What is the definition of a watershed?

A watershed is defined as an area of land where all the water that falls within that area—through rain, snowmelt, or other precipitation—eventually drains into a common body of water, such as a lake, reservoir, or wetland. This encompasses not only the water that flows directly into these bodies of water but also includes the various pathways and processes that lead precipitation to converge in these locations.

The distinction in this definition emphasizes the importance of watersheds as natural systems that control the movement and quality of water within the environment. This involves understanding how water is collected, filtered, and transferred within terrestrial ecosystems, showing the interconnectedness of different land forms and water bodies.

The other options, while relating to water runoff, do not encapsulate the broader concept of a watershed. The incorrect options focus on specific aspects of runoff into particular water bodies or situations that do not fully define a watershed’s scope. For instance, option A suggests only the drainage into a river without the comprehensive idea of collection; option C relates to drought conditions, which do not pertain to the hydrological process involved in a watershed; and option D restricts the definition to agricultural land use, which does not inherently involve the water flow or storage characteristics that define a watershed