Identifying the impacts of climate change on hydroelectiricity production and water supply in the seyhan basin using cmip6 simulations: A case of karakuz dam and hepp project

Evaluating the impacts of climate change on water resources projects is crucial for ensuring their long-term sustainability. This study presents an integrated modeling framework to assess the reliability of a multi-purpose reservoir under various climate scenarios, using the Karakuz Dam Hydroelectric Power Plant (HEPP) in Türkiye as a case study. For this purpose, precipitation and temperature simulations from 24 global circulation models (GCMs) included in the Coupled Model Intercomparison Project Phase 6 (CMIP6) were analyzed using different statistical bias correction methods to generate best-performing multi-model ensemble projections. These projections encompass the CMIP6 historical experiment scenario as well as two future shared socio-economic pathway (SSP) scenarios: the medium-forcing SSP245 and the high-forcing SSP585. The Soil and Water Assessment Tool (SWAT) was used to simulate reservoir inflows based on the ensemble projections, and lake evaporation estimates were incorporated to assess the total available water volume for hydropower generation, domestic supply, and downstream ecological flow requirements. Reservoir operations were simulated for the historical baseline period (1969-2014) and three future periods: near-term (2025-2049), mid-term (2050-2074), and long-term (2075-2099). The results indicate potential reductions in annual energy production of up to 16.6% under SSP245 and up to 46.6% under SSP585. Despite these projected reductions, domestic and environmental water demands are expected to be met under all scenarios. The study highlights the importance of adaptive water management strategies to mitigate the adverse effects of climate change on hydropower systems and to maintain their resilience and functionality.