Three Phase Runoff Model for Small Prairie Rivers: I. Frozen Soil Phase Assessment

Abstract

The Conceptual Model used in this study attributes virtually all major runoff events from small prairie basins to snowmelt and rainfall on frozen soil. To model these events, two parameters are estimated: the frozen soil (snowmelt) contributing area, and the related depression storage losses. A method for assessing these parameters is developed using a small watershed in east central Alberta, Ribstone Creek near Czar. A climatic model with a daily time step has been utilized to predict the spring runoff depths at 34 climate stations for 13 years. These data are interpolated with spatial analysis techniques to a one kilometre grid over the study area to develop estimates of runoff depth for a watershed. Inclusion of estimates of winter ET and spring infiltration to frozen soils improves the statistical significance of the results. The analysis supports the argument that the frozen soil contributing area and depression storage losses are relatively constant, and that the principal factor determining runoff variability is the spring snow-water equivalent.