Future of Snowmelt Hydrology and Hydropower: A Case Study of Türkiye’s Mountainous Basins

Climate change significantly impacts global water resources, particularly in snow-fed mountainous basins where reservoir operations and hydropower generation are crucial. This study investigates future snowmelt runoff, water resource management, and hydropower production under climate change scenarios for two headwater basins in Türkiye: Peterek on the Çoruh River in the Eastern Black Sea region and Göksu on the Seyhan River in the Mediterranean region. These basins were selected for their similar topographies but distinct climatic conditions, representing regions predicted to experience varying climate change impacts.

An ensemble of five Global Climate Models (GCMs) from the CORDEX-Europe database, adjusted for local bias corrections, was employed under Representative Concentration Pathways (RCP) 4.5 and RCP 8.5 scenarios, along with Global Warming Levels (GWL) from the Paris Climate Agreement. The HBV-Light model simulated future reservoir inflows (2020–2099), revealing significant reductions in snow accumulation and inflows due to rising temperatures and altered precipitation patterns. Reservoir operations and hydropower generation projections were conducted using the Water Resources Assessment and Planning (WEAP) model, predicting a 4–9% reduction in hydropower generation for the Çoruh Basin and a 10–35% reduction for the Seyhan Basin over the final decades (2076–2099).

To adapt to these changes, four alternative management strategies were evaluated to optimize reservoir operations under climate challenges. This study emphasizes the importance of comprehensive scientific assessments for policymakers in understudied, snow-dominated transboundary river basins, particularly those with significant energy production potential. The findings contribute to improved water and energy management by providing critical insights into climate-driven changes in reservoir storage, flow patterns, and hydropower generation.