectoral girdle. |
| urbanization | To become a developed city, or changing from rural to an urban state. |
| broodline | The generation of pink salmon that reproduces every other year |
| hydrogeologic | Those factors that deal with subsurface waters and related geologic aspects of surface waters. |
| protozoa | Large microrganisms, which consume bacteria. |
| influent | Water, wastewater, or other liquid flowing into a reservoir, basin, or treatment plant. |
| hydraulic conductivity | the rate at which water can move through a permeable medium. |
| realized niche | Describes the part of the fundamental niche that a species actually occupies. |
| federal snow sampler | A snow sampler consisting of five or more sections of sampling tubes, one which has a steel cutter on the end. The combined snowpack measuring depth is 150 inches. This instrument was formerly the Mount Rose Type Snow Sampling Set. |
| representative sample | A portion of material or water that is as nearly identical in content and consistency as possible to that in the larger body of material or water being sampled. |
| on-site meteorological services | Meteorological services provided at or near the site of a wildland fire or major project site, normally, but not necessarily, utilizing a mobile fire weather support unit. NWS personnel provide forecasts, summaries, and updates directly to the official having overall planning responsibility for the fire or project. These services are usually provided on a reimbursable basis. |
| trophic composition | that portion of an Index of Biotic Integrity that is a metric measuring the proportion of species and proportions of omnivores, insectivores, and omnivores. |
| urbanization | Expansion of cities into rural regions because of population growth |
| salinity intrusion | The movement of saltwater into a body of freshwater |
| test fish | Fish used for research purposes. |
| unconformity | A break in the sequence of sedimentary strata |
| stilling basin | A basin constructed to dissipate the energy of fast-flowing water (e.g., from a spillway or bottom outlet), and to |
| sugar | Type of carbohydrate chemically based on carbon, oxygen, and hydrogen. |
| throughfall | precipitation falling through the vegetation cover to the surface |
| capillary action | Movement of water along microscopic channels |
| corrosion | a generic term for chemical weathering. |
| hydrologic soil groups | The classification of soils by their reference to the intake rate of infiltration of water, which is influenced by texture, organic matter content, stability of the soil aggregates, and soil horizon development. |
| depression storage | The storage of water in low areas, such as ponds, and wetlands. |
| soil moisture | Water contained in the upper regions near the earth's surface. |
| hydroelectric power | Electric energy generated by means of a power generator coupled to a turbine through which water passes. |
| xenobiotic | Any biological substance, displaced from its normal habitat; a chemical foreign to a biological system. |
| community forests | a UK policy begun in 1990 to improve derelict areas on the edge of urban areas |
| closed-basin lake | A lake which has no outlet, from which water escapes only by evaporation. |
| proportional symbols | data presentation where the size of a symbol, or the divisions of a symbol, are proportional to the size of the data being represented. |
| automatic gain control | Any method of automatically controlling the gain of a receiver, particularly one that holds the output level constant regardless of the input level. |
| heavy metals | Metals that have a density of 5.0 or higher and a high elemental weight |
| validation | comparison of computer model results with a set of data that were not used for calibration. |
| composite volcano | Volcano created from alternate layers of flows and exploded rock |
| heterocercal | Said of the tail when the vertebrae curve upward into the upper lobe of the caudal fin. |
| hydrology | The science of waters of the earth, their occurrence, distribution, and circulation; their physical and chemical properties; and their reaction with the environment, including living beings. |
| full employment | the level at which all those of legal age who wish to work are actually employed, with the exception of the frictionally unemployed |
| key watershed | As defined by National Forest and Bureau of Land Management District fish biologists, a watershed containing (1) habitat for potentially threatened species or stocks of anadromous salmonids or other potentially threatened fish, or (2) greater than 6 square miles with high-quality water and fish habitat. |
| ascope | A deflection-modulated display in which the vertical deflection is proportional to target echo strength and the horizontal coordinate is proportional to range. |
| diffusion | The movement of gas molecules or aerosols into liquids, caused by a concentration gradient. |
| universe | All of the observable phenomena in the celestial cosmos. |
| spring tide | Tide that occurs every 14 to 15 days and coincides with the new and full moon |
| cloudburst | a torrential downpour of rain, which by it spottiness and relatively high intensity suggests the bursting and discharge of water from a cloud all at once. |
| millibar | Unit of atmospheric pressure |
| base level | The lowest level to which a land surface can be reduced by the action of running water. |
| ablation area or zone | The region of a glacier where more mass is lost by melting or evaporation than is gained. |
| water application efficiency | The ratio of the volume of water stored in the root zone of a soil during irrigation to the volume of water applied. |
| mitchell act | The Mitchell Act of 1938 (Public Law No |
| mist | A visible aggregate of minute water particles suspended in the atmosphere that reduces visibility to less than 7 statue miles, but greater than or equal to 5/8 statue miles. |
| kaf | A thousand acre feet, same as .504 thousand second foot days. |
| unimodal | A distribution having only one localized maximum, i.e., only one peak. |
| nws | National Weather Service. |
| natural control | A stream gaging control which is natural to the stream channel, in contrast to an artificial control structure by man. |
| cold air funnel | Funnel clouds, usually short-lived, that develop from relatively small showers or thunderstorms when the air aloft is very in cold |
| biome | large-scale natural community named for its dominant vegetation. |
| hypoxic waters | Waters with dissolved oxygen concentrations of less than 2 mg/L, the level generally accepted as the minimum required for life and reproduction of aquatic organisms. |
| isohaline | A line (or surface) connecting points of equal or constant salinity in water bodies or groundwater. |
| induction | Inference of a generalized conclusion from particular instances |
| fathom | The common unit of depth in the ocean for countries using the English system of measurement |
| sedimentation | Letting solids settle out of wastewater by gravity during treatment. |
| predator | Consumer organism who feeds on prey |
| acre-foot | The amount of water required to cover one acre to a depth of one foot |
| electrolysis | Process where electrical energy will change in chemical energy |
| streamflow | The rate at which water passes a given point in a stream or river, usually expressed in cubic feet per second (cfs). |
| zero datum | A reference "zero" elevation for a stream or river gage |
| outlet channel | A waterway constructed or altered primarily to carry water from man-made structures, such as terraces, tile lines, and diversions. |
| ranching | vast, extensive livestock farms, usually found in remote, marginal areas which are not viable for other types of farming. |
| holistic | Concerned with a complete system. |
| geothermal | Terrestrial heat, usually associated with water as around hot springs. |
| elevation | The measure of height with respect to a point on the earth's surface above mean sea level |
| snowpack | The total ice and snow on the ground, including fresh and older snow and ice. |
| radial velocity | A type of velocity that expresses motion toward or away from a given location |
| prime meridian | The location from which meridians of longitude are measured |
| hard water | Water high in multivalent cations, such as calcium and magnesium |
| riprap | Usually refers to rocks or concrete structures used to stabilize stream or river banks from erosion. |
| orographic precipitation | Is precipitation that forms when air is forced to rise because of the physical presence of elevated land |
| irrigation structure | Any structure or device necessary for the proper conveyance, control, measurement, or application of irrigation water. |
| kettle | A shallow basin or bowl shaped depression formed when a large block of ice is buried in outwash or diamicton during ablation |
| cfu | colony forming units. Concentrations of water quality indicator organisms such as fecal coliform bacteria are measured in cfu/100 ml. |
| raw sewage | Untreated wastewater and its contents. |
| guideline | Administrative constraints applicalbe in developing a plan and criteria directing the actions taken to achieve objectives. |
| freshwater swamp | Forested or shrubby wetlands. |
| acre-foot | A quantity or volume of water covering 1 acre to a depth of 1 ft; equal to 43,560 ft3 or 325, 851 gal. |
| reserve capacity | Extra treatment capacity built into solid waste and wastewater treatment plants and interceptor sewers to accommodate flow increases due to future population growth. |
| capillarity | (1) The degree to which a material or object containing minute openings or passages, when immersed in a liquid, will draw the surface of the liquid above the hydrostatic level |
| interflow runoff | The parts of runoff, caused by precipitation and/or snowmelt, that enters the ground and moves in upper levels of the soil mantle above the water table, heading towards the streams. |
| naturalized conditions | an estimate of natural conditions obtained by attempting to remove effects of human activities from a set of measured conditions. |
| federal land managers | This category includes the Bureau of Indian Affairs; the Bureau of Land Management; the National Park Service, all part of the U.S |
| tile drainage | Land drainage by means of a series of tile lines laid at a specific depth and grade. |
| property protection | Measures that are undertaken usually by property owners in order to prevent, or reduce flood damage |
| solar day | Time required for the Earth to complete one rotation relative to the Sun. |
| juvenile water | Water formed chemically within the earth and brought to the surface in intrusive rock. |
| steppe | the temperate grasslands of Eurasia which stretch from Hungary to Mongolia. |
| eye | The center of a tropical storm or hurricane, characterized by a roughly circular area of light winds and rain-free skies |
| operational losses | Losses of water resulting from evaporation and seepage. |
| gray water | Wastewater from a household or small commercial establishment that specifically excludes water from a toilet, kitchen sink, dishwater, or water used for washing diapers. |
| global warming | Warming of the Earth's average global temperature because of an increase in the concentration of greenhouse gases |
| westerlies | Dominant winds of the mid-latitudes |
| river | an overland flow of water which forms a vital link in the hydrological cycle. |
| vadose zone | the zone between land surface and the water table where the moisture content is less than saturation (except in the capillary fringe) and pressure is less than atmospheric |
| tropical weather discussion | These messages are issued 4 times daily by the Tropical Analysis and Forecast Branch (TAFB) to describe significant synoptic weather features in the tropics. One message will cover the Gulf of Mexico, the Caribbean, and the Atlantic between the equator and 32 degrees North and east of 140 degrees West. Plain language is used in these discussions. |
| impermeable | Material that does not permit fluids to pass through it. |
| gaging station | the site on a stream, lake or canal where hydrologic data is collected. |
| ice cap | a large area of ice |
| maintainable yield | """The largest catch that can be maintained from the population, at whatever level of stock size, over an indefinite period |
| volatile organic compounes | a group of chemicals that react in the atmosphere with nitrogen oxides, heat and sunlight to form ozone; VOCs are referred to as hydrocarbons. |
| condensation | The process by which a gas or vapor changes into a liquid. |
| laminar flow | Streamline flow in which successive flow particles follow similar path lines and head loss varies with velocity to the first power. |
| heat of vaporization | the amount of heat necessary to convert a liquid (water) into vapor. |
| qpferd | NCEP Excessive Rainfall Discussion. |
| rope cloud | In satellite meteorology, a narrow, rope-like band of clouds sometimes seen on satellite images along a front or other boundary |
| subduction zone | Linear area where tectonic subduction takes place. |
| conservation | The process or means of achieving recovery of viable populations. |
| seal | (Hydraulics) The watertight seal established in the annular space between the outermost water well casing and the drill hole to prevent the inflow and movement of surface water or shallow ground water, or to prevent the outflow or movement of water under artesian pressures |
| human geography | Field of knowledge that studies human-made features and phenomena on the Earth from a spatial perspective |
| turbine intake screens | Large screens, which may have moving or non moving parts, designed to be placed in a dam's turbine intake at an angle to deflect juvenile fish from the intakes into a bypass system. |
| percent saturation | The amount of a substance that is dissolved in a solution compared to the amount that could be dissolved in it. |
| development model | a theory of development -why and how it occurs |
| emdc | see economically more developed country. |
| grassed waterway | natural or constructed watercourse or outlet that is shaped or graded and planted in suitable vegetation for the disposal of runoff water without erosion. |
| alvusion | a sudden or perceptible change in a river's margin, such as a change in course or loss of banks due to flooding. |
| fry | A recently hatched fish. |
| asos | An acronym for Automated Surface Observing System. See Automated Surface Observing System. |
| swamp | a type of wetland dominated by woody vegetation but without appreciable peat deposits |
| graywater | Waste water from a household or small commercial establishment which specifically excludes water from a toilet, kitchen sink, dishwasher, or water used for washing diapers. |
| hail spike | When looking at a WSR-88D Cross-Section, one will occasionally see a distinctive spike above the actual top of the thunderstorm |
| biota | plant and animal life. |
| aids | see acquired immune deficiency syndrome |
| hook echo | A radar reflectivity pattern observed in a thunderstorm, appearing like a fish hook and indicating favorable conditions for tornadic development |
| water quality-based toxics control | an integrated strategy used in NPDES permitting to assess and control the discharge of toxic pollutants to surface waters |
| gradient | Elevation divided by ground distance, for example, a fall of one kilometer over two kilometers on the ground would result in a 50% gradient |
| putrefaction | Biological decomposition of organic matter; associated with anaerobic conditions. |
| mean depth | The average depth of water in a stream channel or conduit |
| specific heat | the amount of heat required to raise the temperature of a kilogram of a substance (water) by 1 degree Celsius. |
| hydrologic model | a computer model of a watershed used to evaluate how precipitation contributes to flow in streams |
| rapid sand filter | Generally a concrete basin filled with graded gravel and coarse sand |
| wetland | An area that is regularly wet or flooded and has a water table that stands at or above the land surface for at least part of the year. |
| stage i precipitation processing | The first level of precipitation processing, occurring within the WSR-88D computer and performed for each volume scan of the radar |
| tidal current | Regional scale ocean current that is created the tidal rise and fall of the ocean surface. |
| fresh:salt water interface | the region where fresh water and salt water meet |
| environmentalism | Advocacy for or work toward protecting the natural environment from destruction or pollution. |
| functional zone | a portion of an urban area have a clearly defined dominant function such as the CBD. |
| rock | A naturally formed mass of minerals. |
| frontage | Land adjacent to something, such as a body of water. |
| vaporize | Conversion of a liquid into vapour. |
| storm track | The path taken by a storm (thunderstorm, mid-latitude cyclone or hurricane) or the average path taken by storms. |
| wastewater infrastructure | The plant or network for the collection, treatment, and disposal of sewage in a community |
| antenna gain | The measure of effectiveness of a directional antenna as compared to an isotropic radiator; maximum values called 'antenna gain' by convention |
| lake-effect snow squall | A local, intense, narrow band of moderate to heavy snow squall that can extend long distances inland |
| hpc | An acronym for the Hydrometeorological Prediction Center. See Hydrometeorological Prediction Center. |
| industrial inertia | the continuing presence of industry in an area, or at a location, after the initial locational factors have ceased to apply. |
| forward integration | vertical integration in a downstream direction e.g |
| thermograph | An instrument that measures and records air temperature. |
| noria | A water wheel with buckets attached to its rim, used to raise water from a stream, especially for transfer to an irrigation channel. |
| volume | The occupation of space in three dimensions |
| awwa | American Water Works Association |
| suspended sediment | Sediment that is transported in suspension by a stream |
| intermittently exposed | A water regime in wetland classification in which surface water is present throughout the year except in years of extreme drought. |
| percolation path | The course followed by water moving or percolating through any other permeable material, or under a dam which rests upon a permeable foundation. |
| dissolved solids | Solids material that totally dissolves in water and can be removed by means of filtration. |
| lightning ground flash density | The number of cloud-to-ground flashes per unit time per unit area. |
| snowmelt flooding | Flooding caused primarily by the melting of snow. |
| pixel | A contraction of "picture element" representing the smallest discrete element of an electronically encoded image ( having both spatial and spectral components) recorded by a satellite sensor. |
| fault plane | The plane that represents the fracture surface of a fault. |
| dry punch | Slang for a surge of drier air; normally a synoptic-scale or mesoscale process |
| kilowatt | A unit of electrical power equal to 1000 watts or 1.341 horsepower. |
| permeability | The ability of a medium to pass a fluid under pressure. |
| gray water | Domestic wastewater composed of wash water from kitchen, bathroom, and laundry sinks and from tubs, and washers. |
| evaporation | the change by which any substance is converted from a liquid state and carried of in vapor |
| patterned ground | Polygonal or circular ground patterns which develop from contrasting size/color soils in poorly drained areas subject to intensive frost action. |
| tolerance model of succession | This model of succession suggests that the change in plant species dominance over time is caused by competition for resources |
| backwater curve | The longitudinal profile of the water surface in an open channel where the water surface is raised above its normal level by a natural or artificial obstruction |
| energy gradient | The change in energy per unit length in the direction of flow or motion. |
| isodop | A contour of constant Doppler velocity values. |
| recarbonization | Process in which carbon dioxide is bubbled into treatment water in order to lower the pH. |
| open talik | Is a form of localized unfrozen ground (talik) in an area of permafrost |
| river miles | Miles from the mouth of a river to a specific destination or, for upstream tributaries, from the confluence with the main river to a specific destination. |
| showalter index | It is a stability index used to determine thunderstorm potential |
| frontolysis | The destruction or dying of a front where the transition zone is losing its contrasting properties |
| estuarine waters | deepwater tidal habitats and tidal wetlands that are usually enclosed by land but have access to the ocean and are at least occasionally diluted by freshwater runoff from the land (such as bays, mouths of rivers, salt marshes, lagoons). |
| peritoneum | Membrane lining the body cavity. |
| dapm | The Data Acquisition Program Manager. |
| corrugation irrigation | Spreading water by directing it into small channels across the field. |
| initial moisture deficiency | The quantity, usually expressed in depth of water in inches upon a unit area, by which the actual water content of a given soil zone (usually the root zone) in such area is less than the field capacity of such zone at the beginning of the rainy season |
| direct runoff | The runoff entering stream channels promptly after rainfall or snowmelt |
| brim | The upper surface of a body of water. |
| residual chlorine | the available chlorine which remains in solution after the demand has been satisfied |
| discontinuous permafrost | Form of permafrost that contains numerous scattered pockets of unfrozen ground. |
| interstices | the void or empty portion of rock or soil occupied by air or water. |
| pumped hydroelectric storage | Storing water for future use in generating electricity |
| alevin | The developmental life stage of young salmonids and trout that are between the egg and fry stage |
| speed shear | The component of wind shear which is due to a change in wind speed with height, e.g., southwesterly winds of 20 mph at 10,000 feet increasing to 50 mph at 20,000 feet |
| cin | An acronym for Convective Inhibition. See Convective Inhibition. |
| nutrient depletion | Detrimental changes at a site in the total amount of nutrients and/or their rates of input, uptake, release, movement, transformation, or export. |
| phosphates | phosphorous-based fertilizers |
| stream piracy | the tendency of one stream to capture the flow of another by eroding a channel that intercepts the other stream's flow. |
| premaxilla | The paired bones forming the front of the upper jaw. |
| natural recharge | The replenishment of groundwater storage from naturally-occurring surface water supplies such as precipitation and stream flows. |
| project evaluation period | Expected useful life of a project beginning at the end of the installation of the project. |
| influent | The stream of water that enters any system or treatment unit. |
| juvenile water | water that originated within the earth and was brought to the surface by intrusive vulcanism. |
| quality of life | a component of development |
| standard surface pressure | The measurement of one atmosphere of pressure under standard conditions |
| emulsion | Dispersion of one liquid in another liquid, occurs when a liquid in insoluble. |
| detritivore | an organism which feeds on dead organic material. |
| compact | A formal agreement between states concerning the use of water in a river or stream that flows across state boundaries. |
| co-operative agriculture | smaller, individual farmers form a co-operative to reduce input costs through bulk buying and improve pricing through greater bargaining power. |
| api method | A statistical method to estimate the amount of surface runoff which will occur from a basin from a given rainstorm based on the antecedent precipitation index, physical characteristics of the basin, time of year, storm duration, rainfall amount, and rainfall intensity. |
| glacial polish | The smooth and shiny surfaces that are produced on rocks underneath a glacier by material carried in the base of that glacier. |
| sedimentation basin | A surface water runoff storage facility intended to trap suspended solids, suspended and buoyant debris, and adsorbed or absorbed potential pollutants that are carried by surface water runoff |
| phenotype-2 | The phenotype is the appearance of an organism resulting from the interaction of the genotype and the environment. |
| limnology hydrobiologist | A person who undertakes the biological study of bodies of water. |
| climate prediction center | One of nine national centers that comprises the National Centers for Environmental Prediction (NCEP). Their mission is to maintain a continuous watch on short-term climate fluctuations and to diagnose and predict them. These efforts are designed to assist agencies both inside and outside the federal government in coping with such climate related problems as food supply, energy allocation, and water resources. |
| equilibrium time | The time when flow conditions become substantially equal to those corresponding to equilibrium discharge or equilibrium drawdown. |
| sector visibility | The visibility in a specific direction that represents at least a 45o arc of a horizontal circle. |
| poles/polar | The poles are the geographic point at 90 degrees latitude North and South on the earth's surface |
| instantaneous flows | The velocity of a volume of water. |
| tributary | A smaller branching stream channel that flows into a main stream channel |
| sima | crustal material made mainly of silica and magnesium. |
| biological integrity | the ability to support and maintain balanced, integrated functionality in the natural habitat of a given region |
| acclimation pond | Concrete or earthen pond or a temporary structure used for rearing and imprinting juvenile fish in the water of a particular stream before their release into that stream. |
| spray irrigation | application of finely divided water droplets to crops using artificial means. |
| subsurface drainage | (1) The process of directing excess water away from the root zones of plants by natural or artificial means, such as by using a system of pipes and drains placed below ground surface level |
| biological treatment | A treatment technology that uses bacteria to consume organic wastes. |
| head | Difference in elevation between intake and discharge points for a liquid |
| unstable | An atmospheric state warm air below cold air. Since warm air naturally rises above cold air (due to warm air being less dense than cold air), vertical movement and mixing of air layers can occur. |
| dnrc | Department of Natural Resources and Conservation. Montana's DNRC was established through the Executive Reorganization Act of 1971. It administers the portions of the Montana Water Use Act that relates to water uses after June 30, 1973. |
| parameter | A variable, measurable property whose value is a determinant of the characteristics of a system such as water |
| standard deviation | The positive square root of the signal variance |
| heterogenic aquifer | an aquifer that has a variety of forms or characteristics, such as differering permeabilities |
| forfeited water right | A water right that is no longer valid because of five or more consecutive years of nonuse. |
| lee effect | The effect of topography on winds to the lee (downwind) side of an obstacle such as a steep island, cliff, or mountain range. |
| potentiometric surface | An imaginary surface representing the static head of ground water in tightly cased wells that tap a water-bearing rock unit (aquifer); or in the case of unconfined aquifers, the water table. |
| impervious | the quality or state of being impermeable; resisting penetration by water or plant roots |
| at-risk fish stocks | Stocks of anadromous salmon and trout that have been identified by professional societies, fish management agencies, and in the scientific literature as being in need of special management consideration because of low or declining populations. |
