Sensitivity Analysis of the USLE Soil Erodibility Factor to Its Determining Parameters

Abstract

The soil erodibility index (USLE K-factor) is one of the major soil erosion predictors. It depends on soil texture, organic matter content, soil structure and soil profile water permeability. Sensitivity analysis of the K-factor to its determining parameters would give an opportunity to control the soil loss through erosion by controlling the parameters, which reduce the K-factor value. The aim of the report is to present the results of analysis of the relative weight of these soil characteristics in the K-factor values.
The relative impact of the soil parameters on K-factor was studied through a series of statistical analyses of data from the geographic database for soil erosion risk assessments in Bulgaria. The results show that the content of particles finer than 0.002 mm has the most significant relative impact on the soil erodibility, followed by the content of particles with size from 0.1 mm to 0.002 mm, the class of the water permeability of the soil profile, the content of organic matter and the aggregation class.