Study on the multi-type drought propagation process and driving factors on the Tibetan Plateau

Abstract

Drought propagation is a complex process that involves various components of the water cycle. Clarifying the pathways and mechanisms of propagation for various types of droughts is crucial. However, most current analyses of drought propagation focus on the relationship between just two types of drought, with limited research on multi-type drought propagation. This study elucidates the propagation pathways of multi-type drought on the Tibetan Plateau (TP) using extended convergent cross mapping (CCM) to determine the propagation time. Additionally, the CCM-based drought duration propagation index (CDDP) and drought intensity propagation index (CDIP) were constructed, and the driving factors of drought propagation were preliminarily explored using the geographic detector. The results indicate that between 1997 and 2017, drought propagation on the TP followed the sequence of meteorological drought, hydrological drought, and agricultural drought, with propagation times of 4.6 months, 4.9 months, and 4.2 months, respectively. Although the overall trends in multi-type drought propagation characteristics are relatively balanced, significant differences exist within individual basins, and neighboring regions exhibit heterogeneous drought propagation patterns. The key driving factors for different types of drought propagation vary, with natural factors and human activities significantly influencing the spatial distribution of drought propagation characteristics, with CDDP being particularly sensitive to these driving factors. This study further elucidates the processes and driving factors behind multi-type drought propagation, offering new research perspectives for understanding the mechanisms of drought propagation.