Hydrologic risk assessment of drought in South Korea according to climate change scenarios using a multiple drought index integrated with a dynamic naive Bayesian classifier

Abstract

According to various climate change scenarios, both the frequency and the intensity of droughts are expected to increase dramatically. In South Korea, the development of drought-response policies must consider climate change due to the large variabilities of climate characteristics at regional scales. In this study, a multiple drought index was computed by combining the standardized precipitation index, streamflow drought index, evaporative stress index, and water supply capacity index, and applying the dynamic naive Bayesian classifier (DNBC). A bivariate drought frequency analysis and hydrologic risk analysis were conducted according to two climate change scenarios described by representative concentration pathways (RCPs). In the short term, a high hydrologic risk was mostly observed throughout South Korea. The central regions, including the Han River, Geum River, and Nakdong River basins, appeared to be particularly vulnerable to drought. From medium-term to long-term perspectives, the hydrologic risk was expected to remain high in some areas of the Geum River basin and the southern coast of South Korea under RCP 4.5 and high in some parts of the Geum River basin and southern portions of the Nakdong River basin under RCP 8.5. This study identified the areas vulnerable to drought and provides significant information for use by policymakers tasked with developing drought-response strategies. © 2024 The Author(s)