Predicting Sediment Yield in Western United States

An equation for predicting the average annual sediment yield from sheet erosion is developed through multiple regression analysis. Most of the variation in yield is explained with data obtained by measurement of four watershed characteristics. A climatic factor as an indirect expression of vegetative cover, the average watershed slope, and two soil factors are the variables used. A good correlation of computed with measured sediment yields is obtained except at the lower rates of sedimentation. Improvements in predictive value can be achieved with experience in judging the necessary adjustments in the vegetative cover factor, through more intensive soil sampling and by use of only longtime sediment yields as the dependent variable. The data selected for this analysis are intended to exclude the influence of extensive gully or stream bank erosion on sediment yield.