Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: March 7, 2001
Publication Date: N/A
Technical Abstract: The Water Erosion Prediction Project (WEPP) model is a new generation of soil erosion prediction technology developed by the U.S. Departments of Agriculture and Interior over the past 15 years. Decisions on soil and water conservation practices to implement based on the use of models such as WEPP can impact on-site soil productivity and off-site water quality, as well as the targeting of millions of dollars in federal conservation program funds. WEPP is a process-based, distributed parameter, continuous simulation soil erosion model for use on personal computers, and can be applied to small watersheds and hillslope profiles within those watersheds. The physical processes that significantly affect erosion by water are represented, including climate prediction (precipitation, temperature, radiation, wind), infiltration, runoff, soil water evaporation/transpiration, plant growth, residue decomposition, soil water percolation, frost/thaw development, snowmelt, soil detachment by raindrops and flowing water, sediment transport, and sediment deposition. WEPP allows users to simulate the impacts of a wide range of practices, including alternative tillage, crop rotations, contouring, strip-cropping, residue addition/removal and irrigation. Databases and interface programs have been developed to assist users in implementing WEPP at their site(s) of interest. This book chapter describes WEPP model development history as well as the results of field studies conducted for model parameterization. Major scientific components of WEPP are presented, as well as the results of model validation studies using extensive data sets from the United States.