Spatial distributions of oxygen and hydrogen isotopes in multi-level groundwater across South Korea: A case study of mountainous regions.

This study presents the spatial distributions of stable isotopes for groundwater according to well depth and spring water across South Korea, using an interpolation model to provide baseline information for hydrological studies. In total, 888 groundwater and 108 spring water samples were collected across South Korea; their oxygen and hydrogen isotopic compositions (δO and δH) were analyzed. δO and δH values biased toward the summer local meteoric water line and low d-excess values indicate that summer precipitation is important for groundwater recharge.