Characterization of wind induced show redistribution with GIS derived parameters

In order to develop a physically based model of spatial snow distribution, parameters that characterize the natural controls affecting distribution patterns are necessary. Stratification of the study area, Blackcap Basin, CA, based on timberline indicates that elevation, radiation, and slope exhibit a strong linear relationship to snow depth below timberline, but above timberline the strength of these relationships is greatly attenuated. Based upon field observations of the increased importance of wind redistribution in the exposed alpine region, we apply two terrain parameters which affect wind patterns on the ground to account for this process in our modeling efforts. Surface curvature, a direct output in most Geographic Information System software, and a wind exposure index derived specifically for this study, are tested for their efficacy in explaining the observed alpine snow distribution. The wind exposure index is shown to be abetter predictor of snow accumulation in the alpine region than any of the aforementioned predictor Curvature measured over a large area effectively discriminates convex regions as areas containing anomalously high and low snow depths. An adequate analysis of localized curvature is hindered by both the spatial resolution of the digital elevation model and registration of the data points.