1980—2020年登陆中国热带气旋及其人口暴露度演变特征

Evolution Characteristics of Tropical Cyclones Landed in China and Their Population Exposure from 1980 to 2020

热带气旋频发于人口密集的中国沿海地区,造成严重的人员伤亡。基于1980—2020年西北太平洋热带气旋数据,研究生成、登陆中国热带气旋的时空分布特点。结合空间化后的同期中国人口数据,采用敏感性实验分析热带气旋暴露人口变化的主要影响因素及其贡献率,揭示登陆中国热带气旋及其人口暴露度演变特征。(1)1980—2020年,西北太平洋海域共生成1 217个热带气旋,270个登陆中国,生成和登陆气旋频数均呈减少趋势;其中,台风及以上等级登陆气旋共计88个,呈缓慢增加趋势,且强台风频数增加明显。(2)台风及以上等级热带气旋登陆地按登陆频次递减为:广东、浙江、海南、福建和江苏,超强台风登陆地集中在广东、浙江、福建和海南。(3)1980—2020年中国台风及以上等级热带气旋的人口暴露总数为35.8亿人,2016年暴露人口共2.5亿人,为历年最多;同期影响面积累计9.5×10^(6)km^(2),广西区累计暴露范围最大,为2.1×10^(6)km^(2)。(4)热带气旋致灾因子对人口暴露度的贡献率在各个时期均最高,超过60%,且随年代际先增后减,2000—2009年贡献率达峰值80.3%;人口和其他因素的贡献率呈现出同步变化,随时间先减后增,且人口因素增幅更大。

Tropical cyclones frequently occur in densely populated coastal areas of China,causing serious casualties.Based on the data of tropical cyclones in the Northwestern Pacific from 1980 to 2020,the present study analyzed the spatiotemporal distribution characteristics of the generation and landfall of tropical cyclones that landed in China.Combined with spatialized population data of China during the same period,sensitivity experiments were conducted to analyze the main influencing factors of the changes in tropical cyclone exposure and their respective contribution rate.The results show that:(1)From 1980 to 2020,a total of 1217 tropical cyclones were generated in the Northwestern Pacific,270 of which landed in China,and the frequency of cyclones generated and those landed in China showed a decreasing trend;among them,88 tropical cyclones of typhoon intensity or higher made landfall,showing a slowly increasing trend,and the frequency of strong typhoons increased significantly.(2)Tropical cyclones of typhoon intensity or higher mainly landed in Guangdong,Zhejiang,Hainan,Fujian,and Jiangsu provinces in descending order of landing frequency,while super typhoons concentrated in Guangdong,Zhejiang,Fujian,and Hainan provinces.(3)From 1980 to 2020,the total population exposed to tropical cyclones of typhoon intensity or higher in China was 3.58 billion,and the exposed population in 2016 was 250 million,the highest in history;the cumulative affected area during the same period was 9.5×10^(6) km^(2),and Guangxi had the largest cumulative exposure area,2.1×10^(6) km^(2).(4)The contribution rate of tropical cyclones to population exposure was the highest in all periods,exceeding 60%;it first increased and then decreased over the interdecadal time scale,reaching a peak of 80.3%during 2000-2009;the contribution rate of population and other factors showed synchronous changes(first decrease and then increase with time),and the increase in the contribution of population was greater.