Research On The Economic Loss Of Primary,secondary And Tertiary Industries From Influential Tropical Cyclone In Southeast Coastal Cities

As the global climate continues to warm,various extreme disasters occur frequently.China is located in the west coast of the Pacific Ocean,which is deeply affected by tropical cyclones.The southeast coastal areas are the most seriously affected by tropical cyclones in China,and their economic losses have a huge impact on regional economic development.Understanding the characteristics of regional tropical cyclone disasters and effectively predicting the future economic loss of tropical cyclone disasters are the basis for regional response to climate change and scientific disaster prevention and management measures.In this study,the tropical cyclones that caused direct economic losses in the region were uniformly called influential tropical cyclones,and 41 cities in the southeast coastal area were divided into three scale cities(small city,medium city and big city)according to the urban permanent population.Using dynamic downscaling model(WRF),economic prediction model,direct economic loss model and other methods,we selected the period from July to October with the highest frequency of tropical cyclones and analyzed the historical period(1984-2019).Under different scenarios of SSP2-4.5 and SSP5-8.5 in the future period(2021-2040),the frequency,intensity,economic exposure of influential tropical cyclones and the change characteristics of economic losses to primary,secondary and tertiary industries in southeast coastal cities can be concluded as follows:(1)A total of 191 influential tropical cyclones threatened southeast coastal cities from 1984 to 2019,and the frequency of influential tropical cyclones with an intensity above STY showed a increasing trend(0.05 significance level).Zhoushan City and Taizhou City of Zhejiang Province,Yangjiang City in Guangdong Province and Putian City and Zhangzhou City in Fujian Province had the most serious frequency;Compared with the base period,the occurrence frequency of influential tropical cyclones in the southeast coastal cities in 2021-2040 shows an increasing trend under SSP2-4.5 and SSP5-8.5 scenarios,especially the influential tropical cyclones with the intensity of typhoon(TY)or above show a significant increasing trend.In space,compared with the base period,under the SSP2-4.5 scenario,18.3% of the southeast coastal areas show an increasing trend,while under the SSP5-8.5 scenario,the areas with an increasing frequency of disaster cyclones account for 86.4%,and the areas with a large increasing frequency of disaster cyclones are the Pearl River Delta and the inland areas of Fujian and Zhejiang provinces.In the future,high-intensity cyclones will occur more frequently and have a tendency to develop inland.(2)From 1984 to 2019,the output value and economic exposure of the primary,secondary and tertiary industries in southeast coastal cities showed an increasing trend,especially the proportion of the output value and economic exposure of the secondary industry was the largest,and the growth rate was the fastest.Under the scenarios of SSP2-4.5 and SSP5-8.5,the total economic exposure of southeast coastal cities showed an increasing trend during 2021-2040,and the growth rate was similar.Compared with 2000-2019,the economic exposure of the primary,secondary and tertiary industries showed an increasing trend under different scenarios,among which the economic exposure of the tertiary industry accounted for the largest proportion and the fastest growth rate.In particular,the economic exposure of disasters caused by cyclones is greater in medium and large cities.Spatially,compared with 2000-2019,the economic exposure of the three industries to influential tropical cyclones in 2021-2040 under the SSP2-4.5 and SSP5-8.5 scenarios shows a gradually decreasing trend from coastal to inland,and the economic exposure is greater under the SSP5-8.5 scenario.Especially in the Pearl River Delta,the middle cities along the coast and the big cities,the economic exposure of the primary,secondary and tertiary industries is greater.Through the analysis of contribution rate of influencing factors,it can be seen that the increase of urban economic exposure is mainly caused by the rapid development of urban economy.(3)From 1984 to 2019,the proportion of city disaster cyclone economic losses in the total disaster cyclone losses in southeast coastal areas increased from 32.1% to 59.3%,and the economic losses of cities of different sizes showed a significant increasing trend(0.05 significant level),especially the large cities accounted for a large proportion of economic losses and increased rapidly.The economic loss centers of the cyclone were southern cities of Guangdong Province,coastal cities of Fujian Province and Zhejiang Province.Compared with the historical period(1984-2019),the economic loss increased by 80.7% during 2021-2040 under the SSP2-4.5 scenario,and 209.6% under the SSP5-8.5 scenario.With the increase of anthropogenic carbon dioxide concentration,the total economic loss of the disaster cyclone increased significantly.Under different scenarios,the economic losses of the primary,secondary and tertiary industries all showed an increasing trend,and under SSP5-8.5 scenario,the increment was larger and the growth rate was faster.Especially,the economic losses of the tertiary industry accounted for the largest proportion and showed an increasing trend,and the threat of influential tropical cyclone disaster was greater in the future.