Manure Phosphorus and Surface Water Protection IV: Assessment of the Risk of Agricultural P Delivery Glossary

gully erosion

Gully erosion, including ephemeral gully erosion, is the cutting of narrow channels resulting from concentration of sheet and rill flow of runoff water.  Ephemeral gullies are small channels of approximately 3"-12” deep. Gullies may be one to several feet deep.

rill erosion

The erosion process which causes the formation of numerous small channels of less than to two to three inches deep.


sheet erosion - The removal of a relatively uniform thin layer of soil for the land surface by unchanneled runoff, or sheet flow.