| This paper mainly studies the problems of geological hazard tendency, which sets the geology disasters in Ningyuan County as an example and applies the GIS in susceptibility assessment to turn the geo-hazard data into geographic information. Taking the software ArcGIS as the operating platform, we can evaluate geological hazards quantitatively with method of information quantity model, which of the evaluation unit is 30×30m2.Finally, it is concluded that the geological hazard susceptibility zoning map is consistent with the existing geological hazard distribution.The main research contents and results of this paper are as follows:(1) We have researched the engineering geological conditions in Ningyuan County from the natural geography, geological environment, geological structure, hydrogeological conditions, vegetation and human engineering activities, etc. We summed up the basic characteristics, structure and material composition of different geological disasters.(2) On the basis of detailed investigation data, we have analyzed the types and the characteristics of geological disasters in the study area and it comes out that the types of geological disasters in this area are landslide and unstable slope and ground collapse. The landslides all have happened in modern and occurred during the rainy season, which of scale are small, of plane shape are mainly semicircular and of slippage are traction. The unstable slopes are mainly natural soil slope, which of flat shape are convex and linear types and of the control plane are mainly between covering layer and bedrock. The ground collapses belong to the natural karst collapse, which of scale are small.(3)Based on the analysis of the influencing factors of geology disaster in the study area, we have select eight main factors: hydrogeological factor, topographic gradient, ground elevation, geological structure, mean annual precipitation, vegetation cover degree, human engineering activity and engineering geological rock group as evaluation index to form the index system of the geological hazards assessment in Ningyuan County. By the spatial analysis function of ArcGIS, we have analyzed the eight evaluation factors quantitatively and established the susceptibility evaluation model of geological disasters which is based on the GIS information.(4) By the spatial overlap and statistical functions of ArcGIS, we have carried out the susceptibility assessment and zoning of geological disaster in Ningyuan county. It results that the high-prone area is 245.80km2 which accounts for 9.8 percent of the whole region, the middle-prone area is 1107.90km2 which accounted for 44.3 percent of the whole region, and the low easy-prone area is 1147.76 km 2 which accounts for 45.9 percent of the whole region. |
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