Factors influencing interrill erosion from semiarid slopes in New Mexico

Abstract

This rainfall simulation study evaluates the effects of slope, vegetation, rock, and soil characteristics on interrill erosion of semiarid slopes of the Guadalupe Mountains of New Mexico. A single-nozzle rainfall simulator applied rainfall on slope gradients ranging from 0-70%. Multicollinearity in the data was corrected for by using partial correlation analysis. Interrill erosion was most influenced by slope gradient; however, the effect of slope gradient was modified by other factors, particularly vegetation. Vegetation greatly lessened interrill erosion, especially during the initial stages of runoff. Shrubs decreased interrill erosion more than did either grasses, litter, or forbs. Sediment concentration was greater from erosion pavements than from well-vegetated plots. Increases in rock cover, however, without corresponding decreases in vegetal cover, afforded additional protection against interrill erosion. Soil texture and soil depth were the most influential soil factors, particularly on steep slopes.