How is a gully defined in terms of its physical characteristics?

A gully is defined as a valley that is typically formed by erosion, specifically by the action of running water. The characteristic that distinguishes a gully is its depth, which is often more than one foot, indicating significant erosion has occurred. This process usually involves the concentration of surface runoff, leading to the removal of soil and sediment over time.

The physical characteristics of a gully include steep sides and a channel that carries water, especially during heavy rains. The presence of running water can enhance the erosion process, deepening the gully and widening its channel. Thus, the definition aligns with the understanding that a gully is not merely a shallow depression or a feature of human activity, but rather a more pronounced geological formation shaped by natural forces.