Indicator-based assessment of groundwater resources sustainability in South Korea

Groundwater level decline and quality deterioration is continuously observed nationwide in South Korea. Meanwhile, the demand for groundwater, which is relatively stable and clean in the face of climate crisis and future industry, is increasing in South Korea. In order to meet sustainable use for growing groundwater demand, it is essential to assess groundwater resources sustainability by taking into account the economic, social, and environmental factors in management and planning of groundwater resources. This study proposes groundwater sustainability management indicators to account for these factors based on DPSIR framework. A case study is performed to assess groundwater resources sustainability on 5 river basins(Han-river, Keum-river, Nakdong-river, Youngsan-river, Seomjin-river) by using indicators with available data in South Korea. The results show that groundwater depletion and contamination is susceptible to occur nationwide with spatial variation. Renewable groundwater resources per capita is evaluated to be approximately ranged from 1,000 to 10,000 m3/yr over the nation, while less than 1,000 m3/yr in the western and southeastern parts of South Korea, which is related to high population and urbanization. Much of Groundwater abstraction occurs with respect to groundwater recharge in the easter areas. Among 5 river basins, groundwater dependence of Geum-river basin area is highest. Overall, the wester parts of Korea including Keum-river, Youngsan-river, Seomjin-river basins, are susceptible to be more stressed. Total nitrogen load is high in subbasins of Han-river and Keum-river basins, but groundwater quality index for nitrate-nitrogen shows different spatial patterns. In South Korea, total e-coli, NO3-N, and Cl- are major contaminants observed in groundwater. The case study shows that proposed groundwater sustainability management indicators can good enough to provide a general view of groundwater resources status. Proposed indicators can also be utilized to evaluate current status of groundwater and policies for National Water Management Basic Plan as well as used as elemental indicators for developing a comprehensive index for necessity. Further data collection and analysis is required for comprehensive assessment of groundwater resources management sustainability.