平原地区洪灾风险评价的GIS方法研究——以荆州6县市为例

RISK EVALUATION FOR FLOOD DISASTERS IN THE PLAIN AREA BASED ON GIS--TAKING SIX COUNTIES IN JINGZHOU AS A RESEARCH EXAMPLE

平原地区因地势低平,水网发达而常遭到洪水的威胁。这种威胁既有来自过境洪水的洪灾,也有来自本地因暴雨引起的涝灾。如何考虑它们两者的相互影响以及洪水灾害的自然与社会经济属性,进行洪水风险评价是一个比较困难的问题。在地理信息系统软件ArcGIS8.1支持下,既考虑过境洪水与本地涝灾,也考虑承灾体的易损性(包括人口、交通线与经济),还考虑抗灾能力,以GRID模块的地图代数作为运算手段,用AHP法确定因子的权重,建立了评估平原地区的洪灾风险的计算模型和评价方法,该模型运用于长江中游洪灾风险比较严重的地区——荆州地区的6县市,取得了比较好的效果。

Because the terrain is low,and the river network is dense,the Jianghan plain areas often suffer from the flood which is brought by the flood passing through the region,and the storm in the area.It is very difficult to evaluate the flood risk,because the flood passing through and waterlogging disaster,and their relation,and the natural attributes and social attributes must be considered all together.Supported by GIS software ArcGIS8.1,considering the flood passing through and waterlogging disaster,also considering the vulnerability of hazard-affected body(including population,traffic lines,economical value),adopting GRID module as calculation method,calculating element weights by AHP,this paper sets up models and evaluation methods for the flood risk in the plain areas.And then choosing six counties in Jingjiang area as an research area,the flood and waterlogging disaster risk are evaluated.