Bank Slope Risk Assessment On The Reservoir Region Of Xiaowan Reservoir Based On RS And GIS

Xiaowan Reservoir is a leading one which lies in the middle and lower reaches ofCascade Hydropower Station of the Lancang River. It is a key project of cascadedevelopment the Lancang River. The Bank Slope geological disasters have beendeveloped by Xiaowan reservoir is numerous. Because of locating in the mountains andcanyons, inconvenient transportation, and other factors, combined with the complicatedengineering geological conditions, only by the field survey cannot it meet the needs ofdisaster prevention and mitigation, which requires to seek a more convenient way toexpand the scope of the investigation and assessment of bank slope of geologicaldisasters, accelerate progress and improve the reconnaissance level and quality, reducethe fieldwork, and improve the efficiency of hydropower engineering geological hazardassessment work.The study object of this article is Slope near the Xiaowan Dam Reservoir,combining with the findings of the previo us section, using GIS and remote sensinginterpretation to analyze the factors affecting the Slope Stability and spatialdistribution characteristics of disaster points of the bank Slope,establishing Xiaowanwatershed geological disaster management system. By contrasting to the typicalevaluation method, using the Analytic Hierarchy Process on the rocky shore slope andsoil bank slope risk to get the main results:（1）On the basis of the topography of the study area and elaborating of theengineering geological conditions, using the high resolution remote sensing images ofthe quickbird to complete detailed investigation of the Bank Slope of the study area, Itcan interpret20disaster points of the rocky shore slope,11disaster points of soil bankslope, including the use of a typical point-West close landslide more detailed remotesensing interpretation, compared with the field investigations and interpretation of theresults fully demonstrates the feasibility of remote sensing techniques. In addition, thisarticle mainly investigate on the bank collapse topography map of the geologicaldisasters, the regional geological structure development, water development conditions,land-use type situation, lithology and rock structure type, seismic, rainfall and reservoirwater level changes of the study area.Statistics and summarized the development of theregional geological hazard location, size, scope, and imaging characteristics. （2）Based on the detailed investigation of the bank slope geological hazards ofthe study area，for the bank slope development characteristics of the Potential bankslopes in Xiaowan near the Dam reservoir area, the article focuses on internal factorsand external factors of geological disasters in the bank slope. Among them, theinternal factors, includ slope, aspect, relative elevation, land-use type, water system,faults and stratigraphic and lithologic and so on, however, seismic, rainfall and waterlevel changes is external factors of bank collapse geological hazards occurrence. Thisarticle uses the function of Buffer analysis of GIS to investigate these factors and thecharacteristics of the spatial distribution of the Bank of geological disasters.（3）On the basis of investigating the Slope Stability factors, in order to improvethe efficiency of disaster prevention and mitigation of the Xiaowan watershed andfacilitate the construction of the geological disaster monitoring and prevention network,the article collates information on geological disasters of Xiaowan watershed andanalyzes it, By means of classifying coding of geological disaster database graphic dataand attribute data,file naming and designing the way of the data combination,usingC++development language, Visual C++Studio, and ArcEngine as a developmentplatform, establishing the Xiaowan basin geological disaster management system.（4）This article extractsand analyzes theterrainslope,terrainaspect,therelativeelevation, land-use types, faults, stratigraphic and lithologic, water systems, waterstorage, seismic, rainfall, etc. ten evaluation factors information, and designs andre-classifies of each index（5）By contrasting the previous results, taking the Uzbek branch bank slope asan example, using the large-scale numerical analysis software FLAC-3D to analyzeon the bank slope of two kinds of conditions in the natural state and after theimpoundment, and reflects particularity of the water level changes of this evaluationindex, then providing an evidence for the assignment of index weights.（6）By sensitivity analyzing geological disasters in the of the study area,completing the data pretreatment. Contrast with the advantages and disadvantages ofgeological hazard assessment model, using the analytic hierarchy process, establishingbank slope geological hazard evaluation mode of the study area, using overlay analysisfunction of GIS to classify Potential bank slopes in the study area.(7) According to the result of classify Potential bank slopes in the study area,the Potential bank slopes in Xiaowan near the Dam reservoir area stay in low risk orno risk-zone, both of which make up89%of study area. Low or no risk-zone meansbank slopes in which is constituted from Bedrock and loose rock mass, and Vegetationcover, the risk of leading to Geological disasters is low. However，11%area isintermediate and high risk-zone，where the bank slopes’ tability are poor effected bystratigraphic and lithologic, evaluation, water storage, etc. it should strengthen bank slope prevention and treatment in high risk-zone for People’s life and property safetyand Economics improvement.