| In recent years, with frequent geological disasters, causing huge losses to human social development, formation and occurrence of geological disasters so that there is an urgent need to have a more in-depth understanding and research. Assessment of geological disaster early warning, provide reasonable guidance for project management in the field, and provide strong security guarantee for economic development. Geological disaster risk assessment as an important way of geological disasters assessment is gradually being known. For disaster risk evaluation of geological disasters before the formerly passive assistance into the disaster after the disaster prevention, disasters and mitigate their defensive work, done before the devastating natural disaster occurs.Thesis in yingxiu town in Wenchuan County and the surrounding area as a study area and its geological hazard assessment, geological disasters, vulnerability assessment and risk evaluation of geological disasters. Although the Wenchuan earthquake is after five or six years, but in yingxiu town of Wenchuan, the quake’s epicenter, and great influence on its geological structure, topography great changes have taken place. So far, yingxiu town there are still many risks of geological disasters, so there is still a very important meaning.Based on the geological hazard in the study area based on the analysis, using remote sensing and GIS in geological hazard risk assessment and vulnerability of identified research area distribution, based on more complete risk evaluation of geological disasters, access to geological disasters risk ratings, the paper work and the results are as follows:(1) based on remote sensing images, respectively, building collapses, landslides and debris flows, land cover remote sensing interpretation of symbols and carry out remote sensing interpretation, making remote sensing interpretation.(2) use of contour lines to build digital elevation models, digital terrain analysis such as slope, the ups and downs of as well as the drainage system, faults, buffer analysis, residential areas, etc.(3) based on the research survey and analysis of geological disaster in the region in identifying geological disasters in the region on the basis of the distribution, type and other characteristics and formation conditions analysis of geological disasters: geo-environmental, lithology, geomorphology, climate and hydrological features such as controlling factors, laying the Foundation for further work on risk assessment.(4) chose for geological hazard, vulnerability and risk evaluation index system of building hazard, vulnerability and risk assessment models.(5) in accordance with the evaluation index system of applying GIS technology to extract geological hazard in the study area, the vulnerability of various indicators, using appropriate evaluation model for geological hazard risk assessment and vulnerability assessment and risk assessment is carried out on the basis of this.Through this research shows that geological disasters in high-risk areas, not necessarily higher risk; risk assessment of geological disasters is based on risk and vulnerability grade, then divided into risk levels. That meets both high risk and high vulnerability areas, to be classed as a high risk area. Due to the small population densities within the study area, building facilities-small and narrow the scope of human activities so that less high vulnerability areas within the study area and the total area is small. Less high risk areas within the study area and its total area is small, but the area of the district is 4.5% in the moderate risk area of the one and only 16.9% at very low risk. Explain most of the study area, there are certain risks and safety concerns about any of these areas should take appropriate preventive measures to reduce disaster losses caused by ash from an erupting. Based on the actual situation and put forward appropriate recommendations, as a study area of post-disaster reconstruction and disaster prevention engineering for reference. |
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