Land degradation vulnerability (LDV) assessment using GIS–AHP in a semi-arid, watershed in South-Central India

Abstract Land degradation vulnerability (LDV) assessment was conducted using multiple landscape, soil and vegetation parameters in an agriculturally important watershed in hot, semi-arid central peninsular region of southern India. LDV assessment in such water-stressed agricultural areas are key to understanding seasonal productivity variations, and achieving sustainable land management while intensifying agriculture to impart local food security in the current climate change regime. Multiple legacy and remotely-sensed digital datasets were used to create a land degradation vulnerability index for the Kaulasa Nala catchment using the Analytic Heirarchical Process (AHP) framework. AHP was used to balance parameter-dependance of key landscape factors during assessment of land degradation vulnerability and productivity variations. The use of expert knowledge gathered from the field during agricultural extension work improved the overall efficacy of using the AHP framework. The analysis indicates the importance of focusing on restoration and regenerative practices in land management to improve both general land productivity at catchment scales, as well as safeguard the current productive areas from further degradation due to coupled topography-climate driven degradative processes. In this study, upland erosion vulnerability contributes to seasonal productivity changes in fertile, down slope lowland. There is a clear indication of lowland foot slopes experiencing depositional processes suffering from productivity degradation, a case of topographic and proximity-induced land quality change. Thus, our study reiterates the importance of multi-scalar and multi-parametric land degradation analysis based on field knowledge for building agricultural resilience in the semi-arid tropics.