Index Development of Drought Risk Assessment on Regional Scale

Abstract

Due to the growing awareness regarding the seriousness of droughts, every year since 2017, a South Korean national drought policy has been established jointly by related ministries. Although the risk of droughts is an important concept widely considered in drought policies around the world, it is not included at the domestic policy of South Korea. In addition, the framework of drought risk assessment has developed into a conceptual model, the verification part of which remains insufficient. Therefore, research must be conducted to explain and verify the risk. In this proposed framework, risk is composed of hazard, exposure, and capacity indicators, and the drought risk index (DRI) is calculated using these three indicators. The hazard indicator refers to the cause of droughts, such as a lack of precipitation. The exposure indicator includes factors that are most significantly influenced by droughts, such as water demand. The capacity indicator, used as socio-economic data, is divided into the coping capacity for reducing and the adaptive capacity for addressing the damage. The DRI is calculated via data preprocessing processes and weighted with random values of 0.1 units. For verification, the Pearson correlation coefficient between the DRI and drought damage estimation is utilized to select weighting coefficient sets. Finally, the future DRI in the 21st century is projected and analyzed under RCP 4.5 and RCP 8.5. The national average DRI is highest in the early 21st century. The highest DRI was calculated to be in the Seomjin River region, and the increase in the number of sub-basins was the largest in the Han River region.