Compound natural disasters in Australia: a historical analysis

Compound disasters pose complex disaster coordination and recovery challenges. To inform disaster planning for catastrophic disasters it is essential to understand their frequency and characteristics. In this study we utilise natural disaster loss databases to identify the frequency of historical compound disasters in Australia, considering their characteristics and climate influences. Results show that compound disasters have occurred frequently and are associated with the highest seasonal losses in terms of both insured financial losses and fatalities. They may occur coincidently with other societal stressors such as wars, recessions and pandemics further exacerbating their consequences. Though their component disasters most frequently occur in eastern Australia, events can comprise disasters in both the east and west of the continent.  There is no temporal trend in their frequency when considering financial losses, but there is a downward trend when considering only fatalities.  It is essential that future disaster risk assessments and plans consider compound disaster scenarios. Relationships with climate drivers may assist to forecast their occurrence.