Geological Hazard Risk Assessment Based On GIS

China is one of the most serious geo-hazard countries in the world. Now, it has been a serious problem which can restrict economic development, endanger people's health and social stabilization, and ultimately influence social economic sustainable development, but comprehensive hazard control has long been limited by the financial ability and technical level. Therefore, geological hazard risk assessment as a hot issue is presented, which provides scientific basis for geological disaster prevention and control has great significance in disaster prevention and reduction, is close relate to economic development and social stability.The formation of geological hazards is a complicated problem with rich contents, which are uncertainty, fuzzy, temporal-spacial inhomogeneity, complicated, etc. This paper takes Tao-River Hydropower station in Gansu as the research unite, adopts the combination of GIS with AHP for geological disaster risk assessment, which can develop each method fully at spatial analysis and multi-indexes evaluation, and in a maximum extent make factors quantization more effective, subjective and objective elements more reasonable.Based on detailed field observation and analysis on influence factors of geological environmental conditions and geological hazards development, this paper selects 7 factors, geomorphological types, fault, slope, land use, population density and highway density, for assessment. Corresponding indexes are determined according to AHP, thematic layers of each factor are conducted and superimposed to the index with the support of GIS, and finally subarea map is taken. According to the risk, the country is divided into the high-risk, medium-risk, low-risk and safe area. The result coincides well with the actual, shows that the coupled method has a good prospect for geological hazard risk assessment.