Geological Disaster Risk Assessment And Countermeasures Of Prevention In Zitong County Of Sichuan Province

Combined indoor comprehensive study with geological disaster survey, the paper analyzes and summarizes the natural geographical and geological condition of geological disaster in Zitong County, and illustrates types of geological disaster, distribution characteristics. Based on the analysis of forming conditions and influential factors for various geological disasters, formation lithology, slope, relative elevation, distance to the disaster, distance to road, distance to river are determined as the evaluation factors for risk assessment study; then the evaluation index system is established.Using GIS technology to process data layers of each evaluation factor, so as to make a overlay analysis for evaluation factors. Based on the Arc Info platform of Arc Map10.0, Extracting target values with Arc Toolbox Spatial analysis tool "Euclidean distance" analysis module, target valu es include the distance from disaster point, from the river, from the road. Based on the DEM of Zitong County, extracting index values of slope and relative elevation. While the index value of lithology is set by the geological map of Zitong County, vector ization and conversion to raster data layers.According to the norms and standards, combined Zitong county’s geographical environment and environmental characteristics with distribution characteristics of the disaster points, the geological disasters in this area are divided into three grades, including high, medium and low grading, besides, the evaluation grading standard indicators are identified and the weight of each evaluation factor is determine by AHP.Using the AHP and Fuzzy Comprehensive Evaluation to make a risk assessment for geological disaster in Zitong County, the risk grades division map is obtained by the two methods. It can verify the evaluation results by what happened, next compare the two analysis methods, and then it is obvious that the fuzzy comprehensive evaluation is more accurate and scientific. Finally, combined with the actual conditions in this area, formulating reasonable control measures.