An integrated assessment of tropical cyclone risks in mainland China by considering hazard, exposure, vulnerability and mitigation

Tropical cyclones (TCs) cause devastating losses of lives and properties every year across the globe. This paper makes use of detailed geographic data on historical TCs and socio-economic conditions for both coastal and inland regions to assess the TC risk in China. Specifically, the mitigation capacity is integrated into the 'Hazard-Exposure-Vulnerability' (HEV) framework, and the TC risks are calculated by using the multiplicative/divisive and additive/subtractive formulae based on indicators of hazards, exposure, vulnerability and mitigation. The estimated TC risks are furthermore validated by using the data of direct economic losses and casualties. The results show that coastal areas in China are generally dominated by high TC risks and that inland areas also suffer considerably due to TC-induced secondary disasters. The TC risks calculated by the additive/subtractive formula can better capture the density of direct economic losses and casualties compared with those calculated by the multiplicative/divisive formula. TC hazard plays an important role in determining TC risks in South China, whereas exposure and mitigation play a critical part in determining TC risks in North China. Overall, the consideration of mitigation capacity makes the calculated TC risks more consistent with the magnitude of direct economic losses and casualties.

Automated summary

This study assesses the risk of tropical cyclones in China using detailed geographic data and socio-economic conditions, and incorporates mitigation capacity into the assessment framework. The results show that coastal areas are generally at high risk, while inland areas also suffer significant losses due to secondary disasters. The additive/subtractive formula better captures the density of direct economic losses and casualties, and different factors play different roles in risk assessment in different regions. The consideration of mitigation capacity improves the consistency between calculated risks and actual losses.