Relation between the soil erosion cover management factor and vegetation index in semi-arid basins

Abstract

The cover management factor is one of the main five factors that is used within the universal soil loss equation to reflect the effect of cropping and management practices on soil erosion rates. It is determined through tables and equations derived in tropical and European conditions, which are not suitable for semi-arid regions with different climate, topography, and soil characteristics. Therefore, this study considers al-Arish basin in Sinai Peninsula, Egypt as a semi-arid study area to generate a cover management factor’s equation in terms of the Normalized Difference Vegetation Index using hydrological modeling and satellite images processing. To verify the proposed equation, it was applied to the Derna catchment in Libya and compared with European and tropical ones with respect to the hydrological outputs. Statistical analysis indicates that the proposed equation determines the cover management factor more accurately than those developed for tropical or European regions, as the correlation coefficient between the cover management factor and the hydrological results was 0.71, while it was about 0.20 for the European and tropical, equations, also the degree of agreement between the proposed equation’s results and the hydrological simulation was 0.768 while it was 0.001 and 0.02 for the tropical and European equations respectively. By utilizing the newly developed equation, the soil erosion can be estimated more accurately for the semi-arid regions, and a better understanding of the relation between the vegetation cover and soil erosion can be drawn.