Wind climatology issues, and the development of a comprehensive wind data base for wind erosion estimates

Wind erosion is a significant issue affecting many agricultural regions of the United States. The USDA-NRCS is charged with assessing the potential wind erosion impacts on private lands from a variety of conservation measures. There is a need for these assessments to be more quantified than in the past, and the tool that will be used to make these assessments is the Wind Erosion Prediction System (WEPS). This modeling system uses either actual or generated weather time series as input. The WINDGEN stochastic wind model, based on a Weibull distribution fit, delivers daily (with disaggregation capability to hourly or finer resolution) values of wind speed and direction in WEPS. The current WINDGEN parameter database was developed from the 1983 NCDC Wind Energy Resource Information System (WERIS). Significant spatial variabilities in WEPS-computed soil erosion have been speculated to be caused by large, and perhaps erroneous, differences between various WERIS wind station parameters. Detailed statistical analyses of wind characteristics were performed on groups of stations in several highly erodible regions exhibiting large within-group parameter differences. WERIS-derived wind statistics and WINDGEN parameters were compared to concurrent datasets. Wind statistics were also examined using newer climate data, and time series analyses were performed to evaluate possible changes in wind regimes and local (site, instrumentation, etc.) effects. From these studies, recommendations will be made regarding the development of a national wind database for wind estimation and wind erosion potential, derived from historical and/or modeled wind information.