AGNPS-UM: applying the USLE-M within the agricultural non point source pollution model

In the Agricultural Non Source Pollution model (AGNPS), grid-cell erosion is predicted for individual rainfall events using the Universal Soil Loss Equation (USLE) even though the USLE is not well suited for this purpose. A new modification of the USLE, the USLE-M, is better suited to predicting event erosion and also provides a mechanism for accounting for the impact of upslope runoff on erosion that is not available with the USLE. A software system that replaces the USLE by the USLE-M in AGNPS is described and its impact illustrated by an example based on a 1-in-10 year event on a 2300 ha catchment near Nundle, New South Wales, Australia.