| k index | The measure of thunderstorm potential based on the vertical temperature lapse rate, the moisture content of the lower atmosphere and the vertical extent of the moist layer. |
| wastewater reclamation | The planned reuse of waste water for specific beneficial purposes. |
| exploitation | Form of competition where the indirect effects of the two or more species or individuals reduce the supply of the limiting resource or resources needed for survival. |
| migration | the movement of oil, gas, contaminants, water, or other liquids through porous and permeable rock. |
| reach | (1) Most generally, any specified length of a stream or conveyance |
| cover | Vegetation used by wildlife for protection from predators, or to mitigate weather conditions, or to reproduce |
| ffg | An acronym for Flash Flood Guidance. See Flash Flood Guidance. |
| injection | The introduction of a chemical or medium into the process water to alter its chemistry or filter specific compounds. |
| cold glacier | one in which ice temperature remains very low (often -30˚C) all year |
| spray irrigation | an common irrigation method where water is shot from high-pressure sprayers onto crops |
| superfund list | A list of the hazardous waste disposal sites most in need of cleanup |
| cirrostratus | A cirriform cloud that develops from cirrus spreading out into a thin layer, creating a flat sheetlike appearance |
| return flow credit | The concept of water use allocations based only on actual Consumptive Use; waters returned to the system are credited, in whole or part, against the original allowable allocations. |
| impervious surface | A constructed hard surface that cannot be penetrated by water, which causes water to run off in greater quantities |
| reimbursable costs | Those costs associated with a water project that are expected to be recovered, usually from direct beneficiaries, and repaid to the funding entity. |
| plagioclimax | the combination of plant species in an area brought about by human interference |
| evolution | Is a process by which species come to possess genetic adaptations to their environment |
| delta | An alluvial deposit, often in the shape of the Greek letter "delta", which is formed where a stream drops its debris load on entering a body of quieter water. |
| morning glory | An elongated cloud band, visually similar to a roll cloud, usually appearing in the morning hours, when the atmosphere is relatively stable. Morning glories result from perturbations related to gravitational waves in a stable boundary layer |
| firn limit | The dividing line between old ice and new snow at the end of the melting season. |
| avalanche advisory | A preliminary notification that conditions may be favorable for the development of avalanches in mountain regions. |
| population crash | Sudden decline in the number of individuals found in a population because of a scarcity of environmental resources that are required for survival, growth, and reproduction. |
| caa | An acronym for Cold Air Advection. See Cold Air Advection. |
| truncated spur | Spurs of hillsides that have been cut off by a glacier, thereby straightening the glacially eroded valley. |
| diurnal | Daily; related to actions which are completed in the course of a calendar day, and which typically recur every calendar day (e.g., diurnal temperature rises during the day, and diurnal falls at night). |
| sediment | The organic material that is transported and deposited by wind and water. |
| lateral moraine | A moraine deposited along the side of a valley glacier. |
| force | Process that changes the state of rest or motion of a body. |
| bankfull stage/elevation | An established river stage/water surface elevation at a given location along a river which is intended to represent the maximum water level that will not overflow the river banks or cause any significant damages from flooding. |
| phreatic water | Water within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table |
| daylight | In the restoration field, a verb that denotes the excavation and restoration of a stream channel from an underground culvert, covering, or pipe. |
| köppen climate classification | System that uses monthly precipitation and temperature data and total annual precipitation data to classify a location's climate into one of five main categories: Tropical Moist Climates; Dry Climates; Moist Mid-latitude Climates with Mild Winters; Moist Mid-Latitude Climates with Cold Winters; and Polar Climates |
| lowland flooding | Inundation of low areas near the river, often rural, but may also occur in urban areas. |
| weephole | Opening left in a revetment, bulkhead, or wall to allow groundwater drainage. |
| trade secret | Any confidential formula, pattern, process, device, information, or set of data that is used in a business to give the owner a competitive advantage |
| eutrophication | an excess of plant nutrients from natural erosion and runoff from the land in an aquatic ecosystem supporting a large amount of aquatic life that can deplete the oxygen supply. |
| outwash | Glaciofluvial sediments deposited by meltwater streams at the edge of a glacier. |
| regulatory floodway | Some maps show an area where construction regulations require special provisions to account for this extra hazard |
| regelation | the refreezing of water into ice after pressure which caused it to melt is released. |
| flash flood warning | A warning by the NWS issued to warn of flash flooding that is imminent or occurring. |
| medium-size water system | A water system that serves 3,300 to 50,000 customers. |
| base flood elevation | The height in relation to mean sea level (MSL) expected to be reached by the waters of the base flood at pertinent points in the floodplain of Riverine areas. |
| peak flow | The maximum flow that occurs over a specific length of time (i.e.: daily, hourly, instantaneous) |
| spray irrigation | The application of water to landscaping by means of a device that projects water through the air in the form of small particles or droplets. |
| subsidence | sinking down of part of the earth's crust due to underground excavation, such as removal groundwater. |
| trophic pyramid | A graphic model describing the distribution of energy, biomass, or some other measurable quantity between the different trophic levels found in an ecosystem. |
| aviation area forecast | This NWS aviation product is a forecast of Visual Flight Rules (VFR) clouds and weather conditions over an area as large as the size of several states |
| headwaters | the uppermost portion of a river course close to the source. |
| flow augmentation | Increased flow from release of water from storage dams. |
| crown cover | The degree to which the crowns of trees are nearing general contact with one another. |
| ncep | An acronym for the National Centers for Environmental Prediction. The National Oceanic and Atmospheric Administration created the National Centers for Environmental Prediction (NCEP) to take advantage of improving technology and better serve the public and modernized National Weather Service |
| hydrologic balance | an accounting of all water inflow to, water outflow from, and changes in water storage within a hydrologic unit over a specified period of time. |
| clinometer | An instrument used to measure angles of inclination |
| frictional force | Force acting on wind near the Earth's surface due to frictional roughness |
| oolitic limestone | limestone formed from ooliths |
| cell | A cell is the smallest self-functioning unit found in living organisms |
| intermediate technology | see alternative technology. |
| coliform bacteria | A group of bacteria used as an indicator of sanitary quality in water |
| leader | The streamer which initiates the first phase of each stroke of a lightning discharge |
| psychrometer | An instrument used to measure the water vapor content of the air |
| temperate deciduous forest | forest that dominates in temperate areas |
| tornado | A vortex of rapidly moving air associated with some severe thunderstorms |
| inch | A fall, as of rain or snow, sufficient to cover the surface to the depth of one inch (2.54 centimeters). |
| flash flood | A flood that rises and falls quite rapidly with little or no advance warning, usually as the result of intense rainfall over a relatively small area |
| magnetic field | The space influence by magnetic force |
| subsidence | 1) The slow sinking of air usually associated with high pressure areas |
| degradation | when high discharge creates a high energy environment in a river channel leading to a lowering of the channel bed. |
| initial water deficiency | The quantity, usually expressed in depth of water in inches upon a unit area, by which the actual water content of a given soil zone (usually the root zone) in such area is less than the field capacity of such zone at the beginning of the rainy season |
| sediment load | The soil particles transported through a channel by stream flow. |
| collection and bypass system | A system at a dam that collects and holds the fish approaching the dam for later transportation or moves them through or around the dam without going through the turbine units. |
| stream | a general term for a body of flowing water. |
| ozone | Tri-atomic oxygen that exists in the Earth's atmosphere as a gas |
| irregularly exposed | A water regime in wetland classification in which the land surface is exposed by tides less often than daily. |
| osmosis | Water molecules passing through membranes naturally, to the side with the highest concentration of dissolved impurities. |
| freshwater | Water containing less than 1 mg/l of dissolved solids of any type. |
| firn | The granular ice formed by the recrystallization of snow; also known as névé. |
| transmigration | the mass resettlement of people within a country to alleviate overcrowding or localized overpopulation. |
| dry microburst | - A microburst with little or no precipitation reaching the ground; most common in semi-arid regions |
| saturated zone | The area below the water table where all open spaces are filled with water. |
| ice fall | The reaction of glacial snow and ice to subglacial changes in gradient |
| solvent | a substance that dissolves other substances, thus forming a solution |
| spillway crest elevation | The point at which the reservoir behind a dam is level with the top of the dam's spillway. |
| gated pipe | (Irrigation) Portable pipe with small gates installed along one side for distributing water to corrugations or furrows. |
| bmp | Best Management Practice |
| bank storage | Water absorbed and stored in the banks of a stream, lake, or reservoir when the stage rises above the water table in the bank formations and stays there for an appreciable length of time |
| ethnic group | a particular group of people within a larger population distinguished by ethnic characteristics. |
| intersection | A place where two streets cross. |
| interception storage requirements | Water caught by plants at the onset of a rainstorm |
| soil solution | Aqueous liquid found within a soil |
| capillary zone | Soil area above the water table where water can rise up slightly through the cohesive force of capillary action. |
| river flood statement | This product is used by the local National Weather Service Forecast Office (NWFO) to update and expand the information in the River Flood Warning. This statement may be used in lieu of a warning if flooding is forecasted, imminent, or existing and it presents no threat to life or property. The statement will also be used to terminate a River Flood Warning. |
| groundwater | Water that can be found in the saturated zone of the soil; a zone that consists merely of water |
| drop structure | A structure specifically designed to carry wastewater from a higher elevation to a lower elevation. |
| haboob | Sudanese name for duststorm or sandstorm with strong winds that carry small particles of dirt or sand into the air, particularly severe in areas of drought. |
| re-entrants | A prominent indentation in an escarpment, ridge or shoreline. |
| sma | The Soil Moisture Accounting Model. |
| mcwd | Minnehaha Creek Watershed District |
| ball valve | A valve regulated by the position of a free-floating ball that moves in response to fluid or mechanical pressure. |
| halite | Sedimentary rock created by the chemical precipitation of sodium and chlorine. |
| population | A group of individuals of the same species occupying a defined locality during a given time that exhibit reproductive continuity from generation to generation. |
| imhoff cone | a clear, cone-shaped container used to measure the volume of settleable solids in a specific volume of water. |
| hydrologic model | A conceptual or physically-based procedure for numerically simulating a process or processes which occur in a watershed. |
| flood of record | The highest observed river stage or discharge at a given location during the period of record keeping |
| ecological impact | The effect that a man-made or natural activity has on living organisms and their non-living (abiotic) environment. |
| subadult | A developmental life stage when fish exhibit most but not all traits of an adult fish. |
| reuse | To use again; recycle; to intercept, either directly or by exchange, water that would otherwise return to the stream system, for subsequent beneficial use |
| trace | A hydrograph or similar plot for an extended-range time horizon showing one of many scenarios generated through an ensemble forecast process. |
| subatomic particles | Extremely small particles that make up the internal structure of atoms. |
| thermograph | Essentially, a self-recording thermometer |
| natural gas | Hydrocarbon based gas, mainly composed of methane, commonly found in the pores of sedimentary rocks of marine origin. |
| eec | see European Economic Community. |
| electrical charge | The charge on an ion, declared by its number of electrons |
| gale warning | A warning for marine interests for impending winds from 28 to 47 knots (32 to 54 miles per hour). |
| dissolve | to enter into a solution divert - to direct a flow away from its natural course divide - a ridge or high area of land that separates one drainage basin from another drainage basin - all of the area drained by a river system drought - a prolonged period of below-average precipitation |
| temperate rain forest | An ecosystem that is dominated by large and very tall evergreen trees |
| earth day | Earth Day is an annual event to raise awareness of taking care of the environment |
| exotic species | Introduced species not native to the place where they are found (e.g., Atlantic salmon to Oregon or Washington). |
| allopatric | Occurring in different geographic regions |
| suspended solids | the small solid particles in water that cause turbidity |
| biological wastewater treatment | The use of bacteria to degrade and decompose organic materials in wastewater. |
| radiation fog | Fog produced results from the air near the ground being cooled to saturation by contact with the cold ground |
| nitrogen cycle | series of flows in an ecosystem which move nitrogen between various stores and allow it to perform functions essential for life |
| wave-cut platform | A flat or slightly sloping bedrock surface that forms in the tidal zone |
| levee | A natural or man-made earthen obstruction along the edge of a stream, lake, or river |
| bed load | Sediment particles resting on or near the channel bottom that are pushed or rolled along by the flow of water. |
| mostly clear | When the predominant/average sky condition is covered 1/8 to 2/8 with opaque (not transparent) clouds. Called Mostly Sunny if it is during the day. |
| conglomerate | Coarse grained sedimentary rock composed of rounded rock fragments cemented in a mixture of clay and silt. |
| base level | The elevation to which a stream-channel profile has developed. |
| board feet | Lumber or timber management term |
| anti-degradation clause | part of federal and water quality requirements prohibiting deterioration where pollution levels are above the legal limit. |
| seepage pit | A covered pit with lining designed to permit treated sewage to seep into the surrounding soil. |
| dbm | A logarithmic expression for power, referenced to 1 milliwatt |
| static water pressure | The pipeline or municipal water supply pressure when water is not flowing. |
| profundal zone | The deep, bottom-water area beyond the depth of effective light penetration |
| sea-level pressure | Average atmospheric pressure at sea-level |
| ground frost | frost within the upper layers of the soil. |
| economic rent | also known as locational rent, the profit to be derived from land |
| tertiary | The geological time period before the Quaternary composed of Paleocene, Eocene, Oligocene, Miocene, and Pliocene. |
| soil | the very upper layer of the land surface made up of mixture of regolith, decomposed organic matter, air and water. |
| dynamic equilibrium | A dynamic equilibrium occurs when a system displays unrepeated average states through time. |
| de-foaming agents | Chemicals that are added to wastewater discharges to prevent the water from foaming when it is discharged into a receiving water body. |
| earth albedo | Is the reflectivity of the Earth's atmosphere and surface combined |
| snow level | The elevation in mountainous terrain where the precipitation changes from rain to snow, depending on the temperature structure of the associated air mass. |
| sinuosity | the endiness-of a river course i.e |
| minimum streamflow | The specific amount of water reserved to support aquatic life, to minimize pollution, or for recreation |
| pyloric | Pertaining to that part of the stomach from which the intestine leads. |
| wind ripples | Wind ripples are miniature sand dunes between 5 centimeters and 2 meters in length and 0.1 to 5 centimeters in height |
| coastal dune | Sand dune that forms in coastal areas |
| geographic isolation | See spatial isolation. |
| basal sliding | When the bottom of a glacier slides directly over subglacial bedrock. |
| hydrogeological cycle | The natural process recycling water from the atmosphere down to (and through) the earth and back to the atmosphere again |
| theodolite | An instrument used in surveying to measure horizontal and vertical angles with a small telescope that can move in the horizontal and vertical planes |
| undeveloped | see economically less developed countries. |
| forebay | the water behind a dam. |
| dry line | A boundary the separates dry and moist air in the warm sector of a mid-latitude cyclone wave |
| set | The direction towards which a current is headed. For example, a current moving from west to east is said to be set to east. |
| parts per billion | A unit frequently used to measure contamination concentration (parts of contamination per billion parts of water) |
| coevolution | The coordinated evolution of two or more species that interact and exert selective pressures on each other that can cause each species to undergo associated adaptations |
| flash flood watch | A statement by the NWS that alerts communities to the possibility of flash flooding in specified areas. |
| isallobar | The line of equal change in atmospheric pressure during a certain time period |
| settling pond | (Water Quality) An open Lagoon into which wastewater contaminated with solid pollutants is placed and allowed to stand |
| ozone advisory | It is issued by the Department of Natural Resources (DNR) through the National Weather Service when ozone levels reach 100. Ozone levels above 100 are unhealthy for people with heat and/or respiratory ailments. |
| salinity | The relative concentration of salts, usually sodium chloride, in a given water sample |
| primary producer | Organisms that occupy the first trophic level in the grazing food chain |
| landscape diversity | The size, shape, and connectivity of different ecosystems across a large area. |
| edge | Where plant communities meet or where successional stages or vegetative conditions with plant communities come together. |
| moisture content | the amount of water lost from soil upon drying to a constant weight, expressed as the weight per unit of dry soil or as the volume of water per unit bulk volume of the soil. |
| hydrogen | colorless, highly flammable element, exists as a gas; most abundant element in the universe |
| snow | A type of solid precipitation that forms in clouds with an air temperature below freezing |
| hydrogeomorphic unit | A land form characterized by a specific origin, geomorphic setting, water source, and hydrodynamic. |
| mantle | the layer of the earth between the crust and the core |
| palmer drought severity index | An index whereby excesses or deficiencies of precipitation are determined in relation to average climate values. The index takes in to account precipitation, potential and actual evapotransporation, infiltration of water into the soil, and runoff. |
| lightning | A sudden visible flash of energy and light caused by an electrical discharges from thunderstorms. |
| river reach | Any defined length of a river. |
| elastic wave | An energy wave that causes elastic deformation in a material without its structure and shape being deformed. |
| electrodialysis | A process that uses electrical currents, applied to permeable membranes, to remove minerals from water. |
| coefficient of roughness | Factor in fluid flow determination expressing the character of a surface and its fractional resistance to flow |
| interorbital | The space between the eyes. |
| storage | 1) Water artificially impounded in surface or underground reservoirs for future use |
| m2/s2 | meters squared per second squared, equivalent to J/kg. See CAPE and CIN. |
| ultramafic | Rock that is rich in magnesium and iron content. |
| bronze age settlement | settlements, or evidence of settlement, dating between 3900BP to 2500BP. |
| subsidence inversion | It is produced by adiabatic heating of air as it sinks and is associated with anticyclones (high pressure) and/or stable air masses |
| surface heat flux | Process where heat energy is transferred into land and ocean surfaces on the Earth |
| lowland flooding | Inundation of low areas near the river, often rural, but may also occur in urban areas. |
| wind rose | A diagram that shows the percent of time that the wind blows from different directions at a given location over a given time. |
| night | The period of the day between dusk and dawn. |
| braided channel | A stream characterized by flow within several channels, which successively meet and divide |
| municipal wastewater facility | Refers to those facilities that receive or dispose of wastewater derived principally from residential dwellings, business or commercial buildings, institutions, and the like |
| freezing fog | Used to describe the phenomena when fog is present and the air temperature is below 0°C |
| moderate flood hazard areas | Areas between the 100-year and the 500-year flood boundaries are termed Moderate Flood Hazard Areas |
| pumped storage plant | A hydroelectric power plant which generates electric energy for peak load use by utilizing water pumped into a storage reservoir during off-peak periods. |
| refraction | Changes in the direction of energy propagation as a result of density changes within the propagating medium |
| confluence | (1) The act of flowing together; the meeting or junction of two or more streams; also, the place where these streams meet |
| pacific salmon treaty | A treaty signed by the United States and Canada in 1984 that governs the harvest of certain salmon stocks in the commercial fisheries of Alaska, Canada and the western continental United States. |
| impermeable | material that does not permit fluids to pass through. |
| topography | The shape of the land. |
| water balance | in any natural system, inputs of water must equal outputs plus or minus changes in storage since water cannot be created or destroyed. |
| cut-off low | A closed cold core low completely removed from the primary westerly flow |
| storet | a national U.S |
| headworks | A flow control structure on an irrigation canal. |
| radar data acquisition | The RDA is the origination point of the WSR-88D radar data that will be eventually used by the radar operator |
| detection limit | the lowest level that can be determined by a specific analytical procedure or test method. |
| bathythermograph | A device used to obtain a record of temperature against depth (pressure) in the ocean |
| rearing | Refers to the amount of time that juvenile fish spend feeding in nursery areas of rivers, lakes, streams and estuaries before migration. |
| sample a | proportion or a segment of a fish stock which is removed for study, and is assumed to be representative of the whole |
| participation agreement | An agreement in which a distributor or developer pays for the cost of the distribution facilities such as conduits, treated water reservoirs or pump stations required to provide service within that district from the nearest existing available source. |
| off-channel area | Any relatively calm portion of a stream outside of the main flow. |
| failure | Collapse or slippage of a large mass of bank material into a stream. |
| drainage basin | A part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. |
| diurnal | in geography, daily, or of each day, where a day means the full 24 hour period. |
| irrigation depletion | The amount of diverted water consumptively used, beneficially and nonbeneficially, in serving a cropped area |
| effective old-growth forest | Old-growth forest largely unmodified by external environmental influences from nearby, younger forest stands. |
| profile | A graph showing variation of elevation with distance along a traverse. |
| peclet number | the relationship between properties of the mesh, fluid velocity, and eddy viscosity for a hydraulic computer model. |
| meander | The turn of a stream, either live or cut off |
| von thunen model | a model to explain differences in agriculture with distance from the market |
| dendrites | Thin branch-like growth of ice on the water surface. |
| sovkhoz | see collective farm. |
| subpopulation | A well-defined set of interacting individuals that compose a proportion of a larger, interbreeding population. |
| immigration | Migration of an organism into an area for the purpose of changing its residence permanently |
| minimum streamflow | the specific amount of water reserved to support aquatic life, to minimize pollution, or for recreation |
| tailwater recovery | Process of collecting irrigation water runoff for reuse. |
| downgradient | the direction that groundwater flows; similar to "downstream" for surface water. |
| current | the portion of a stream or body of water which is moving with a velocity much greater than the average of the rest of the water |
| dip slope | the gentle slope formed by the upper plane of the dipping, harder bed of rock in a cuesta. |
| igneous rock | Rocks formed by solidification of molten magma either beneath (intrusive igneous rock) or at (extrusive igneous rocks) the Earth's surface. |
| onfarm | Activities (especially growing crops and applying irrigation water) that occur within the legal boundaries of private property. |
| organic matter | plant and animal residues, or substances made by living organisms |
| organelles | these species manufacture photosynthetic pigments but lack chloroplasts, the specialized photosynthetic organelles in higher plants, in some situations an increase in blue-green algae can indicate an environmental stress such as pollution. |
| erosional landform | Is a landform formed from the removal of weathered and eroded surface materials by wind, water, glaciers, and gravity |
| hyetograph | A graphical representation of rainfall intensity with respect to time. |
| rock flour ** | Pulverized rock of the smaller size sediment classes (silts and clays) produced by glacial milling can give outwash streams a milky appearance. |
| fractus | Ragged, detached cloud fragments; same as scud. |
| cuesta | where a more resistant strata of rock is left upstanding when less resistant strata on either side are degraded more rapidly |
| anaerobic | a life or process that occurs in, or is not destroyed by, the absence of oxygen. |
