Propagation of meteorological to hydrological drought for different climate regions in China

Drought can lead to considerable agricultural, ecological, and societal damage. Improving our understanding of the propagation relationship between meteorological and hydrological drought is necessary to lessen drought impacts. The different drought responses and underlying mechanisms among different climate types are not yet sufficiently understood. By applying the standardized precipitation index and standardized runoff index, we investigated the propagation relationship between meteorological and hydrological drought. Because of short-term response between meteorological and hydrological droughts, the propagation time was considered among time scales of 1-12 months. Wavelet analysis was employed to examine the two types of drought from 1902 to 2014. Our results showed that arid environments had a weaker propagation relationship than moist environments. There was a stronger relationship between the two types of drought in summer and autumn than in spring and winter. The climate was not the only factor impacting drought propagation; land (cover and topographic feature) may also impact propagation time and intensity from meteorological to hydrological drought. This study analyzed and highlighted that the most susceptible regions in China and global scale, respectively. The most susceptible regions were tropical and subtropical Chinese southern zones in China and equatorial and warm temperate climate zones in global; however, arid climate zones showed little interaction between the two kinds of drought. Other factors that impact drought propagation, such as land cover, landforms, and human activity, should be considered in future research.