Author
Submitted to: Aeolian Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 10/12/2012 Publication Date: 8/1/2013 Citation: Wagner, L.E. 2013. A history of wind erosion prediction models in the United States Department of Agriculture: The Wind Erosion Prediction System (WEPS). Aeolian Research. 10:9-24. Interpretive Summary: This manuscript is a review of the history of modeling within the United States Department of Agriculture (USDA), beginning with the Wind Erosion Prediction System (WEPS). Development of WEPS was officially inaugurated in 1985 by USDA-Agricultural Research Service (USDA-ARS) scientists. It was in response to customer requests, especially from the USDA Soil Conservation Service (SCS), for improved wind erosion technology at the time. WEPS was conceived to address deficiencies in the then 20 year old, predominately empirical, Wind Erosion Equation (WEQ) widely used by SCS. It sparked an endeavor that relied on novel laboratory wind tunnel research as well as extensive field studies, to adequately uncover the physical relationships between surface properties and their influence on wind erosion. The result is that WEPS incorporates many process-based features and other capabilities not available in any other wind erosion simulation model today. The USDA Natural Resource Conservation Service (NRCS) has now recently implemented WEPS as a replacement for WEQ within their agency. However, the road to achieve that state was not easy and required years of close interaction between ARS and NRCS. The history of the development of WEPS, its unique features, and solutions to selected critical issues encountered by NRCS prior to implementation are presented and discussed. Technical Abstract: Development of the Wind Erosion Prediction System (WEPS) was officially inaugurated in 1985 by United States Department of Agriculture-Agricultural Research Service (USDA-ARS) scientists in response to customer requests, particularly those coming from the USDA Soil Conservation Service (SCS), for improved wind erosion prediction technology. WEPS was conceived to address deficiencies in the then-20-year-old, predominately empirical Wind Erosion Equation (WEQ) widely used by SCS, and it sparked an endeavor that relied on novel laboratory wind tunnel research as well as extensive field studies to adequately uncover the physical relationships between surface properties and their susceptibility to and influence on wind erosion. The result is that WEPS incorporates many process-based features and other capabilities not available in any other wind erosion simulation model today. The USDA Natural Resource Conservation Service (NRCS) has now recently implemented WEPS as a replacement for WEQ within their agency. However, the road to achieve that replacement also required years of close interaction between ARS and NRCS. NRCS had to ensure they had suitable national-scale WEPS databases (e.g., on climate, wind, soil, crops, operations, crop/management rotation files and barriers) working well before implementation. User input simplifications were required as well as modifications to the reports. Run-time concerns also arose during the lengthy testing and evaluation process. Many of these were strictly non-wind erosion science issues that had to be addressed before NRCS could officially implement and begin using WEPS within their agency. Some issues were significant, and several rounds of testing were conducted nationwide by NRCS over a five-year period following delivery of WEPS to their agency for official testing on April 4, 2005. The history of the development of WEPS, its unique features and its solutions to selected critical issues encountered by NRCS prior to implementation are here presented and discussed. The history and development of wind erosion modeling within the USDA prior to WEPS is described in detail in a separate work by Tatarko, et al. (see this issue). |