宁波市台风灾情评估和基于层次分析法的风险评估

EVALUATION OF TYPHOON DISASTER IN NINGBO AND RISK ASSESSMENT BASED ON ANALYTICAL HIERARCHY PROCESS

筛选了1956—2016年间对宁波地区影响大、具有较完整灾情记录的台风个例30个,分析了台风灾情特征,并进行灾情评估;利用模糊算法和层次分析法,建立宁波地区台风风险评估模型。结果表明:近年来台风导致的死亡人数、倒塌房屋数量、水利和农作物受灾呈下降趋势;但是经济损失越来越大,浙江登陆台风造成养殖业的损失也有增大趋势。实际灾情指数(ADI)达到1级特重的台风有4个,达到2级(严重)及以上的有9个,ADI总体呈减小趋势。风险评估指数(RAI)与实际灾情指数(ADI)的相关系数为0.78,二者等级的一致率为73%;不一致的样本中,2000年之前风险评估等级小于灾情等级,2000年之后风险评估等级大于灾情等级。风险评估指数RAI和直接经济损失率的相关系数为0.7。业务中,可根据风险评估模型计算即将影响台风的RAI,利用直接经济损失率与RAI的拟合方程或者相近RAI的历史台风,估算其可能造成的经济损失。

This paper selects 30 typhoon cases which had great impact on Ningbo area and had complete disaster records from 1956 to 2016.The characteristics of typhoon disaster are analyzed and the disaster assessment is carried out.Then,a risk assessment model of typhoon disaster in Ningbo is established by using fuzzy algorithm and Analytic Hierarchy Process(AHP).The results show that the confirmed death toll,the number of collapsed houses,the water conservancy facilities and crop damage have been declining in recent years.However,the economic losses are increasing,and the losses of aquaculture are also increasing.There are 4 typhoons'Actual Disaster Index(ADI)reached Grade 1(extreme heavy),and 9 typhoons belong to Grade 2(serious)or above.The trend of ADI is decreasing.The correlation coefficient between the Risk Assessment Index(RAI)and ADI is 0.78,and the consistency rate of grad is 73%.As for the inconsistent cases,prior to the year of 2000,the grade of RAI was lower than the grade of ADI,but the situation was reversed after 2000.In addition,the correlation coefficient between RAI and the direct economic loss rate is 0.7.Therefore,the RAI of typhoon will be calculated by the risk assessment model.Then,using the fitting results of the direct economic loss rate to RAI or historical typhoons of similar RAI,it is possible to estimate the direct economic losses caused by it.