| recreation report | This National Weather Service product is used to relay reports on conditions for resorts and recreational areas and/or events. This report may also contain forecast information. Reports for recreational areas and resorts are often routine products, typically for a season, but possibly year-round. NWFO Gaylord uses this product in the winter for the ski resorts in northern Michigan. It is called a "Ski Report". |
| pulse duration | The time in which a radar pulse lasts |
| mean areal precipitation | The average rainfall over a given area, generally expressed as an average depth over the area. |
| relief | the shape of the land particularly as it pertains to elevation. |
| spray | (1) A cloud or mist of fine liquid particles, as of water from breaking waves |
| meander belt | The area between lines drawn tangential to the extreme limits of fully developed meanders. |
| composite reflectivity contour | This WSR-88D radar product is a line contoured image of composite reflectivity (CR). Contour intervals and number of contours are changed at the User Control Processor. There is also a combined attribute table available for this product. It is used to view a contoured image of higher reflectivity values; examine storm structure features such as overhang, tilt, Weak Echo Regions (WER), and Bounded Weak Echo Regions (BWER); estimate height of higher dBZ's and echo tops; and locate the bright band (where snow is melting and becoming rain) |
| flowing well | An Artesian Well having sufficient head to discharge water above the land surface; a well where the Piezometric Surface lies above the ground surface.. |
| secchi disc | A circular plate, generally about 10-12 inches (25.4-30.5 cm) in diameter, used to measure the transparency or clarity of water by noting the greatest depth at which it can be visually detected |
| visible trade | import and export of physical goods |
| subsurface irrigation system | Irrigation by means of underground porous tile or its equivalent. |
| water quality standards | laws or regulations, promulgated under Section 303 of the Clean Water Act, that consist of the designated use or uses of a waterbody or a segment of a waterbody and the water quality criteria that are necessary to protect the use or uses of that particular waterbody |
| nohrsc | The National Operational Hydrologic Remote Sensing Center |
| reservoir surface | The surface of a reservoir at any level. |
| central north pacific basin | The region north of the Equator between 140W and the International Dateline |
| groundwater table | The upper surface of the zone of saturation, except where the surface is formed by an impermeable body. |
| sphere calibration | Reflectivity calibration of a radar by pointing the dish at a metal sphere of (theoretically) known reflectivity |
| calorie | In meteorology, it is the amount of heat required to raise the temperature of one (1) gram of water one (1) degree Celsius |
| pitted topography | Landscape characterized by numerous kettle holes on a glacial outwash plain. |
| compliance | meeting all applicable drinking water regulations. |
| environmental system | A system where life interacts with the various abiotic components found in the atmosphere, hydrosphere, and lithosphere. |
| kame | A low, but steep-sided hill or mound composed of poorly sorted sands and gravels deposited in strata by meltwater plunging into crevasses near the melting edge of an ablating glacier. |
| makeup water | Water added to the flow of water used to cool condensers in electric power plants |
| cloud | A visible collection of minute particle matter, such as water droplets and/or ice crystals, in the free air |
| ageing | "A fish that is less than 1 year old (counted from time of spawning by its parents) is considered a subyearling, or zero-age |
| demographic transition model | a theory of population change over time |
| absolute humidity | A type of humidity that considers the mass of water vapor present per unit volume of space |
| groundwater recharge | The addition of water to the zone of saturation |
| pond | a body of water usually smaller than a lake and larger than a pool either naturally or artificially confined. |
| project crop water requirement | The project crop water requirement is the annual amount of water required to meet the total project's crop consumptive use plus leaching requirement, and adjusted for natural precipitation (expressed in acre-feet per year). |
| vapor | The gaseous state of a substance which under ordinary conditions exists as a liquid or solid. |
| conservation | Preserving and renewing, when possible, human and natural resources such as water |
| methyl orange alkalinity | A measure of the total alkalinity in a water sample in which the color of methyl orange reflects the change in level. |
| porosity | 1) The ratio of pore volume to total volume of the formation |
| channelization | natural or intentional straightening and/or deepening of streams so water moves faster and causes less flooding. Channelization can sometimes exacerbate flooding in other downstream areas. |
| interceptor tunnels | Any large volume pipe or conduit having a deeper invert elevation to accept or intercept the sewer flow of smaller sanitary sewers |
| sea breeze | A current of air flowing inland, associated with warmer surface temperatures inland than at sea |
| husbandry | The scientific management and control of the hatchery environment for the production of fish or wildlife. |
| snow squalls | They are intense, but limited duration, periods of moderate to heavy snowfall |
| placoid scale | Small plate-like scales that have a rough exterior edge found on sharks and related species. |
| ria | the flooded lower valley of a river caused by a relative rise in sea-level to form a small inlet. |
| transverse rolls | Elongated low-level clouds, arranged in parallel bands and aligned parallel to the low-level winds but perpendicular to the mid-level flow |
| redox | Shortened term for reduction/ oxidation reactions |
| drifts | Normally used when referring to snow or sand particles are deposited behind obstacles or irregularities of the surface or driven into piles by the wind. |
| cubic foot per second | (ft3/s also CFS) is the rate of discharge representing a volume of 1 cubic foot passing a given point during 1 second and is equivalent to 7.48 gallons per second or 448.8 gallons per minute or 0.02832 cubic meter per second. |
| fossil water | water that has become detached from the hydrological cycle having lain, untouched and without addition, in deep aquifers since prehistoric times. |
| epoch | Geologic time unit that is shorter than a period. |
| radiation fog | A type of fog that is also called ground fog |
| wave-pounding | the breakdown of rock through the sheer impact force of waves |
| calcium hypo chlorite | A chemical that is widely used for water disinfection, for instance in swimming pools or water purification plants |
| biotic factors | the influence of living organisms on the growth and distribution of plants such as shade provided by leaves or seed dispersal by animals. |
| fao | see Food and Agriculture Organisation. |
| pyroclastic material | Pieces of volcanic rock thrown out in a volcanic explosion. |
| production-line | the organization of a factory so that each stage of the manufacture is physically next to the one before and a good moves along the line being added to as it goes until it is complete. |
| basin recharge | Rainfall that adds to the residual moisture of the basin in order to help recharge the water deficit |
| z-list | OSHA's Toxic and Hazardous Substances Tables (Z-1, Z-2, and Z-3) of air contaminants; any material found on these tables is considered hazardous. |
| check dam | A small dam constructed in a gully or other small watercourse to decrease the streamflow velocity, minimize channel erosion, promote deposition of sediment, and to divert water from a channel. |
| nephelometric | method of measuring turbidity in a water sample by passing light through the sample and measuring the amount of light deflected. |
| overland flow | a land application technique that cleanses wastewater by allowing it to flow over a sloped surface |
| thermal pollution | an increase in air or water temperature that disturbs the climate or ecology of an area. |
| altostratus | It is a bluish veil or layer of clouds having a fibrous appearance |
| center/vortex fix | The location of the center of a tropical or subtropical cyclone obtained by reconnaissance aircraft penetration, satellite, radar, or synoptic data. |
| ubac | a north-facing slope. |
| eif | Enhanced IFLOWS Format. |
| precipitation process | The altering of dissolved compounds to insoluble or badly soluble compounds, in order to be able to remove the compounds by means of filtration. |
| isothermal atmosphere | An atmosphere in hydrostatic equilibrium in which the temperature is constant with altitude and in which, the pressure decreases exponentially upward. |
| henry's law | A way of calculating the solubility of a gas in a liquid, based on temperature and partial pressure, by means of constants. |
| separatism | the efforts of certain groups to create autonomous regions, or even achieve national independence, for a particular area within an existing nation-state. |
| nivation hollow | Ground depression found in periglacial areas that is created by nivation. |
| salinization | Pedogenic process that concentrates salts at or near the soil surface because evapotranspiration greatly exceeds water inputs from precipitation. |
| standard atmosphere | A standard atmosphere has been defined by the International Civil Aeronautical Organization (ICAO) |
| logarithmic scale | Measurement scale based on logarithms |
| backshore slope | Sloping bank landward of the shore |
| flooded ice | Ice which has been flooded by melt water or river water and is heavily loaded by water and wet snow. |
| full pool | The maximum level of a reservoir under its established normal operating range. |
| dune | A dune is a hill or a ridge made of sand |
| glaciation | The transformation of the landscape through the action of glaciers. |
| greenhouse effect | the name for the system by which the earth retains some insolation |
| basic | Substance having a pH greater than 7. |
| aquatic | Growing in water, living in water, or frequenting water. |
| conduction | The transfer of heat through a substance by molecular action or from one substance by being in contact with another. |
| stoke's law | A method to calculate the rate of fall of particles through a fluid, based on density, viscosity and particle size. |
| safe water | Water that does not contain harmful bacteria, toxic materials, or chemicals, and is considered safe for drinking. |
| erosion | the degradation and removal of rock material by an agent (water, wind or ice) |
| technology-based treatment requirements | NPDES permit requirements based on the application of pollution treatment or control technologies including BTP (best practicable technology), BCT (best conventional technology), BAT (best available technology economically achievable), and NSPS (new source performance standards). |
| moraine | Unsorted till (diamicton) deposited either along the sides (lateral moraine) or the ends of an ablating glacier (end or terminal moraine); or the material below a retreating glacier (ground moraine). |
| receiver | The electronic device which detects the backscattered radiation, amplifies it and converts it to a low-frequency signal which is related to the properties of the target. |
| hic | Hydrologist in Charge of an RFC. |
| phenols | organic compounds that are byproducts of petroleum refining; tanning; and textile, dye, and resin manufacturing |
| riprap | Rock or other material with a specific mixture of sizes referred to as a "gradation" used to stabilize streambanks or riverbanks from erosion or to create habitat features in a stream. |
| flood prevention | Methods or structural measures used to prevent floods. |
| matter | Anything which is solid, liquid, or gas and has mass. |
| boundary conditions | definition or statement of conditions or phenomena at the boundaries of a model; water levels, flows, and concentrations that are specified at the boundaries of the area being modeled. |
| littoral zone | The area on, or near the shore of a body water. |
| strata | layers of deposited material. |
| neutral solution | Any water solution that is neutral (pH approximately 7) or has an equal quantity of hydrogen ions (H+) than hydroxide ions (OH-) |
| quantitative precipitation forecast | A forecast of rainfall, snowfall or liquid equivalent of snowfall. |
| municipal discharge | Discharge of effluent from wastewater treatment plants, which receive wastewater from households, commercial establishments, and industries in the coastal drainage basin. |
| nitrogen | A colorless, tasteless, odorless gas that is the most abundant constituent of dry air |
| braided stream | A complex tangle of converging and diverging stream channels (Anabranches) separated by sand bars or islands |
| water demand | The water requirements for a particular purpose, such as irrigation, power production, municipal supply, plant transpiration, or storage. |
| flume | A sloped channel that is utilized to convey water and is commonly constructed of wood or concrete |
| spreading basin | A surface facility, often a large pond, used to increase the percolation of surface water into a Ground Water Basin. |
| leached layer | A soil layer or an entire soil profile from which the soluble materials (CaCO3 and MgCO3 and material more soluble) have been dissolved and washed away by percolating waters. |
| segment | a water body or portion of a water body that is individually defined and classified |
| depth of runoff | The total runoff from a drainage basin, divided by its area |
| pre-spawning mortality | Generally refers to non-fishery mortality of adult salmon and steelhead between the time the fish enter the Columbia River and the completion of spawning. |
| cohesion | a molecular attraction by which the particles of a body are united throughout the mass whether like or unlike |
| ground water | Water within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table |
| coordinated universal time | The time in the zero degree meridian time zone |
| wildlife tree | A live tree retained to become future snag habitat. |
| abrasion | Removal of stream-bank soil as a result of sediment-laden water, ice, or debris rubbing against the bank. |
| carbon monoxide | A colorless, odorless, and tasteless gas that is produced by the incomplete burning of fossil fuels |
| biota | All living organisms of a region, as in a stream or other body of water. |
| soil erosion | The detachment and movement of soil from the land surface by wind or water. |
| precipitation | Includes atmospheric hail, mist, rain, sleet and snow which descends upon the earth; the quantity of water accumulated from the above events. |
| culvert | A buried pipe that allows streams, rivers, or runoff to pass under a road. |
| sidelobe | A secondary energy maximum located outside the main radar beam |
| project outflow | The volume of water per unit of time released from a project. |
| slash and burn | another term for shifting cultivation. |
| frost/freeze advisory | This product is issued by the National Weather Service when freezing temperatures or conditions conducive to the formation of frost occur during the growing season. |
| terminal fisheries | Fisheries near freshwater (usually the mouth of rivers or bays or near a hatchery release site) where the targeted species is returning to spawn. |
| habitat | The place where a population (e.g |
| freezeup date | Date on which the water body was first observed to be completely frozen over. |
| reach | The distance between two specific points outlining that portion of the stream, or river for which the forecast applies |
| stream segment | Refers to the surface waters of an approved planning area exhibiting common hydrological, natural, physical, |
| dust | Small particles of earth or other matter suspended in the air |
| gulf stream | A warm, swift, narrow ocean current flowing along the East Coast of the United States. |
| recycled water | Water that is used more than one time before it passes back into the natural hydrologic system. |
| solute | material dissolved in water. |
| coastal management | the attempt to mitigate the effects of erosion and flooding in coastal areas |
| radiation | The emission of energy from an object in the form of electromagnetic waves and photons. |
| capillary phenomena | A phenomenon of water movement caused by Capillarity. |
| irrigation | The controlled application of water to cropland, hayland, and/or pasture to supplement that supplied through nature. |
| deposition | An exothermic physical process whereby water vapor passes directly to the frozen state |
| average power | Pulsed radars transmit over a very low duty cycle; i.e., many intense but short and widely separated pulses |
| softening | The removal of calcium and magnesium from water to reduce hardness. |
| tropical storm | It is a warm-core tropical cyclone that has maximum sustained surface wind speed (using the U.S |
| watershed | An area of land whose total surface drainage flows to a single point in a stream. |
| farm delivery requirement | The Crop Irrigation Requirement plus farm losses due to evaporation, deep percolation, surface waste, and nonproductive consumption |
| steppe | Russian term for mid-latitude grasslands. |
| wave length | The least distance between particles moving in the same phase of oscillation of a wave |
| settleable solids | Those suspended solids in wastewater that will settle over a certain period of time and are removed in that way. |
| organ | Group of cells and tissues that have a particular function for an organism. |
| ecotone | the transition zone between very diverse ecosystems e.g |
| substation | A location where observations are taken or other services are furnished by people not located at NWS offices |
| drainage divide | Topographic border between adjacent drainage basins or watersheds. |
| purification | Steps taken to eliminate impurities and pollution from water. |
| consumption pattern | The variation in the amount of water a customer uses over time. |
| velocity aliasing | Ambiguous detection of radial velocities outside the Nyquist co-interval |
| inactive storage capacity | The portion of capacity below which the reservoir is not normally drawn, and which is provided for sedimentation, recreation, fish and wildlife, aesthetic reasons, or for the creation of a minimum controlled operational or power head in compliance with operating agreements or restrictions. |
| diversity | See Species Diversity. |
| eutrophication | The process of enrichment of water bodies by nutrients and the subsequent depletion of dissolved oxygen it produces.. |
| striations/stria | Gouges in bedrock or on glacial sediments which record abrasion by the moving glacier |
| arable | cultivation of crops such as cereals, legumes, roots and leaves. |
| lotic system | A flowing body of fresh water, such as a river or stream |
| mist | A collection of microscopic water droplets suspended in the atmosphere |
| wastewater | disposed water that enters the sewer system from homes, schools or businesses/industry that cannot be reused unless it is treated. |
| lorenz curve | a line graph that portrays the (un)evenness of a geographical distribution |
| benthos | All plants and animals living on or closely associated with the bottom of a body of water. |
| static water depth | the vertical distance from the centerline of the pump discharge down to the surface level of the free pool while no water is being drawn from the pool or water table. |
| hypothesis | the proposition of a relationship between variables which can then be tested and either rejected or accepted. |
| environmental evaluation | That part of the planning process by governmental agencies that inventories and estimates the potential effects on the human environment of alternative solutions to resource problems, determines the need for an Environmental Assessment (EA) or an Environmental Impact Statement (EIS), and aids in the consideration of alternatives and the identification of available resources. |
| fixed energy | A process, like photosynthesis, where organisms repackage inorganic energy into organic energy. |
| rebound | The upwarping of Earth's crust after additional weight is removed from it |
| clapotis | phenomenon where pattern of incoming sea waves exactly matches waves reflected by a sea wall or a sea cliff resulting in a static pattern of crests and troughs just offshore. |
| initial moisture deficiency | The quantity, usually expressed in depth of water in inches upon a unit area, by which the actual water content of a given soil zone (usually the root zone) in such area is less than the field capacity of such zone at the beginning of the rainy season |
| magnetron | A self-exciting oscillator tube used to produce the radio frequency signal transmitted by some radars |
| flow model | (1) A digital computer model that calculates a hydraulic head field for the modeling domain using numerical methods to arrive at an approximate solution to the differential equation of ground-water flow |
| plane of the ecliptic | Hypothetical two-dimensional surface in which the Earth's orbit around the Sun occurs. |
| wastewater | water that has been used in homes, industries, and businesses that is not for reuse unless it is treated. |
| fragmentation | in agriculture, the splitting of a landholding into smaller, more disparate parts usually due to inheritance being applied inefficiently. |
| volatilization | The process where a solid or liquid substance is converted into a gas. |
| ribbon lake | long, narrow, shallow lake formed in the bottom of a glacial trough due to a segment of over-deepening and/or blocking by deposits such as terminal moraine. |
| collector sewer | A sewer located in the public right-of-way that collects wastewater discharges through building sewers, and conducts such flows to larger interceptor sewers, lift stations and treatment works. |
| baobab tree | a pyrophitic tree found in savannah areas |
| landsat | Series of satellites launched by NASA for the purpose of remotely monitoring resources on the Earth |
| stilling basin | A basin constructed to dissipate the energy of fast-flowing water (e.g., from a spillway or bottom outlet), and to protect the streambed from erosion. |
| pollutant | Particles, gases, or liquid aerosols in the atmosphere which have an undesirable effect on humans or their surroundings |
| water surface elevation | the elevation of a water surface above or below an established reference level, such as sea level. |
| nitrogen dioxide | A gas produced by bacterial action in the soil and by high temperature combustion |
| distribution graph | A unit hydrograph of direct runoff modified to show the proportions of the volume of runoff that occur during successive equal units of time. |
| backsiphonage | reverse seepage of water in a distribution system. |
| sediment control | The control of movement of sediment on the land, in a stream or into a reservoir by means of manmade structures; such as debris dams, wing dams, or channelization; land management techniques, or natural processes. |
| underflow | The lateral motion of water through the upper layers until it enters a stream channel |
| biota | All living organisms in a region or ecosystem. |
| median tolerance limit | The concentration of a test substance at which just 50 percent of the test animals are able to survive for a specified period of exposure. |
| natural ionizing radiation | Ionizing radiation that comes from natural sources in the environment. |
| gaia hypothesis | The Gaia hypothesis states that the temperature and composition of the Earth's surface are actively controlled by life on the planet |
| scarification | Extensive movements of soil, sediment, and rock material caused by humans. |
| cloud-water lightning | Lightning occurring between cloud and water. |
| import substitution | the establishment and/or explicit government support for an industry producing goods that were formally exclusively, or nearly exclusively, imported |
| load shaping | The adjustment of storage releases so that generation and load are continuously in balance. |
| wasteway | (1) Channel for conveying or discharging excess water or wastewater |
| eccentricity | Minor/major axis at least 0.7. |
| physical geography | Field of knowledge that studies natural features and phenomena on the Earth from a spatial perspective |
| glade | An open, spacious Wetland, as in the Everglades. |
| tropical cyclone update | This brief statement is issued by the National Hurricane Center in lieu of or preceding special advisories to inform of significant changes in a tropical cyclone or the posting or cancellation of watches and warnings. |
| summer | Season between spring and fall |
| compensation point | The point under water at which plant photosynthesis just equals plant respiration |
| graben | the block of crust at the base of a rift valley which has slipped downwards due to the divergence of the crust on either side. |
| nutrient | as a pollutant, any element or compound, such as phosphorous or nitrogen, that fuels abnormally high organic growth in aquatic ecosystems |
| irrigated crop acreage | The total amount of land area that is irrigated, including acreage that is double cropped. |
| ephemeral stream | A stream that flows only in direct response to precipitation, and thus discontinues its flow during dry seasons |
| maximum spillway discharge | Spillway discharge (cfs) when reservoir is at maximum designed water surface elevation. |
| hamlet | a small settlement with a purely residential function |
| multiple-purpose reservoir | A reservoir planned and constructed to provide water for more than one purpose, e.g., irrigation, recreation, and flood control. |
| servo loop | In radar meteorology, a generic description of hardware needed to remotely control the motion of the antenna dish. |
| slaking | See wetting and drying. |
| transferrin | Transferrin is a serum protein that is characterized by its specific ability to reversibly bind iron and other metal ions and exhibits a high degree of polymorphism. |
| saturation | the condition of a liquid when it has taken into solution the maximum possible quantity of a given substance at a given temperature and pressure. |
| low-level outlet | An opening at a low level from a reservoir generally used for emptying or for scouring sediment and sometimes for irrigation releases. |
| dam | a structure of earth, rock, or concrete designed to form a basin and hold water back to make a pond, lake, or reservoir. |
| geostrophic wind | wind blowing parallel to isobars because of deflection of the pressure-gradient force by the Coriolis Force. |
| free ground water | Unconfined ground water whose upper boundary is a free water table. |
| slurry | a watery mixture of insoluble matter resulting from some pollution control techniques. |
| composite sample | A series of water samples taken over a given period of time and weighted by flow rate. |
| sedimentation | Settling of solid particles in a liquid system due to gravity. |
| meander belt width | The distance between lines drawn tangential to the extreme limits of fully developed meanders |
| lilapsophobia | The fear of tornadoes and hurricanes. |
| patterned ground | Term used to describe a number of surface features found in periglacial environments |
| climate | generalized weather at a given place on earth over a fairly long period; a long term average of weather |
| microorganism | Extremely small organism that can only be seen using a microscope. |
| ceiling light | An instrument consisting of a drum and an optical system that projects a narrow vertical beam of light onto a cloud base. |
| drainage area | An area having a common outlet for its surface runoff (also see Watershed and Catchment Area). |
| crater | the depression found at the summit of a volcanic cone. |
| thermal pollution | Discharge of heated water from industrial processes in receiving surface water, causing death or injury of aquatic organisms. |
| co-managers | Federal, state, county, local, and tribal agencies that cooperatively manage salmonids in the Pacific Northwest. |
