GEOLOGY

Detailed explanation-1: -The steeper the slope, the less infiltration and more runoff. The greater the soil is saturated with water, the less infiltration and the more runoff. The more permeably the ground, the more water that can infiltrate and the less runoff.

Detailed explanation-2: -Clay is the smallest material there thus it would allow the least a, out of rainwater to infiltrate the surface.

Detailed explanation-3: -When rainfall is greater than soil infiltration rate, surface runoff occurs. Factors affecting runoff include rainfall intensity, slope, soil water storage capacity, and infiltration rate [12].

Detailed explanation-4: -The correct answer is (1) firmly packed clay-sized particles. Tightly-packed particles such as clay and silt are not very permeable. In this case, the water cannot flow down quickly into the soil. Therefore, a heavy rainstorm is likely to cause runoff.