How does gully erosion differ from rill erosion?

Gully erosion is characterized by the formation of deeper and wider channels in the landscape compared to rill erosion. While rill erosion involves the development of small, shallow channels that are typically inches deep and formed by the concentrated flow of water, gully erosion occurs when these rills expand over time due to increased water flow, often as a result of land use changes or intense rainfall. This process leads to larger, more pronounced channels that can significantly alter the land profile.

Rill erosion is often seen in its infancy, where the soil is not yet deeply incised. As water continues to flow and erode the soil, these rills can deepen and widen, eventually progressing to what we define as gully erosion. Thus, the transition from rill to gully erosion illustrates the erosion process’s dynamic nature and highlights the importance of managing water flow and vegetation cover to prevent soil loss.

The other choices contain inaccuracies regarding the definition and characteristics of erosion types. For instance, gully erosion does not specifically form in floodplain areas, nor is it primarily caused by wind. Additionally, rill erosion can occur during various rainfall intensities, not exclusively heavy rainfall. Therefore, option B accurately captures the essential distinction between gully and rill erosion.