What condition indicates a low runoff coefficient from an area?

A low runoff coefficient indicates that a smaller portion of rainfall will convert to surface runoff, while a larger portion is either absorbed by the ground or evaporates. High vegetation cover is crucial in this context because vegetation increases infiltration rates and promotes soil moisture retention. Plants and their root systems create a permeable surface that allows water to soak into the ground, reducing the amount of water that runs off into drainage systems.

In contrast, hard surfaces like concrete are impermeable and significantly increase the runoff coefficient since they do not allow water to penetrate. Similarly, highly compacted soil also limits the infiltration capacity, leading to higher runoff. Urban development typically involves extensive areas of impervious surfaces, further contributing to increased runoff. Therefore, high vegetation cover stands out as the characteristic condition that facilitates lower runoff coefficients.