SHEET EROSION

A type of soil erosion caused by raindrop impact during intense rainfall. ‘Rainsplash erosion’ is initiated by the force of raindrops impacting on bare soil, which dislodges the soil particles. This material is then transported downslope by overland flow. In sheet erosion, a layer of soil is removed from the land surface (e.g. a field), which, in agriculture, can lead to the removal of topsoil and a gradual change in the profile or the slope of the field. Sheet erosion contrasts with rill erosion, where the flow is concentrated in small channels. Sometimes, both forms of soil erosion occur together—with sheet erosion occurring on the upper slopes gradually giving way to rill erosion as flow concentrates on rough ground. Fields that have been recently ploughed following vegetation removal are particularly vulnerable to sheet erosion. Landmanagement techniques to reduce sheet erosion include contour ploughing at right angles to the slope.

[See alsosoil conservation]