Terms of Hydrology (W)

wadi :

Channel which is dry except in the rainy season.

wading measurement :

Discharge measurement made by an observer crossing the stream bed on foot a ...

wading rod :

Note: This may be used from boats or ice cover at shallow depth. (TR)

wash load :

Relatively fine material, in near-permanent suspension in a stream system, ...

wash-out (precipitation) :

Removal of substances such as dust, aerosols and gases from the atmosphere ...

waste water :

Water containing waste, i.e. liquid or solid matter discharged as useless f ...

water :

Liquid phase of a chemical compound consisting of approximately two parts b ...

water balance :

Inventory of water based on the principle that during a certain time interv ...

water bleeding :

Water forced through a crack in an ice cover.

water body :

Mass of water distinct from other masses of water.

Water conservation :

Measures introduced to reduce the amount of water used for any purpose, and ...

water deficit :

Cumulative difference between potential evapotranspiration and precipitatio ...

water demand :

Actual quantity of water required for various needs over a given period as ...

water duty :

Quantity of water required to satisfy irrigation-water requirements per uni ...

water equivalent of snow :

Amount of water that would be obtained if the snow sample were completely m ...

water equivalent of snow cover :

Vertical depth of a water layer which would be obtained by melting a snow c ...

water hammer :

Very rapid pressure wave in a conduit, mainly resulting from a sudden valve ...

water level :

Elevation of the free-water surface of a body of water relative to a datum ...

water loss :

(1) In a water balance: sum of water lost from a given land area during any ...

water management :

Planned development, distribution and use of water resources.

water need :

Quantity of water required, over a given period, to satisfy fully a known o ...

water policy :

Collection of legislation, legal interpretations, governmental decisions, a ...

water quality :

Physical, chemical, biological and organoleptic properties of water.

water requirement :

Total quantity of water per unit area required by crops for their normal gr ...

water resources :

Water available, or capable of being made available, for use in sufficient ...

water resources assessment :

Determination of the sources, extent, dependability and quality of water re ...

water resources management system :

Group of water engineering structures and related water bodies serving one ...

water sampler :

Device used to obtain a sample of water, either discretely or continuously, ...

water supply forecast :

Statement of the expected volume of available water, with associated time d ...

Water supply system :

All storage reservoirs, pumps, pipes and works required for providing water ...

water surplus :

(1) Cumulative (positive) difference between precipitation and potential ev ...

water system :

Group of related water bodies behaving as a unified whole.

Water table :

Surface within the zone of saturation of an unconfined aquifer over which t ...

water table contour :

Line connecting all points on a water table which have the same elevation a ...

water table slope :

Change in elevation of a water table per unit distance in a direction norma ...

water use :

Use of water or altering of its natural condition with the intention of inc ...

water-carrying capacity :

Maximum discharge capable of being conveyed in any cross section of a water ...

watercourse :

Natural or man-made channel through or along which water may flow.

waterfall :

Vertical fall or the very steep descent of a stream of water.

water-level recorder :

Instrument recording water levels in the course of time.

waterlogged :

Condition of land when the water table stands at or near the land surface a ...

watershed management :

Controlled use of drainage basins in accordance with predetermined objectiv ...

waterway :

(1) Navigable width of a river, channel, lake, etc. (2) Width of opening fo ...

wave :

Disturbance in a body of water propagated at a constant or varying speed (c ...

wave propagation :

Displacement of waves through water or along the water surface.

weather :

State of the atmosphere at a given time as defined by the various meteorolo ...

Weber number :

Dimensionless parameter expressing the ratio of inertia forces to surface t ...

Weibull distribution :

Fisher-Tippett type III extremal probability distribution.

weighted mean :

Mean or average of quantities to which have been attached a series of weigh ...

Weir :

Overflow structure which may be used for controlling upstream water level o ...

well :

Shaft or hole sunk, dug or drilled into the earth to extract water.

well capacity :

Maximum rate at which a well will yield water under a stipulated set of con ...

well development (AU) :

In well construction, to develop a well is to remove, by any of several mea ...

well efficiency :

Ratio of the theoretical drawdown in a well divided by the actual drawdown ...

well function :

Mathematical function by means of which the unsteady drawdown can be comput ...

well loss :

Component of the total drawdown in a production well due to the turbulent f ...

wet year :

Year in which precipitation or streamflow is significantly above normal.

wet-line correction :

Depth correction to a sounding line measurement for that portion of the lin ...

wetted area :

That part of the cross-sectional area of a stream of flowing water which is ...

wetted perimeter :

Length of the wetted contact between a stream of flowing water and its cont ...

wetting front :

Air/water interface in the process of water infiltrating into a soil.

wetting liquid :

Liquid for which the contact angle is less than 90°.

whirlpool :

Large eddy or vortex in a water body.

wilting point :

Moisture content of the soil at which the leaves of plants growing in that ...

wind daily run :

Distance represented by integration of the wind speed measured at the point ...

wind set-up :

Increase in water level as a result of wind.

wire-weight gauge; wire-weight gage (A) :

Manual stage gauge consisting of a fine cable or wire attached to a weight ...

withdrawal :

Extraction of water from surface or subsurface reservoirs.

world water balance :

Water balance for the combined land and sea areas of the Earth.