What term describes the drainage area that feeds a river system?

What term describes the drainage area that feeds a river system?

• A. Delta
• B. Watershed
• C. Catchment
• D. Basin

Answer: (C)

The essential idea is the area of land where rainfall drains into a river and its tributaries. That area is called the catchment. It’s the zone from which every drop of water eventually makes its way into the river system, shaped by the landscape that guides flow toward the river. The boundary that separates one catchment from another is the watershed, which is part of how we understand and map catchments, but the term we're after for the drained area itself is catchment. By contrast, a delta is a landform at the river’s mouth where sediment settles as it enters a larger body of water, and a basin can be used similarly in some contexts but isn’t the precise term for the area that feeds the river in this sense.

The essential idea is the area of land where rainfall drains into a river and its tributaries. That area is called the catchment. It’s the zone from which every drop of water eventually makes its way into the river system, shaped by the landscape that guides flow toward the river. The boundary that separates one catchment from another is the watershed, which is part of how we understand and map catchments, but the term we're after for the drained area itself is catchment. By contrast, a delta is a landform at the river’s mouth where sediment settles as it enters a larger body of water, and a basin can be used similarly in some contexts but isn’t the precise term for the area that feeds the river in this sense.