Optimum selection and placement of agricultural best management practices in Pinios river basin for the mitigation of nitrates water pollution and water scarcity

The intensification of agricultural activities, which are crucial for sustaining crop productivity in rural areas, can also lead to the depletion of water supplies and the degradation of water quality. The challenge of addressing nitrates water pollution and water scarcity at a river basin scale requires the consideration of trade-offs between economic and environmental targets. The adoption of Best Management Practices (BMPs) in agriculture to deal with the issue is becoming increasingly widespread. This study implemented the Soil Water Assessment Tool (SWAT) model to evaluate nitrates discharges and water conservation in response to alternative agricultural management practices. The model was embedded within a decision support tool, enhanced by a multi-objective optimization algorithm to analyze the alternatives, suggesting the most efficient allocation of BMPs to address the above-mentioned water objectives at a basin scale. Applying a four-objective optimization process, various mitigation strategies, including individual and combined changes in livestock and farming practices, were examined in Pinios river basin, proving the methodology's resilience and relevance. Through the use of cost-efficient measures, modelers can identify and prioritize appropriate management strategies by combining process-based hydrological models with fast and precise cost estimations.