What term describes the area of land drained by a river and its tributaries?

The term "drainage basin" refers to the entire area of land where precipitation collects and drains off into a common outlet, such as a river and its tributaries. This area is defined by the topographical boundaries known as watershed divides, which determine the direction that water will flow. Within a drainage basin, all the water that falls as rain or snow will flow into the river system, impacting the ecosystem and human activities in the area.

Understanding drainage basins is crucial for grasping concepts related to hydrology, water management, and environmental science. They play an essential role in flood management, water quality, and the health of freshwater ecosystems. This term is widely used in geographic studies, emphasizing its importance in understanding how water systems operate within a landscape.