|1.||catchment basin, drainage area, Also called: drainage basin the area of land bounded by watersheds draining into a river, basin, or reservoir|
|2.||the area from which people are allocated to a particular school, hospital, etc|
area from which all precipitation flows to a single stream or set of streams. For example, the total area drained by the Mississippi River constitutes its drainage basin, whereas that part of the Mississippi River drained by the Ohio River is the Ohio's drainage basin. The boundary between drainage basins is a drainage divide: all the precipitation on opposite sides of a drainage divide will flow into different drainage basins.
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