Water that stays on top of the land and flows back to a water source.

• A. surface run-off
• B. groundwater
• C. open water
• D. water cycle

Answer: (A)

Surface runoff is the movement of water that stays on top of the land after it rains and flows toward a water source. After precipitation, some water infiltrates the soil and becomes groundwater, but when the ground is saturated or the rainfall is heavy, the surface cannot absorb it fast enough, so it runs off over the land. This runoff collects in streams and rivers and eventually returns water to lakes, rivers, or oceans. Open water refers to the bodies of water themselves, not the process of water moving across the land, and the water cycle is the whole set of processes that move and change water through the environment, which includes runoff as one part.