Increasing compound hazard of landfalling tropical cyclones in China during 1980–2020

Abstract

Identifying the geographical regions where tropical cyclone (TC) activities are changing most is critical for policymakers to develop long‐term strategies for coastal disaster prevention. However, the key concerns for assessing the variation trends of the regional hazard caused by landfalling TCs are limited by data availability in the spatio‐temporal coverage and homogeneity. In this study, based on the high spatio‐temporal resolution ERA5 reanalysis data and a quasi‐Lagrangian approach, we investigate the long‐term variation trend of the compound hazard resulting from wind and precipitation during the landfall of the TCs in the coastal areas of China from 1980 to 2020. Two hotspot areas of TCs hazards are identified, one in the Taiwan Strait and surrounding areas, and the other in the Hainan Island and the northern South China Sea. The observed compound hazard in the former hotspot area shows a noticeable increasing trend over the past 40 years at a rate of 5% per year, while the latter hotspot area displays a robust decreasing trend. This variation pattern of the hazard trend is mainly attributed to the increased frequency of intense TCs (typhoon intensity grade and above) and the northward movement of TC track in China. The number of intense landfalling TCs in southeastern China nearly tripled in 2000–2019 compared to those in 1980–1999. The widespread increase in the compound hazard also suggests a rise in the disaster risk for the middle‐ and high‐latitude coastal regions of China, which require an immediate development and execution of advanced prevention strategies.