Typhoon Disaster Risk Division And Assessment In Ningbo City

This paper is aimed at building an evaluation system to assess typhoon disaster using the geographic information data,meteorological data,and social and economic data.The normalization of data,grey relational analysis,regression analysis,analytic hierarchy process and weighted comprehensive evaluation were used to make comprehensive risk analysis and assess of typhoon disasters in Ningbo,Zhejiang.Sixteen evaluation indicators were selected to analyze typhoon disaster risk in Ningbo from four aspects,including disaster causing factors,disaster environment,disaster bearing body and disaster prevention and mitigation capability.The typhoon risk assessment index and the comprehensive evaluation model based on GIS were constructed,and the comprehensive risk zoning map of 1000m spatial resolution was formed.The risk assessment was divided into five levels:high,higher,middle,lower and low risk.This paper focused on the disaster losses caused by typhoon under the framework of typhoon disaster risk assessment in Ningbo.According to the data of seventeen disasters caused by typhoon from 1981 to 2014,the direct economic loss,the number of housing loss,the area of crop disaster and the number of death of the population were selected as the evaluation indexes of the disaster situation.On the basis of the grey correlation analysis,the regression analysis was used to establish the evaluation equation of the disaster degree of the typhoon disaster in Ningbo.The results shown that:(1)The comprehensive risk of Ningbo is higher than that of the southwest,the areas with high risk and higher risk of typhoons are mainly in Ningbo and Cixi;The middle risk area is in Yuyao and Xiangshan county,the low risk and lower risk area is the southern part of Ningbo and the southwest area.Although the capacity of Ningbo urban disaster prevention and reduction is high,the potential loss of typhoon disaster is small,but due to the high gross production value and the large population density,it will bring unpredictable loss once the typhoon is encountered.(2)The frequency of typhoons causing typhoons in Ningbo is consistent with the trend of direct economic losses,all of which are increasing year by year,however,due to the strengthening of the defense measures,the number of deaths,the number of housing losses and the area of crops affected by the typhoon are decreasing year by year,which shows that the government's ability to prevent and reduce disaster is gradually increasing.Among the seventeen typhoons analyzed,the 9711 typhoon"WINNIE" disaster in 1997 is the most serious,the 1109 typhoon "plum blossom" in 2011 is the worst case.