The Revised Universal Soil Loss Equation

THERE are many changes for estimating erosion by water in RUSLE, the revised universal soil loss equation. The changes include the following: Computerizing the algorithms to assist with the calculations. New rainfall-runoff erosivity term values (R) in the western United States, based on more than 1,200 gauge locations. Some revisions and additions for the eastern United States, including corrections for high R-factor areas with flat slopes to adjust for splash erosion associated with raindrops falling on ponded water. Development of a seasonally variable soil erodibility term (K). A subfactor approach for calculating the cover-management term (C), with the subfactors representing considerations of prior land use, crop canopy, surface cover, and surface roughness. New slope length and steepness (LS) algorithms reflecting rill to interrill erosion ratios. The capacity to calculate LS products for slopes of varying shape. New conservation practice values (P) for rangelands, stripcrop rotations, contour factor values, and subsurface drainage. History of the USLE Although the universal soil loss equation (USLE) is a powerful tool that is widely used by soil conservationists in the United States and many foreign countries, research and experience since the 1970s have provided improved technology that is incorporated in the …