基于Copula函数的华南台风灾情重现期研究

利用1981-2014年华南台风灾情数据，选取受灾人口、农作物受灾面积和直接经济损失，应用Copula函数理论，计算灾情重现期，分析台风灾害的灾情.首先，借助Clayton Copula函数构造三变量的联合分布，计算单变量重现期、联合重现期及同现重现期，并求出该重现期下的设计值.计算结果表明联合重现期的设计值要优于单变量重现期和同现重现期的设计值．因此，选取联合重现期的设计值作为防灾标准的最优参考，并将联合重现期记为灾情重现期．然后，计算2015-2017年登陆华南台风灾害的灾情重现期，并对台风灾害的灾情进行分析．发现台风灾情重现期越长的台风造成的灾情越严重．最后，利用灾情重现期与致灾重现期对台风灾害的发生频率作综合性分析，可以为台风灾害的风险评估提供一种新思路．

Study on the Return Period of Typhoon Disaster in South China Based on Copula Function

Based on the data of typhoon disaster in South China from 1981 to 2014, this paper selects the affected population, affected area of crops and direct economic loss, calculates the recurrence period of disaster and analyzes the disaster situation of typhoon by using copula function theory. Firstly, with the help of Clayton Copula function, this paper constructs the joint distribution of three variables, calculates the single variable return period, joint return period and co-occurrence return period, and obtains the design value under the return period. The calculation results show that the design value of joint return period is better than that of single variable return period and co-occurrence return period. Therefore, the design value of joint return period is the best standard for disaster prevention, and the joint return period is recorded as the return period of disaster situation. Then, the recurrence period of the typhoon disaster that landed in South China in 2015-2017 is calculated by using the recurrence period of the disaster, and the disaster situation of the typhoon is analyzed. It is found that the longer the recurrence period, the more serious the typhoon disaster. Finally, a comprehensive analysis of the frequency of typhoon disaster is made by using the recurrence period of disaster and the recurrence period of disaster, which also provides a new idea for the risk assessment of typhoon disaster.