EVALUATION OF EPICS WIND EROSION SUBMODEL USING DATA FROM SOUTHERN ALBERTA

Wind erosion models have been used to assess policy impacts on soil er osion, but validation of models has been difficult until recently. We evaluated the Environmental Policy Integrated Climate (EPIC) wind eros ion submodel by comparing simulation results to field measured wind er osion sediment losses. Using standard model inputs and actual wind vel ocities, wind erosion was simulated for a field near Lethbridge, Alber ta (49 degrees 37'N, 112 degrees 38'W) where field measurements of win d erosion were made in April 1992 on a Dark Brown Chernozemic soil. Th e EPIC submodel predicted erosion losses for each day that erosion was measured, and approximated the magnitude of erosion on six of the sev en erosion events. EPIC significantly overestimated erosion for one ev ent and also simulated erosion on 3 d when no erosion was recorded. Fi eld length had a larger effect on simulation results during large eros ion events than for smaller events. The effect of surface soil water c ontent on wind erosion appeared to be captured by the model, but only limited data were available to evaluate this aspect. Other portions of the model such as the effects of surface roughness and vegetative cov er could not be evaluated in this study.