Spatiotemporal distributions of influential tropical cyclones and associated economic losses in China in 1984-2015

In China, influential tropical cyclones (ITCs) are defined as those that cause significant national economic losses. Based on direct economic losses, socioeconomic data, and tropical cyclone track data from the National Climate Centre of the China Meteorological Administration and the National Bureau of Statistics, this study investigated 249 ITCs that occurred during 1984-2015. National economic losses directly attributable to each ITC were normalized by the Consumer Price Index to facilitate a comparison of annual variability, and the spatiotemporal distribution of ITC-related economic losses was analyzed using different statistical methods. The Pearson correlation method was used to analyze annual variations, while abrupt changes were detected by the Moving t test, and the Yamamoto and Mann-Kendall tests. The possibility of periodicity of ITC frequency and economic losses was investigated using Red-noise spectra and wavelet analysis. The results revealed that although 249 ITCs affected China during 1984-2015, no significant monotonic trend in annual frequency was detectable; however, a significant upward trend was found for strong ITCs (ITC intensity greater than that of typhoons). Among the 22 provinces affected, Guangdong Province in southern China has the highest frequency of ITCs. An abrupt change in the annual frequency of ITCs occurred in 2007, and a periodic 3-6-year pattern was detected. Annual direct economic losses during 1984-2015 were approximately 44.7 billion CNY, and they have increased at the rate of 1.8 billion CNY annually. The severest losses occurred in 1996. Although an obvious abruption occurred in 1992, a 2-3-year periodicity was detected in ITC-related losses. Temporally, most affected provinces showed a slight increase in ITC-related losses. Spatially, ITC-related losses were greatest in Zhejiang and Guangdong provinces. These findings could be helpful for raising local awareness and ensuring the preparedness of local government for mitigating ITC-related damage.