An integrated framework to assess the optimal implementation of buffer strips in Mediterranean agricultural regions: Insights from the real-world case study of Rio Santa Marina watershed (Southern Italy)

Diffuse non-point source pollution from fertilizers, pesticides and soil erosion poses a significant threat to the water quality of agro-urban lands, driven by intensive farming and urban growth. In this context, buffer strips are widely recognized as an effective nature-based adaptation measure to mitigate the spreading of diffuse pollution. Although the EU Common Agricultural Policy (CAP) promotes their adoption through eco-schemes and incentives, real-world implementation remains often limited and this is largely due to farmers reluctance to allocate productive land for buffers as well as the lack of comprehensive cost-benefit assessments demonstrating their economic viability. To address these gaps this study applies an integrated framework to quantitatively evaluate riparian buffer strip implementation and its potential benefits in Mediterranean agricultural basin regions that are highly vulnerable to climate-change impacts. In this extent, as a real-world case study, we select the Rio Santa Marina basin, a headwater tributary of the Sarno River (Campania, Italy) that is a severely polluted watercourse characterized by intensive agricultural activity principally in the upper part of the watershed. This integrated framework combines data on the topography, irrigation channel networks, land use and land cover, crop types and agricultural productivity to quantify the implications of buffer strip installation. This analysis supports the optimization of buffer placement while accounting for potential reductions in farmer’s income. In parallel, a cost-benefit analysis will evaluate financial feasibility and farmer’s willingness to adopt CAP-supported buffer designs. The study will support policymakers and water managers by providing: (i) a high-resolution spatial assessment of land suitable for buffer strip implementation (ii) a scenario-based buffer strip designs that maximize diffuse pollution reduction while minimizing the land subtracted from agriculture and (iii) a policy-oriented cost-benefit analysis to strengthen adoption under EU CAP eco-schemes. Ultimately, the project will offer a validated, scalable decision-support system to improve water quality in accordance with EU Water Framework Directive across agro-urban basins in Europe.