| silicate magma | Magma that is felsic in composition. |
| outflow | The water that is released from a project during the specified period. |
| environmental assessment | The critical appraisal of the likely effects of a proposed project, activity, or policy on the environment, both positive and negative. |
| acre | A measure of area equal to 43,560 ft2 (4,046.87 m2) |
| deglomeration | the dispersal of businesses from an area due to rising costs, especially those of specialized labour and land rents |
| denudation | stripping of surface cover |
| boreal forest | High to mid-latitude biome dominated by coniferous forest |
| freezing | An exothermic physical process in which liquid water changes into solid ice (0C at 1 atm) |
| shortwave | A small wave that moves around long waves in the same direction as the air flow in the middle and upper troposphere |
| underground water | Water below the surface of the ground. |
| flowing well | A well drilled into a confined aquifer with enough hydraulic pressure for the water to flow to the surface without |
| backwashing | Reversing the flow of water back through the filter media to remove entrapped solids. |
| river | A long narrow channel of water that flows as a function of gravity and elevation across the Earth's surface |
| clarifier | a tank in which solids settle to the bottom and are subsequently removed as sludge. |
| semipermeable | A medium that allows water to pass through, but rejects dissolved solids, so that it can be used to separate solids from water. |
| sanitary sewer | A sanitary sewer is a pipe located in a street or easement that is designed to transport wastewater away from sanitary fixtures inside your house or place of business. |
| overflow regulator | A device in combined sewer systems for diverting wet weather flows that exceed downstream capacity to an overflow. |
| interflow | The lateral motion of water through the upper layers until it enters a stream channel |
| jet streak | A concentrated region within the jet stream where the wind speeds are the strongest |
| convergence line | A horizontal line along which horizontal convergence of the airflow is occurring |
| hatcheries | a place for hatching fish eggs humus - decomposed bits of plant and animal matter in the soil hydroelectric plant - a power plant that produces electricity from the power of rushing water turning turbine-generators hydrologic cycle - the natural recycling process powered by the sun that causes water to evaporate into the atmosphere, condense and return to earth as precipitation hydrology - the scientific study of the behavior of water in the atmosphere, on the Earth's surface and underground |
| check dam | A small dam constructed in a gully or other small water course to decrease the streamflow velocity, minimize channel erosion, promote deposition of sediment and to divert water from a channel. |
| faulting | tectonic movements which create faults in rock strata. |
| minimal flood hazard areas | Areas between the 100-year and the 500-year flood boundaries are termed Moderate Flood Hazard Areas |
| cation exchange | Chemical trading of cations between the soil minerals and organic matter with the soil solution and plant roots. |
| mcd | An acronym for Mesoscale Discussion. See Mesoscale Discussion. |
| river flow model | A simulation, generally mathematical, of a river's or drainage basin's Hydrologic Cycle, through a series of mathematical equations quantifying system inflows and outflows |
| colonization | The establishment of a species in an area not currently occupied by that species |
| observation well | A non-pumping well used for observing the elevation of the water table or piezometric surface. |
| meta-population | A population comprising local populations that are linked by migrants, allowing for recolonization of unoccupied habitat patches after local extinction events. |
| false ogives | Light and dark bands on the glacier formed by rock avalanching. |
| agglomeration | A process of bringing smaller particles together to form a larger mass. |
| resolution | In relation to radar, it is the ability to read two distinct targets separately |
| seepage | percolation of water through the soil from unlined canals, ditches, laterals, watercourses, or water storage facilities. |
| watershed management organization | Watershed Management Organizations are creations of the state, and are appointed by the cities in which they are located |
| water control | (Soil and Water Conservation) The physical control of water by such measures as conservation practices on land, channel improvements, and installation of structures for water retardation and sediment detention |
| rossby wave | See long wave. |
| base station | A computer which accepts radio signals from ALERT gaging sites, decodes the data, places the data in a database, and makes the data available to other users. |
| recyclable | Refers to such products as paper, glass, plastic, used oil, and metals that can be reprocessed instead of being disposed of as waste. |
| turning point | A temporary point whose elevation is determined by additions and subtractions of backsights and foresights respectively. |
| craton | Stable foundation core of the Earth's various plates of continental crust |
| tributary | (1) A stream which joins another stream or body of water |
| accretion | Snow accretion is the growth of precipitation particles by collision of ice crystals with supercooled liquid droplets which freeze on impact. |
| embargo | an order to prohibit trade with a particular country. |
| transmitter | The radar equipment used for generating and amplifying a radio frequency (RF) carrier signal, modulating the carrier signal with intelligence, and feeding the modulated carrier to an antenna for radiation into space as electromagnetic waves |
| reflection of waves | The process whereby waves bounce off a steep shoreline or structure rather than refracting or breaking, as they would in shallower waters. Reflected waves interact with oncoming waves to create confused sea conditions. See Refraction of Waves. |
| sedimentary rock | Rocks formed by the deposition, alteration and/or compression, and lithification of weathered rock debris, chemical precipitates, or organic sediments |
| leaching efficiency | The ratio of the average salt concentration in drainage water to an average salt concentration in the soil water of the root zone when near field capacity (also defined as the hypothetical fraction of the soil solution that has been displaced by a unit of drainage water). |
| trade winds | Surface winds that generally dominate air flow in the tropics |
| suspended sediment | very fine soil particles that remain in suspension in water for a considerable period of time without contact with the bottom |
| watch box | Slang for a severe thunderstorm or tornado watch. |
| algae | simple rootless plants that grow in sunlit waters in proportion to the amount of available nutrients |
| high water use turf | A surface layer of earth containing regularly mowed grass, with its roots, which requires large volumes and/or frequent application of water throughout its life |
| eddy | A small rotating area of water. |
| effective precipitation | the part of precipitation which produces runoff; a weighted average of current and antecedent precipitation "effective" in correlating with runoff |
| landslide | A mass of material that has slipped downhill under the influence of gravity, frequently occurring when the material is saturated with water. |
| ice wedge | Wedge-shaped, ice body composed of vertically oriented ground ice that extends into the top of a permafrost layer |
| overturned fold | A fold in rock layers where one limb is pushed past the perpendicular |
| perihelion | It is the point in the Earth's orbit when it is closest to the Sun (147.5 million km) |
| grease ice | Thin plates of organized ice crystals on the surface of water. |
| salt-water barrier | A physical facility or method of operation designed to prevent the intrusion of salt water into a body of fresh water. |
| infiltration | The movement of water through the soil surface into the soil. |
| aneroid barometer | An instrument designed to measure atmospheric pressure |
| algae | Single- or multi-celled organisms that are commonly found in surface water, such as duckweed |
| minor flooding | A general term indicating minimal or no property damage but possibly some public inconvenience. |
| theodolite | An instrument used in surveying to measure horizontal and vertical angles with a small telescope that can move in the horizontal and vertical planes. |
| hamada | A very flat desert area of exposed bedrock. |
| snow core | A sample of either freshly fallen snow, or the combined old and new snow on the ground |
| dry floodproofing | A dry floodproofed building is sealed against floodwaters |
| transport | two types: In human geography, the movement of goods or people by vehicle In physical geography, the movement of sediment load by water, wind or ice. |
| global village | the idea that the world is 'shrinking' as technology allows faster and cheaper communication at the global scale |
| main canal system | A canal that delivers water from a primary source of supply to several points of diversion or canal-side turnouts to smaller distribution systems. |
| cubic feet per second | A unit expressing rates of discharge |
| qpf | A spatial and temporal precipitation forecast that will predict the potential amount of future precipitation for a specified region, or area. |
| well injection | the subsurface placement of fluids into a well. |
| daily mean | The average temperature for a day computed by averaging either the hourly readings or, more commonly, the maximum and minimum temperatures. |
| cation | A negatively charged ion, resulting from dissociation of molecules in solution. |
| landing | Any place on or adjacent to the logging site where logs are assembled for further transport. |
| bod | Biochemical Oxygen Demand |
| pelean eruption | after the 1902 eruption of Mount Pel |
| sling psychrometer | Psychrometer that uses a rotating handle and a whirling motion to ventilate its wet-bulb thermometer. |
| alluvium | Sediment eroded from adjacent areas and deposited by running water in and along rivers and streams. |
| breakup period | The period of disintegration of an ice cover. |
| hydrographic study area | An area of hydrological and climatological similarity so subdivided for study purposes. |
| pervious zone | A part of the cross section of an embankment dam comprising material of high permeability. |
| public water system | a system for the provision to the public of water for human consumption through pipes or other constructed conveyances. In Texas, a public water system is one that serves at least 15 service connections or serve at least 25 individuals at least 60 days out of the year. |
| hydrogeology | the geology of groundwater, with particular emphasis on the chemistry and movement of water. |
| migration | properly, any movement of a living organism across space, or between locations |
| pathogens | Any agent that causes disease, such as a virus, protozoan, bacterium or fungus. |
| type n coho | A coho stock that rears in ocean waters off the mouth of the Columbia River and northward to the northern Washington coast. |
| melting | The change of a solid into a liquid. |
| kelt | A spent or spawned out steelhead salmon. |
| reuse | The additional use of previously used water. |
| location | A place where something can be found. |
| organic compound | a ring molecule of six carbons and six hydrogens with three shared or resonant double carbon-to-carbon bonds, known as an aromatic compound. |
| total dissolved solids | The quantity of dissolved material in a given volume of water |
| toxicity reduction evaluation | a study conducted to determine the source(s) of toxicity in a discharge effluent so that these sources can be controlled sufficiently to allow a discharger to comply with their permit limits. |
| lichen | Organism that consists of a symbiotic joining of a species of fungi and a species of algae. |
| dissolve | the process by which solid particles mix molecule by molecule with a liquid and appear to become part of the liquid. |
| benthic zone | The lower region of a body of water including the bottom. |
| freshwater | Water that contains less than 1,000 mg/L (milligrams per liter) of dissolved solids; generally, more than 500 mg/L is considered undesirable for drinking and many industrial uses. |
| minimum tillage farming | A farming technique that reduces the degree of soil disruption |
| return seepage | Water which percolates from canals and irrigated areas to underlying strata, raising the ground-water level, and eventually returning to natural channels. |
| base | An alkaline substance that has a pH that exceeds 7,5. |
| tarn | Small circular lake on the floor of a cirque basin. |
| bear's cage | Slang for a region of storm-scale rotation, in a thunderstorm, which is wrapped in heavy precipitation |
| extinction | Disappearance of a species from all or part of their geographic range |
| livestock | animals domesticated and kept by humans either for food or to do work. |
| minimum | The least value attained by a function, for example, temperature, pressure, or wind speed |
| phiezometer | An instrument used to measure pressure head in a conduit, tank, soil, etc |
| mountain wave | A wave in the atmosphere caused by a barrier, such as a mountain |
| jet stream | an upper atmosphere wind which blows in a narrow band from west to east |
| high clouds | These clouds have bases between 16,500 and 45,000 feet in the mid latitudes |
| stepped leader | A leader which initiates the very first stroke and establishes the channel for all subsequent streamers of a lightning discharge. |
| flood routing | Process of determining progressively the timing, shape, and amplitude of a flood wave as it moves downstream to successive points along the river. |
| moisture | Refers to the water vapor content in the atmosphere, or the total water, liquid, solid or vapor, in a given volume of air. |
| herbicide | a chemical used to control/prevent weed growth in arable farming. |
| headlands | A strip of land that juts seaward from the coastline |
| parapatric | Having some geographic overlapping of distributions with the potential for gene flow between populations |
| administrative order | a legal document signed by U.S |
| shore ice | An ice sheet in the form of a long border attached to the bank or shore. See border ice. |
| riparian zone | a stream and all the vegetation on its banks. |
| territory | The area that an animal defends, usually during breeding season, against intruders of its own species. |
| aquifer | Permeable layers of underground rock, or sand that hold or transmit groundwater below the water table that will yield water to a well in sufficient quantities to produce water for beneficial use. |
| urban decay | aging inner city areas often experience a loss of industry meaning fewer jobs and triggering a downward spiral of economic and therefore social decline. |
| fjord | a narrow, steep-sided coastal inlet which can extend up to a couple of hundred kilometres inland |
| distillation | water treatment method where water is boiled to steam and condensd in a separate reservoir |
| epeirogenic | gentle but large-scale uplift of the crust, or ontinent building- |
| hazard | an event or condition which threatens people and property |
| finite volume | a method of solving the governing equations of a numerical model by dividing the spatial domain into a mesh of nodes and corresponding volumes around each node |
| gallon | A unit that is now almost entirely out of date |
| mean temperature | The average of temperature readings taken over a specified amount of time |
| trickling filter | a treatment system in which wastewater is trickled over a bed of stones or other material covered with bacteria that break down the organic waste and produce clean water. |
| import | Water piped or channeled into an area. |
| priority date | The date of establishment of a water right |
| parametric data | Data such as rating curves, unit hydrographs, and rainfall/runoff curves which define hydrologic variables in models. |
| region | an area defined from its surroundings by common characteristics of physical landscape, economy or function. |
| flash flood guidance | An internal product produced by the RFCs containing rainfall threshold values which must be exceeded in order to produce a flash flood. |
| landslide | Term used to describe the downslope movement of soil, rock, and other weathered materials because of gravity. |
| mcl goal | Under the Safe Drinking Water Act, a non-enforceable concentration of a drinking water contaminant, set at the level at which no known or anticipated adverse effects on human health occur and which allows an adequate safety margin |
| lateral | (1) A branch canal or pipeline that diverges from the main canal or other branches |
| giardiasis | a disease that results from an infection by the protozoan parasite Giardia Intestinalis, caused by drinking water that is either not filtered or not chlorinated |
| phase | Physical matter is defined to occur in three phases; solid, liquid and gas. |
| ecosphere | The mantle of earth and troposphere inhabited by living organisms; the "bio-bubble" that contains life on earth, in surface waters, and in the air |
| riparian vegetation | Vegetation growing on the banks of a stream or other body of surface water. |
| unconsolidated formation | Natural earth formations that have not been turned to stone, such as alluvium, soil, gravel, clay, sand and overburden. |
| irregularly flooded | A water regime in wetland classification in which tidal water alternately floods and exposes the land surface less often than daily. |
| domestic consumption | The quantity, or quantity per capita, of water consumed in a municipality or district for domestic uses or purposes during a given period, generally one day |
| mor | a humus layer with high levels of acidity |
| washout | (1) Erosion of a relatively soft surface, such as a roadbed, by a sudden gush of water, as from a downpour or floods |
| t. d. | An acronym for Tropical Depression. See Tropical Depression. |
| reservoir | bay or other system, based upon flow rates into and out of the system, (see residence time). |
| globe | A round model of the earth. |
| treated effluent | Water that has received primary, secondary, or advanced treatment to reduce its pollution or health hazards and is subsequently released from a wastewater facility after treatment. |
| valve | Mechanical device for controlling or stopping flow of water in a pipe. |
| fahrenheit temperature scale | A temperature scale where water at sea level has a freezing point of +32°F and a boiling point of +212°F |
| accuracy | Degree of conformity of a measure to a standard or true value. |
| infiltration | paving, roofs, roadways or other human structures, impervious cover increases runoff and affects the quantity and composition of non-point source pollution, the quality or state of being impermeable, resisting penetration by water or plant roots. |
| updraft base | Alternate term for a rain-free base. |
| directional shear | The component of wind shear which is due to a change in wind direction with height, e.g., southeasterly winds at the surface and southwesterly winds aloft |
| mos | An acronym for Model Output Statistics. See Model Output Statistics. |
| hydrologic unit | A distinct watershed or river basin defined by an eight-digit code. |
| polder | An area of low-lying land, especially in the Netherlands, that has been reclaimed from a body of water and is protected by dikes. |
| piping | The progressive development of internal erosion by seepage, appearing downstream as a hole or seam discharging water that contains soil particles. |
| hydraulic fill dam | A dam constructed of materials, often dredged, that are conveyed and placed by suspension in flowing water. |
| qg | An abbreviation for quasigeostrophic. |
| centrifugal pump | A device that converts mechanical energy to pressure or kinetic energy in a fluid by imparting centrifugal force on the fluid through a rapidly rotating impeller. |
| mesa | A mesa is a land formation with a flat area on top and steep walls - usually occurring in dry areas. |
| cheimatophobia | The fear of cold. |
| husbandry | (Agriculture) The act or practice of cultivating crops and breeding and raising livestock |
| longevity | lit |
| pool | Scoured depression found on the bed of streams |
| phengophobia | The fear of daylight or sunshine. |
| thermal | A relatively small-scale, rising air current produced when the Earth's surface is heated |
| enterprise zone | in the UK, a policy of the 1980s to encourage economic growth, often in deprived inner city areas, by making it easier and cheaper to establish industrial activity through tax and rates allowances and exemptions and simpler planning procedures |
| secondary wave | See S-wave or shear wave. |
| resident fish | Occupying headwater reaches; may disperse locally, but generally considered non-migratory. |
| reference wetland | A wetland within a relatively homogeneous biogeographic region that is representative of a specific hydrogeomorphic wetland type. |
| scouring | see abrasion. |
| aliquot | A measured portion of a sample taken for analysis |
| off-site enhancement | The improvement in conditions for fish or wildlife species away from the site of a hydroelectric project that had detrimental effects on fish and/or wildlife, as part or total compensation for those effects |
| porosity | the degree to which a rock or soil is porous. |
| floodplain | Land built of sediment that is regularly covered with water as a result of the flooding of a adjacent stream. |
| duplexer | A device in the waveguide which protects the sensitive receiver from the full power of the transmitter; usually contains one or more TR (transmit-receive) tubes. |
| offstream use | Water withdrawn or diverted from a ground or surface-water source for use at another place |
| hydrosphere | the earth water habitats: oceans & seas, lakes & rivers, ice and underground water. |
| crack | A separation formed in an ice cover of floe that does not divide it into two or more pieces. |
| snowfield | An area of permanent snow accumulation |
| stream flow | The flow of water in a river or stream channel. |
| in-channel storage | Water storage volume in a canal above the minimum water level required for conveyance. |
| tac | Total allowable catch is the total regulated catch from a stock in a given time period, usually a year. |
| sedimentation | a large scale water treatment process where heavy solids settle out to the bottom of the treatment tank after flocculation. |
| richter scale | a measure of the total amount of energy released during an earthquake |
| barrier beach | low-lying, bar-shaped sand and/or coral island lying parallel to but slightly away from a coastline |
| acidic | The condition of water or soil in which the amount of acid substances are sufficient to lower the pH below 7.0. |
| cellulose | A type of carbohydrate |
| sprinkler irrigation | See Irrigation. |
| stable equilibrium | In a stable equilibrium the system displays tendencies to return to the same equilibrium after disturbance. |
| underground storage tank | (Water Quality) (1) Any one or combination of underground tanks and any connecting underground pipes used to contain an accumulation of regulated substances |
| stratosphere | The layer of the atmosphere located between the troposphere and the mesosphere, characterized by a slight temperature increase and absence of clouds |
| large woody debris | Pieces of naturally occurring wood larger than 10 ft long and 6 in |
| meander | Sinuous shaped stream channel |
| infiltration and inflow | (Water Quality) The entrance of groundwater (infiltration) or of surface water (inflow) into sewer pipes |
| monstatic radar | A radar that uses a common antenna for both transmitting and receiving. |
| evapotranspiration | The total amount of water that is transferred from the earth's surface to the atmosphere |
| santa ana winds | The hot, dry winds, generally from the east, that funnel through the Santa Ana river valley south of the San Gabriel and San Bernadino Mountains in southern California, including the Los Angeles basin |
| flora | plant population of a region. |
| species diversity | Number of different species in a given region. |
| denitrification | Conversion of nitrates into gaseous nitrogen and nitrous oxide. |
| semi-confined aquifer | An aquifer partially confined by soil layers of low permeability through which recharge and discharge can still occur. |
| upslope fog | Fog produced by air flowing over topographic barriers |
| eif | Enhanced IFLOWS Format |
| cartilaginous fishes | A major group of fishes including sharks and rays. |
| feedback | in a system, an output which causes changes to that system inputs |
| clear skies | Skies are clear when no clouds or obscurations are observed or detected from the point of observation. |
| fracture zone | An area which has a great number of fractures. |
| gpp | see gross primary productivity. |
| water table aquifer | an aquifer confined only by atmospheric pressure (water levels will not rise in the well above the confining bed). |
| distributional limit | Spatial boundary that defines the edge of a species geographical range. |
| rainfall component | That part of the flow of a channel attributed to rain falling directly on the surface of the channel. |
| photosynthetic autotroph | An organism that produces food molecules inorganically by using light and the chemical process of photosynthesis |
| kame terrace | a terrace of stratified sand and and gravel deposited by streams between a glacier and an adjacent valley wall. |
| sedimentation tanks | wastewater tanks in which floating wastes are skimmed off and settled solids are removed for disposal. |
| intermediate zone | The subsurface water zone below the root zone and above the capillary fringe. |
| brook | a small stream. |
| benchmark | A permanent point whose known elevation is tied to a national network |
| flood plain | Level land that may be submerged by flood waters. |
| corrie glacier | the glacier found in a corrie which has been responsible for its formation. |
| ceremonial or subsistence harvest | Harvests of fish by Native Americans for ceremonies and to support traditional lifestyles. |
| equlibrium yield | The yield in weight taken from a fish stock when it is in equilibrium with fishing of a given intensity, and (apart from effects of environmental variation) its biomass is not changing from one year to the next |
| alpha index | a measure of connectivity in a network |
| leakage | A species of ions in the feed of an ion exchanger present in the effluent. |
| endemic | (Ecology) Confined to, or Indigenous in, a certain area or region, as an endemic plant or animal. |
| resolution | The breaking of an emulsion into its individual components. |
| fluid | continuous, amorphous state of matter in which molecules move freely past one another; has the tendency to assume the shape of its container. |
| irrigation return flow | applied water that is not transpired, evaporated, or deep-percolated into a groundwater basin but returns to a surface water supply. |
| bankfull stage/elevation | An established river stage/water surface elevation at a given location along a river which is intended to represent the maximum water level that will not overflow the river banks or cause any significant damages from flooding. |
| chlorine demand | the difference between the amount of chlorine added to water, sewage, or industrial wastes and the amount of residual chlorine remaining at the end of a specific contact period |
| retailing | sale of goods and services to the public. |
| parasitism | The act of living in close association with another living organism at that organisms expense. |
| dense fog advisory | This product is issued by the National Weather Service when widespread fog reduces visibility to less than or equal to 1/4 mile. |
| interbasin transfer | the physical transfer of water from one watershed to another; regulated by the Texas Water Code. |
