Squaring the cycle: the integration of Groundwater processes in nutrient budgets for a basin-oriented remediation Strategy

Long term projection of N and P concentrations in surface and ground waters cannot be entirely achieved unless groundwater features and processes affecting nutrients at the watershed scale are considered. This work presents the general approach of the INTEGRON project whose aim is to "square the cycle" in nutrient budgets, evaluating the role of groundwater as a temporary/permanent sink or as a release term at the catchment scale, in the Adda and the Ticino basins (northern Italy). An integrated approach is currently tested, which considers surface and groundwater, N and P species combining hydrogeology, biogeochemistry and socio-hydrogeology. The availability of nutrient excess, the nutrient increase in rivers during the irrigation period, and nitrate trends in different groundwater bodies confirm that groundwater in the area acts as both sink and source term of nutrients. Given the complexity of the studied system, the proposed multidisciplinary approach can permit to effectively implement science-based management strategies for water protection that consider both the social and environmental domains.