基于场次洪涝灾害的损失函数构建方法

A method for constructing loss functions based on flood disaster events

构建洪涝灾害损失函数对于认识洪涝灾害损失的发展规律、提高灾害损失的评估时效性具有重要意义。提出了耦合洪涝致灾因子空间分布的动态模拟、社会经济数据空间化处理、灾害直接和间接损失计算以及曲线拟合的场次洪涝灾害损失函数构建方法,构建了洪涝灾害损失—时间函数,并建立了函数参数的调整策略,在上海市开展了实例研究。研究结果表明:场次洪涝灾害直接经济损失的发展过程呈“S型”曲线的变化特征,可将weibull分布函数作为其损失函数;减停产损失的日变化过程呈“L型”曲线的变化特征,可将双曲递减函数作为其损失函数;产业关联损失的日变化过程呈“倒U型”曲线的变化特征,可将Hoerl函数作为其损失函数;累计产业关联损失约为停产或减产损失的1.77倍,间接经济损失约为直接经济损失的1.29倍;损失函数参数与灾害发生概率多呈非线性的单调递增或递减关系,基于拟合参数的洪涝灾害损失评估相对误差在5%以内。本研究的方法被证实具有较高的模拟精度,为认识洪涝灾害损失的发展规律和提高洪涝灾害损失评估时效性提供了新途径。

The construction of flood disaster loss functions is of great significance for understanding the development law of flood disaster loss and improving the timeliness of loss assessment.A method for constructing loss functions based on urban flood disaster events is proposed,which is coupled with dynamic simulation of spatial distribution of flood disaster factors,spatial processing of socio-economic data,calculation of direct and indirect disaster losses,and curve fitting.A case study was carried out in Shanghai to construct flood disaster loss-time functions,and the adjustment strategy of function parameters was established.The results show that under the rainfall scenario of Chicago rain type,the development process of direct economic losses from flood disasters shows an S-shaped curve and Weibull distribution function can be used as the loss function.The development process of daily loss from production reduction and shutdown shows an L-shaped curve and hyperbolic decline curve function can be used as the loss function.The development process of daily industry-related loss shows an inverted U-shaped curve and Hoerl distribution function can be used as the loss function.The cumulative industry-related loss is about 1.77 times of the loss of production reduction or shutdown,and the indirect economic loss is about 1.29 times of the direct economic loss.The parameters of the loss function and the probability of disaster occurrence exhibit a nonlinear monotone increasing or decreasing relationship,the relative error of flood loss assessment based on fitting parameters is less than 5%.The method in this study has been proven to have high simulation accuracy,providing a new way to understand the development law of flood disaster loss and improve the timeliness of flood disaster loss assessment.