Investigating the spatial and temporal characteristics of compound dry hazard occurrences across the pan-Asian region

Abstract

Climate extremes have grown increasingly severe and frequent, posing significant threats to both economies and ecosystems. Prior research largely focused on individual hazard occurrences, often overlooking the compounded effects of multiple extreme events. With the escalating anthropogenic activities and increasing temperatures in Asia, there is an imperative need to investigate the occurrence of compound dry hazards (CDHs). This study aims to conduct a comprehensive assessment of CDHs in Asia, with a specific focus on examining the co-occurrence of heatwaves, droughts, fire dangers, and extreme winds over a 42-year period from 1980 to 2021. To be specific, our research focuses on evaluating interannual variability, identifying geographical hotspots, analyzing temporal shifts in cascading compound events, and exploring the dependence structure within CDHs. Our results indicate a significant increase in the spatial extent of CDHs in recent decades, with varying patterns in annual average frequencies across Asian regions. Particularly significant is the concentration of CDH hotspots within developing countries situated in East Asia, South Asia, and Southeast Asia. Moreover, our analysis highlights substantial increases in both the frequency and duration of cascading events (CEs), particularly in densely populated areas across North, Central, East, and West Asia. Conversely, South Asia experiences conspicuous declines in CEs. Lastly, our investigation into the dependence structure among CDHs illustrates varying degrees of interdependence among dry hazards and diverse spatial relationships across different Asian regions. We believe that these findings are highly valuable for enhancing natural risk management, improving climate model accuracy, and fortifying strategies to address the evolving risks associated with compound climate extremes under climate change.