Author(s): Kyung Soo Jun
Linked Author(s): Kyung Soo Jun
Keywords: Blue water; Green water; Water footprint; Water security assessment; SWAT;
Abstract: Water security is a growing concern, as it is related to public health, food security, and ecosystem protection. We estimated the water security of the Han River basin in South Korea, based on indicators of water scarcity and vulnerability, by incorporating the concept of blue and green water footprints. Monthly blue water flow, green water flow, and green water storage were calculated by applying the Soil and Water Assessment Tool (SWAT). Blue water was calculated as the sum of water yield and ground water storage, and green water was represented by actual evapotranspiration and soil water content; these hydrological components were obtained from the well-calibrated SWAT model. The results reveal that temporal distribution of blue water flow is influenced by the rainfall pattern, and the monthly green water flow (i.e., actual evapotranspiration) shows a clear seasonal pattern. Annual blue water and green water flows show an increasing trend during the simulation period, while green water storage shows a decreasing trend. Water security was estimated considering water demand by human activities (e.g., agricultural, domestic, and industrial use) and the required environmental flow. Our results provide temporal (i.e., monthly and annual) variabilities of water scarcity and vulnerability for water security assessment. This study can help to better understand the status of water resources, and identify the period of water stress in the Han River basin, and thus can improve water resource planning and management of this region.