Study On The Methods Of Geo-hazards Risk Assessment In Qinling Mountain

The Qinling Mountain is an area where geo-hazards are most developed. In the rainy season, a lot of geo-hazards will occur due to the heavy rain, with great casualties and losses. In order to get the methods on early warning and disaster reduction for geo-hazards in the towns of Qinling Mountain, Feng County in Shaanxi province is taken as an example. Based on the analysis of disaster regularity and supported by Geological Survey Project of Baoji City in Shaanxi Province, and in accordance with the sequence of "susceptibility-hazard-risk", the risk assessment and management on landslides, rock falls and debris flows suffering rainfall were discussed with the help of statistical analysis method and mechanical model. Some results are obtained:1. The developmental character and distribution regularity was revealed. The geo-hazards include rock falls, landslides and debris flows, mainly distributed in the areas with great human activities, rivers and little vegetation. The metal mining tailings was prone to form potential debris flow when suffering rainfall and was very serious. The geo-environmental factors include landform, formation lithology, river erosion, vegetation cover and fault, etc. The main reason for geo-hazards is rainfall and cutting slope.2. The geo-hazard susceptibility was analyzed based on the comprehensive statistics method on the amount of information in the regional area and local area. The AUC curve indicated that in the same assessment region, the results based on the local statistics analysis was more accurate; and as for the same method, the accuracy increased with the geological logging preciseness.3. The geo-hazard risk assessment was discussed using the statistics method and the stability analysis on mechanical model of slope. The AUC curve indicated that the results based on statistics method are more accurate; the accuracy of stability analysis mainly depended on the data of formation lithology and underground water, and it was fit for the slope with single stratum or strata with little difference. The risk assessment on debris flow was analyzed with analytic hierarchy process and fuzzy comprehensive evaluation. And the debris flow risk was classified into four grades.4. Combined with the geo-hazard characteristics in mountain area, the risk assessment method on geo-hazard in regional area and the evaluation standard of tolerable risk were put forward. Based on the disaster-bearing body value statistics and its vulnerability assessment, the estimation on social risk of personnel and property caused by geo-hazards in Feng County was performed. The risk grade was classified according to experience of tolerable risk, and the related control measures were proposed. As a...