Evolution Trend Of Tropical Cyclones And Their Economic Losses In Prefecture-level Cities Along The Southeastern Coast Of China Under The Background Of Global Warming

The southeast coast of China is one of the most severely affected areas in the world by tropical cyclones.This paper takes 27 coastal prefecture-level cities in Zhejiang,Fujian,and Guangdong as the research area.Meteorological observation and socio-economic data from1984 to 2019 are used for the first time to analyze characteristics of tropical cyclones and economic losses in those regions above during historical period.Based on international coupled model,the global climate model data provided in the 6th stage(cmip6)is compared with the shared socio-economic data offered by the school of Geographic Sciences,Nanjing University of information technology.Among them,dynamic downscaling model WRF and vulnerability curve construction are applied.Under scenarios of ssp2-45 and ssp5-85,the evolution trend of tropical cyclones and corresponding losses in these regions from 2020 to 2050 are given.The main conclusions are as follows:(1)From the characteristics of tropical cyclones:Number of cyclones generated in the Northwest Pacific and Landfalling Tropical Cyclones in China decreases slightly from 1984 to2019.The amount of landfall cyclones in southeast coastal cities does not change significantly,but the intensity increases.The number of cyclones will continue to decline from 2020 to 2050.Tropical cyclones landing times in 57% of the cities in Southeast China increases.The intensity of cyclones in 69% of cities investigated increases significantly and increased with growing greenhouse gas emissions.Spatially,in the historical period,areas with the highest rate of landing cyclones and the highest intensity scattered in the southwest coast of Guangdong and the central part of Fujian.In the future,the landing point of high intensity tropical cyclone will move northward obviously.In 90% of the coastal cities in Fujian and Zhejiang,both frequency and intensity of landing tropical cyclones increase,especially in the north of Fujian and the south of Zhejiang.Guangdong declines accordingly.In the same time,the northward movement of cyclones will intensify with the acceleration of global warming.(2)From the perspective of economic losses caused by tropical cyclone:tropical cyclones in southeast coastal cities increase at a rate of 560 million per year.The southern Zhejiang and the southwest coastal cities of Guangdong bear the biggest economic losses.However,in terms of the proportion of GDP,coastal cities in southern Zhejiang are lower than those in southwest Guangdong.In the coming future,tropical cyclone losses in coastal cities of China will continue to rise.The average loss of ssp245 path in 2020-2050 will increase by 20.7% compared with1989-2019.Ssp585 path scenario increased to 40.3%.Spatially,the area with the highest loss is mapping from the southwest coastal cities of Guangdong to the border area of Fujian and Zhejiang.