Impact of agriculture water management interventions on hydrological processes in a fragile watershed of Western India

Abstract

Water management interventions play an important role in ensuring sustainable food production and mitigating climate risks. This study was carried out in a watershed located in low rainfall (400-600 mm) region of western India. The paper analyses the changes in hydrological processes with the implementation of various rainwater harvesting (RWH) interventions using field measurements and SWAT simulation. The model was calibrated using the runoff gauging, storage levels, soil loss and groundwater measurements between 2000 and 2006. Various agricultural water management interventions have helped to enhance groundwater recharge from 30 mm to 80 mm, reduced surface runoff from 250 mm to 100 mm and enhanced base flow. The structures were filled 2 to 3 times depending on rainfall variability and total precipitation. The RWH interventions were found to build system resilience by enhancing groundwater availability even in dry years, which was the main reason for crop intensification and protected the landscape from heavy erosion. Sediment erosion reduced more than 75 percent compared to non-intervention stage. Moreover, 100-150 ha fallow land was brought under cultivation with high value crops such as horticulture, vegetables and fodder. The household income increased manifolds compared to non-intervention stage. The study showed about 50 percent reduction in downstream water availability, which could be the major concern. However, there are number of ecosystem trade-offs such as improved base flow and reduction in soil loss. The study is useful for larger scale decision making about optimal water harvesting for achieving sustainable development goals.