| freezing level | The lowest altitude in the atmosphere, or a given location, at which the air temperatures is 32 degrees. |
| dry wash | A streambed that carries water only during and immediately following rainstorms. |
| snow line | Altitudinal or latitudinal limit separating zones where snow does not melt during the summer season from areas in which it does |
| milldam | A dam constructed across a stream to raise the water level so that the overflow will have sufficient power to turn a mill wheel. |
| ionosphere | A region in the atmosphere above 50 kilometers from the surface where relatively large concentrations of ions and free electrons exist |
| talus slope | A slope that is composed of talus. |
| shield | A large stable area of exposed very old (more than 600 million years) igneous and metamorphic rock found on continents |
| cross-sectional area | Area perpendicular to the direction of flow. |
| geodesy | the science of measuring the surface of the earth. |
| non-aqueous phase liquid | contaminants that remain undiluted as the original bulk liquid in the subsurface, such as spilled oil. |
| littoral zone | area on or near the shore of a body of water. |
| septum/septa | Dividing lines between chambers or compartments (such as nasal sinus) |
| discrete variable | a variable which can only be measured in whole, individual units if it is to have any real meaning e.g numbers of people. |
| riss | European glaciation related to North American Illinoian glaciation. |
| pulse resolution volume | A discrete radar sampling volume, of dimensions (horizontal beamwidth * vertical beamwidth * 1 range gate). |
| biota | Collectively, the plants, microorganisms, and animals of a certain area or region. |
| ice crystals | Ice crystals are hexagonal in internal structure |
| glacier meal | Finely ground rock particles produced by glacial abrasion. |
| pieces | "Individual items, as in the expression ""two dollars a piece"" |
| transhipment | the transfer of cargo between ships or between two different modes of transport. |
| critical habitat | Under the Endangered Species Act, critical habitat is defined as (1) the specific areas within the geographic area occupied by a federally listed species on which are found physical and biological features essential to the conservation of the species, and that may require special management considerations or protections; and (2) specific areas outside the geographic area occupied by a listed species, when it is determined that such areas are essential for the conservation of the species. |
| frequency curve | A curve that expresses the relation between the frequency distribution plot, with the magnitude of the variables as abscissas and the number of occurrences of each magnitude in a given period as ordinates |
| food chain | the transfer/flow of energy through an ecosystem |
| herbaceous | Vegetation or parts of plants with little or no woody tissue. |
| inch-degrees | The product of inches of rainfall multiplied by the temperature in degrees above freezing (Fahrenheit Scale), used as a measure of the snowmelting capacity of rainfall. |
| arête | A knife-edged rock divide between two glacial cirques. |
| normal annual precipitation | Average annual precipitation during a base period. |
| intraspecific | Occurring among members of a single species. |
| soil moisture | Water diffused in the upper part of the Unsaturated Zone (Zone of Aeration) of the soil, from which water is discharged by the Transpiration of plants, by Evaporation, or Interflow. |
| estuary | Somewhat enclosed coastal area at the mouth of a river where nutrient rich fresh water meets with salty ocean water. |
| hdrain | An Hourly Digital Rainfall Product of the WSR-88D. |
| predation | Hunting and killing another animal for food. |
| wellhead protection area | a protected surface and subsurface zone surrounding a well or well field supplying a public water system to keep contaminants from reaching the well water. |
| flood | The temporary inundation of normally dry land areas resulting from the overflowing of the natural or artificial confines of a river or other body of water. |
| tundra | High latitude biome dominated by a few species of dwarf shrubs, a few grasses, sedges, lichens, and mosses |
| central business district | a centrally-located (in space and/or time) zone of an urban area, containing the principal commercial, professional, retail and governmental functions. |
| sheet flow | Flow that occurs overland in places where there are no defined channels, the flood water spreads out over a large area at a uniform depth |
| right rear quadrant | see Right Entrance Region. |
| feedback loop | Process where the output of a system causes positive or negative changes to some measured component of the system. |
| gravity | Is the process where any body of mass found in the universe attracts other bodies with a force proportional to the product of their masses and inversely proportional to the distance that separates them |
| creel census survey | The collection of data concerning the number of fish caught by sport fishers on a particular stream or in a particular area. |
| compensation | Management activities that replace all or part of fish stocks or their habitat lost through development or other activities. |
| landscape area | The entire parcel less the building footprint, driveways, non-irrigated portions of parking lots and required off-street parking |
| uv | Ultra Violet |
| bank stability | occurs when the channel bank configuration does not change significantly over time. |
| haines index | This is also called the Lower Atmosphere Stability Index. It is computed from the morning (12Z) soundings from RAOB stations across North America |
| pretreatment | processes used to reduce, eliminate, or alter the nature of wastewater pollutants from non-domestic sources before they are discharged into publicly owned treatment works (POTWs). |
| radar cross section | The area of a fictitious, perfect reflector of electromagnetic waves (e.g., metal sphere) that would reflect the same amount of energy back to the radar as the actual target (e.g., lumpy snowflake). |
| wind sock | A tapered fabric shaped like a cone that indicates wind direction by pointing away from the wind |
| mechanical flotation | A term used in the mineral industry to describe the use of dispersed air to produce bubbles that measure 0.2 to 2 mm in diameter. |
| cobble | Substrate particles that are smaller than boulders and are generally 64-256 mm in diameter |
| convergent lifting | The vertical lifting of parcels of air through the convergence of opposing air masses in the atmosphere |
| resource | anything that we use for survival in the first place and wealth generation in the second |
| flow line | a mapping technique using a line to show volume of a movement along a route |
| hygroscopic | a substance that attracts water. |
| tropical air mass | An air mass that forms in the tropics or subtropics over the low latitudes |
| bourne | a seasonal river which flows in normally dry valleys during wetter periods of the year. |
| velocity azimuth display | This WSR-88D radar product displays a graphical plot of mean radial velocity versus azimuth angle for a particular altitude. A best fit sine wave is overlaid on the plot of velocity points if a sufficient number (25) of data points exists. This wave is used to compute wind speed and direction for a specific height is symmetry and root mean square error thresholds are not exceeded. It is used to: 1) Check suspicious or missing wind data on the VAD Wind Profile (VWP); 2) Determine the potential strength of wind gusts; 3) Identify jets (low/mid/high level); and 4) Identify thermal advection patterns, vertical wind shear, depths of frontal surfaces, and the development of isentropic lift situations. The usefulness of this radar product is sometimes limited by lack of scatters at times. |
| frontal fog | Is a type of fog that is associated with weather fronts, particularly warm fronts |
| product resolution | The smallest spatial increment or data element that is distinguishable in a given Doppler radar product. |
| river | but some comes from public sources. |
| lateral moraine | Moraine situated along the edge of a mountain glacier, consisting of debris that fell from the adjacent valley wall. |
| upslope flow | Air that flows toward higher terrain, and hence is forced to rise |
| detergent | synthetic washing agent that helps remove dirt and oil |
| deep-sea trench | see ocean trench. |
| dewater | remove or separate a portion of the water in a sludge or slurry to dry the sludge so it can be handled and disposed; remove or drain the water from a tank, trench, or aquifer. |
| salr | see saturated adiabatic lapse rate. |
| equlibrium catch | The catch (in numbers) taken from a fish stock when it is in equilibrium with fishing of a given intensity, and (apart from the effects of environmental variation) its abundance is not changing from one year to the next. |
| in-situ stripping | treatment system that removes or strips volatile organic compounds from contaminated groundwater or surface water by forcing an air stream through the water and causing the compounds to evaporate. |
| right of capture | the idea that the water under a person's land belongs to that person and they are free to capture and use as much as they want |
| net primary productivity | Total amount of chemical energy fixed by the processes of photosynthesis minus the chemical energy lost through respiration. |
| organic matter | Mass of matter that contains living organisms or non-living material derived from organisms |
| less developed | see economically less developed countries. |
| glacial polish | The abrasion of bedrock surfaces by materials carried on the bottom of a glacier |
| euryhaline | Having a wide tolerance to salinity. |
| aquifer | an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall. |
| consumptive use | the quantity of water not available for reuse |
| flood | Inundation of a land surface that is not normally submerged by water from quick change in the level of a water body like a lake, stream, or ocean. |
| pore pressure | The interstitial pressure of water within a mass of soil, rock, or concrete. |
| recharge well | Used in conjunction with artificial or induced ground water recharge techniques, the recharge well works directly opposite of pumping wells to induce surface water into the ground water system |
| natural flow | the rate of water movement past a specified point on a natural stream |
| paleosol | A soil exhibiting features that are the result of some past conditions and processes. |
| vip | An acronym for Video Integrator and Processor. This processor was used on the WSR-57 and WSR-74C radars to indicate rainfall rates. It is still used occasionally on WSR-88D radar products. This processor contours radar reflectivity (in dBZ) into six VIP levels. |
| mixed economy | the most common form of national economic organization, somewhere between a command economy and a market economy |
| duration | Size criteria must be met for at least 6 hours. |
| unsaturated flow | Movement of water in a porous medium in which the pore spaces are not filled with water and the direction of flow is from the wetter zone of higher potential to one of lower potential. |
| census | the collection of data about a population |
| atmosphere | layer of gases surrounding earth and held there by gravity |
| mean seal level | A measure of elevation above sea level. |
| southeast trade winds | See trade winds. |
| precession of the equinox | Wobble in the Earth's polar axis |
| capillary zone | The soil area just above the water table where water can rise up slightly through the cohesive force of capillary action |
| parts per million | Expressed as ppm; a measure of concentration |
| anomalous propagation | This refers to the non-standard propagation of a beam of energy, radio or radar, under certain atmospheric conditions, appearing as false (non-precipitation) echoes |
| eutrophication | The natural process by which lakes and ponds become enriched with dissolved nutrients, resulting in increased growth of algae and other microscopic plants. |
| geographic cycle | Theory developed by William Morris Davis that models the formation of river-eroded landscapes |
| tombolo | A coastal feature that forms when a belt sand and/or gravel is deposited between an island and the mainland |
| solute | any substance derived from the atmosphere, vegetation, soil, or rock that is dissolved in water. |
| destructive wave | a steep, high frequency wave which causes a net loss of material from the beach as the backwash is stronger than the swash. |
| climate diagnostics center | This agency is part of the National Oceanic & Atmospheric Administration (NOAA). Their mission is to identify the nature and causes of climate variations on time scales ranging from a month to centuries |
| temperate deciduous forest | Forested biome found in the mid-latitudes and dominated by deciduous vegetation. |
| gustnado | Slang for a gust front tornado |
| asap | AHOS SHEF Automatic Processing System |
| fresh breeze | Small trees in leaf begin to sway; crested wavelets from on inland waters; moderate waves, taking a more pronounced long form; many whitecaps appear on lakes. |
| meniscus | The curved surface of the liquid at the open end of a capillary column. |
| carbon adsorption | a treatment system that removes contaminants from ground water or surface water by forcing it through tanks containing activated carbon treated to attract the contaminants. |
| comparative advantage | the idea that areas tend to be more efficient in certain economic activities than others and so should specialise in them in order to maximize their quality of life through trade. |
| forfeited water right | a water right canceled because of several consecutive years of nonuse. |
| leaf area index | The area of one side of leaves per unit area of soil surface. |
| check gate | A gate located at a check structure used to control flow. |
| organic soil | Soil order (type) of the Canadian System of Soil Classification |
| set-aside | the policy within the EU, begun in the late 1980s, in which farmers are paid for keeping land out of production |
| smog | Generic term used to describe mixtures of pollutants in the atmosphere |
| inundation map | A map delineating the area that would be inundated in the event of a dam failure. |
| instream flow needs | Those habitat requirements within the running water Ecosystem related to current velocity and depth which present the optimum conditions of density (or diversity) or physiological stability to the aquatic organisms being examined at various life cycle stages. |
| circum-pacific belt | A zone circling the edge of the Pacific Ocean basin where tectonic subduction causes the formation of volcanoes and trenches |
| ohm's law | I = E / R, where I is current (amperes), E is electromotive force (i.e., voltage) and R is resistance (ohms) |
| physical weathering | (also mechanical weathering) a process of weathering which results in smaller pieces of the same rock material being produced. |
| trace | A rainfall amount less than 0.01 of an inch. |
| large water system | A water system that services more than 50,000 customers. |
| proportional | Cause and effect relationship between two variables where a positive or negative change in the quantity of one causes a predictable similar quantity change in the other. |
| bathymetric chart | A map delineating the form of the bottom of a body of water, usually by means of depth contours (see Isobaths). |
| sandar * | Flat outwash plains caused by glacial melting feature braided streams and sinous sand and gravel bars. |
| salination | The process whereby soluble salts accumulate in the soil. |
| allogenic | when an external environmental factor causes a process to occur. |
| mesoscale convective system | A large organized convective weather system comprised of a number of individual thunderstorms |
| chezy's roughness | a coefficient in Chezy's equation that accounts for energy loss due to the friction between the channel and the water. |
| el | An acronym for Equilibrium Level. See Equilibrium Level. |
| wind power | the generation of electricity by turbines which are turned by wind. |
| renewable energy | A source of energy that is replaced by natural phenomena, such as firewood or the water held by a dam and used for hydroelectric purposes |
| bicarbonates | Salts containing the anion HCO3- |
| littoral transport | The process of sediment moving along a coastline |
| pluton | Any mass of intrusive igneous rock. |
| embankment | An artificial deposit of material that is raised above the natural surface of the land and used to contain, divert, or store water, support roads and railways, or for other similar purposes. |
| interstitial water | Water in the pore spaces of soil or rock. |
| wind | The horizontal motion of the air past a given point. Winds begin with differences in air pressures |
| nautical mile | A unit of distance used in marine navigation and marine forecasts |
| drought index | Computed value which is related to some of the cumulative effects of a prolonged and abnormal moisture deficiency |
| needle ice | A form of periglacial ground ice that consists of groups ice slivers at or immediately below the ground surface |
| sediment | Sediment is material suspended in water, that consists mostly of soil, but can also contain cigarette butts, litter, etc., which is carried by stormwater into the city's storm drain system and eventually into a body of water. |
| cloud-air lightning | Streaks of lightning which pass from a cloud to the air, but do not strike the ground. |
| trans-mountain diversion | The conveyance of water from one watershed to another, usually from the Western Slope to the Front Range. |
| flood stage | An above average elevation for the water level at high flows. |
| discharge | the volume of water in a channel passing a particular point in a particular time, usually cubic metres per second or cumecs |
| natal | Birth place. |
| falcate | Hooked or curved like a sickle. |
| wmo | Watershed Management Organization |
| tributary | a stream that contributes its water to another stream or body of water. |
| volcanic plume | the cloud of gases and solids ejected into the atmosphere from a volcano and then carried by the wind. |
| aeration tank | A tank that is used to inject air into water. |
| diffused solar radiation | Solar radiation received by the Earth's atmosphere or surface that has been modified by atmospheric scattering. |
| esp | Extended Streamflow Prediction |
| flood stage | elevation at which overflow of the natural banks of a water course begins. |
| surface water | An open body of water, such as a stream or a lake. |
| point discharge | Instantaneous rate of discharge, in contrast to the mean rate for an interval of time. |
| retrogressive succession | Succession where the plant community becomes simplistic and contains fewer species and less biomass over time. |
| municipal discharge | discharge of effluent from treatment plants that receive wastewater from households, commercial establishments, and industries. |
| sediments | suspended sediments, TDS, total dissolved solids, particulate matter turbidity and solutes in natural waters. |
| artesian aquifer | a geologic formation in which water is under sufficient hydrostatic pressure to rise above the top of the aquifer in the subsurface |
| awips | Advanced Weather Interactive Processing System |
| inclined staff gage | A staff gage that is placed on the slope of a stream bank and graduated so that the scale reads directly in vertical depth. |
| sedimentation | (1) The combined processes of soil erosion, entrainment, transport, deposition, and consolidation |
| synoptic chart | Any map or chart that depicts meteorological or atmospheric conditions over a large area at any given time. |
| field-moisture capacity | The quantity of water which can be permanently retained in the soil in opposition to the downward pull of gravity. |
| resource | something valuable that can be used to support life or make it easier |
| flood wave | A rise in streamflow to a crest and its subsequent recession caused by precipitation, snowmelt, dam failure, or |
| transient flow | Unsteady flow during a change from a steady-flow state to another steady-flow state. |
| mixed liquor | (Water Quality) In wastewater treatment, the liquid in the aeration tank of an activated sludge system; a mixture of activated sludge and water containing organic matter undergoing activated sludge treatment in an aeration tank. |
| subsolar point | The location on the Earth where the Sun is directly overhead |
| star | A large and very massive, self-luminous celestial body of gas that illuminates via the radiation derived from its internal source of energy. |
| desorption | The opposite of adsorption; the release of matter from the adsorption medium, usually to recover material. |
| hydraulic model | a computer model of a segment of river used to evaluate hydraulic conditions |
| nucleus | The center of an atom, that contains protons and neutrons and carries a positive charge. |
| pumped storage project | A hydroelectric power plant and reservoir system in which water released for generating energy during peak load periods is stored and pumped back into the upper reservoir, usually during periods of reduced power demand. |
| total column ozone | A measurement of ozone concentration in the atmosphere. |
| stable canal system | A canal system in which flow disturbances are attenuated. |
| moist adiabatic lapse rate | See saturated adiabatic lapse rate. |
| tragedy of the commons | the idea that no one takes responsibility for things that everybody owns. |
| nutrient cycling | Circulation or exchange of elements such as nitrogen and carbon between nonliving and living portions of the environment. |
| flowage | (1) The act of flowing or overflowing |
| wire weight gage | A river gage comprised of a weight which is lowered to the water level |
| wetland | An area where the ground is temporarily, seasonally, or permanently saturated by surface water or groundwater, and that, under normal circumstances, is occupied by water-loving or water-tolerant vegetation. |
| flashiness | a measure of a river or stream's tendency to carry a high percentage of its flow volume in large, infrequent events rather than more moderate flows that occur frequently. |
| ground moraine | A gently rolling ground surface underlain by till deposited beneath a glacier and usually bordered by terminal moraines. |
| contour line | on topographical maps, the isolines connecting points of equal height above sea-level. |
| turbidity | the measure of suspended sediment maintained in water by turbulent flow. |
| uniformitarianism | Is a theory that rejects the idea that catastrophic forces were responsible for the current conditions on the Earth |
| macroscale | Large scale, characteristic of weather systems several hundred to several thousand kilometers in diameter. |
| tidal flat | the surface exposed only at low tide. |
| iflows | The Integrated Flood Observing and Warning System. |
| nocturnal | Related to nighttime, or occurring at night. |
| gallery | (1) A passageway within the body of a dam or abutment; hence the terms "grouting gallery," "inspection gallery," and "drainage gallery." (2) A long and rather narrow hall; hence the following terms for a power plant: "valve gallery," "transformer gallery," and "busbar gallery." |
| palatines | Paired bones in the roof of the mouth, lateral to vomer; may bear teeth. |
| humidification | The addition of water vapour to air. |
| dry bulb thermometer | A thermometer used to measure the ambient temperature |
| specific humidity | The mass of water vapor per unit mass of moist air. |
| passage | The movement of migratory fish through, around, or over dams, reservoirs and other obstructions in a stream or river. |
| rainfall duration | The period of time during which rainfall occurs, exceeds a given intensity, or maintains a given intensity. |
| gypsum | Sedimentary rock created by the chemical precipitation of calcium, sulfur, and oxygen. |
| lining | Application of an internal lining material to the wall of an existing sewer for structural and/or protective reasons |
| fixed ground water | water held in saturated material that it is not available as a source of water for pumping. |
| dropsonde | A radiosonde dropped with a parachute from an aircraft rather than lifted by a balloon to measure the atmosphere below. |
| leachate | Water that contains solute substances, so that it contains certain substances in solution after percolation through a filter or soil. |
| creek | A small stream of water which serves as the natural drainage course for a drainage basin of nominal, or small size |
| body wave | Type of seismic wave that travels through the interior of Earth. |
| conservation | The process or means of achieving recovery of variable populations. |
| isoheight | Same as a contour depicting vertical height of some surface above a datum plane. |
| littoral drift | The sediment that is transported by waves and currents through beach drift and longshore drift along coastal areas. |
| self-regulation | The ability of some systems to maintain a steady state equilibrium through positive and negative feedbacks. |
| inosilicate | Subclass of the silicate class of minerals |
| alluvial | relating to, composed of, or found in alluvium. |
| base level | The subterranean elevation below which a stream cannot vertically erode sediment |
| offshore forecast | This National Weather Service marine forecast is designed to serve users who operate beyond the coastal waters where it usually requires more than a day or more of sailing to and from port. These users are mainly commercial fishermen and merchant shipping and, to a lessor extent, government and research vessels and large recreational craft. |
| sinking | controlling oil spills by using an agent to trap the oil and sink it to the bottom of the body of water where the agent and the oil are biodegraded. |
| stream | A general term for a body of water flowing by gravity; natural watercourse containing water at least part of the year |
| canadian high | High pressure system that develops in winter over central North America. |
| radioisotope or radioactive isotope | A unstable isotope of an element |
| tap | A physical connection made to a public water distribution system that provides service to an individual customer. |
| cyclone | extremely low pressure system |
| project yield | The water supply attributed to all features of a project, including integrated operation of units that could be operated individually |
| operational concept | Mode of operating a canal with respect to location of priorities; usually supply oriented (upstream concept) or demand oriented (downstream concept). |
| afos | Automation of Field Operations and Services. This system was installed in the early to mid 1980s and it is being replaced by Advanced Weather Interactive Processing System (AWIPS). |
| aeration | Any active or passive process by which intimate contact between air and liquid are assured, generally by spraying liquid in the air, bubbling air through water, or mechanical agitation of the liquid to promote surface absorption of air. |
| decibel | This is a logarithmic expression comparing the energy that the radar emits (Z1) to the energy that radar receives back from a radar target (Z2) |
| plunge pool | the pool found at the base of a waterfall created by the additional erosional energy that falling water and load has. |
| buccal | Pertaining to the cheeks or the cavity of the mouth. |
| hybrid | An offspring that results from the mating of individuals of different races or species. |
| rill | A very small steep sided channel carrying water |
| erosion control | Materials, structures, and actions utilized and taken to reduce or prevent erosion. |
| orogeny | period of mountain-building. |
| blowdown | the water drawn from boiler systems and cold water basins of cooling towers to prevent the buildup of solids. |
| clint | flat-topped block that forms the 'paving stone' in a limestone pavement. |
| maximum unambiguous range | The greatest distance a pulse can travel and return before the next pulse is transmitted. R_max = c / (2*PRF), where c is the speed of light, PRF is pulse repetition frequency. |
