ABSTRACT

Compound disasters, defined here as two or more disasters occurring within a three-month window and within a given jurisdiction, pose complex disaster coordination and recovery challenges. Planning for the management of such disasters would benefit from a better understanding of their frequency and their underlying climate influences. Here we utilise an Australian natural disaster database of normalised insurance losses to show compound disasters are responsible for the highest seasonal financial losses. Though their component events occur most frequently in the eastern seaboard, they may also comprise disasters on both sides of the continent. There has been no temporal trend in their frequency since 1966. A new compound disaster scale is proposed for Australian conditions. A bootstrapping analysis reveals the pairing of Bushfire and Tropical Cyclone to occur far less often than would be expected by chance. This is because these perils occur most frequently under contrasting climate states. Climate variability influences the frequency, intensity and type of perils contributing to compound disasters with the clearest relationship being with the El Niño Southern Oscillation. Given that ENSO is the most predictable climate driver at seasonal timescales, this may assist better forecasting of their occurrence and higher degrees of readiness.

摘要

复合灾难，此处定义为在三个月窗口内和给定管辖范围内发生的两次或更多灾难，构成复杂的灾难协调和恢复挑战。更好地了解此类灾害的发生频率及其潜在的气候影响，将有助于规划此类灾害的管理。在这里，我们利用澳大利亚自然灾害标准化保险损失数据库来显示复合灾害是造成最高季节性财务损失的原因。虽然它们的组成事件最常发生在东部沿海地区，但它们也可能包括大陆两侧的灾难。自 1966 年以来，它们的频率没有时间趋势。针对澳大利亚的情况提出了一种新的复合灾害量表。自举分析表明，丛林大火和热带气旋的配对发生的频率远低于偶然预期的频率。这是因为这些危险最常发生在对比鲜明的气候状态下。气候变化会影响导致复合灾害的风险的频率、强度和类型，最明显的关系是厄尔尼诺南方涛动。鉴于 ENSO 是季节性时间尺度上最可预测的气候驱动因素，这可能有助于更好地预测它们的发生和更高的准备程度。导致复合灾害的危险强度和类型与厄尔尼诺南方涛动最明显的关系。鉴于 ENSO 是季节性时间尺度上最可预测的气候驱动因素，这可能有助于更好地预测它们的发生和更高的准备程度。导致复合灾害的危险强度和类型与厄尔尼诺南方涛动最明显的关系。鉴于 ENSO 是季节性时间尺度上最可预测的气候驱动因素，这可能有助于更好地预测它们的发生和更高的准备程度。