我国地震人员损失评估经验概率模型

Empirical probability model for estimating earthquake casualties in China

对地震人员伤亡的准确预测是震后救灾资源调度和救援人员分配的重要依据。基于PAGER系统中的双参数累积对数正态分布模型,分别讨论了3种建立我国地震人员损失预测模型的方法,并通过历史地震的受灾情况对其预测效果进行验证。其中,直接采用PAGER系统中提供的我国参数和以极震区烈度为变量建立的预测模型的准确性均不理想。考虑到多数震害调查资料中各烈度区受灾数据的缺失,选取数据较为详实的2008年四川汶川8.0级地震,根据已知受地震影响的25个市县的人员损失总数,综合考虑烈度区面积、人口数和烈度对地震人员损失数的影响,将每个市县的人员损失总数进行分配,最终得到不同烈度区的人员死亡率和受灾人数,回归得到模型参数后,建立我国地震人员损失评估经验概率模型。经验证分析,该模型预测结果与震例结果十分接近,远好于前2种方法得到的预测模型。同时,该模型的残差频率的正态性较好,根据预测结果建议的地震应急响应级别均与震例的实际情况相符。

Accurate prediction of earthquake casualties is an important basis for post-earthquake relief resources dispatch and rescue personnel allocation.Based on the two-parameter cumulative log-normal distribution model in the PAGER system,three methods for establishing an estimating model for earthquake casualties in China are discussed separately and their estimating results are verified by using historical earthquake cases.Among them,the accuracy of the estimating models built by directly taking the parameters provided in the PAGER system for China and by using the intensity of the extreme seismic zone as the variable are both unsatisfactory.Considering the lack of casualties of each intensity zone in the survey after earthquakes,the 2008 Wenchuan earthquake of magnitude 8.0 in Sichuan,which has more detailed data,was selected.The total number of earthquake casualties in each city and county were assigned to finally obtain the fatality rate and afflicted population in different intensity zones after considering the effects of the area,population and intensity,and the model parameters were obtained by regression,an empirical probability model for estimating earthquake casualties in China was established.The analysis shows that the estimating statistical data of the model are very close to the statistical data of the verified earthquake and much better than those obtained by the first two methods.Meanwhile,the normality of the residual frequencies of the model is good,and the suggested earthquake emergency response levels obtained from the estimating results are all consistent with the actual disaster situation.