Binchuan County, Yunnan Province, Geological Hazard Zonation Evaluation Studies

This paper has analysed the essential feature and formed conditions of the geological hazards development of Binchuan in details.On the basis of qualitative analysis,the paper introduces the gray correlation method,analysis the relation between primary and secondary of the geological hazards influence factors of Binchuan by quantitative way,thus selects 7 evaluation factors,adopts fuzzy comprehensive evaluation method to quantitative make a zonation of the geological hazards of Binchuan by their occurrence probability,and have had out the basic understanding that the following:1,The geological environment of Binchuan is complicated,there are lots of geological hazards,the major geological hazards as landslides,debris flow and unstable slope(a total of 215,including 142 landslides,54 debris flows and 19 unstable slopes). The geological hazard makes some buildings destroy and the farmland damage,threaten the security of lives and properties of the local people seriously.2,The characteristic of distribution of space-time of the geological hazards is obvious.In space,Binchuan geological hazards in the east is most greatest,followed by the western and central,which shows that the factors of geological structures affects the distribution of hazard significantly(mostly,distribution of geological hazards in tectonic belt such as Binchuan fault,Yupao Jiang fracture,Pingchuan fracture,Lawu fracture).In terms of time,geological hazards occurred during the rainy season(from June to September),the majority are brought out because of continued rainfall.3,On the basis of qualitative analysis about the geological hazards influence factors of Binchuan,using the gray correlation method quantitative analysis of geological hazards influence factors,have drawn the various factors affecting ranking: rock group's structure,terrain slope,human project activity,density of some development of the geological hazards,rainfall,earthquakes,geological structure,to the river system,vegetation coverage rate in the earth's surface.4,On the basis of MAPGIS information model,have set up the geological hazard graphics library,including basic information picture layer,engineering geological rock picture groups layer,geomorphologic map layer,structural map layer,rainfall picture layer,geological hazard picture layer,etc.Appraises and predicts the space to the geological hazard of Binchuan country based on the space analyses of MAPGIS.5,Using the fuzzy comprehensive evaluation to quantitative make a zonation of the geological hazards of Binchuan by their occurrence probability and dividing it into three grades:high probability,moderate-high probability and moderate probability,which,in the most moderate-high probability for 1028.21 km2,accounting for 39.14%of the county area;756.86km2 high probability,accounting for 28.81%;841.93 km2 moderate probability,accounting for 32.05%.6,have described the method system on regional geological hazard assessment tentatively.Have defined the concept appraised to the dangerous dividing area in geological likely to suffer from dividing area of geological hazards in the area;Have set up the screening of the evaluation index and quantization method tentatively,and has set up the basic frame of geological dangerous zoning of calamity of county(city).this is the main thesis of this theoretical achievements and innovation.