Quantitative Risk Assessment of Population Affected by Tropical Cyclones Through Joint Consideration of Extreme Precipitation and Strong Wind—A Case Study of Hainan Province

Abstract

Tropical cyclone disasters frequently occur in the southeastern coastal areas of China, and the concentration of population and economy has further increased the risk of tropical cyclone disasters in this region. The effects of tropical cyclones on populations involve a complex interaction between hazard intensity, environmental factors, exposure level, and fortification capacity. Therefore, quantifying the relationship among these factors is imperative for early warnings, risk assessments, and mitigation strategies for tropical cyclone disasters. In this study, a comprehensive tropical cyclone quantitative risk assessment approach considering the joint relation between strong wind and extreme precipitation and environmental, exposure and fortification factors was developed using the generalized additive model (GAM) and copula function for the case of Hainan province, China. The 10 min maximum wind speed (MW), maximum daily rainfall (MR), elevation (ELE), total population (POP), and time (t) were ultimately selected by the GAM as explanatory variables for the affected population rate (APR). A 50% increase in the MW produced a 48.779%–82.657% increase in the APR, a 50% increase in the MR produced a 19.534%–25.631% increase in the APR, and a 50% increase in the POP produced a 0.796%–15.193% decrease in the APR. The APR obviously increased with the return period increase in Hainan province. The APR of cites (counties) ranged from 0.443 to 0.632 for a once-in-10-year return period and ranged from 0.518 to 0.829 for a once-in-50-year return period.