| continental shelf break | Boundary zone between the continental shelf and slope. |
| reach | An expanse of a stream channel. |
| zooplankton | Small aquatic animals that are suspended or swimming in water. |
| resolution | The degree to which a radar distinguishes detail in a spatial pattern. |
| irrigation releases | Refers to those waters released from storage primarily for irrigation |
| ground water flow | The movement of water through openings in sediment and rock that occurs in the Zone of Saturation. |
| pseudo-cold front | A boundary between a supercell's inflow region and the rear-flank downdraft (or RFD) |
| mare clausum | A navigable body of water, such as a sea, that is under the jurisdiction of one national and closed to all others. |
| international date line | A line drawn almost parallel to the 180 degree longitude meridian that marks the location where each day officially begins |
| dryline storm | Generally, any thunderstorm that develops on or near a dry line |
| fallow | (1) Allowing cropland, either tilled or untilled, to lie idle during the whole or greater portion of the growing season |
| detour index | a measure of connectivity in a network which compares actual distance between vertices with the straight line distance. |
| thermal wind | It is a theoretical wind that blows parallel to the thickness lines, for the layer considered, analogous to how the geostrophic wind blows parallel to the height contours |
| severe weather analysis | This WSR-88D radar product provides 3 base products (reflectivity (SWR), radial velocity (SWV), and spectrum width (SWW)) at the highest resolution available along with radial shear (SWS). These products are mapped into a 27 nm by 27 nm region centered on a point which the operator can specify anywhere within a 124 nm radius of the radar. It is most effective when employed as an alert paired product with the product centered on alert at height that caused the alert. It is used to examine 3 base products simultaneously in a 4 quadrant display; and analyze reflectivity and velocity products at various heights to gain a comprehensive vertical analysis of the thunderstorm. |
| gps | An acronym for Global Positioning System. A network of satellites which provide extremely accurate position and time information |
| lakes | ponds and reservoirs, (see lotic). |
| sand filtration | Sand filtration is a frequently used and very robust method to remove suspended solids from water |
| tributary | A stream that contributes its water to another stream or body of water. |
| landfall | The coastline location where a tropical storm or hurricane moves from ocean onto land. |
| urban regeneration | the improvement of urban areas which have been in decline. |
| ground water prime supply | The long-term average annual percolation to the major ground water basins from precipitation falling on the land and from flows in rivers and streams |
| cbd | see central business district |
| organelles | in eukaryotic cells that carry out photosynthesis, where the chlorophyll pigments and related enzymes are located, specialized structures that carry out photosynthesis in plants and algae. |
| deglaciation | the removal of glacier cover (glacial retreat) when ablation outstrips accumulation. |
| pebble | a smooth, rounded fragment of rock that is larger than gravel but smaller than a boulder, in the range of 10-100mm in diameter. |
| world health organisation | an office of the UN which overseas international efforts to improve general health conditions and to address international threats such as pandemics |
| tropopause jets | Jet streams found near the tropopause |
| wetlands | Lands that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support and that, under normal circumstances, do support a prevalence of vegetation typically adapted for life in saturated soil conditions. |
| energy dissipater | A structure which slows fast-moving spillway flows in order to prevent erosion of the stream channel. |
| carbon dioxide | an atmospheric gas which has in modern times made up approximately 0.03% of the atmosphere by volume |
| weather map | Map that displays the condition of the physical state of the atmosphere and its circulation at a specific time over a region of the Earth. |
| oml | An Operations Manual Letter |
| mark-recapture study | A study that estimates population size by marking a segment of the population at one time and later measuring the ratio of marked animals to total animals. |
| weather forecast office | This National Weather Service office is responsible for issuing advisories, warnings, statements, and short term forecasts for its county warning area. |
| platform | A generic radar term, often used to encompass the pedestal and antenna assembly; sometimes including the radar control, display and analysis hardware and software as well. |
| tropical storm summaries | These are written by the Hydrometeorological Prediction Center* (HPC) after subtropical and names tropical cyclones have moved inland and advisories have been discontinued. These advisories will be terminated when the threat of flash flooding has ended or when the remnants of these storms can no longer be distinguished from other synoptic features capable of producing flash floods. Storm summaries will not be issued for storms that enter the coast of Mexico and do not pose an immediate flash flood threat to the coterminous United States. They will be initiated when and if flash flood watches are posted in the United States because of an approaching system. Storm summaries will continue to be numbered in sequence with tropical cyclone advisories and will reference the former storm's name in the text. Summaries will be issued at 0100, 0700, 1300, and 1900 Eastern Daylight Time (EDT). The only exception will be the first one in the series may be issued at a nonscheduled time. |
| main stem | The reach of a river/stream formed by the tributaries that flow into it. |
| impulse | See upper level system. |
| levée | the naturally raised bank of a river |
| channel efficiency | the ability of the channel to conserve energy that may otherwise be lost to friction |
| water supply outlook | A seasonal volume forecast, generally for a period centered around the time of spring snowmelt (e.g., April-July) |
| stream | also a relatively high flow as measured by either gauge height or discharge quantity. |
| contour interval | Difference in elevation between two successive contour lines |
| ultraviolet | Electromagnetic radiation that has a wavelength shorter than visible light and longer than x-rays |
| food chain | A sequence of organisms, each of which uses the next, lower member of the sequence as a food source. |
| dredging | Cleaning, deepening, or widening of a waterway, using a machine (dredge) that removes materials by means of a scoop or a suction device. |
| nutrients | Nitrogen and phosphorus occur naturally in water, soil and air |
| unconfined aquifer | Aquifer that is not restricted by impervious layers of rock. |
| thrust fault | A geologic fault where the hanging wall is forced over the foot wall. |
| oscillator | The general term for an electric device that generates alternating currents or voltages |
| rainfall frequency | The frequency, usually expressed in years, at which a given rainfall intensity and duration can be expected to be equaled or exceeded. |
| el nino | a periodic reversal in the usual pressure, wind and precipitation patterns of the tropical Pacific region which can have severe implications for human activity |
| anchor ice | Submerged Frazil ice attached or anchored to the river bottom, irrespective of its formation. |
| calcium carbonate | CACO3 - a white precipitate that forms in water lines, water heaters and boilers in hard water areas; also known as scale. |
| voc | Volatile Organic Compound |
| liquefaction | Temporary transformation of a soil mass of soil or sediment into a fluid mass |
| basal slipping | during summer time in warmer glacial areas, limited melting lubricates the base of the glacier allowing it to move more freely |
| area of influence | The area covered by the drawdown curves of a given pumping well or combination of wells at a particular time. |
| hanging valley | a small glacial valley entering a larger one someway up the side of the latter |
| resource management system | A combination of conservation practices identified by the primary use of land or water that, if effected, will at a minimum protect the resource base by meeting tolerable soil losses, maintaining acceptable water quality, and maintaining acceptable ecological and management levels for the selected resource use |
| pedon | A basic soil sampling unit |
| ecological diversity | See ecosystem diversity. |
| precambrian | a span of geologic time lasting from 4600m to 570m years ago. |
| forest management | the strict control of forest areas either to maintain them in a particular form (usually as forest parks for recreation and leisure) or for the purpose of farming the trees in a sustainable manner. |
| wastewater operations and maintenance | Actions taken after the construction of a Wastewater Treatment Plant to assure that the facilities will be operated, maintained, and managed to reach prescribed effluent levels in an optimum manner. |
| cirque | An amphitheater-like basin, high up on a mountain, that is the source area of a mountain glacier. |
| wind speed | The rate of the motion of the air on a unit of time |
| residue studies | Research which examines the recalcitrance, bioavailability, toxicity, solubility, etc |
| discontinuity | Comparatively large contrast in meteorological elements over a relatively small distance or period of time |
| vector | the unaffected carrier of a disease. |
| moderate breeze | Raises dust, loose paper; small branches moved; small waves, becoming longer; fairly frequent white caps appear on lakes. |
| pangaea | the name that Wegener gave to his proposed single supercontinent in his theory of continental drift. |
| sloping gage | A staff gage used to register the elevation of the water surface in a stream channel, conduit, reservoir or tank, with a scale graduated to represent vertical elevation |
| high water | (1) High tide |
| evaporation opportunity | The ratio of the rate of evaporation from a land or water surface in contact with the atmosphere, to the Evaporativity under existing atmospheric conditions |
| sima layer | The part of the crust that forms the ocean basins and lower layers in the crust and is composed of relatively heavy, basaltic rocks. |
| mesolow | A small scale low pressure center, ranging from the size of an individual thunderstorm to many tens of miles. |
| la niٌa | opposite of El Niٌo. |
| plankton | Tiny plants and animals that live in water. |
| orographic | Related to, or caused by, physical geography (such as mountains or sloping terrain). |
| ordovician | Geologic period that occurred roughly 438 to 505 million years ago |
| rating curve | A graph showing the relationship between the stage, usually plotted vertically (Y-axis) and the discharge, usually plotted horizontally (X-axis). |
| crossbreeding | "Reproduction between two distinct conspecific gene pools (compare with ""hybridization,"" which generally refers to reproduction between distinct species or higher taxa) |
| contamination | the introduction into water of sewage or other foreign matter that will render the water unfit for its intended use. |
| npp | see net primary productivity. |
| routing parameters | coefficients that, along with mathematical routing equations, can be used to estimate the attenuation and lag (time delay) associated with the movement of flow through a length of stream channel. |
| loess | in glacial environments there is a large amount of small, fine-grained material found in the outwash plain |
| mesonet | A regional network of observing stations (usually surface stations) designed to diagnose mesoscale weather features and their associated processes. |
| saline water | Water that contains more than 1,000 milligrams per liter of dissolved solids |
| tolerance range | Limits of tolerance a species has to an abiotic factor or condition in the environment. |
| impermeable | Material that does not permit fluids to pass through it. |
| sdm | Station Duty Manual |
| canal | A constructed open channel for transporting water. |
| permanent hardness | Water hardness that cannot be reduced or removed by heating the water, a reflection of the presence of dissolved calcium, magnesium, iron and other divalent metal ions |
| decomposer | A type of detritivore |
| indicator | Any biological entity or process, or community whose characteristics show the presence of specific environmental conditions or pollutants. |
| city action team | group of civil servants charged by 1980s and 1990s UK government with formulating solutions to inner city decay, particularly problems of unemployment and derelict land. |
| sporadic permafrost | where mean annual temperature is just below 0 |
| riffle | A reach of stream that is characterized by shallow, fast-moving water broken by the presence of rocks and boulders. |
| piping | The process by which water forces an opening around or through a supposedly sealed structure, such as a check dam or levee |
| boulder | a size-classification of rock pieces |
| national estuary program | a program established under the Clean Water Act Amendments of 1987 to conserve and manage estuaries, restore and maintain their chemical, physical, and biological integrity, and control point and nonpoint pollution sources. |
| perfected water permit | A permit issued after the permittee has initiated Beneficial Use of water in accordance with the terms and conditions of the conditional water permit |
| diastrophism | movements producing positional changes in the crust |
| rectangular coordinate system | System that measures the location of points on the Earth on a two-dimensional coordinate plane |
| flood-base discharge | A value of high flow usually computed during the first 5 years of station operation that, on the average, is exceeded about three times per year. |
| isopleth | A line connecting equal points of value |
| imf | see International Monetary Fund. |
| aggradation | deposition of load within river channels. |
| kame-terrace | Flat-topped ridges built of stratified sand and gravel deposed by a melt water stream between an ablating glacier or a stagnant ice lobe and a higher wall or lateral moraine |
| mineral | Any naturally occurring inorganic material with an orderly internal arrangement of atoms and specific physical and chemical properties. |
| canal freeboard | The amount of canal lining available above maximum design water depth. |
| ghetto | an area, usually in slum condition, where an ethnic group is dominant. |
| endangered species | one having so few individual survivors that the species could soon become extinct in all or part of its region. |
| incidental waste water reclamation | Treated waste water returned to fresh-water streams or other water bodies |
| percolation | movement of water into openings or pores in rock or soil and its downward movement by gravity; contributes to ground water replenishment. |
| funnel cloud | A tornado which is beginning its descent from the base of a cumulonimbus cloud |
| science | Science is a way of acquiring knowledge |
| developing | a term for a country or region that is enjoying ever increasing levels of economic development |
| ice jam | The accumulation of ice at a specific location along a stream channel |
| outburst flood | See Jokulhlaup. |
| fountainhead | The upper end of a confined-aquifer conduit, where it intersects the land surface. |
| cement grout | a mixture of water and cement in the ratio of not more than 5-6 gallons of water to a 94 pound sack of portland cement which is fluid enough to be pumped through a small diameter pipe. |
| outlet glaciers | Valley glaciers which permit ice to move from accumulation areas through mountainous terrain to the sea. |
| climax community | Plant community that no longer undergoes changes in species composition due to succession. |
| local flooding | Flood conditions which occur over a relatively limited area. |
| weirs | A regulating device in a sewer that permits dry weather flow in a combined sewer to enter an interceptor, but causes the storm flow to leap over for a controlled overflow. |
| translucent | Not transparent, but clear enough to allow light to pass through. |
| sahel | a region in the centre of West Africa on the margins of the Sahara and prone to drought. |
| perforation of wells | Holes in the casing of wells which allow water to flow into the well. |
| icebergs | Floating chunks of ice which calved off the glacier 5/6th underwater 1/6th above |
| cumulative impact analysis | A review of the cumulative environmental, social and economic impacts of proposed water projects and activities associated with development within an ecosystem or drainage area. |
| evapotranspiration | Combination of evaporation from free water surfaces and transpiration of water from plant surfaces to the atmosphere. |
| chinook wind | The name of a North American wind that occurs on the leeward side of mountains |
| melting | the changing of a solid into a liquid. |
| air transportatable mobile unit | A modularized transportable unit containing communications and observational equipment necessary to support a meteorologist preparing on-site forecasts at a wildfire or other incident. |
| stage iv precipitation processing | The fourth level of precipitation processing, performed automatically and/or interactively at NCEP |
| anadromous | Pertaining to fish that spend a part of their life cycle in the sea and return to freshwater streams to spawn. |
| water conserving irrigation system | Irrigation systems including a combination of drip irrigation, soaker hoses, bubblers, and low-trajectory spray heads for water distribution; zoning irrigation for different water-demand plant types; electronic timers with five-day programming and rain override devices, irrigation schedules for early morning watering every five to seven days; and soil moisture sensors. |
| occluded front | see occlusion. |
| rostow model of growth | after W.W |
| alluvium | A general term for detrital deposits made by stream processes on riverbeds, floodplains, and alluvial fans; esp |
| indicator tests | (Water Quality) Tests for a specific contaminant, group of contaminants, or constituent which signals the presence of something else |
| sea-level | average elevation of the surface of the oceans. |
| salt | A chemical class of ionic compounds formed by the combination of an acid and a base |
| critical size | The average size of the fish in a year-class at the time when the instantaneous rate of natural mortality equals the instantaneous rate of growth in weight for the year-class as a whole |
| pediment | concave, rock-cut, slope found between a cliff face and a valley floor in arid and semi-arid areas. |
| aerobic | life or processes that require, or are not destroyed by, the presence of oxygen. |
| laminar flow | parallel flow of different portions of an overall flow. |
| frequency band | A range of frequencies, between some upper and lower limit. |
| domestic consumption | The quantity, or quantity per capita, of water consumed in a municipality or district for domestic uses or purposes during a given period, generally one day |
| fill dam | Any dam constructed of excavated natural materials or of industrial waste materials. |
| decomposition | breakdown of organic material in the litter by detritivores |
| quantitative water assessment | Use of analyses of water properties and concentrations of compounds and contaminants in order to define water quality. |
| athalassohaline | water with a different proportion of dissolved salts than is usual in seawater. |
| headcutting | The action of a bedscarp or headward erosion of a locally steep channel or gully. |
| saltation | Transport of sediment initiated by moving air or water where particles move from a resting surface to the transport medium in quick continuous repeated cycles. |
| land | The entire complex of surface and near surface attributes of the solid portions of the surface of the earth, which are significant to man |
| recolonization | The reestablishment of an organism in a habitat that it previously occupied. |
| corrosive | A substance that deteriorates material, such as pipe, through electrochemical processes. |
| floodproofing | The process of protecting a building from flood damage on site |
| overflow standpipe | A standpipe located in a dam or other structure at an elevation that allows removal of excess water, preventing overflow. |
| occluded front | A transition zone in the atmosphere where an advancing cold air mass sandwiches a warm air mass between another cold air mass pushing the warm air into the upper atmosphere. |
| pipeline | A conduit of pipe, especially one used for the conveyance of water, gas, or petroleum products. |
| unit hydrograph theory | Unit Hydrograph Theory states that surface runoff hydrographs for storm events of the same duration will have the same shape, and the ordinates of the hydrograph will be proportional to the ordinates of the unit hydrograph |
| summer solstice | The summer solstice denotes the first day of the summer season |
| river cliff | steep slope on the outer bend of a river where erosion allows for undercutting. |
| brackish ice | Ice formed from Brackish water. |
| public utility district | A government unit established by voters of a district to supply electric or other utility service. |
| snowmelt flooding | Flooding caused primarily by the melting of snow. |
| permanent monument | Fixed monuments or reference markers placed away from the dam which allow movements in the horizontal and vertical Control Points on the dam to be observed by using accurate survey procedures. |
| variable ceiling | Occurs when the height of a ceiling layer increases and decreases rapidly, The ascribed height is the average of all the varying values. |
| vertical aerial photograph | Photograph taken from a overhead or near overhead angle from a platform in the atmosphere. |
| automated event-reporting gage | River stage gages, IFLOWS pressure transducer type gages can be programmed to report if water surface rises or falls by a predetermined amount |
| kinetic rate coefficient | A number that describes the rate at which a water constituent such as a biochemical oxygen demand or dissolved oxygen rises or falls. |
| upstream | Toward the source of the flow, or located in the area from which the flow is coming. |
| non-renewable resource | Resource that is finite in quantity and is being used faster than its ability to regenerate itself. |
| anemophobia | The fear of air drafts or wind. See Ancraophobia. |
| hyporheic zone | the zone under a river or stream comprising substrate whose interstices are filled with water. |
| attenuation | Any process in which the flux density (power) of a beam of energy is dissipated. |
| inceptisols | Soil order (type) of the United States Natural Resources Conservation Service Soil Classification System |
| net rainfall | The portion of rainfall which reaches a stream channel or the concentration point as direct surface flow. |
| enrichment | the addition of nutrients such as nitrogen and phosphorous from wastewater effluent or agricultural runoff to surface water |
| fault | a break in the continuity of rock strata |
| magnetosphere | Zone that surrounds the Earth that is influenced by the Earth's magnetic field. |
| nocturnal thunderstorms | Thunderstorms which develop after sunset |
| channel density | The ratio of the length of stream channels in a given basin to the area of the basin, expressed in feet per acre (meters per hectare). |
| vertical integration | when companies at different stages of the same industry merge or buy one another |
| self-employment | work as a freelancer or owner operator. |
| contract farming | where large agribusinesses, usually food processing companies or supermarket chains, contract farmers to provide them with particular types of produce. |
| coal | Sedimentary rock composed of the compacted, lithified and altered remains of plants |
| dambrk | The Dam Break Forecasting Model. |
| resources | That which is, or may be, readily available as a source of supply or support |
| carbonates | Chemical compounds related to carbon dioxide. |
| leaf area index | A measure of the total area of leaves, twigs, stems, etc |
| blowing snow | Wind-driven sand that significantly reduces surface visibility to less than 7 miles. |
| ceiling | The height of the lowest layer of broken or overcast clouds. |
| crest | (1)The highest stage or level of a flood wave as it passes a point |
| adult equivalent population | The number of fish that would have returned to the mouth of the Columbia River in the absence of any prior harvest. |
| geomorphology | That branch of both physiography and geology that deals with the form of the earth, the general configuration of its surface, and the changes that take place in the evolution of land forms |
| sandur | see outwash plain. |
| spectral density | A radar term for the distribution of power by frequency. |
| transparent | A condition where a material is clear enough not to block the passage of radiant energy, especially light. |
| roml | Regional Operations Manual Letter |
| whole-effluent toxicity | the aggregate toxic effect of an effluent measured directly by a toxicity test. |
| gabbro | An intrusive igneous rock that develops from mafic magma and whose mineral crystals are coarse |
| submergent plants | see aquatic plants. |
| nuée ardente | the superheated gases found in a pyroclastic cloud. |
| ftp | A method of data transfer that can take place between Frame Relay Networks, and Workstations. |
| afterbay | The tail race of a hydroelectric power plant at the outlet of the turbines |
| lava | molten rock flowing on the surface |
| alluvium | sediments deposited by erosional processes, usually by streams. |
| altocumulus | These clouds are composed of mainly water |
| reservoir surface area | The surface area of a reservoir when filled to the normal pool or water level. |
| facultative bacteria | Bacteria that can live under aerobic or anaerobic conditions. |
| erosion | the wearing away of the land surface by wind, water, ice or other geologic agents |
| hydrograph | A chart that measures the amount of water flowing past a point as a function of time. |
| streambank protection works | Structure placed on or near a distressed stream bank to control bank erosion or prevent failure. |
| subsidence | a dropping of the land surface as a result of ground water being pumped |
| incised stream | one which has cut deeply down into the landscape. |
| river basin | the area drained by a river and its tributaries. |
| ts | Total Solids |
| stress | Force applied to an object per its unit area |
| toe drain | A drain which carries seepage away from the dam and can allow seepage quantities to be measured. |
| pool/riffle ratio | The ratio of surface area or length of pools to the surface area or length of riffles in a given stream reach; frequently expressed as a relative percentage of each category |
| tropical savanna | See savanna. |
| controlled drainage | (Irrigation) Regulation of the water table to maintain the water level at a depth favorable for optimum crop growth. |
| armoring | the formation of an erosion-resistant layer of relatively large particles on a streambed or bank resulting from removal of finer particles by erosion. |
| plate tectonics | refers to the folding and faulting of rock and flow of molten lava involving lithospheric plates in the earth's crust and upper mantle. |
| arroyo | A water-carved channel or gully in arid country, usually rather small with steep banks, dry most of the time, due to infrequent rainfall and the shallowness of the cut which does not penetrate below the level of permanent ground water. |
| fish guidance efficiency | The proportion of juvenile fish passing into the turbine intakes that are diverted away from the turbines and into bypass facilities. |
| kilowatt | The electrical unit of power which equals 1,000 watts or 1.341 horsepower. |
