基于GIS的丹江流域洪水灾害危险性评价

Hazard Assessment of Flood Disaster in Danjiang Basin Based on GIS

从形成洪水灾害的自然属性出发,选取近30年年均降水量、地形高程、坡度和水系分布作为致灾因子和孕灾环境的评价指标,对丹江流域洪水灾害危险性进行评价。运用GIS空间分析工具,对降水量因子、综合地形因子和水系因子进行叠加分析,得到丹江流域洪水灾害空间分布特征。结果表明:丹江干流下游和一级支流老灌河、淇河和滔河下游河谷两侧洪水灾害危险性等级最高;丹凤县以上的丹江流域范围,除商丹盆地以外,洪水灾害的危险性等级最低;高危险、较高危险、中等危险、较低危险和低危险的面积分别为1447、4598、4710、5122、935 km^2,分别占丹江流域总面积的8.6%、27.3%、28.0%、30.5%、5.6%。研究结果为丹江流域防洪减灾政策制定与决策部署提供科学参考。

Based on the natural attributes of flood disasters,the average annual precipitation in recent 30 years,terrain elevation,slope and distribution of water system were selected as the factor indexes of disaster-inducing factor and disaster-pregnant environment to evaluate the flood disaster hazard of the Danjiang River Basin.Using spatial analysis tools of GIS,the precipitation factor,comprehensive terrain factor and water system factor were overlaid,and the spatial distribution characteristics of flood disaster in Danjiang River Basin are obtained.The results show that:the lower reaches of the main stream of the Danjiang River and the lower reaches of the first-level tributaries,Laoguan River,Qi River,and the of Tao River,have the highest hazard level of flood disaster;the Danjiang River Basin above Danfeng County,except for the Shangdan Basin,has the lowest hazard levels of flood disaster;the areas of the highest hazard,higher hazard,medium hazard,lower hazard and the lowest hazard are 1447,4598,4710,5122,935 km^2,respectively,accounting for the total area of the Danjiang River Basin 8.6%,27.3%,28.0%,30.5%,5.6%.The research results provide a scientific reference for policy formulation and decision-making deployment on flood prevention and disaster reduction in the Danjiang River Basin.