Agricultural and Hydrological Drought Propagation of Meteorological Drought

Drought is an extreme climate phenomenon characterized by lower precipitation over several months to years than usual and can be divided into meteorological drought, agricultural drought, hydrological drought, and socioeconomic drought. Drought propagation refers to the process of transferring from one type of drought to another.

This study quantified the correlation and transition characteristics between meteorological and agricultural (or hydrological) droughts from 1991 to 2021 in the Andong Dam basin and Hapcheon Dam, which belongs to the Nakdong River basin in the Republic of Korea. The standardized precipitation index (SPI), standardized soil moisture index (SMI), and standardized runoff index (SRI) were used as drought indices to characterize meteorological, agricultural, and hydrological droughts, respectively. Correlation analysis was performed to evaluate the correlation and propagation time between meteorological and agricultural (or hydrological) droughts, and probability of propagation was quantified using a copula-based model.

A strong correlation between meteorological and agricultural (or hydrological) drought was found in summer, and a relatively weak correlation was found in autumn. In addition, there was a difference in correlation between the Andong Dam basin and the Hapcheon Dam basin. The drought propagation time was different from season to season. The probability of occurrence of drought was analyzed by dividing the severity of each type of drought into four stages, and it was found that the probability of occurrence of agricultural (or hydrological) drought simultaneously increased as the severity of meteorological drought increased.

Acknowledgments

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. NRF-2022R1A2B5B01001750).