Use of the Revised Universal Soil Loss Equation (RUSLE) to Predict Event Soil Loss

Abstract

Soil erosion is an important environmental and economic problem. Information about soil loss from erosion by water may be used to assess ecosystem health and function. Erosion events can be expensive and potentially dangerous. The US Environmental Protection Agency (EPA) states that sediments are the largest pollutant of our Nation's water bodies on a volume basis. The average annual land development rate from 1992-1997 was 1.3 million hectares (3.2 million acres), which was more than double the average rate occurring over the previous ten years (Benson, 1999). Erosion control plans become more important with the increase of land disturbances. Much of the soil loss information for erosion control is based on the Revised Universal Soil Loss Equation (RUSLE). RUSLE, previously the Universal Soil Loss Equation (USLE), was developed to estimate average annual soil loss from agricultural fields. The equation reliably predicts soil loss on an annual basis, but there is a need to be able to accurately predict soil loss for durations of less than one year. This project evaluated whether RUSLE could be applied to accurately predict soil loss from single rainfall events by comparing measured soil loss values to values predicted by the equation. Event soil erodibility factors (RUSLE K factors) were back calculated and compared to published average annual K factor values to confirm the use of RUSLE to predict event soil loss. The equation was found to be a reliable predictor of event soil loss on loam and sandy loam soils, but not on the silty clay loam soil.