Rill Erosion

Rill erosion is the process by which numerous sub-parallel and randomly occurring small channels are formed on slopes by running water. Usually, if channel cross sections are smaller than 900 cm2 (square centimeters; 30 cm x 30 cm), they are called erosion rills. If they are bigger, they are called erosion gullies, and the erosion process associated with them is called gully erosion. Between the rills, the removal of soil is done by sheet (inter-rill) erosion, dominated by raindrop splash and sheet flow. Rill erosion is the most effective sub-process of soil erosion by water, contributing up to 80% of the total (rill + interrill) soil erosion.

Rills occur when overland flow starts to become concentrated. Overland flow with sufficient kinetic energy generates a shear stress ...