The Study Of Hazard Assessment About Landside In Wushan County

Wushan county, Chongqing City, locates in th heart of the Three Gorges Reservoir, geographical hazards is very serious, especially landslide hazards. The construction of the Three Gorges Reservoir and the town for the migration, the enlargement of the city scale and the building of the basic establishment such as shipside, road, electricity net and the telecommunication net etc. will impel the development of the wushan society and economy very much. However, there are more hills and more cragged slopes, less lands and more dense population, complex geologic condition in wushan, and wushan county also locates the semi-tropical climate region with high frequency rainstorm. The construction of the Three Gorges Reservoir and the development of the people economical activity in the Three Gorges Reservoir will more prick up the area and dangerous degree of the geographical hazards. Enhancement of the hazard assessment will have the actual significations on the nipping in the bud, appropriate protection and reasonable exploitation on environment, protecting the life and belongings of the wushan people.The fast development of the geographical information system theory and technology make the application scope of the GIS expand nearly all area about the spatial information. Landslide hazards assessment is a complex process with more information which comes from many sources, in the process, more quantity and complex data will be analyzed, the data-base with strong management function and the strong analysis function is needed. GIS with strong spatial analysis function and managing spatial data function can become the tool of the landslide hazards assessment. Taking the landslide hazards in wushan county as research object, combining the spatial analysts of GIS and the symbolic statistic model, this paper assessed the landslide hazards. In the paper, the assessing unit is 25m×25m ,using information value model and sensitivity value method the landslide hazards in wushan county was assessed. The final hazards assessment map tallied with landslide distributing. According to the research in the paper, the conclusion is the following.(1) According to the landslide hazards assessment in wushan, some rules of the wushan landslide distributing in space open out. The rules are following: the landslide hazards distributing is zonal, the high and the higher hazards area are mainly distributed the area below 400m in vertical space, and the higher hazards areas are near to the road, which showed that the people activities affect on the earth's surface very much, and create the condition of the landslide.(2) About the assessing method, the methods based on the symbolic statistic model are selected, which reduced the artificial affection in the process, and promote the objectivity and the reality of the assessing results.(3) GIS software is used mainly to research, some statistic calculating process is also used the calculating function of the GIS software itself, not using the other statistic software, and avoid the data transformed in each kind software.(4) The assessing unit is 25m×25m ; comparatively, the precision is very high.The practice showed that the assessing method of the hazards based on the spatial analysis of GIS and symbolic statistic model have very good effect. The assessing results have objective and reality, and can become the foundation of the wushan economy and society layout. The assessing methods based on the continuously perfection can generalize the other area.