城市自然灾害风险分析新方法

A new method of urban natural disaster risk analysis

从风险具有的不确定性和复杂性入手,将城市灾害综合风险看做是基于危险性和易损性的不确定系统.通过判断风险确定的和不确定的影响因素,基于集对分析思想,建立了城市灾害综合风险评价模型.利用客观的降维方法——投影寻踪确定了因素的权重,降低了风险分析问题的复杂性.重点研究了集对联系度中差异性系数的客观量化方法,将其偏向性和偏向程度加入风险不确定性的计算中,得到了风险阈值的范围,进而得出了风险不确定性的大小.利用该方法对某市做了动态风险分析评价和趋势预测,并得出该市处于中度风险的可能性为52%的结论.该方法解决了以往灾害风险分析中多需要历史灾害数据或大样本数据的问题,为更多的目标物风险分析提供了可行方法.

Based on uncertainty and complexity of disaster,the urban integrated disaster risk was taken as an uncertain system containing hazards and vulnerability.The risk assessment model was set up with the set pair analysis approach after determining the certain and uncertain factors.The weight of each factor was ensured using project pursuit approach which was an impersonal dimensiondecreasing method good for reducing the complexity of the risk analysis.The objective quantifying method of otherness coefficient in set pair affiliation was paid more attention to.Its deflection was used in the calculation of risk uncertainty for getting the threshold of risk and the uncertainty value further.The dynamic risk in the city was analyzed and the trend was forecasted using this method.The result shows that the probability of middle risk is 52%.This approach resolves the problem that much more history disaster data or samples data are needed for disaster risk analyses so that risk analyses for more objectives become feasible.