Projection of the Relationship between Climate Change Groundwater Resources Based on the MODFLOW Model

Climate change, a phenomenon that has been occurring since ancient times, has accelerated in recent years. This study investigates the impact of climate change on groundwater resources using the MODFLOW model. To achieve this, the water balance was first calculated, and then temperature and precipitation data for the near future (2031–2050), mid-term (2051–2070), and long-term (2071–2090) periods were estimated using global climate data. These estimated temperature and precipitation values were input into the MODFLOW 2005 model. The results showed that, under two climate change scenarios—shared socioeconomic pathways (SSPs) SSP2-4.5 and SSP5-8.5—the monthly averages of both minimum and maximum temperatures are expected to increase across all months of the year. In the optimistic scenario (SSP2-4.5), precipitation and aquifer recharge are projected to remain at current levels on average; however, groundwater levels are anticipated to decline by approximately 22 meters by 2089, with annual and seasonal fluctuations persisting in the long term. In contrast, the pessimistic scenario (SSP5-8.5) predicts a significant reduction in both precipitation and aquifer recharge, leading to a more pronounced decrease in groundwater levels. In this scenario, groundwater levels are expected to drop by about 30 cm per year in the long term, largely due to changes in precipitation patterns and aquifer recharge rates.