基于改进物元可拓模型的城市洪灾风险评价

Evaluation of Urban Flood Damage Risks Based on Improved Matter-Element Extension Model

城市洪灾风险评价是城市制定防洪减灾措施的重要依据,为了克服现有评价模型的局限性,从灾害学的角度考虑,从致灾、孕灾、承灾和减灾4个方面建立了城市洪灾风险评价指标体系,并采用改进物元可拓模型进行分析评价。该模型在一般的物元可拓模型的基础上作出两点改进:其一,用贴近度代替关联度进行等级评定;其二,采用变权法确定指标权重。以丽水市为例进行洪灾风险评价,评价结果为Ⅳ级(较危险),与丽水市实际洪灾风险情况基本相符。

Urban flood-damage risks assessment is the basis for the development of flood control and disaster relief measures.In order to overcome the limitations and shortcomings of the existing models,an improved matter-element extension model with variable weight was built,and urban flood risk evaluation system was built from four aspects of catastrophology: disaster-causing,disaster-gestating,disaster-bearing,and disaster-relief.In this paper,two improvements were made on the basis of normal matter-element extension model: first,to put nearness instead of correlation degree; second,to use variable weight method to calculate the index weight.Taking Lishui City as an example of flood risk assessment,the final result was grade IV,which agreed with the actual situation of Lishui City.