What is the primary effect of a rainstorm on soil according to erosion studies?

The primary effect of a rainstorm on soil, as highlighted in erosion studies, is the detachment of soil particles and sealing of the soil's surface. When rain falls, especially in significant amounts, the energy from the raindrops can dislodge soil particles, initiating the erosion process. This detachment is crucial because it makes the soil more susceptible to further erosion from runoff and wind.

Moreover, heavy rainfall can lead to the sealing of the soil surface, which occurs when finer soil particles fill the spaces between larger particles, resulting in a compacted layer that reduces the soil’s permeability. This sealing effect can hinder water infiltration, exacerbating surface runoff and increasing the potential for erosion. The combination of particle detachment and surface sealing poses a significant risk to soil stability and health, as it can lead to the degradation of soil quality and increased sediment delivery to waterways.

In contrast, the other options represent outcomes that are generally not immediate effects of rainstorms on soil. Increased water infiltration and reduced runoff may occur under certain conditions, such as with well-managed soils or less intense precipitation. The formation of rills and gullies is typically a result of prolonged erosion processes rather than an immediate effect of a single rainfall event. Lastly, the creation of dense