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Watersheds
7.8C Watersheds
Term | Definition |
---|---|
WATERSHED | Area of land where surface water & groundwater drain into a particular body of water separated from each other by drainage divides. |
DRAINAGE DIVIDE | Geographical barrier, such as a ridge, hill, or mountain, separating 1 watershed land area from another. |
SURFACE WATER | Water from precipitation that drains into a gully that flows into a stream, which then flows into a river, lake, reservoir, estuary, wetland, or ocean. |
GROUNDWATER | Water that collects in cracks & pores in underground soil & rock layers. |
WATER TABLE | Top of the saturation zone, below which water fills all open spaces between the rock. |
SATURATION ZONE | Below the water table where all spaces not filled with solid material fill with water. |
AQUIFER | Layer of permeable rock that allows water to flow through. |
PERMEABLE ROCK | Allows water movement to flow through the material; opposite of impermeable. |
SUBSIDENCE | Sunken land surface due to underlying compression of earth material as a result of the removal of groundwater. |
POINT SOURCE WATER POLLUTION | Single identifiable & localized source of water pollution, such as waste-water discharge into a stream. |
NON-POINT SOURCE WATER POLLUTION | Pollutants introduced into surface or groundwater that are without a specific location source, such as water flowing over a lawn that has been fertilized & then into a drain. |
PERCOLATION | Downward movement of water through soil & rock due to gravity. |
IMPERMEABLE ROCK | Rock that does not allow liquid to flow through it. |