Identification of suitable sites for surface rainwater harvesting in the drought prone Kumari River basin, India in the context of irrigation water management

Water scarcity is one of the most pressing concerns facing the world in the 21st century. The groundwater re-serves are being depleted at a much faster rate than they can be replenished by precipitation. This problem can be avoided through the proper identification of rainwater harvesting sites and management of the water resources. Kumari River basin is a semi-arid, hard rock landscape where water scarcity has been a serious concern for decades. The main objective of this research is to identify suitable sites for surface rainwater harvesting (SRWH) in Kumari River basin using Geographic Information Systems (GIS) and the Analytic Hierarchy Process (AHP) techniques. To estimate the SRWH sites in the Kumari basin, 12 factors are taken into consideration. The suit-ability map is classified into 4 classes of which 20.26% show high suitability zones, 32.74% are moderately suitable zones, 29.40% are less suitable zones and 17.60% are unsuitable zones. The validation has been done by Receiver Operator Characteristic (ROC) curve using the 52 existing check dam sites, whose predictive accuracy value is 87.4%, which indicates an excellent accuracy rate of the model. Through this study, sites for the con-struction of SRWH structures, including 32 suitable check dam sites, 17 earthen dam sites, 35 percolation tank sites, 24 farm pond sites, and 19 gulley plug sites, have been proposed. The findings of this study will help policymakers and planners in developing sustainable water resources management plans and scientific strategies to enhance irrigational potentiality.