erosion

1. the wearing away of the land surface by rain, running water, wind, ice, gravity, or other natural or anthropogenic agents, including such processes as gravitational creep and tillage 2. the detachment and movement of soil or rock fragments by water, wind, ice, or gravity; kinds of erosion include the following:

accelerated erosion erosion much more rapid than normal, natural, or geologic erosion, primarily as a result of the influence of human activities or, in some cases, of other animals or natural catastrophes that expose bare surfaces, e.g., fires

geologic erosion the normal or natural erosion caused by geologic processes acting over long geologic periods and resulting in the wearing away of mountains, the building up of floodplains, coastal plains, etc. —also natural erosion

gully erosion the removal of soil by water running in narrow channels, which may be eroded to depths ranging from 1 to 2 ft (0.30 to 0.61 m) to as much as 75 to 100 ft (22.86 to 30.48 m)

rill erosion the removal of soil by numerous small channels only several inches deep —note rills occur mainly on recently cultivated soils or recent cuts and fills

sheet erosion the movement of a thin, fairly homogeneous layer of soil material by surface runoff water —note sheet erosion may be imperceptible, particularly when caused by wind, or else evidenced by numerous fine rills

slip erosion a sliding downhill of the mantle rock —note the large-scale, spectacular form of slip erosion is a landslide

splash erosion the splattering of small soil particles caused by the impact of raindrops on wet soils —note the loosened and spattered particles may or may not be subsequently removed by surface runoff

streambank erosion the scouring of material and the cutting of channel banks by running water

streambed erosion the scouring of material and cutting of channel beds by running water This definition last updated 10/26/2008