aquifer - geologic formation which contains and transmits water from one point to another in quantities sufficient for economic use.
aquifuge - geologic formation that can neither store or transmit water.
base flow - flow coming from ground water or spring contributions, which may be considered as the normal day-to-day flow.
conductivity - the volume rate of flow of water through the soil under a gradinet of unity; dependant soil moisture content.
cone of depression - a change (depression) in the water table surface at the site of an active well, due to water withdrawl.
direct surface runoff - occurs when percipitaion or snow melt moves across the land surface.
drainage basin - the tract of land (both surface and sub-surface) drained by a river and its tributaries.
evaporation - th enet rate of vapor transfer dependant upon solar radiation vapor pressure differnces, temperature, wind, atmospheric pressure an dth equality of th eevaporating water
evapotranspiration - water lost to the atmosphere from plant tissue and open water surfaces.
ground water - water that has percolated downward from the ground surface throug the soil pores.
hydrograph - a continous graph showing the properties of streamflow with respect to time.
hydrologic cycle - a continous process by which water is transported frmo the oceans to the atmosphere to the land an dback to the sea.
infiltration - water movemnt into the soil.
interception - percipitation that is blocked by the canopy of trees from reaching the ground.
juvenille water -formed chemically within the earth and brought to the surface by intrusice rocks.
percolation - the movement of water through the soil.
permeability - a function of grain size diameter, used to describe the ease at which water penetrates the soil surface.
piezeometric surface - the level of the water table where if a well is open to the atmosphere below this level, a free flowing spring will be produced.
percipitaion - the primary input in a hydrologic budget that can be in wet from (smow, rain, hail etc.) or dry form (particles that settle to earth due to gravity).
spillway - pipe flow through turbine or outlet works from a resevior.
storage - a reserve of water.
transpiration - soil moisture or ground water directly transmitted to the atmospher by vegetation.
watershed - the land area that ccontributes surface runoff to any point of interest.