Study On The Application Of Analytic Hierarchy Process (AHP) In Geological Hazard Risk Assessment

China is a country in which geological disasters occur frequently, and it is threatened by geological disasters seriously. Due to special topography and climate condition in the Qinghai-tibet plateau regions, there have complex geological conditions, fragile geological environments, frequent geological disasters, and ecological environment is very fragile. Risk assessment can effectively avoid or alleviate the people’s life and property losses caused by geological disasters. To explore the assessment index system and method, research on establishing a scientific evaluation index system, standard and mode is needed. It is beneficial to disaster prevention and mitigation, and scientific of post-disaster reconstruction. It also helps the government do post-earthquake recovery and reconstruction work of disaster relief, and take correct decision and provide technical support, which can better avoid and reduce the losses caused by geological disasters, maintain the people’s life and property security, promote economic and social sustainable development, provide scientific basis for construction land examination and approval, provide theory support for the construction of disaster prevention and mitigation.This thesis selects the Yushu prefecture "4.14" post-earthquake restoration and reconstruction in Gyegu town democratic north relocation planning area as the research area. According to identifying the study area with regional data and geological environmental conditions, the author uses the qualitative analysis method to study risk assessment of the area including three slope debris flow and six potential instability. The result show that the potential unstable slope geologic disaster danger risk for Q1and Q2, Q4-Q6is medium, risk for Q3is small, and risk for mudslides N1, N2are medium. In this thesis, the analytic hierarchy process (AHP) is used for quantitative risk analysis of the research area. Based on necessary and reasonable factors as evaluation factors, the assessment results are as follows. The risk for mudslides N1, N2, and potential unstable slope Q1,Q2,Q4-Q6are medium, and potential unstable slope Q3small. Combining the results from above two analysis methods, it is concluded that the study area is divided into three parts including level (Ⅰ) area,(Ⅱ) and (Ⅲ) geological disasters hazard regionalization. Finally, the suitability evaluation is taken for the construction sites in the studyarea, and the corresponding geological disaster prevention and control measures are alsopropose.This thesis uses the analytic hierarchy process (AHP) for geological disaster risk assessmentand the evaluation result is reliable. Such approach is feasible and has strong maneuverability.Therefore, it can provide reference for other similar regional geological hazard risk assessment,and it has great scientific and practical significance.