Risk Assessment Of The Debris Flow Gully At Qiulinpu Village Of Fangshan Distract In Beijing

Debris flow is a kind of commonly occurred geological disaster phenomenon,especially develops in mountainous area. It has the characteristics of abruptness. Inrecent years, with the rapid growth of the social economy and the social constructionin our country, in result, ecological environment of the mountains become worsening,creating conditions for the outbreak of the floods and mudslides disasters. It hasthreaten the safety of people’s life and property in mountains. Risk assessment ofdebris flow disaster is the basis and premise in the knowing of debris flow hazardsand doing a good job in disaster prevention. It has the extremely important status. As aresult, it is particularly urgent to do the risk assessment and divide the risk level andformulate the corresponding effective measures to prevent and control debris flowdisaster in mountainous area of each city. This thesis carried out the debris flow riskassessment on a single gully at Qiulinpu village of Shijiaying town in Fangshandistract in Beijing. Based on the assessment, it established the debris flow riskmanagement system of Qiulinpu village gully. In this paper, the research direction andresearch achievements listed below:(1) This paper investigates the basic characteristics of the debris flow gully inQiulinpu village, including the natural geographic and geological environmentalconditions, etc., focusing on the human engineering activities and the research ofsocial economy within the basin.(2) Analyzed the formation conditions of debris flow of Qiulinpu village. One ofthe most factors that can trigger the debris flow activities are: favorable terrainconditions, loose solid source and sudden large range rainfall weather.(3)Determine the movement characteristics of debris flow in Qiulinpu village.Through collecting industry experience formula and specification respectively, thisarticle calculated the debris flow of fluid density, velocity, peak flow, total quantity ofa debris flow process, the overall impact, mudslides climb and maximum height underdifferent frequency. Under the condition of the frequency of1%, the design of bulkdensity of debris flow is1.4t/m3, a rushed out of the total solid matter are3.8×104m3.The result is the important index in the evaluation of the risk assessment.(4) This paper adopts the quantitative comprehensive evaluation method, therespectively using of Analytic Hierarchy Process and the method of Liu Xilin single debris flow hazard assessment for risk assessment. It analysis the evaluation results ofthree kinds of methods and compares their advantages and disadvantages andapplicability comprehensively. Through the calculation of three methods, we finallydecided the risk of debris flow gully as medium risk. Using Liu Xilin vulnerabilitydegree assessment method, the calculated results for the debris flow gully is highlyvulnerable. According to the general risk evaluation formula, the risk degree of debrisflow gully in Qiulinpu village is moderate risk.(5)Set up risk management system of debris flow gully in Qiulinpu village. Inorder to realize the maximum risk reduce of debris flow disaster in Qiulinpu village,this article from three aspects constructed risk management system of debris flow thatare risk analysis, analysis control and emergency response, and put forward the riskcontrol strategy of debris flow gully in Qiulinpu village.