Excerpt
THE Water Erosion Prediction Project (WEPP) combines knowledge of soil erosion processes with other important processes in a simulation model to predict soil erosion by water (6, 9). WEPP models soil erosion as a process of rill and interrill detachment and transport (8). This is much different than the universal soil loss equation (USLE), in which the factors understood to affect soil erosion were quantified in an empirical technology (19). Because WEPP deals with soil erosion prediction in a different manner than the USLE, new soil erodibility parameters are required. This was identified early in the project as a critical component for the successful development of the WEPP technology (7).
Soil erodibility in WEPP
The susceptibility or resistance of a soil to detachment and transport usually is recognized as a major determinant of soil erosion for a particular site. Generally, soil erosion models, including the USLE, incorporate a soil's susceptibility to erosion as a single parameter, termed soil erodibility, in the portion of the model dealing with soil detachment and transport. Even such models as CREAMS (17), which are process-based, use the USLE soil erodibility values to compute needed erodibilities.
Interrill erosion is the detachment and transport of soil particles by raindrops and …
Footnotes
J. M. Laflen is research leader at the National Soil Erosion Research Laboratory, Agricultural Research Service, U. S. Department of Agriculture, West Lafayette, Indiana 47907. W. J. Elliot is an assistant professor of agricultural engineering, Ohio State University, Columbus. J. R. Simanton, is a hydrologist with the Aridland Watershed Management Research Unit, ARS, USDA, Tucson, Arizona. C. S. Holzhey is director of the National Soil Survey Laboratory, Soil Conservation Service, USDA, Lincoln, Nebraska. K. D. Kohl is a soil and water engineering specialist, Iowa State University Extension Service, Storm Lake, Iowa.
- Copyright 1991 by the Soil and Water Conservation Society
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