Dongchuan Landslide Hazard Evaluation Using Remote Sensing And GIS

Dongchuan district is located in the northeast of yunnan province,in the northern edge of the Yunnan-Guizhou plateau area, runned throughout Xiaojiang river valley.It has obvious vertical zoning affected by the atmospheric circulation and topography, wet and dry season, local rainstorm which always triggered Iandslide.Landslide hazard survey in Dongchuan can effectively know the landslide feature, the law of development, to provide evidence for the disaster prevention.In this paper, combining GIS and RS to evaluate the landslide hazaed area, a case study of Dongchuan County.The paper is based on the project Resource.l 02C geology and mineral resources and geological hazards application model and key technologies organizad by Ministry of land and Resources organization.Based on the collection of landslide and influencing factors in Dongchuan District.Using RS and GIS technology to process and analysis the landslide and influencing factors,know the impact of each factor and landslide development.The paper uses the Information value model and logistic regression model combined with certainty coefficient to caculate the result of the risk of landslide and evaluate the rusult of zoning.Paper main research content is as follows:1.The research classes each feature and satistics the distrubution of the existed landslides in the classifaciton factors, caculating the information and certainty coefficiento of the classifaciton factors, obtained landslide-prone condiction:(1) evaluation:evaluation range of landslide-prone is 800-2000m;(2)slope:landslide always occurred at 30°-60°; (3)aspect:the aspect of landslide-prone is wes?northwest north;(4)curvature:the curvature range of landslide-prone is less than-3, (5)To the fault diatance:landslide-prone area is in the distance range of 1000m;(6)To the river diatance:landslide-prone area is in the distance range of 500m;(7) type of rock structure:thin-bedded hard rock and soft rock clip interbedded rock group, Pt2; Semi-solid clastic intermediated-acidic group, Kz; massive hard rock to intermediated-acidic group, Pz were the landslide-prone area;(8)vegetation converage:The vegetation converage of landslide-prone area is 0-0.3.2.By overlay analysis obtain the rusults of two statistical model.Using the area under curve to verify the accuracy of the model, the accuracy of the information model is 78.32%, logistic regression model is 71.54%. lower than the information model.3.The evaluation results are classified as very low risk zone, low risk zone, medium risk zone, high risk zone and very high risk zone.From the zone map, the high risk and very high risk area focus on the north beside the Jinsha river? northeast and central beside the Xiaojiang river,belongs to Xiaojiang watershed,and it is in the activities of Xiaojiang Fault belt, western has Pudu fracture with violent geological activity influenced on slope stability. The low risk and lower risk area are mainly distributed in the western, southeastern and southwestern with high elevation and gentle slope or steep hill.The medium risk zone was between in the high risk area and low risk area.the difference of the evaluation result using two model is in the divided of the low risk zone and medium risk zone.