黄河山东段沿线区域洪灾风险评估

Flood disaster risk assessment of regions along Shandong section of the Yellow River

黄河山东段位于黄河下游,是典型的"地上悬河"。以黄河山东段沿线区域为研究区,从致灾因子、孕灾环境的自然属性和承灾体的社会属性两方面出发,选取降水、地形、水系、植被作为洪灾危险性评估因子,人口密度、GDP密度、单位面积粮食产量、交通密度作为洪灾易损性评估因子,利用GIS技术和层次分析法,获得了5个级别的洪灾风险等级分布图。结果表明,低风险区占11%,较低风险区占47%,中等风险区占31%,较高风险区占7%,高风险区占4%。在67个县市区中,高风险等级区面积占县市区百分比大于50%的有3个;较高风险等级区有6个;低风险等级区面积占县市区百分比大于90%的有6个。以山东黄河"96·8"洪水的淹没范围和受灾损失程度对评估结果进行验证,认为与实际情况较吻合,结果合理。

Shandong section of the Yellow River is located in the lower reaches of the Yellow River. It is a typical suspended river on the ground. Taking region along Shandong section of the Yellow River as study area, and in consideration of natural properties of disaster-formative factors and disaster pregnant environment, as well as the social attributes of hazard affected body, this paper finished a flood disaster risk map of five grades by using GIS techniques and AHP method. Rainfall, terrain, water system, vegetation were selected as hazard assessment factors, population density, GDP density, grain yield per unit area and traffic density, were selected as vulnerability assessment factors. The results show that, low risk regions account for 11%, light risk regions account for 47%, medium risk regions account for 31%, and higher risk regions account for 7%, the highest risk region accounts for 4%. In 67 counties and cities, there are 3 whose highest risk region area are over 50%, 6 with higher risk level and 6 whose low risk region area account for over 90%. By the simple verification, it is believed that the assessed results agree with actual situations.