Water Management Strategies for Conserving Aquatic Ecosystems in Agricultural Watersheds

Increasing agricultural intensity places a strain on aquatic systems. Nutrient runoff, siltation, and hydrologic disturbance endanger downstream aquatic communities. Conservation strategies for management are often developed without ecosystem benefits being accounted for, leading to decisions being made without a solid, empirical basis. This research offers an integrated solution using a SWAT-MODFLOW model in the Kaveri River basin for assessing the impacts of integrating precise irrigation and riparian vegetated buffer strips. A combination of remote sensing data, historical climate records, and in situ measurements was used to develop and calibrate the model for evaluating multiple conservation strategies. Important results show that, during high-intensity rainfall events, nutrient loads can significantly increase, and monocultures show hot spots of pollution. The riparian buffer strip application led to a 35% decrease in surface runoff velocity and sediment transport; however, the integrated effect of precise irrigation combined with appropriate nutrient management decreased the annual nutrient load of both nitrate and phosphate by 28%. The developed conservation techniques effectively stabilize the aquatic system by decoupling it from agriculture. This indicates that the strategy can be adopted on a large scale, providing an evidence-based decision-making approach for Integrated Water Resources Management (IWRM) and global Sustainable Development Goal (SDG) 6, enabling policymakers to maintain both agricultural sustainability and aquatic habitat conservation.