Assessing future water shortages at Boryeong dam, South Korea, under CMIP6 climate scenarios using the SWAT model

Climate change is significantly impacting water resource management, with increasing droughts threatening water availability worldwide. This study assesses future water shortages at Boryeong dam in Chungnam Province, South Korea, under Coupled Model Intercomparison Project Phase 6(CMIP6) climate scenarios using the Soil and Water Assessment Tool (SWAT) model. The research integrates data from 18 Global Climate Models (GCMs) across multiple Shared Socioeconomic Pathways (SSPs) to analyze projected inflows, outflows, and reservoir storage capacity. The results indicate an overall increase in annual precipitation and inflow, with mean inflows rising from 5.26 m³/s (historical period: 1981-2010) to 6.64 m³/s under SSP5-8.5 by 2071-2100. While most projections suggest improved water supply resilience, certain models predict intensified shortages, with estimated shortage volumes ranging from 7.54 million m³ to 1,914 million m³, highlighting the urgency of adaptive water management strategies. The study employs downscaling and bias correction techniques to enhance hydrological predictions, and simulations reveal significant uncertainties in future water levels. To mitigate potential shortages, policy recommendations include diversifying water sources, optimizing dam operations, and improving emergency water transfer infrastructure. The research underscores the importance of proactive planning in ensuring long-term water security in the face of climate variability.