The Correlation And Disaster Assessment Of Typhoon Impact On Aquaculture Facilities In China

China is not only the largest aquaculture country in the world,but also one of the countries with the most serious typhoon disasters in the world.The disasters caused by typhoon landing,such as gale,rainstorm and storm surge,are extremely destructive,and pose a serious threat to China’s coastal facility fisheries.It is very important to understand the spatial and temporal conditions of typhoons landing in China and the distribution characteristics of facility fisheries,to explore the impact of typhoons on the spatial layout of facility fisheries,and to carry out disaster risk assessment and management of coastal typhoon facility fisheries.Therefore,based on the track data of typhoon in the Northwest Pacific from 1989 to 2018,the survey data of fishery and various statistical yearbooks,this paper studies the correlation between typhoon and facility fishery and disaster assessment in China’s coastal provinces.The main conclusions are as follows:ESDA and Kriging interpolation were used to analyze the temporal and spatial distribution characteristics of typhoon and aquaculture fishery.The results show that: In recent 30 years,typhoons landed in China’s coastal areas showed a decreasing trend,with the most frequent landing season in summer,followed by autumn,and the least in winter.In terms of landing location,Guang Dong>Tai Wan>Hai Nan>other provinces;in terms of impact scope,in recent four years,Guang Dong>Fu jian=Hai Nan>Tai Wan>other provinces,southern Guangdong,central Fujian and northern Zhejiang and northern Tai Wan are the regions with the highest typhoon wind speed;in terms of landing intensity,typhoons,severe tropical storms and tropical storms are the most.The distribution of aquaculture facilities in China’s coastal fisheries is different.The overall distribution trend of deep-water cage and ordinary cage is consistent in china,which is more in the South than in the north,while raft aquaculture is relatively evenly distributed.Zhejiang and Fujian belong to high-high area,Liaoning is low-low area,Shandong,Jiangsu and Hebei are located in low-high area;from the perspective of facility type,the spatial agglomeration of traditional cage is the most obvious,and the spatial correlation of deepwater cage is the weakest.Based on Chi-square test,rank sum test and regional center of gravity method,the correlation between the distributed pattern of aquaculture facilities and the wind speed and frequency of typhoons were discussed.The results showed that: The distribution of traditional cage was linearly correlated with the wind speed and frequency of typhoon.And its distribution would be more affected when the typhoon reaches 8(wind speed>17.1 m/s)and higher levels.The distribution of deep water cage was only affected by the wind speed of typhoon,especially for the high-speed(wind speed>24.4 m/s)typhoon.According to the comprehensive index of typhoon,the center of gravity of raft culture was found to be the farthest away from the center of gravity of typhoon,indicating its distribution was the most considerably affected by typhoon.When the typhoon reaches level 6(wind speed>10.8 m/s),its disaster status would be more significant.Raft culture is suitable to be distributed in the sea area where typhoon reaches level 6 and lower levels.Tradition is widely distributed,which can be set in the sea area with level8 wind force such as inner bay.Deep cage is suitable to be distributed in the open sea area.Based on the theory of natural disaster system,a complete risk assessment system and model of typhoon disaster suitable for facility fishery were constructed,which considered the typhoon disaster factors,vulnerability of facility fishery and disaster reduction and prevention.The results show that: The spatial distribution of typhoon damage degree and facility fishery vulnerability in coastal areas is similar,and both are greater in the South than in the north.In terms of the degree of disaster damage,Guangdong is the most severely affected,followed by Fujian,Hebei and Shanghai are very small.In terms of vulnerability,Fujian is the highest,followed by Guangdong,and the vulnerability of most provinces is in the range of 0～0.3,which belongs to lowmedium risk area.From the perspective of disaster reduction and prevention ability,Shandong is the strongest at 0.8,followed by Jiangsu and Guangdong.Due to the low social and personal disaster reduction ability of Hainan,the typhoon disaster reduction ability is the lowest.The regional difference of typhoon comprehensive risk is obvious,Guangdong and Fujian are the high disaster risk areas.Zhejiang and Hainan are in higher risk areas.Shandong and Jiangsu are in general risk areas,Guangxi and Liaoning are low risk areas,while Beijing and Tianjin have the lowest risk of typhoon disaster due to less typhoons and the least developed facility fishery.Based on the distribution characteristics of aquaculture facilities and typhoon disaster risk zoning of facility fishery,it is suggested that Fujian Province and Guangdong Province should reduce the raft culture;Guangdong should speed up the construction of protective dike and seawall,Fujian should carry out disaster education and increase investment in fishery facilities;Guangdong has accelerated the construction of protective dikes and seawalls,and Fujian has carried out disaster education and increase investment in fishery facilities.“The compound fishery” should be actively developed in Hainan and Zhejiang Province.Hainan should also increase the fixed investment in fishery and strengthen the publicity of residents’ participation in medical insurance,especially agricultural insurance.Zhejiang should improve the anti typhoon performance of fishery facilities and improve social infrastructure services.Northern coastal provinces are less affect by the typhoon disaster,under the advantage of raft culture varieties,we can actively build recreational fishery relying on marine ranching.Shandong continued to strengthen the management of typhoon prevention for facility fishery,such as reasonable planning of raft culture location,adding typhoon shelter,etc.Jiangsu should focus on early warning management of typhoon disaster.Other provinces focus on non engineering measures,such as strengthening public awareness of disasters and formulating typhoon prevention programs.