Method to predict cropland ephemeral gully erosion

Erosion of farmland due to concentrated flow is very severe on many unprote cted fields across the United States. Small channels can turn into large gu llies if not controlled. These small channels are routinely obliterated by tillage of the field and other routine farm operations only to be reformed again. Opposing slopes adjacent to an ephemeral gully allow runoff to reest ablish a channel in approximately the same location. Since the 1960s, the U niversal Soil Loss Equation (USLE) has been used to estimate rill and sheet erosion. This paper describes the Ephemeral Gully Erosion Model (EGEM). EG EM is a modification of the Agricultural Research Service Ephemeral Gully E rosion Estimate (EGEE) computer model to meet the Natural Resources Conserv ation Service (NRCS) needs. Limited field data obtained by NRCS were used t o validate the single event component of EGEM. This paper presents a summar y of these studies. There were no data available at the time of the model d evelopment to validate the average annual concept of the model. ARS conduct ed validation studies for the EGEE model. (C) 1999 Published by Elsevier Sc ience B.V. All rights reserved.