Submitted to: ASAE Annual International Meeting
Publication Type: Abstract Only
Publication Acceptance Date: January 3, 2001
Publication Date: January 3, 2001
Citation: In: J.C. Ascough II and D.C. Flanagan, Proc. Int. Symp. Soil Erosion Research for the 21st Century, 3-5 January 2001, Honolulu, HI. St. Joseph, MI: pp 380-383.
The USDA process-based soil erosion models (WEPP - Water Erosion Prediction Project and WEPS - Wind Erosion Prediction System) have been developed over the past 10 years, and are designed to replace older prediction technologies. Both WEPP and WEPS simulate weather and field conditions, including plant growth, residu decomposition, hydrology, and management practices on a daily basis. The USDA Natural Resources Conservtaion Servic (NRCS) has requested that WEPP and WEPS be combined into a single model that is capable of simulating both wind and water erosion processes and utilizes the same components for all common processes (for example plant growth and residue decomposition). The USDA Agricultural Research Service (ARS) has begun a project to create a common model. Development of a common plant growth component requires the completion of several tasks, including identification of inputs and outputs common to both WEPP and WEPS, as well as determination of unique variables required to meet specific needs of th individual erosion models. For example, the wind erosion force is horizontal to the soil surface, so WEPS uses the stem silhouette area and leaf area information. In contrast, raindrop erosive force is mostly vertical to the soil surface, so WEPP uses canopy cover and raindrop fall height from the canopy to the ground. The common growth model must also be be able to simulate several different crops growing simultaneously over the landscape, as well as multiple species growing competitively with each other at the same time (intercropping or rangelands). The objective of this presentation will be to describe the development of a common WEPP/WEPS plant growth component, and provide a status report on progress towards completion.