Adapting Mediterranean Landscapes to Hydrological Extremes

In the Mediterranean region, changes in the hydrological cycle are evident, either due to increased drought intensity and frequency or the occurrence of extreme precipitation events. The impacts of these phenomena challenge the resilience of socio-ecological systems, posing a threat to the region's sustainability. In an effort to address this, the LandEX project aims to enhance the resilience of landscapes by spatially optimising a suite of synergistic measures that leverage the multiple benefits of Nature-based Solutions. In this work, we calibrated a SWAT+ eco-hydrological model to assess the impact of adaptation strategies on hydrological processes under a baseline scenario (2004-2010). Adaptation strategies, co-created in collaboration with regional stakeholders, were modelled in the Gilão catchment (Southern Portugal), a semi-arid area highly vulnerable to hydrological extremes. We evaluated the effectiveness of measures against a set of predefined Flood and Drought indicators. Preliminary results, testing the individual effect of each measure, suggest that structural NbS, such as check dams, contribute to reducing peak-flow more effectively than non-structural NbS (e.g., agroforestry, conservation agriculture, or riparian vegetation) during extreme precipitation events. Contrastingly, non-structural NbS demonstrated improved resilience towards hydrological drought by limiting evapotranspiration. Upcoming work will assess the overall effect of the adaptation strategies combining multiple NbS on flow regulation and drought mitigation under different climate change scenarios. Identifying the most effective adaptation strategies to mitigate the impacts of hydrological extremes will enable decision-makers and field practitioners to enhance the resilience of socio-ecological systems in the region.