Water that flows over the ground surface is called

• A. Runoff
• B. Groundwater
• C. Ponds and lakes
• D. Wetlands

Answer: (A)

Water that flows over the ground surface is called runoff. It occurs when precipitation cannot infiltrate the soil quickly enough—due to heavy rain, a saturated or compacted ground, or an impervious surface—so the water travels downslope as overland flow and may feed streams. Groundwater is water that has infiltrated and moves underground, not along the surface. Ponds and lakes are standing bodies of water on the surface, not flowing across the landscape, and wetlands are areas that stay saturated or flooded for periods of time but don’t describe rapid surface flow. Runoff links rainfall to streams and erosion and is the term that fits water moving over the surface.