Modeling of Rainfall Erosion

Abstract

A combined stochastic and deterministic method has been developed to evaluate soil erosion from overland flow. The exponential distributions for rainfall duration and intensity are combined with rainfall‐runoff relationships for discrete storms. A general equation for.sediment discharge is suggested from dimensional analysis with different sets of coefficients representing several existing equations. The expected value of soil erosion during one rainfall event is theoretically derived using hypergeometric series. When applied to the Chaudiére watershed near Québec, this equation converges very rapidly, and the first term of the series is recommended. Utilizing sediment‐delivery ratios, the sediment yield computed from the total soil erosion is in good agreement with the suspended load measured in the Chaudiére River.