Author(s): Jiyu Seo; Jeongeun Won; Sangdan Kim

Linked Author(s): Jiyu Seo, Jeongeun Won, Sangdan Kim

Keywords: Copula; Environmental drought; EDDI; SPI; Water temperature

Abstract: Drought is a natural phenomenon that can occur in all climates with various severities and spatial coverages. It is also a complex natural hazard with devastating effects on aquatic ecosystems. In this study, the environmental drought was analyzed from the perspective of water temperature, which is a representative influencer of aquatic ecosystems and plays an important role in the overall health of aquatic ecosystems, including distribution of aquatic species. In this study, the effect of drought on the water temperature in the river section was analyzed using the meteorological drought index, the Standardized Precipitation Index (SPI) and the Evaporative Demand Drought Index (EDDI). The target river is the Nakdong River located in the southeastern part of the Korean Peninsula. By using the SPI of the atmospheric moisture supply side and the EDDI of the atmospheric moisture demand side, it was attempted to reflect the meteorological drought stress caused by two causes: atmospheric moisture supply and demand. The dependence structure between the water temperature and the drought index for each season was constructed based on the Copula theory. As a result of analyzing the possibility of environmental drought by water temperature, both SPI and EDDI showed a high possibility of environmental drought caused by high temperature in spring, summer, and fall in most river sections of Nakdong river watershed, and a high possibility of environmental drought caused by low water temperature in winter. Finally, the environmental drought risk map was prepared after quantifying the environmental drought risk through the estimated environmental drought potential. Through the environmental drought risk map, it was possible to identify river sections vulnerable to water temperature changes during drought by watershed and by season. Acknowledgment This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2019R1A2C1003114).

DOI: https://doi.org/10.3850/IAHR-39WC252171192022775

Year: 2022