Study On Risk Assessment Of Luobu Landslide In Qin'an County, Gansu Province

Every year landslide disasters caused more than ten million direct economic losses and hundreds of people dead or missing in our country. Faced with such serious landslide disasters, in order to reasonably confirm and measure the influence degree of the landslide hazard to life and property, and then guide the landslide disaster prevention and mitigation measures, a risk evaluation with landslide risk assessment theories and methods is needed. Currently, there are no uniform standards and technical specifications to guide the single-landslide risk assessment, so it makes sense to research the single-landslide risk assessment.Based on the comprehensive analysis the research achievements of landslide disaster risk assessment theories and methods both at home and abroad, this paper built a complete single-landslide risk assessment system. As a application of the above proposed system, the author took Luobu landside as an example. Single-landside risk assessment contents 4 aspects:single-landslide hazard's essential feature analysis, instability analysis, vulnerability of calamity and landslide risk assessment. In various stages of the assessment, the author presented calculation methods of single-landslide disaster probability, hazard scope, vulnerability of calamity, total risk of the disaster.Using the Single-landside hazard risk assessment system this paper built, assessment luobu landslide's risk. With Analytical Hierarchy Process (AHP), based on field work in the wild, engineering drilling and laboratory tests, it turns out that Luobu landslide's risk is 0.377, which means the stability is good enough. Then using the GIS platform on Luobu landslide Sub-regional risk assessment, got that Luobu landslide's risk mainly depends on the 2nd landslide. So when use the thrust transfer coefficient method analyze the stability of the 2nd landslide of Luobu, The results show that the 2nd one's annual probability of partial instability is 0.059, overall instability is 0.0416.At the same time, analysis the vulnerability of element at risk within potential hazard range of the 2nd landslide of Luobu, getting the hazard-affected probability and loss rate of element at risk, and calculating the value loss. At last, through the risk assessment formula get the correspondingly economic risk are 0.2912 million yuan and 0.959 million yuan. And it will bring no population risk when it just localized slide but the whole instability's population risk is 17.83.I hope this paper proposed assessment system about single-landslide risk and the practical application in Luobu landslide can be referenced by the other single-landslide risk assessment.