What is "gully erosion" characterized by?

Gully erosion is specifically characterized by the formation of deep, narrow channels caused by the concentrated flow of water, especially during heavy rainfall events. This form of erosion typically occurs in areas where water accumulates and runs off in small streams or channels, leading to the removal of soil along the banks of these channels, which can become progressively larger and deeper over time.

This process is particularly significant in landscapes that are susceptible to heavy rainfall or have disturbed soil, where the lack of vegetation fails to adequately hold the soil in place. When it rains, water begins to flow and erode the soil, initially creating small rills that can evolve into larger and more defined gullies if not managed properly.

The other options do not accurately represent gully erosion. For instance, erosion caused by wind on exposed soil refers to a different process known as wind erosion. Erosion that occurs in flat, open fields or due to ice melting highlights different environmental factors and processes, such as sheet erosion or frost heave, rather than focusing on the specific conditions leading to gully formation.