Validation of the wind erosion stochastic simulator (WESS) and the revised wind erosion equation (RWEQ) for single events

The wind erosion stochastic simulator (WESS) is a single event wind erosion model that is the core of the wind erosion submodel of the environmental policy integrated climate (EPIC) erosion model. WESS uses inputs of soil texture, erodible particle diameter, soil roughness, soil water content, crop residue, and 10 min average wind speeds to predict the erosion at several user-selected distances within a given field. The revised wind erosion equation (RWEQ) makes annual or period estimates of wind erosion based on a single event wind erosion model that includes factors for wind and rainfall, soil roughness, the erodible fraction of soil, crusting, and surface residues. In this study, we compared estimates of wind erosion at multiple points in a field for 24 events at Big Spring, Texas with the predictions of WESS and compared estimates of maximum sediment transport capacity (Qmax), critical field length at which Qmax is attained (S), and soil loss (SL) calculated from field measured data collected at six locations and 41 events with the predictions of RWEQ. Compared to observed estimates of erosion for the 24 events, WESS under-predicted 9 events, accurately predicted 8 events, and over-predicted 7 events. In general, RWEQ underestimated Qmax and SL and overestimated S.