The role of severe storms in soil erosion: A problem needing consideration

Abstract

The prediction of soil erosion and the design of conservation management practices for the control of erosion are based on long-term average precipitation patterns. However, soil erosion losses are often dominat ed by a few severe storms of high intensity and high precipitation amounts. These rare storms show possible weakness in our design of conservation management systems. The Universal Soil Loss Equation (USLE) (Wischmeier and Smith 1978) was developed to predict long-term average erosion amounts from cultivated fields for use in conservation planning. The Revised Universal Soil Loss Equation (RUSLE) (Renard et al. 1991) has the same form as the USLE but includes a number of subfactors to the main factors. The extensive database used to develop the USLE also supports RUSLE. Significant additions to the original database improve the versatility and application of RUSLE compared to the USLE (Renard et al. 1994). The C factor in RUSLE, which divides the year into bimonthly intervals and recalculates soil loss ratios for every tillage operation, is more sensitive to variations in canopy cover, surface residue, and surface roughness than is USLE. The K factor is also adjusted to account for seasonal changes such as freezing and thawing, soil moisture …