Climate Change Impacts on Water Availability in Mediterranean Balkan River Basins: A Case Study of the Seman River Basin, Albania

The Mediterranean region is considered one of the world’s primary climate change hotspots, where rising temperatures and declining precipitation are expected to intensify droughts and water scarcity. In Albania, the Seman River Basin is of major importance for irrigated agriculture, hydropower production, and regional water supply. This study investigates future hydrological changes in agricultural sub catchments of the Seman Basin using the WASA-SED hydrological model forced with EURO-CORDEX regional climate projections.

Eight EURO-CORDEX regional climate model simulations were evaluated against observed precipitation and temperature data for the period 1991–2020 using a multi-criteria ranking framework. The best-performing climate model combinations were selected, bias-corrected, and applied to six hydrological subcatchments characterized by contrasting elevations and land-use conditions under RCP4.5 and RCP8.5 scenarios for the period 2021–2100.

Results indicate a robust decline in mean annual discharge across all sub catchments during the near future (2021–2050), with projected reductions ranging from 9% to 32% relative to the historical baseline. The most significant and consistent signal is the intensification of summer low-flow conditions, particularly in low-elevation agricultural catchments where irrigation demand is already increasing. High-elevation sub catchments show altered snowmelt dynamics and seasonal runoff redistribution. Long-term projections reveal divergence between emission scenarios: under RCP8.5, increased winter precipitation partially offsets annual runoff reductions in some sub catchments, while summer discharge remains substantially reduced in all scenarios.

The findings highlight the growing vulnerability of Mediterranean agricultural basins to climate-driven hydrological change and emphasize the need for adaptive water management strategies, including irrigation modernization, drought preparedness, and improved reservoir management. This research provides one of the first sub catchment-scale climate-hydrological assessments for Albania and demonstrates the applicability of the WASA-SED model for climate impact studies in data-sparse Mediterranean environments.