Physicochemical properties of inland wetland soils in the Han River basin and estimation of carbon storage using the kriging method

As global efforts toward carbon neutrality accelerate, awareness of the critical role of natural ecosystems as carbon sinks has increased. Wetlands, although they cover only 5 8% of the Earth’s land surface, are estimated to store approximately 20 30% of global soil carbon, making them highly effective carbon reservoirs. Despite thir importance, inland wetlands in South Korea remain underrepresented in national carbon assessments. This study quantified soil carbon storage in the inland wetlands of the Han River Basin. A total of 250 sampling sites were selected using conditional Latin hypercube sampling, and soil samples were collected across four depth intervals(0-10 cm, 10-30 cm. 30-60 cm, 60-100 cm). The physicochemical properties of soils were analyzed by depth to support accurate estimation. The relationships among soil physicochemical properties and carbon storage were examined, and the spatial distribution of soil carbon stocks was predicted using ordinary kriging. Results demonstrated variations in carbon storage likely associated with differences in soil conditions and vegetation cover. Prior studies suggested that long-term ecosystem restoration and vegetation management significantly enhance the carbon sequestration potential of wetland soils. The findings of this study provide essential baseline data for improving the accuracy of South Korea’s national greenhouse gas inventory and for the development of country-specific emission factors. Applying this methodology to other major watersheds, such as the Yeongsan and Nakdong Rivers, may further support systematic assessment and management of carbon storage across Korea’s inland wetland ecosystems.