基于组合赋权的多情景内涝灾害风险评估

Multi-scenario waterlogging disaster risk assessment based on combination weighting

城市内涝灾害频发会对城市社会经济发展构成巨大威胁,对城市内涝灾害风险进行评估,是降低内涝损失的有效途径。通过综合考虑城市内涝灾害系统中的致灾因子、孕灾环境和承灾体3个组成要素,结合水力模型情景模拟结果,共选取11个具有代表性的指标,建立城市内涝灾害风险评价指标体系,并结合主观层次分析法(AHP)和客观熵权法(EWM)组合赋权,构建城市内涝灾害风险评估模型。以广州市天河区为例,对该评估模型进行验证。结果表明:水力模型模拟结果可以充分反映出不同情景降雨下致灾因子的危险性,通过内涝风险等级与内涝积水叠加分析得出,风险等级较高的位置均处于内涝积水和地区重要程度较高的区域。该评估模型充分考虑了社会和自然的综合作用,具有较高的可靠性。随着暴雨重现期的增大,高风险区域面积显著增加,在实际应用中,通过风险评估可以确定出城市防汛的重点关注区域,以便于防汛资源的优先配置,为城市防灾减灾管理提供参考。

The frequent occurrence of urban waterlogging disasters poses a huge threat to urban social and economic development.Assessing the risk of urban waterlogging disasters is an effective way to reduce waterlogging losses.This study comprehensively considers the 3 components of the disaster-causing factors,the disaster-pregnant environment and the disaster-bearing body in the urban waterlogging disaster system,combined with the results of the hydraulicmodel scenario simulation,and selects a total of 11 representative indicators to establish the urban waterlogging disaster risk assessment index system.The system combined with the combination of subjective analytic hierarchy process(AHP)and objective entropy weight method(EWM),builds an urban waterlogging disaster risk assessment model.Tianhe District of Guangzhou City was taken as an example to verify the urban waterlogging disaster risk assessment model.The results show that the hydraulic model simulation results can fully reflect the risk of disaster-causing factors under different rainfall scenarios.Through the superposition analysis of the waterlogging risk level and the waterlogging accumulation,the locations with higher risk levels are located in the waterlogging accumulation and areas with a higher degree of importance.The evaluation model fully considers the comprehensive effects of society and nature and has high reliability.With the increase of the rainstorm return period,the area of high-risk areas increases significantly.In practical applications,the key areas of urban flood control can be determined through risk assessment,to facilitate the priority allocation of flood control resources and provide a reference for urban disaster prevention and mitigation management.