基于GIS技术的巴东新城区滑坡灾害危险性区划

GIS-based Landslide Hazard Zonation of the New Badong County Site

基于ArcGIS8软件平台开发了三峡库区巴东县新城区滑坡灾害信息系统,通过全面分析巴东新城区滑坡灾害的地形条件,工程地质岩组、构造与斜坡结构类型、人类工程活动、水的作用等影响因素,建立了相应的滑坡灾害危险性评价指标体系。采用基于GIS技术的信息量模型和敏感性评价方法,实现了巴东县新城区滑坡灾害危险性区划,其中,高危险区面积3.30km2,占7.1%;中危险区面积5.77km2,占12.4%;低危险区面积16.40km2,占35.3%;基本安全面积21.05km2,占45.2%,可以作为巴东新城区城镇建设规划和减灾防灾的参考依据。

With the ArcGIS8 software platform, the authors constructed a spatial database mainly for the landslides in the new Badong County site, which includes 13 primary map-layers, 1190 features, 2450 pieces of attribute data and 3600 pieces of external attribute data for 40 landslides. On the basis of comprehensive analysis of the present landslides in the new site of Badong County, the authors analyzed the main factors controlling the formation of landslides. These factors involve such aspects as ① topography and geomorphy, ② tectonic setting and slope structure, ③ engineering geological layer combination, ④ human activities, ⑤ the effects of water. From the above factors, 17 indexes were selected for landslide hazard zonation. With the statistic analysis and spatial analysis function of ArcGIS8 and the necessary development of the software and according to the principle of the information model and sensitivity analysis, the selected indices were quantified,and the raster map of landslide hazard zonation with information model and the raster map of sensitivity of landslide hazards were formulated. After comparing the two raster maps and the data of investigation, the compilation of the landslide hazard zonation was carried out with the result automatically mapped. According to the result of landslide hazard zonation, the high-grade area is 3.30 km^2, accounting for 7.1% of the total study area; the medium-grade area is 5.77 km^2, accounting for 12.4%; the low-grade area covers 16.40 km^2, accounting for 35.3%; and the area without landslides, i.e., the stable area, covers 21.05 km^2, accounting for 45.2%.