Which conditions are most likely to result in runoff?

• A. Sloping areas
• B. Areas with little ground cover
• C. Intense rainfall
• D. All of the above

Answer: (D)

Runoff happens when rainfall can't soak in fast enough, so water flows across the surface. Sloping areas push water downhill, increasing surface flow. Areas with little ground cover have less vegetation and litter to protect the soil, so infiltration drops and more water runs off. Intense rainfall delivers a large amount of water quickly, saturating the soil and exceeding its ability to absorb it. When these factors are present together, runoff is most likely to occur. Since each condition contributes on its own, all of them together make runoff even more probable, which is why the best answer is that all of these conditions contribute to runoff.