Study on risk assessment of compound disasters caused by typhoon-induced gales and storms: A case study of Fuzhou City

Abstract

[Objective] Scientific evaluation of disaster risks is crucial for improving regional disaster prevention capabilities and formulating targeted measures for disaster prevention, response, and mitigation. [Methods] Taking Fuzhou City as an example, the ground meteorological observations, historical typhoon disaster data, and 1 km-grid survey data of population, economy, buildings, and other disaster-bearing bodies were utilized. Then, the Copula function and risk matrix model were used to assess the compound disaster risks from typhoon-induced gales and storms under different return periods. [Results] The results indicated that:(1) under the scenario of 1 000-year compound return period, the design values of typhoon extreme wind speed and cumulative rainfall in Minqing County were the smallest, with the values being 26.03 m/s and 463.72 mm, respectively. Luoyuan County and Changle District showed the maximum design values under this compound return period, reaching 57.78 m/s and 1 173.87 mm, and 65.42 m/s and 1 094.27 mm, respectively.(2) As the level of return period increased, the hazard levels of disaster-inducing factors exhibited an increasing trend from the eastern coastal areas to the western mountainous areas. Moderately high and high vulnerability zones of disaster-bearing bodies were primarily distributed in the main urban area of Fuzhou City and the southeastern coastal towns, demonstrating strong spatial correlation with the concentration of population, economy, and buildings.(3) The risk of typhoon disasters in Fuzhou City generally exhibited a pattern of “high in the east and low in the west”. As the level of return period increased, disaster risks escalated from the northeastern and southeastern coastal areas to inland areas. The risks in the main urban area of Fuzhou City, Changle District, Luoyuan County, and Fuqing City were higher than other regions.(4) Under the conditions of extreme disasters(such as 1 000-year return period), medium-high and high-risk zones were mainly concentrated in the northeast, southeast, and main urban area of Fuzhou City, accounting for 34.5% of the total area of the city. [Conclusion] The risk of typhoon disasters in Fuzhou City generally exhibits a pattern of “high in the east and low in the west”. As the level of return period increases, the disaster risk gradually intensifies from the northeastern and southeastern coastal areas to inland areas. Under the conditions of extreme disasters(such as 1 000-year return period), medium-high and high-risk zones are mainly distributed in the northeast, southeast, and main urban area of Fuzhou City.

Keywords

typhoon / disaster risk / compound disaster / Copula function / Fuzhou City / climate change / precipitation / risk assessment