| wind shift | A change in wind direction of 45 degrees or more in less than 15 minutes with sustained wind speeds of 10 knots or more throughout the wind shift. |
| trihalomethanes | are formed when water containing organic materials is disinfected with chlorine, these compounds are toxic, the formation of these compounds can be minimized by filtering or otherwise removing the organic compounds before chlorination. |
| pulse repetition frequency | The number of pulses transmitted per second by a radar. Typical PRF's may range from 300-1200 Hz |
| progradation | The natural extension of a shoreline seaward. |
| acre-foot | The volume of water that will cover one acre to a depth of 1 foot. |
| osmosis | The selective passage of liquids through a semipermeable membrane in a direction which tends to make concentrations of all substances on one side of the membrane equal to those on the other side |
| brisk | 15 to 25 mph winds |
| phenogram | A graphical means of depicting genetic relationships among populations in the form of a branching tree (also often referred to as a dendrogram) |
| biota | the plant (flora) and animal life (fauna) of a region or ecosystem. |
| council housing | in the UK, housing funded by local government with help from central government |
| gallery | A passageway within the body of a dam or abutment. |
| furrow dams | Small earth ridges or rows used to impound water in furrows. |
| range | in human geography, the maximum distance that people are willing to travel to obtain a good or service |
| epicenter | Surface location of an earthquake's focus. |
| empirical | (Statistics) Based on experience or observations, as opposed to theory or conjecture. |
| ground water registration | A statement made by a well owner registering the Beneficial Use of ground water. |
| potable water | Water that is safe for drinking and cooking. |
| wind erosion | the removal of particles from the surface by wind, and the degrading processes caused when these particles are thrown against rock. |
| gravitational head | Component of total Hydraulic Head related to the position of a given mass of water relative to an arbitrary datum. |
| bifurcation ratio | Quantitative ratio determined between the parts of systems that display branching |
| mean lower low water | The average height of the lower of two unequal daily low tides over 19 years |
| freezing rain | Rain that falls as liquid and freezes upon impact to form a coating of glaze on the colder ground or other exposed surfaces |
| robinson projection | Map projection system that tries to present more accurate representations of area |
| i | i = square root of (-1); a mathematical operator which, when multiplied with a number or parameter, has the effect of turning the vector 90 degrees counter clockwise from its original position |
| headwater basin | A basin at the headwaters of a river |
| freezing | The change in state of matter from liquid to solid that occurs with cooling |
| backwater pools | A pool type formed by an eddy along channel margins downstream from obstructions such as bars, rootwads, or boulders, or resulting from backflooding upstream from an obstructional blockage |
| relative humidity | ratio of water vapour in the air compared to the maximum possible at that temperature and pressure, expressed as a percentage. |
| recurrence interval | The average amount of time between events of a given magnitude |
| unconfined aquifer | an aquifer that discharges and recharges with an upper surface that is the water table unsaturated zone - the subsurface zone, usually starting at the land surface and ending at the water table, that includes both water and air in spaces between rocks usable storage capacity - the quantity of groundwater of acceptable quality that can be economically withdrawn from storage |
| geothermal energy | Heat energy derived from the Earth's interior. |
| correlation | the degree of association between two sets of data either positive -as one increases so does the other -or negative -as one increases the other decreases |
| safetynet | A satellite based part of the Global Maritime Distress and Safety System (GMDSS) for automatically disseminating safety information, including weather warnings and forecasts, to mariners almost anywhere on the world's oceans. |
| cold core low | A low pressure area which is colder at its center than at its periphery |
| liner | (1) (Water Quality) A low-permeability material, such as clay or high-density polyethylene, used for the bottom and sides of a landfill |
| diffuser | A component of the ozone contacting system in an ozone generator that allows diffusion of an ozone containing gas. |
| unit hydrograph duration | The time over which one inch of surface runoff is distributed for unit hydrograph theory. |
| ferc | Federal Energy Regulatory Commission; formerly the Federal Power Commission. |
| wetland | an area of land that is permanently saturated up to or very near to the surface. |
| thermometer | An instrument used for measuring temperature |
| dry deposition | The transport of gases and minute liquid and solid particles from the atmosphere to the ground surface without the aid of precipitation or fog |
| attenuation | a) Radar definition: It refers to the reduction of the radar beam power due to the reflection or absorption of energy when it strikes a target |
| transmissivity | refers to the rate at which limestone allows the transmission of water |
| geyser | a thermal spring that erupts intermittently and to different heights above the surface of the Earth; eruptions occur when water deep in the spring is heated enough to turn into steam, which forces the liquid water above it out into the air glacial striations - lines carved into rock by overriding ice, showing the direction of glacial movement glacier - a large mass of ice formed on land by the compacting and recrystallization of snow; glaciers survive from year to year, and creep downslope or outward due to the stress of their own weight groundwater - water under ground, such as in wells, springs and aquifiers gullying - small-scale stream erosion |
| tidal range | the difference in height between low tide and high tide. |
| dambrk | The Dam Break Forecasting Model. |
| site plan review | Site Plan Review is a regulatory process in which the City seeks to ensure that land being developed for commercial, industrial, or residential use is developed, or redeveloped, and operated in a way that complies with City codes and is compatible with the surrounding community. |
| ambient background concentration | a representative concentration of the water quality in a receiving water body, determined from monitoring |
| subsurface seepage | Subsurface seepage is movement of water through soils from above-lying bodies of water. |
| final clarifier | (Water Quality) A gravitational settling tank installed as part of some wastewater treatment plants and placed after the biological treatment step |
| watch status reports | This product lets the NWFO know of the status of the current severe weather watch (Tornado or Severe Thunderstorm). During the severe weather watch, the Storm Prediction Center (SPC) will issue these reports periodically. These reports will describe, in plain language, the current evaluation of the severe weather situation and whether the watch will expire or be reissued. A status report is not issued if a cancellation or replacement has been issued at least 1 hour prior to the expiration time of the original watch. |
| rock slide | Large scale mass movement of rock materials downslope. |
| activated sludge | Product that results when primary effluent is mixed with bacteria-laden sludge and then agitated and aerated to promote biological treatment, speeding the breakdown of organic matter in raw sewage undergoing secondary waste treatment. |
| industrial revolution | Major change in the economy and society of humans brought on by the use of machines and the efficient production of goods |
| chemical weathering | Breakdown of rock and minerals into small sized particles through chemical decomposition. |
| closed basin | A basin draining to some depression or pond within its area, from which water is lost only by evaporation or percolation |
| large woody debris | Pieces of wood larger than 10 feet long and 6 inches in diameter, in a stream channel. |
| genetic conservation | The preservation of genetic resources in breeding populations. |
| system | A system is a set of interrelated components working together towards some kind of process. |
| tributary | a smaller river or stream that flows into a larger river or stream |
| mesocyclone | This WSR-88D radar product displays information regarding the detection of the following 3 types of azimuthal shear patterns: |
| deep well | A well whose pumping head is too great to permit use of a suction pump. |
| methane | a naturally occurring gas which is associated with decomposition and with oil deposits |
| lysimeter | A device to measure the quantity or rate of downward water movement through a block of soil usually undisturbed, or to collect such percolated water for analysis as to quality. |
| reservoir volume | The volume of a reservoir when filled to normal pool or water level. |
| concrete | A mixture of water, cement, sand, and pebbles |
| ecosystem diversity | The variety of unique biological communities found on the Earth |
| rain gauge | Instrument that measures the rain that falls at a location over a period of time. |
| angler-day | The time spent fishing for any part of a day by one person. |
| buoyancy | The tendency of a body to float or rise when submerged in a fluid. |
| holding time | the maximum amount of time a sample may be stored before analysis. |
| perennial stream | A stream that flows from source to mouth throughout the year. |
| cape | An acronym for Convective Available Potential Energy. See Convective Available Potential Energy. |
| macroinvertebrate | Invertebrates visible to the naked eye, such as insect larvae and crayfish. |
| chloramines | A chemical complex that consists of chlorine and ammonia |
| artesian zone | a zone where water is confined in an aquifer under pressure so that the water will rise in the well casing or drilled hole above the bottom of the confining layer overlying the aquifer. |
| basalt aquifers | Aquifers found in basalt rock in areas of past volcanic activity, particularly in the Pacific Northwest region of the United States and in Hawaii. |
| routing | The methods of predicting the attenuation of a flood wave as it moves down the course of a river. |
| fish passage efficiency | The proportion of juvenile fish passing a project through the spillway, sluiceway, or juvenile bypass system, as opposed to passing through the turbines. |
| blowing dust | Dust that is raised by the wind to heights of six feet or greater |
| antenna | A transducer between electromagnetic waves radiated through space and electromagnetic waves contained by a transmission line. |
| global warming | An overall increase in world temperatures which may be caused by additional heat being trapped by greenhouse gases. |
| riparian area | An area of land and vegetation adjacent to a stream that has a direct effect on the stream |
| recessional moraines | End moraines created during occasionally stabilization of the ice front during retreat. |
| attraction | Drawing fish to dam fishways or spillways through the use of water flows. |
| pedogenesis | Process of soil formation. |
| rainsplash | Soil erosion caused from the impact of raindrops. |
| mangrove swamp | a type of wetland forest made up of salt-adapted trees found in the inter-tidal zone of tropical coast areas |
| sea breeze | A diurnal coastal breeze that blows onshore, from the sea to the land |
| berm | (1) A narrow ledge or path as at the top or bottom of a slope, stream bank, or along a beach |
| salinity | A measure of the quantity of dissolved salts in sea water |
| buffer strip | A barrier of permanent vegetation, either forest or other vegetation, between waterways and land uses such as agriculture or urban development, designed to intercept and filter out pollution before it reaches the surface water resource. |
| density of snow | The ratio, expressed as a percentage, of the volume which a given quantity of snow would occupy if it were reduced to water, to the volume of the snow |
| acid aerosol | Very small liquid or solid particles that are acidic and are small enough to become airborne. |
| emergence | The process during which fry leave their gravel spawning nest and enter the water column. |
| cyclogenesis | Process of cyclone formation, maturation, and death. |
| output | Movement of matter, energy, or information out of a system |
| nadir | Refers to a low or the lowest point, as the lowest point of a lake or other body of water attained of a certain period of time (period of record). |
| ground water runoff | That part of the runoff which has passed into the ground, has become ground water, and has been discharged into a stream channel as spring, or seepage water. |
| draft | Release of water from a storage reservoir. |
| drought | Abnormal dry weather for a specific area that is sufficiently prolonged for the lack of water to cause serious hydrological imbalance. |
| forebay | The part of a dam's reservoir that is immediately upstream from the powerhouse. |
| o horizon | Topmost layer of most soils |
| field diversion | An interception channel near the contour to carry runoff to a waterway |
| regolith | Loose layer of rocky material overlying bedrock. |
| endangered species act | A 1973 Act of Congress that mandated that endangered and threatened species of fish, wildlife, and plants be protected and restored. |
| longshore current | A water current that moves parallel to the shoreline. |
| pascal's law | When an external pressure is applied to any confined fluid at rest, the pressure is increased at every point in the fluid by the amount of external pressure applied |
| rockfill dam | An embankment dam of earth or rock in which the material is placed in layers and compacted by using rollers or rolling equipment. |
| upstream blanket | An impervious layer placed on the reservoir floor upstream of a dam |
| dust bowl | in the USA, the area of degradation of the agricultural land of the High Plains region in the 1930s when overexploitation of the land exposed the area to a higher impact when drought arrived |
| plan position indicator | Also known as a PPI Scope, it is a radar indicator scope displaying range and azimuth of targets in polar coordinates. |
| streams | rivers, lakes and reservoirs, a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge, large drainage basins contain many smaller drainage sub-basins, (see watershed). |
| pediment | A gradually sloping bedrock surface located at the base of fluvial-eroded mountain range |
| benthic deposits | Bottom accumulations which may contain bottom-dwelling organisms and/or contaminants in a lake, harbor, or stream bed. |
| municipal sewage | Liquid wastes, originating from a community |
| espinit | ESP Initialization Program |
| peak wind speed | The maximum instantaneous wind speed since the last observation that exceeded 25 knots. |
| land use | the dominant activity taking place on an area of land. |
| contour strip farming | A kind of contour farming in which row crops are planted in strips, between alternating strips of close-growing, erosion-resistant forage crops. |
| filter strip | A strip or area of vegetation used for removing sediment, organic matter, and other pollutants from runoff and waste water. |
| live capacity | The total amount of storage capacity available in a reservoir for all purposes, from the dead storage level to the normal water or normal pool level surface level |
| polder | reclaimed land created by the construction of an embankment or dyke to hold back water that would otherwise flood the new surface. |
| cwm | see corrie |
| isobaric surface | A surface along which the atmospheric pressure is everywhere equal. |
| economic growth | the growth of gross national product over time |
| cumulonimbus cloud | They are the ultimate manifestation of instability |
| flood damage | The direct and indirect economic loss caused by floods including damage by inundation, erosion, or sediment deposition |
| truncate | In glaciers, truncated surfaces occur along the sides of valley glaciers, beneath mountain and continental glaciers, and across the tops of sediments previously laid down. |
| lagoon | (1) A shallow lake or pond, especially one connected with a larger body of water |
| anvil zits | Slang for frequent (often continuous or nearly continuous), localized lightning discharges occurring from within a thunderstorm anvil. |
| biosphere | Part of the Earth where life is found |
| gendarmes | Ice towers such as seracs and penitantes. |
| x-rays | Very energetic electromagnetic radiation with wavelengths intermediate between 0.01 and 10 nanometers (0.1-100 Angstroms) or between gamma rays and ultraviolet radiation. Essentially all X-Rays from space are absorbed in the Earth's upper atmosphere. |
| nearest neighbour analysis | a measure of how clustered or evenly spaced a distribution of points on a plane is. |
| inflow | Rainwater entering the sewerage or wastewater system from areas not intended to drain to the sewerage or wastewater system. |
| map | The average rainfall over a given area, generally expressed as an average depth over the area. |
| egg take | The number of eggs taken at hatcheries when adult salmon and steelhead are spawned. |
| coliform bacteria | Bacteria that serve as indicators of pollution and pathogens when found in water |
| detergent | A water-soluble cleansing agent, other than soap. |
| zone of saturation | The zone in which all the connected interstices or voids in permeable rock or soil formation are filled with water under pressure equal to or greater than atmospheric pressure. |
| fujita scale | A scale used to classify the strength of a tornado |
| estimate | A statement of the value of a quantity or function based on a finite number of samples. |
| hydraulic conductivity | The rate at which water can move through a permeable medium. |
| plankton | microscopic floating plant and animal organisms of lakes, rivers, and oceans. |
| hydrologic basin | the drainage area upstream from a given point on a stream. |
| sinusoidal equal-area projection | Map projection that represents areas in their true form on a two-dimensional map |
| stream bank | Sides of the stream channel. |
| population parameter | A value used to represent a certain quantifiable characteristic of a population |
| nutrient | Any substance that promotes growth with living organisms |
| employment structure | the percentage of people employed in each of the four major employment sectors. |
| emergent plants | see aquatic plants. |
| dust plume | A non-rotating "cloud" of dust raised by straight-line winds. Often seen in a microburst or behind a gust front. |
| root pressure | Pressure exerted in the roots of plants as the result of Osmosis, causing exudation from cut stems and Guttation of water from leaves. |
| ksfd | A volume of water equal to 1,000 cubic feet of water flowing past a point for an entire day |
| hyetograph | A graphical representation of rainfall intensity with respect to time. |
| max parcel level | This signifies the highest attainable level that a convective updraft can reach; therefore, it is a good indication of how tall a thunderstorm may reach. |
| nocturnal jet | This wind speed maximum occurs just above the nocturnal inversion at night |
| treatment | Any method, technique, or process designed to remove solids and/or pollutants from wastestreams and effluents. |
| flood plain | A natural area adjacent to a stream or river where water overflows during extreme storm events |
| open channel system | A system of conveyance channels where the top flow boundary is a free surface (e.g., canal systems). |
| automatic controller | A solid state timer capable of operating valve stations to set the days and length of time water is applied. |
| absolute recruitment | The number of fish which grow into the catchable size range in a unit of time (usually a year). |
| time-height display | An intensity-modulated display which has height as the vertical coordinate and time as the horizontal coordinate; usually used for vertically-pointing antennas only. |
| rift valley | a valley created by the subsidence of land between two parallel faults undergoing tensile forces which pull them apart. |
| tornado | A violently rotating column of air in contact with and extending between a convective cloud and the surface of the earth |
| base flow | Sustained or fair-weather runoff--generally that portion of the streamflow derived from discharging ground water or other delayed sources such as lakes or snow fields. |
| loam | a soil having roughly equal proportions of clay, sand and silt. |
| maritime effect | The effect that large ocean bodies have on the climate of locations or regions |
| bacteria | Microscopically small single-cell organisms, that reproduce by fission of spores. |
| day length | Period of time for a location on the Earth when insolation from the Sun is being received. |
| salinisation | the deposition of salts at the surface of a soil in areas where evapotranspiration exceeds precipitation so drawing water up through the soil and with it salts that had been dissolved in it. |
| easterlies | Usually applied to the broad patterns of persistent winds with an easterly component, such as the easterly trade winds. |
| pressure gage | An instrument, graduated in any units desired, for registering the pressure of solids, liquids, or gases. |
| littoral | most properly the area at a coast between the highest and lowest tides |
| chemical weathering | a weathering process in which the resultant material is chemically different to the original rock |
| land subsidence | The sinking or settling of land to a lower level in response to various natural and man-caused factors, for example: [1] earth movements; [2] lowering of fluid pressure (or lowering of ground water level); [3] removal of underlying supporting materials by mining or solution of solids, either artificially or from natural causes; [4] compaction caused by wetting (Hydrocompaction); [5] oxidation of organic matter in soils; or [6] added load on the land surface |
| dense fog advisory | Advisory issued when fog reduces visibility to 1/8 mile or less, creating possible hazardous conditions. |
| head race | A channel which directs water to a water wheel; a forebay. |
| euphotic zone | surface layer of an ocean, lake, or other body of water through which light can penetrate |
| mistral | the French term for a katabatic wind. |
| continental climate | typical climates of interior areas well away from the influence of the sea |
| saltwater intrusion | The invasion of saltwater into freshwater aquifers in coastal and inland areas |
| spc mesoscale discussions | A mesoscale discussion issued by the Storm Prediction Center (SPC) in Norman, Oklahoma as a routine/daily, but nonscheduled, short-term (0-6 hours) product to communicate the current judgment of the SPC to the user community. It also provides guidance on other short-term mesoscale phenomenon that may be of significance (for example heavy snow potential, the formation of dense fog, etc.). |
| buried manhole | A manhole that is not visible at ground surface. |
| first world | old term for the Economically More Developed World. |
| nutrients | nitrates and phosphates, usually resulting in an increase in biomass and productivity, (see oligotrophic). |
| palsa | A mound of peat that develops as the result of the formation of a number ice lenses beneath the ground surface |
| topographic map | Map that displays topography through the use of elevation contour lines |
| peak gust | The highest instantaneous wind speed observed or recorded. |
| delta | A delta is a low, watery land formed at the mouth of a river |
| clear-cut | A harvest in which all or almost all of the trees are removed in one cutting. |
| incubation | The period of time from egg fertilization until hatching. |
| hydrograph | A graphic representation or plot of changes in the flow of water or in the elevation of water level plotted against time |
| pastoral farming | the rearing of animals for meat, milk, wool, skins etc. |
| minimum flow level | The level of stream flow sufficient to support fish and other aquatic life; to minimize pollution; or to maintain other instream uses such as recreation and navigation. |
| speciation | The natural process by which new species evolve from existing ones. |
| approach velocities | Water velocities at or near the face of a fish screen. |
| temperate climate | Climates with distinct winter and summer seasons, typical of regions found between the Tropics of Cancer and Capricorn and the Arctic and Antarctic Circles |
| trickle irrigation | method in which water drips to the soil from perforated tubes or emitters. |
| sexual reproduction | Any process of reproduction that does involve the fusion of gametes. |
| groundwater flow | the flow of water through the groundwater store. |
| lap | (1) To wash or slap against with soft liquid sounds |
| ground ice | General term used to describe all bodies of ice in the ground surface of the permafrost layer |
| ogee | A reverse curve, shaped like an elongated letter S |
| gage height | The water-surface elevation referred to some arbitrary gage datum |
| lentic system | a nonflowing or standing body of fresh water, such as a lake or pond |
| capillary forces | forces that cause ground water to rise above the surface of the saturated zone into the spaces between soil particles in the unsaturated zone. |
| pressure unsteady | A pressure that fluctuates by 0.03 inch of mercury or more from the mean pressure during the period of measurement. |
| zone forecast product | This National Weather Service product will provide the general public with a clear statement of the expected weather conditions within a given county or set of counties. The forecast will include: sky condition, temperature, type of precipitation and its probability, and wind direction and speed (this is normally given only during the first 2 periods of the forecast). |
| significant wave height | The average height (trough to crest distance) of the one-third highest waves. An experienced observer will most frequently report heights equivalent to the average of the highest one-third of all waves observed. |
| effective porosity | The ratio, usually expressed as a percentage, of the volume of water or other liquid which a given saturated volume of rock or soil will yield under any specified hydraulic condition, to the given volume of soil or rock. |
| perched groundwater | Water in a saturated zone of material underlain by a relatively impervious stratum which acts as a barrier to downward flow and which is separated from the main ground water body by a zone of unsaturated material above the main ground water body. |
| continental effect | The effect that continental surfaces have on the climate of locations or regions |
| li | An acronym for Lifted Index. See Lifted Index. |
| imhoff cone | A clear, cone-shaped container used to measure the volume of settleable solids in a specific volume of water. |
| isobath | A contour (or surface) of equal depth in a body of water. It is plotted on a bathymetric chart. It is also a contour or surface of equal depth of the water table below the ground surface. |
| ground water outflow | That part of the discharge from a drainage basin that occurs through the ground water |
| floodplain | The flat or nearly flat land along a river or stream that is covered by water during a flood. |
| p-wave | a seismic wave released during an earthquake which travels in a collision fashion and can thus travel through gases, liquids and solids. |
| raw water | Intake water prior to treatment or use for drinking water. |
| likely | A National Weather Service precipitation descriptor for a 60 or 70 percent chance of measurable precipitation (0.01 inch). When the precipitation is convective in nature, the term numerous will occasionally be used. See Precipitation Probability (PoP). |
