Erosion Risk Assessment for Prioritization of Soil and Water Conservation Measures in the Semi-Arid Region: A Remote Sensing and GIS-Based Approach

Abstract

Erosion risk assessment is essential for implementing effective soil and water conservation (SWC) measures, presenting complex challenges, especially in data-scarce semi-arid regions of India. This study addresses these challenges by applying a comprehensive approach to prioritize intervention areas, thus enhancing erosion management efficiency in the Devgadh Baria Watershed (DBW) in Gujarat, India. The primary objective is to systematically prioritize sub-watersheds (SWs) through geomorphometric and LULC analyses and propose appropriate SWC measures for high-priority areas. Utilizing remote sensing (RS) and geographical information systems (GIS) techniques, the study delineates SWs and assesses their vulnerability using seven distinct morphometric parameters and LULC classes, including agricultural land, forest, wasteland, and built-up areas. The combined analysis integrates these parameters to produce compound values for all 30 SWs, resulting in a refined priority ranking. SW26, initially very high priority in morphometric analysis due to steep slopes and minimal drainage density, shifted to medium priority in the combined analysis, reflecting effective agricultural management practices that reduce erosion. Conversely, SW7 remained a very high priority across both analyses, indicating consistent high erosion risk due to a significant built-up area and limited forest cover. SW30 shifted from high to medium priority, influenced by balanced agricultural activities and lower slopes. SWs 6 and 24 transitioned from very high to medium priority, while SW22 remained high, supported by moderate forest cover and beneficial soil types mitigating erosion. This research underscores the scientific importance of integrating morphometric and LULC analyses for precise SW prioritization. The combined approach enhances erosion risk assessments and supports targeted SWC strategies, crucial for effective watershed management in semi-arid regions. The findings provide actionable insights that align with global sustainability goals, contributing to improved soil conservation and water resource management.