Soil erosion risk mapping for natural resource conservation planning in Karnataka region, Southern India

Abstract

District-wise soil erosion risk (SER) maps were prepared for the state of Karnataka with the objectives of prioritizing the districts of the state in order of the simplified weighted erosion risk index values, and to provide an estimate of the areas needing immediate attention in terms of conservation measures with the existing technology of natural resource management. The SER values for each district were computed by extracting the information on grid-wise soil erosion and soil loss tolerance limit values existing on the country-scale in a GIS environment. The results revealed that around 77% of the state can be considered as safe, and does not call for immediate soil conservation measures. The remaining area (4.18 M ha) requires conservation planning through prioritization. Six districts, viz., Koppal, Bagalkote, Belgaum, Gubarga, Bellary and Dharwad, with one-third of their areas showing net positive values require soil loss mitigation measures through phased planning. In order to obtain a clearer picture and categorize the districts based on their extent of vulnerability, the weighted erosion risk values were computed. Belgaum, Uttara Kannada and Bijapur were identified as the worst-affected districts in terms of soil erosion and therefore need immediate attention for natural resource conservation.