Researches On Debris Flow Hazards Evaluation Indexes System And Method In Beijing

Based on the research of the distribution law of mudflow and their forming condition in Beijing area, this paper studied on the evaluation index system of mudflow disaster and established evaluation indexes system of mudflow hazards in Beijing area. In addition, by combing extensible comprehensive evaluation model and analytical hierarchy process, this paper evaluated the risk of mudflow disaster in Miyun district of Beijing and main results are as follows:1. Mudflow is one of paroxysmal geological hazards in Beijing area, which distributed on west mountain and north mountain of Beijing. Mudflow disaster is of irregular periodicity.2. The hazards of mudflow in this region showed in three aspects: direct hazard, indirect hazard and further hazard. Firstly, the direct hazard can result in dying and hurting of people, destroying of all kinds of engineering, and loss of wealth and economy. Moreover, the indirect hazard results mainly in shutdown and stopping production in industry, reducing production in agriculture and pasture, and interrupting transportation. In the end, further hazard results in mainly damages of land resource and environment, which will sustain long time and prevents the sustainable development of economy.3. Regional geological environment and style, distribution, influencing factors of mudflow disaster as well as forming mechanism are analyzed and studied. Moreover, by reviewing lots of literature and combining experience of former researchers, evaluation index system is created in order to reflect the true situation of mudflow disaster of the investigation area and lay foundation for preventing disasters.4. In the former risk evaluation, risk and venerability is evaluated separately and the value of weight was assigned according to correlation of influencing factors, which made risk evaluation index and venerability index subjective. In this paper, the weight value was obtained by analytical hierarchy process and the risk and venerability are considered together to do extensible evaluation model. Hence, the later way is good for process management and getting reasonable calculation.6. In order to show risk degree of each unit of mudflow hazards, the risk index was divided into four grades. Moreover, the grade map of mudflow hazards was made.Study on risk evaluation indexes of debris flow disasters is very complicated work, and is in the searching development stage for the moment. This paper is our research outcome, provide theory foundation for further research such as disaster-protection and disaster-subtraction.