Prioritization of agricultural sub-watersheds in semi arid middle region of Gujarat using remote sensing and GIS

Abstract

In this study, proven capability of remote sensing and GIS are used for watershed prioritization. 19 different sub-watersheds are prioritised through geomorphological analysis and suitable structures are proposed for soil and water conservation in a Limkheda agricultural watershed situated in semi arid middle region of Gujarat, India. Remote sensing images such as SRTM are used to delineate the watershed and to generate slope thematic maps, soil maps are applied to generate soil type, whereas LISS III remote sensing image is used for generating land use maps. Prioritization of sub-watersheds using geomorphological analysis is carried out by seven different linear and shape parameters. Then different sub-watersheds are prioritised by assigning ranks using compound parameter. After prioritization, land use, soil type and land slope categories of sub-watersheds are integrated to propose suitable soil and water conservation structures. In this study, it is proposed that soil conservation measures should be adopted as per the priority assigned to reduce the adverse effect on the land and environment. Overall, it is concluded in this study that delineation of watersheds into sub-watersheds and prioritization of these sub-watersheds are very relevant, helpful and important in semi-arid regions of middle Gujarat, where there is high diversity in agricultural practices and size of land holdings. Adaptation of soil conservation measures priority-wise will not only reduce the soil erosion but also increase the water availability in the surface and as groundwater and will further reduces the possibility of droughts as well as floods and finally environmental hazards.