Analysis Of Risk Characteristics Of Typhoon Disasters In Coastal China

Typhoon is one of the products of air-sea interaction,which often accompanied by high winds,heavy rains and storm surges.Because of great destructive power and serious harm so that it causes great losses to the natural environment,social economy and even sustainable human development.It is significant to master the characteristics and pattern of typhoon activity for typhoon prediction,warning and disaster prevention and mitigation.This paper mainly focuses on landfalling typhoon in the coast of China,and analyzes the number,time and location of landfalling typhoon(tropical cyclones at or above the tropical depression)in China during the period of 1951-2017.Furthermore,by establishing buffer zone and constructing distance function model in GIS,the influence frequency,distance and range of landfalling typhoon are analyzed at pixel scale,and the spatial distribution data of population density,GDP density and other indexes are combined with the spatial distribution data of landfall typhoon.The effects of landfall typhoon on the economic and social development of China's coastal areas were analyzed and revealed.The main conclusions are as follows:(1)Based on the typhoons data in the Northwest Pacific Ocean Region from 1951 to 2017,the characteristics of landfalling typhoons,such as number,intensity and landfalling location,were statistically analyzed over the considering period,and then the trends in future of the landfalling typhoons were carried out by employing Rescaled Range Analysis method.The results showed that the average number of landfalling typhoon was 7.4/a,which showed a general downward trend,the dropping magnitude were 0.03/10 a respectively.There was no typhoon occurred from January to March.The most frequent period of typhoons landfall was from June to October,especially in August.As far as the intensity of landing typhoon is concerned,the intensity of landing typhoon tends to decrease,but the number of high intensity typhoon increases.The results of R/S analysis show that the number and intensity of landfalling typhoon will increase slowly in the future.The Landfalling place of typhoons were mainly in Guangdong,Taiwan,Fujian,Hainan,and Zhejiang.The landfalling location of typhoons display a trend of eastward and northward shift,and the tendency will continue in the future.(2)The impact frequency and intensity of the landfalling typhoon in China are distributed in a band,gradually decreasing from the coast to the inland,and the corresponding influence range and proportion decrease with the increasing of the influence frequency and intensity.In terms of pixel scale effect frequency which landfalling typhoons in China from 1978 to 2017 is 141,and the most affected areas are the east Yue,west Yue,the Pearl River Delta,southern of Fujian and Northeast Hainan,middle east of Taiwan.The most intensive regions are Quanzhou,Fuzhou,Putian and other areas of Fujian Province,followed by Eastern Hainan,Pearl River Delta,EastYue,Eastern of Fujian,and Wenzhou,Yueqing,Taizhou and other southeast areas of Zhejiang Province.(3)The spatial distribution of population,GDP factor and vulnerability index is different.In the capital cities of Beijing-Tianjin-Hebei Urban Agglomeration,Yangtze River Delta,Pearl River Delta and some other middle east of provinces capital city,the disaster-bearing body index is the highest because of its large population and high level of economic development.The surrounding areas of the provincial capital city and the edge areas of the Yangtze River Delta and the Pearl River Delta,such as Suzhou,Qingdao and Dongguan,because of population and GDP are relatively dense,so that there is a higher vulnerability index of the disaster-bearing bodies.In the southwest of China,such as Yunnan-Kweichow Plateau and most inland areas of Fujian and Zhejiang provinces,because of sparse population,single industry and the slow economic development,so the vulnerability of the whole disaster-bearing body is low.(4)Combined with the influence frequency and vulnerability index of bearing body,the comprehensive disaster risk analysis of the impact area of the landfalling typhoon in China is listed as follows.The disaster risk caused by thee landfalling typhoon in China tends to decrease from the east coast to the inland,especially Yangtze River Delta,the Pearl River Delta and the coastal areas of Fujian and Zhejiang have the highest disaster risk index over 0.4.The inland areas of Fujian and Zhejiang,middle east of Guangdong,southern Jiangxi,central Jiangsu,middle east of Anhui,and Jiaodong Peninsula,the disaster risk comes second.The disaster risk index of Yunnan-Kweichow Plateau,middle west of China,Weihe Plain and Northeast China is weak,and all of them are the least risk of typhoon.