Submitted to: Current and Emerging Erosion Prediction Technology Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 8/10/1995
Publication Date: N/A
Technical Abstract: The USDA-WEPP computer model is a new generation of soil erosion prediction technology for use in soil and water conservation planning and assessment. The WEPP computer model is based on fundamentals of stochastic weather generation, infiltration theory, surface runoff, erosion mechanics, plant growth, residue management and decay, winter processes, irrigation, tillage, soil consolidation, and soil surface sealing. Significant advantages of the new technology are: 1) capabilities for estimating spatial and temporal distributions of net soil loss, 2) since the model is process based it can be extrapolated to a broad range of conditions which may not be practical or economical to field test, and 3) the ability to better predict offsite delivery of sediment, including particle size information. Testing and evaluation studies have been conducted by comparing the model to an extensive natural runoff plot database, by comparing to RUSLE and the USLE, and by evaluating confidence intervals for runoff and soil loss predictions. Databases for soils and climate for the United States have been developed. The model also has a relatively complete listing of tillage implements with the needed WEPP input parameters. Growth and residue decay parameters for the major crops in the U.S. have been established for WEPP, and the CPIDS program is available to help the user determine parameters for other crops. The WEPP model is a very powerful tool for estimating soil loss and selecting agricultural management practices for reducing both off-site sediment delivery and on-site loss of soil productivity.