Analysis of Drought Propagation Through a Comparison of the Whole Time-Series Approach and the Drought Event Approach

Abstract Submission: The propagation of meteorological drought to hydrological drought is emerging as an important issue in watershed management and water resource planning. Previous researches have compared hydrological changes before and after dam construction using a whole time-series approach, but this approach has limitations as the correlation between meteorological and hydrological drought indices may vary depending on the drought characteristics. Therefore, this study aims to apply the drought event approach to evaluate the drought resistance of dams through the drought propagation analysis technique. It also compares the results of the whole time-series approach and the drought event approach to explore the differences between the two methodologies. The subject of the study is the Hapcheon Dam in the Hwanggang B basin in the southeastern part of the Korean Peninsula, and drought events are identified using the standardized precipitation index (SPI) and standardized runoff index (SRI). The SWAT+ model was applied to simulate natural and adjusted flows before and after dam construction under the same climatic conditions. The analysis showed that the propagation threshold and the return period of each drought characteristic increased compared to before the dam was constructed. The correlation between SPI and SRI also varied by index condition, confirming the limitations of analyzing drought propagation over the entire time series. The study is expected to provide insights into changes in the dynamics of drought propagation due to dam construction, providing valuable insights into understanding the past and future impacts of climate variability on hydrologic systems.

ACKNOWLEDGMENTS

This work was supported by Korea Environment Industry & Technology Institute(KEITI) through Research and Development on the Technology for Securing the Water Resources Stability in Response to Future Change Project, funded by Korea Ministry of Environment(MOE)(RS-2024-00332300).

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