Numerical Evaluation of Large-Scale Groundwater Extraction in Groundwater System at Wellfields in the Namwon Area of Jeju Island, South Korea

A regional water supply system in Jeju Island, South Korea, comprising 23 wellfields with 5 to 10 groundwater extraction wells (20–100 m spacing), provides the residents of island. Regular large-scale pumping and excessive these have resulted a decrease levels. Using numerical model, we aimed assess effect at four Namwon, located southeastern part The model estimated an approximately 0.16–0.21 decline levels, which is consistent field observations. Minor declines are inherently influenced by hydrogeological setting study area, involves high precipitation rates flow that facilitates rapid replenishment. However, also shows levels expected intensify 0.20–0.77 cases extreme drought periods increasing pumping. In addition, this suggests sufficient well wellfield separation distances should be considered prevent interference effects areas, such as western island, increased due extraction.