| ozone action day | A "heads-up" message issued by the Department of Natural Resources (DNR) through the National Weather Service when ozone levels may reach dangerous levels the next day. This message encourages residents to prevent air pollution by postponing the use of lawn mowing, motor vehicles, boats, as well as filling their vehicle gas tanks. |
| outflow channel | A natural stream channel which transports reservoir releases. |
| headwater | (1) The source and upper reaches of a stream; also the upper reaches of a reservoir |
| sewage | Waste fluid in a sewer system. |
| chromosphere | A thin layer of relatively transparent gases above the photosphere of the sun |
| urban flash flood guidance | A specific type of flash flood guidance which estimates the average amount of rain needed over an urban area during a specified period of time to initiate flooding on small, ungaged streams in the urban area. |
| backwater curve | The longitudinal profile of the surface of a liquid in a non-uniform flow in an open channel, when the water surface is not parallel to the invert owing to the depth of water having been increased by the interposition of an obstruction such as a dam or weir |
| exfoliation dome | A physical weathering feature associated with granite that is the result of the erosion of overburden material and pressure-release |
| dam | A concrete or earthen barrier constructed across a river and designed to control water flow or create a reservoir. |
| mesoscale | The scale of meteorological phenomena that range in size from several kilometers to around 100 kilometers |
| inferential statistics | Statistical test that makes generalizations about a population based of the numeric information obtained from a sample based on the laws of probability. |
| national response center | The 24-hour a day federal operations center receives notifications of all releases of oil and hazardous substances into the environment |
| gentrification | the renovation of the housing fabric in an old, usually inner-city area, when more affluent groups displace lower income groups en masse over a relatively short period of time |
| mariculture | The cultivation of marine organisms for use as a food resource. |
| price current meter | A current meter with a series of conical cups fastened to a flat framework through which a pin extends |
| instream use | use of water that does not require withdrawal or diversion from its natural watercourse; for example, the use of water for navigation, recreation, and support of fish and wildlife. |
| evaporation | the transformation of water liquid to water gas (or vapour) by energy from heat or air movements. |
| scour | To remove or sweep away material. |
| pressure sewers | A system of pipes in which water, wastewater, or other liquid is pumped to a higher elevation. |
| mesic | Moderately wet. |
| direct run-off | Water that flows from the ground surface directly into streams, rivers, and lakes. |
| process wastewater | Any water that comes into contact with any raw material, product, byproduct, or waste. |
| valley glacier | a glacier which extends from a larger body of ice, often in a corrie, and moves downslope, initially following existing river channels but increasingly cutting its own bigger, straighter trough. |
| dissolved oxygen | amount of oxygen gas dissolved in a given quantity of water at a given temperature and atmospheric pressure |
| levee | An embankment constructed to prevent a river from overflowing (flooding). |
| cumulus mediocris | Cumulus clouds characterized by moderate vertical development with upper protuberances not very marked in appearance |
| ground water hydrology | The branch of Hydrology that deals with ground water; its occurrence and movements, its replenishment and depletion, the properties of rocks that control ground water movement and storage, and the methods of investigation and utilization of ground water |
| feldspar | the generic name for a group of minerals made up of aluminium silicate along with calcium, potassium or sodium |
| convection | Convection involves the transfer of heat energy by means of vertical mass motions through a medium. |
| usable stock | The number or weight of all fish in a stock that lie within the range of sizes customarily considered usable (or designated so by law) |
| consolidated formation | naturally occurring geologic formations that have been lithified (turned to stone) |
| ray | One of the supports of a fin. |
| prior appropriation doctrine | the system for allocating water to private individuals used in most Western states |
| inter-tidal zone | the land between the low tide mark and high tide mark |
| fluid | Having particles which easily move and change their relative position without a separation of the mass, and which easily yield to pressure; capable of flowing; liquid or gaseous. |
| psychrophobia | The fear of the cold. |
| dead storage | The volume in a reservoir below the lowest controllable level. |
| radiation fog | a fog formed when warm moist air is cooled to the dew point by the ground. |
| genetically modified crop | the placing of a gene from one organism into another so that the latter can take on a quality of the former that it doesn otherwise have |
| resident sockeye salmon | The progeny of anadromous sockeye salmon parents that spend their adult life in freshwater and are observed together with their anadromous siblings on the spawning grounds. |
| roll cloud | A dense, cigar shaped cloud found above the gust front of a thunderstorm |
| elastic limit | Maximum level of elastic deformation of a material without rupture. |
| spillway | the channel or passageway around or over a dam through which excess water is diverted. |
| liter | The basic unit of measurement for volume in the Metric System equivalent to 0.001 cubic meters (10-3 m3); also equal to 61.025 cubic inches or 1.0567 liquid quarts. |
| national priorities list | EPA's list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial action under Superfund |
| persistence | Refers to the length of time a compound stays in the environment, once introduced. |
| channel stabilization | Erosion prevention and stabilization of velocity distribution in a channel using jetties, drops, revetments, vegetation, and other measures. |
| surfactant | A detergent compound that promotes lathering. |
| monostatic radar | This is a radar that uses a common antenna for both transmitting and receiving. |
| ice blocks | Chunks of the glacier remain as ice blocks after glacial outburst floods which may remain as kettle lakes. |
| heavy snow discussion | This message discusses the potential for heavy snowfall in the contiguous United States. The threshold value in this product for heavy snow is 4 inches or more in a 12-hour period. However, this product discusses all potential snowstorms, including those not expected to attain the threshold. Although the focus is on the meteorological reasoning for the forecast, the impact of numerical model forecasts and model differences are also explained. This narrative is a 3-part product. The first part is a synopsis and short-term forecast for the few hours before the main 12-hour forecast period. The second part includes the 12-hour forecast and the accompanying meteorological reasoning. The third part is a meteorological discussion of the outlook period that extends 12 hours beyond the forecast period. There is an accompanying graphic for each forecast under the AFOS identifier 93S. The HSD is issued 4 times a day from September 15 to May 15 and other times as needed as described below. A revised or amended HSD may be issued as necessary. Routine issuances are as follows: |
| swell | A relatively smooth ocean wave that travels some distance from the area of its generation. |
| cirque | Glacially eroded rock basin found on mountains |
| density | Mass divided by the same unit system in volume stated as "pounds per cubic inch," "pounds per cubic foot," or "grams per cubic centimeter (cc)" |
| runoff percentage | Runoff expressed as a percentage of the precipitation. |
| breakpoint chlorination | addition of chlorine to the point where all organic matter and ammonia compounds have been destroyed and any additional chlorine becomes a free chlorine residual available for disinfection. |
| field capacity | the amount of water held in soil against the pull of gravity. |
| stratified drift | Sediments laid down by glacial meltwater show unconfined sorting. |
| surface water | water on the Earth's surface, such as in river, stream, lakes and reservoirs. (Ground water would be under the surface.) |
| topsoil | the top layer of soil; topsoil can grow better crops partly because it has more organic matter (humus), allowing it to hold more water than lower soil layers toxic - poisonous; harmful to living organisms transpiration - evaporation of water through the leaves of plants trihalomethanes, trichloroethylene, perchloroethylene - organic compounds which may be harmful to health at certain levels in drinking water turbidity - the state of having sediment or foreign particles suspended or stirred up in water |
| mica | Silicate mineral that exhibits a platy crystal structure and perfect cleavage |
| cross flow filtration | A process that uses opposite flows across a membrane surface to minimize particle build-up. |
| law of the minimum | This biological law suggests that organisms are normally limited by only one single physical factor that is in shortest supply relative to demand. |
| rangeland | Land-use type that supplies vegetation for consumption by grazing and browsing animals |
| drought | although there is no universally accepted definition of drought, it is generally the term applied to periods of less than average precipitation over a certain period of time |
| nutrient depletion | Detrimental changes on a site in the total amount of nutrients and/or their rates of input, uptake, release, movement, transformation, or export. |
| grass/forb | Herbaceous vegetation. |
| flood loss reduction measures | The strategy for reducing flood losses |
| sandstorm | A strong wind carrying sand particles through the air |
| shield volcano | a volcanic cone made up of multiple layers of basaltic lava. |
| pacific high | High pressure system that develops over the central Pacific Ocean near the Hawaiian Islands |
| parapet wall | A solid wall built along the top of a dam for ornament, for the safety of vehicles and pedestrians, or to prevent overtopping. |
| outlet discharge structure | Protects the downstream end of the outlet pipe from erosion and is often designed to slow down the velocity of released water to prevent erosion of the stream channel. |
| roml | Regional Operations Manual Letter |
| estuary | A coastal body of water that is semi-enclosed, openly connected with the ocean, and mixes with freshwater drainage from land. |
| core-periphery model | a model seeking to explain a spatial pattern of economic growth in which one centre or region in a country develops an economic advantage over the rest of the country |
| pumping test | A test that is conducted to determine aquifer or well characteristics |
| dielectric constant | For a given substance, the ratio of the capacity of a condenser with that substance as dielectric to the capacity of that condenser with a vacuum as dielectric |
| detection efficiency | The percentage of the total number of cloud-to-ground flashes that the network locates and records and is a function of range. |
| firn | A permeable aggregate of small ice grains with densities greater than 0.55 up to 0.82 where begins glacial ice. |
| water requirement | The total quantity of water, regardless of its source, required for production of crops at their normal growth under field conditions |
| tropical wave | A trough or cyclonic curvature maximum in the trade wind easterlies and it is not classified as a tropical cyclone. |
| wasteway | An open ditch or canal that discharges excess irrigation water or power plant effluent into the river channel. |
| frontal precipitation | See convergence precipitation. |
| clean | Water that is free from foreign matter or pollution; not infected; unadulterated. |
| primary treatment | First stage of wastewater treatment in which solids are removed by screening and settling. |
| outlet | Point where water exits from a stream, river, lake, reservoir, tidewater, or artificial drain |
| tor | blocks of granite which appear balanced on one another. |
| isodrosotherm | The line drawn on a weather map connecting points of equal dew point. |
| pulse severe thunderstorms | These are single cell thunderstorms which produce brief periods of severe weather (3/4 inch hail, wind gusts in the excess of 58 miles an hour, or a tornado). |
| black ice | Thin, new ice on fresh or salt water that appears dark in color because of its transparency |
| dynamic ice | Pressure due to a moving ice cover or drifting ice. |
| casing | a tubular structure intended to be watertight installed in the excavated or drilled hole to maintain the well opening and, along with cementing, to confine the ground waters to their zones of origin and prevent the entrance of surface pollutants. |
| sedimentation | Deposition of sediment. |
| storage-required frequency curve | A graph showing the frequency with which storage equal to or greater than selected amounts will be required to maintain selected rates of regulated flow. |
| electromagnetic energy | Energy stored in electromagnetic waves or radiation |
| range | The area or region over which an organism occurs. |
| flotation | A solids-liquid or liquid-liquid separation procedure, which is applied to particles of which the density is lower than that of the liquid they are in |
| irrigation | The controlled application of water to arable lands to supply water requirements not satisfied by rainfall. |
| infiltration rate | The amount of water absorbed by the soil per unit of time, usually expressed in inches per hour. |
| ripple | (1) A specific undulated bed form found in sand bed streams |
| backwater | (1) A small, generally shallow body of water attached to the main channel, with little or no current of its own |
| brine | (1) Water saturated with or containing large amounts of a salt, especially of sodium chloride |
| cfu | Colony Forming Units |
| mostly cloudy | When the predominant/average sky condition is covered by more than half, but not completely covered by opaque (not transparent) clouds. In other words, 5/8 to 7/8 of the sky is covered by opaque clouds. Same as Considerable Cloudiness. |
| neap tide | a low tidal range caused when the angle of a line drawn from the sun to the earth and then to the moon is 90- In this twice-monthly situation the gravitational pulls of sun and moon are in opposition thus the high tide is not so high and the corresponding low tide is not so low. |
| eccentricity | Geometric shape of the Earth's orbit |
| horn | Pyramidal peak that forms when several cirques erode a mountain from three or more sides. |
| volcano | a mountain created by the eruption and deposition of lavas and ashes from a vent in the ground in a volcanic area. |
| waste | the unwanted by-products of human activity |
| isobath | An imaginary line on the earth's surface or a line on a map connecting all points which are the same vertical distance above the upper or lower surface of a water-bearing formation or aquifer. |
| perennial yield | The maximum quantity of water that can be annually withdrawn from a groundwater basin over a long period of time (during which water supply conditions approximate average conditions) without developing an overdraft condition |
| subsurface water | All water which occurs below the ground surface. |
| recreational forest | forests maintained for recreation activities such as bird-watching, cycling, horse-riding, camping etc. |
| recharge | The processes involved in the addition of water to the zone of saturation; also the amount of water added. |
| effluent | The water leaving a water or wastewater treatment plant. |
| hardness | a water-quality indication of the concentration of alkaline salts in water, mainly calcium and magnesium |
| water budget | A provision of the Columbia River Basin Fish and Wildlife Program that calls for increasing Columbia and Snake River Flows during the spring fish migration with the intent of increasing downstream survival of migrating juvenile salmon and steelhead. |
| monera | Group, at the kingdom level, in the classification of life |
| inversion | A departure from the usual increase or decrease of an atmospheric property with altitude |
| streambank stabilization | The lining of streambanks with riprap, matting, etc., or other measures intended to control erosion. |
| second-growth forest | Stand of forest that is the result of secondary succession. |
| water quality | the condition of water as it relates to impurities water reclamation - treating wastewater so that it can be used again water table - (1) the boundary in the ground between where the ground is saturated with water (zone of saturation) and where the ground is filled with water and air (zone of aeration); (2) the upper surface of the saturated zone that determines the water level in a well in an unconfined aquifer water vapor - the gaseous state of water watershed - a geographical portion of the Earth's surface from which water drains or runs off to a single place like a river; also called a drainage area well - a hole or shaft drilled into the earth to get water or other underground substances |
| chloroplast | Organelle in a cell that contains chlorophyll and produces organic energy through photosynthesis. |
| pitot tube | A device for measuring the velocity of flowing water using the velocity head of the stream as an index of velocity |
| insolation | The amount of solar radiation received in a specific area |
| drought | A continuous and lengthy period during which no significant precipitation is recorded. |
| kinetic energy | The energy due to motion. |
| mineral water | Contains large amounts of dissolved minerals such as calcium, sodium, magnesium, and iron |
| bank-full capacity | the rate of water flow that completely fills a channel; the flow rate at which the water surface is level with the flood plain. |
| haze | A concentration of salt particles or other dry particles not readily classified as dust or other phenomenon |
| bright band | The enhanced layer of radar echo caused by the difference in radar reflectivity of ice and water particles |
| leisure | time free from work or other obligation |
| sedimentary rock | any rock formed from sediments under pressure from other overlying sediments. |
| fjord | A narrow, steep-sided, elongated estuary formed from a glacial trough inundated by seawater. |
| operational plan | An action plan that generally addresses how the objectives in a specific geographic area will be attained. |
| clear-cut harvest | A timber harvest method in which all trees are removed in a single entry from a designated are, with the exception of wildlife trees or snags, to create an even-aged stand. |
| holding pond | a small basin or pond designed to hold sediment laden or contaminated water until it can be treated to meet water quality standards or be used in some other way. |
| hydrosphere | region that includes all the earth's liquid water, frozen water, floating ice, frozen upper layer of soil, and the small amounts of water vapor in the Earth's atmosphere. |
| striations | scratch marks or grooves found on a rock surface that has experienced glacial abrasion. |
| ferricretes | Sedimentary rock created by the chemical precipitation of iron. |
| earthflow | A rapid type of downslope mass movement that involves soil and other loose sediments |
| chernozem | soil type often found in continental interiors with a temperate grassland biome type |
| benthos | The plant and animal organisms that live on the sea floor |
| riparian owner | One who owns land bounding upon a river or water course. |
| longshore drift | The movement and deposition of coastal sediments because of longshore currents. |
| demand management | Reductions of water usage accomplished either through temporary measures such as restrictions during a drought, or through long-term conservation programs |
| blowing spray | Salt spray that is raised by the wind to heights of six feet or greater |
| sheet flow | See overland flow. |
| divide | The topographic ridge that separates drainage basins. |
| gage height | The height of the water surface above the gage datum (reference level) |
| terminal fall velocity | Velocity at which a particle being transported by wind or water falls out of the moving medium |
| pilot report | A report of in-flight weather by an aircraft pilot or crew member |
| supply augmentation | Alternative water management programs such as conjunctive use, water banking, or water project facility expansion that increase supply. |
| nephophobia | The fear of clouds. |
| inselberg | lit |
| polychlorinated biphenyls | toxic industrial chemical compound substances that were used in the manufacture of plastics and as insulating fluids in electrical transformers and capacitors |
| ir | An acronym for Infrared. See Infrared Satellite Imagery. |
| bedload | That part of the sediment load in which the particles of material move on or near the streambed. |
| biotite | Rock forming mineral of the mica group. |
| landslide | A movement of earth down a steep slope. |
| rhumb line | A line of constant compass direction or bearing which crosses the meridians at the same angle |
| discharge curve | A curve that expresses the relation between the discharge of a stream or open conduit at a given location and the stage or elevation of the liquid surface at or near that location |
| wet floodproofing | An approach to floodproofing which usually is a last resort |
| pollutant | (1) Something that pollutes, especially a waste material that contaminates air, soil, or water |
| biome | Largest recognizable assemblage of animals and plants on the Earth |
| homing | The ability of a salmon or steelhead to correctly identify and return to their natal stream, following maturation at sea. |
| superimposed drainage | a drainage pattern that formed on one set of rocks which have since been removed and so bears no relation to the set of rocks on which it is now found. |
| plume | the area taken up by contaminant(s) in an aquifer. |
| chocolatta north | A West Indian gale that blows from the northwest. |
| suspended load | Portion of the stream load that is carried almost permanently suspended in flowing water. |
| eddy | A circular current of water, usually resulting from an obstruction. |
| nationalisation | government policy which compels certain industries to transfer their ownership from private ownership to public ownership |
| psychrometer | A Hygrometer used to determine relative humidity of the atmosphere |
| mitigation | (1) (Environmental, General) Actions designed to lessen or reduce adverse impacts; frequently used in the context of environmental assessment |
| outwash | a deposit of sand and gravel formed by streams of meltwater flowing from a glacier. |
| nyquist frequency | The highest frequency that can be determined in data that have been discretely sampled |
| outer convective bands | These bands occur in advance of main rain shield and up to 300 miles from the eye of the hurricane |
| privatization | the change of ownership of a firm or industry sector from government to private hands. |
| discharge | the volume of water that passes a given location within a given period of time |
| ecotone | Boundary zone between two unique community types. |
| ice field | Large level area of glacial ice found covering a large expanse of land |
| headwater advisory program | A Program which uses the Antecedent Precipitation Index (API) method of estimating runoff, unit hydrograph theory and stage-discharge ratings to produce hydrologic forecasts for headwater basins. |
| whirlwind | A small, rotating column of air; may be visible as a dust devil. |
| germination | The beginning of vegetative growth of a plant from a seed. |
| prescriptive water rights | Water rights which are acquired by diverting water and putting it to use in accordance with specified procedures, e.g., filing a request with a state agency to use unused water in a stream, river, or lake. |
| un | United Nations |
| irrigation frequency | Time interval between irrigations. |
| geodesy | The science that measures the surface features of the Earth. |
| transpiration | process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, such as leaf pores |
| toxicant | a substance or a mixture of substances within a short period of time, usually 96 hours or less, after exposure |
| irrigation | the controlled application of water for agricultural purposes through manmade systems to supply water requirements not satisfied by rainfall. |
| red flag | This a fire weather program which highlights the onset of critical weather conditions conducive to extensive wildfire occurrences. |
| occluded mesocyclone | A mesocyclone in which air from the rear-flank downdraft has completely enveloped the circulation at low levels, cutting off the inflow of warm unstable low-level air. |
| dendrochronology | observation of a core or cross-section of a tree trunk shows a pattern of essentially concentric rings, each representing a year of growth |
| aboveground sewer | An unburied sewer (generally a sanitary sewer), supported on piers, pedestals or bents to provide a suitable grade line. |
| vested water right | the right granted by a state water agency to use either surface or ground water. |
| eldw | economically less developed world -collectively all the economically less developed countries (ELDCs). |
| deep percolation | the percolation of water through the ground and beyond the lower limit of the root zone of plants into a groundwater aquifer. |
| sawrs | Indicates manual weather observations are the primary source of reporting the weather at the airport. |
| velocity | Distance traveled per unit time. |
| a/d converter | Ananlog-to-digital converter |
| isothermal process | Any thermodynamic change of state of a system that takes place at constant temperature. |
| dry line | The boundary between the dry desert air mass of the Southwest U.S |
| ice shove | On-shore ice push caused by wind, and currents, changes in temperature, etcetera. |
| temperature | A measure of the warmth of the ambient air measured by a suitable instrument such as a thermometer. |
| nonsymbiotic mutualism | Mutualistic interaction where the mutualists live independent lives yet cannot survive without each other |
| hydrosphere | The region that includes all the earth's liquid water, frozen water, floating ice, frozen upper layer of soil, and the small amounts of water vapor in the earth's atmosphere. |
| cartridge filter | Disposable filter device that has a filter range of 0.1 micron to 100 microns. |
| gill-net fishery | Any fishery where the gear is limited to the use of gill nets only |
| continental divide | The elevated area that occurs on a continent that divides continental scale drainage basins. |
| basin | A surface area having drainage system consisting of a surface stream and its tributaries and impounded bodies of water |
| pressure gage | A device for registering the pressure of solids, liquids, or gases |
| floc | A flocculent mass that is formed in the accumulation of suspended particles |
| uplands | (1) The ground above a floodplain; that zone sufficiently above and/or away from transported waters as to be dependent upon local precipitation for its water supplies |
| unit hydrograph | The discharge hydrograph from one inch of surface runoff distributed uniformly over the entire basin for a given time period. |
| headwater advisory program | A Program which uses the Antecedent Precipitation Index (API) method of estimating runoff, unit hydrograph theory and stage-discharge ratings to produce hydrologic forecasts for headwater basins. |
| incidental take | """Take"" of a threatened or endangered species that is incidental to, and not the purpose of, the carrying out of an otherwise lawful activity." |
| vomer | The most anterior bone of the roof of the mouth; may bear teeth. |
| self-sufficiency | the ability to survive without outside help. |
| snow | precipitation in the form of branched hexagonal crystals, often mixed with simple ice crystals, which fall more or less continuously from a solid cloud sheet |
| eldc | see economically less developed country. |