Regional variability in climate change impacts on agricultural reservoir water balance and tailored adaptation strategies under SSP scenarios in South Korea

Abstract In this study, the impact of climate change on the main water balance factors of agricultural reservoirs was examined using Shared Socioeconomic Pathways (SSPs). Trends in reservoir inflow, net irrigation water requirement, and required storage were analyzed for the past 40 years (1981–2020) and projected for the future (2031–2070) using a multi-model ensemble (MME) of 18 GCMs. The results indicate that while reservoir inflow exhibited a consistent increasing trend across all study regions due to projected precipitation rises, the responses of net irrigation water requirements and required storage were highly variable by region. Based on these divergent trends, the study regions were classified into four distinct types. For each type, tailored adaptation strategies were proposed, ranging from demand-side management (e.g., precision irrigation) to infrastructure-led adaptation (e.g., increasing storage capacity). These findings emphasize that climate change adaptation for agricultural water management must transcend uniform approaches and instead focus on region-specific strategies that address localized hydrological vulnerabilities.