<p>&#160; &#160; Groundwater is the largest freshwater resource available on Earth, and many coastal regions are depending on groundwater as a primary freshwater source. For example, in Busan and Incheon, two of the largest coastal cities in South Korea, 5.7% and 7.0% of freshwater uses are from groundwater while only 1.8% is from groundwater in Seoul, the capital of the country. Globally, groundwater availability is diminishing primarily by population increase, and especially in coastal regions, this problem is exacerbated by overexploitation and seawater intrusion, which causes groundwater contamination and further reduces its availability. Here, we view the groundwater system and its management for sustainability as a complex problem that is associated with various social, economic, and environmental factors. By adopting the City Blueprint Approach (CBA), which has been used extensively for assessing the sustainability of integrated water management of numerous cities on the globe, we identify water management factors that potentially have direct and indirect links and feedbacks with groundwater variables. We selected Busan and Incheon as case studies for coastal cities that are facing the risk of groundwater salinization by seawater intrusion. This study aims to 1) assess City Blueprint (CB) of selected coastal cities, 2) identify major factors for coastal groundwater management through correlation analysis, and 3) suggest management options regarding identified factors for sustainable groundwater management of the study areas. Our results on CB indicate that the groundwater quality and quantity of the selected cities are currently in &#8216;good&#8217; status. Also, from the correlation analysis, we identified heat risk and freshwater scarcity as the major factors that potentially can affect groundwater quantity. For groundwater quality, the factors of voice and accountability, regulatory quality, and rule of law and control of corruption, most of which had not been explicitly considered for groundwater management, were identified as the major factors. Some of these factors were assessed from &#8216;little concern&#8217; to &#8216;very concern&#8217; for both cities. These results indicate that, regarding the linkages between groundwater variables and other factors in concern, more actions beyond environmental factors should be taken for sustainable groundwater management. This study helps to understand how non-conventional factors could contribute to coastal groundwater, and can provide extensive options for sustainable groundwater management.</p><p>&#160;</p><p><strong>Acknowledgement</strong>: This research was supported by the Development program of Minimizing of Climate Change Impact Technology through the National Research Foundation of Korea (NRF), funded by the Korean government (Ministry of Science and ICT) (NRF-2020M3H5A1080775).</p>
Assessment of transboundary aquifer resources in Asia: Status and progress towards sustainable groundwater management
