基于组合赋权的聊城市洪涝灾害风险评估

Flood Disaster Risk Assessment in Liaocheng City Based on Combination Weighting

为了提高城市应对洪涝灾害的应急能力,以山东省聊城市为研究区,基于洪涝灾害评估的基本原理,从洪涝灾害的致灾因子、孕灾环境及承灾体脆弱性3个方面,选择年平均降雨量、高程、坡度、与水体距离、人口密度、土地利用类型、国内生产总值等数据,构建洪涝灾害评估指标体系;利用层次分析法和熵值法分别确定各指标的主观和客观权重,并用距离函数法确定指标的主客观综合权重;利用地理信息系统对赋权后的各栅格图进行叠加计算,得到研究区洪涝灾害危险性、易损性及洪涝灾害风险等级分区。结果表明:聊城市洪涝风险较高地区主要分布在降雨量多、水系发达、人口分布密集且经济发展水平高的东昌府区;西南部地区和东北部地区降雨量少,人口稀疏,洪涝灾害风险较低;研究区洪涝风险呈现自西南向东北先增大后减小的趋势。

To improve the emergency response capacity of cities in dealing with flood disasters,taking Liaocheng City in Shandong Province as the study area,based on the basic principles of flood disaster assessment,a flood disaster assessment index system was constructed by selecting indicators such as annual average precipitation,elevation,slope,distance from water bodies,population density,land use type,Gross Domestic Product(GDP),from three aspects of causative factors of flood disasters,disaster-prone environment,and vulnerability of disaster-affected bodies.The subjective and objective weights of each indicator were determined using the analytic hierarchy process and entropy method,and the comprehensive weights of the indicators were determined using a distance function.Using geographic information system,the weighted grid maps were calculated to obtain the flood hazard,vulnerability,and flood risk zoning maps of the study area.The results show that the areas with higher flood risk in the study area are mainly distributed within Dongchangfu District,where there is high precipitation,well-developed water systems,dense population distribution,and high levels of economic development.The southwestern and northeastern parts of the study area have lower flood risk due to lower precipitation and sparse population.The flood risk in the study area increases first and then decreases from southwest to northeast.