基于GIS的福建闽江上游山洪灾害风险区划

GIS-based Risk Zoning of Flood Disasters in Upstream of the Minjiang River

风险区划是山洪灾害防治工作中的重要环节,在理解山洪灾害地域分异规律的基础上进行区划,可为科学地分析山洪灾害致灾因子,为恰当地采取防治措施提供依据。以多年降水均值、土壤类型、坡度、高程、最长汇流路径长度、最长汇流路径比降、糙率、稳定下渗率、人口密度、地均GDP、土地利用状况和植被覆盖度12项因子,通过层次分析法与德尔菲法结合确定权重,进行空间叠加分析,完成闽江上游山洪灾害危险评价图、易损性图和山洪灾害风险区划图。并与1985—2013年近30年的灾害数据进行集成分析,比较山洪灾害风险区划与灾害发生情况,以期为不同风险地带的土地利用规划提供决策,为山洪易灾区居民提供风险信息。

For the prevention and treatment of flash flood disasters,the zoning of risk based on the master of their regional differentiation laws is an important link to scientifically analyze the disaster factors of the flood disasters and take appropriate preventive measures. Using 12 factors including multi-year averaged rainfall,soil type,slope,elevation,length of the longest convergence route,gradient of the longest convergence route,roughness,steady infiltration rate,population density,per unit area GDP,land use and vegetation coverage,and with a combination of AHP and Delphi methods adopted to determine the weights,the spatial overlay analysis was performed to complete flash flood hazard assessment map,vulnerability map and flood disaster risk zoning map at upper reaches of the Minjiang River. The maps were integrated with the disaster data in 1985-2013 to analyze and compare the flood disaster risk zoning and the actual disaster occurrence situations,so as to provide decision-making support for land use planning of different risk zones as well as the risk information to habitants in the disaster vulnerable zones.