What defines a watershed?

A watershed is defined as the area drained by a river or stream, which encompasses all the land that contributes water to that water body. This includes not only the river or stream itself but also the surrounding land where precipitation falls and flows towards the waterway.

The concept of a watershed is essential in understanding hydrologic systems, as it highlights how water moves through a landscape and connects various ecological processes. It plays a crucial role in resource management, particularly in areas like water supply, flood control, and environmental conservation.

The option that mentions an area of land that collects rainfall is too broad since not all land collecting rainfall necessarily drains into a specific river or stream. Similarly, identifying a watershed merely as a single ecosystem overlooks the complex interactions between various ecosystems that exist within a watershed. The option regarding the size of a tree's canopy is unrelated to watershed definition, as it focuses specifically on individual tree characteristics rather than the larger hydrological context.