Effects of agricultural activities on water quality: catchment-scale modeling of nutrient pollution and management in cultivated lands, case studies of northern spain and southeastern sweden

Abstract

The intensification of agriculture to meet the increasing food demands and changing climate dynamics necessitates sustainable land and water resource management. This doctoral thesis examines the complex interaction between agricultural activities and water quality by exploring two agricultural-dominated watersheds in northern Spain and southeastern Sweden using the Soil Water Assessment Tool (SWAT) model. The research focuses on (i) evaluating the SWAT model’s applicability in the study areas, (ii) assessing the effects of changing from rainfed to irrigated agriculture, (iii) understanding the effects of climate change on water quantity and quality, and (iv) quantifying the efficacy of agricultural best management practices (BMPs) in minimizing nutrient export. Overall, this dissertation emphasizes the crucial need for a comprehensive grasp of agricultural impacts on water quality. The research not only elucidates the complicated dynamics of agricultural activities and water quality by utilizing advanced hydrological modeling approaches but also provides stakeholders with practical tools to guide informed decision-making. The findings of this research provide a transformative approach toward protecting water quality, nurturing resilient ecosystems, and promoting sustainable agricultural practices in diverse geographical contexts.