What term refers to the part of the water cycle where an excess of water runs off the soil and eventually reaches rivers, lakes, and oceans?

• A. Infiltration
• B. Runoff
• C. Evaporation
• D. Transpiration

Answer: (B)

Runoff is the part of the water cycle where excess water flows over the land surface and eventually makes its way into rivers, lakes, and oceans. It happens when rainfall or snowmelt overwhelms the soil’s ability to absorb water, or when the ground is already saturated, so water cannot infiltrate. Infiltration is the opposite process—water seeping into the soil to become groundwater or soil moisture. Evaporation is the change of liquid water to water vapor from surfaces, and transpiration is water lost from plants. The scenario described fits runoff, since the water is moving across the surface toward waterways.