Vulnerability And Risk Assessment Based On The Road Line G212 Longnan Section In Highway Debris Flow Disaster

The highway is the great artery of the national economy, takes important part in the transportation of our country, but the debris flow seriously affects its normal operation and the traffic safety. The debris flow is a common natural disaster in the mountainous area; our country mountainous region approximately composes two-thirds of the national territory area. As a linear structure, highway pass through various types of terrain units inevitably, involving a variety of complex geological and topographical conditions, is suffering each kind of disaster's threat. Natural factors and human activities together, leading debris flow of China's Western highway is widely distributed, diverse, active and serious. For the past many years, debris flow caused an average annual direct economic losses amounting to several billion Yuan as much as nearly thousand people's death. The debris flow disaster is regional and the road is linear, the debris flow to highway's destruction is the spot, but the inflection is the line and surface. So the highway debris flow disaster's appraisal should be thought of the spot, the line and the surface. The debris flow hazard assessment has a clear difference and characteristics, which different with the physical geography debris flow hazard assessment. Therefore to strengthen the highway of debris flow hazard assessment study has important theoretical significance and value.The article relies on G212 Longnan debris flow-prone areas about the road-building to debris flow risk assessment and classification for the main content, focused on the following aspects were studied:Firstly, this paper based on the G212 Longnan above the formation of debris flow conditions, the characteristics of disasters, its distribution, to elaborate the harm of the road.. And then based on these features, utilizing the generalized analysis judgment to the road to carry out a comprehensive analysis of road debris flow hazard assessmentSecondly, receiving the disaster body to the road debris-rock flow to carry on the classification, in accordance with its own characteristics to use the road rank, length of routes,road network density, infrastructure protection facilities,the natural environment indicators, forecasting and early warning systems that affect their vulnerability to the factors, according to these factors to determine the road for disaster vulnerability analysis. The basis of which the type of protective device involves a wide variety of structures discussed is more complex, a separate chapter for discussion. Due to the limited time available in this article, in this part of the evaluation, select a wide range of applications, more mature theoretical system of bridges as the main study, using the second fuzzy evaluation method vulnerability protection facilities were evaluated and graded.Finally, the disaster loses including the economic loss and the non-economic loss, the economic loss may divide into the direct economic losses and the indirect economic loss, the non-economic loss mainly includes the loss which the personnel casualty, the environment destroy, Economic loss appraisal of disasters is an indispensable part of the current evaluation system.