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

The term that accurately describes the area drained by a river and its tributaries is "drainage basin." A drainage basin encompasses all the land where precipitation collects and drains off into a common outlet, usually a river or stream. Essentially, it includes the main river and all of its tributaries, which feed into it, creating a complete system of waterways that direct water toward a single point. This term captures the concept of the entire area that contributes to the river's flow, making it fundamental in hydrology and geography when studying water systems.

While "watershed," "catchment area," and "river basin" may seem similar, they can have nuances that distinguish them from the more comprehensive concept of a drainage basin. For instance, "watershed" is often used to refer to a high point that separates different drainage basins rather than the entire area itself, and "catchment area" typically emphasizes the area that collects precipitation directly into a specific body of water, sometimes suggesting smaller or specific contexts. On the other hand, "river basin" can be interchangeable with "drainage basin" in some contexts but may not emphasize tributaries as explicitly. Thus, "drainage basin" is the most precise term to describe the