The Study Of Interpretation Of Large Scale Landslides And Hazard Assessment In Wulong County Based On RS & GIS

The landslide disaster is one of the worst natural disasters with large economic loss and personnel casualty in the world.It is the urgent need of the affected areas as well as the mission beared by the workers on landslide to investigate and monitor effectively landslide distribution and status of activities for landslide prediction and assessment under the grim situation.It can provide a scientific basis of the landslide prevention and the resettlement work.The "3s" technologe gradually becomes an important method on landslide information extraction and hazard assessment since 1990.Remote sensing(RS) can access to the surface information quickly and comprehensively to investigate geological disasters widely at home and abroad.Remote sensing images become the most basic and important source to obtain information of landslide and its developing environment.Geographic Information System(GIS) is a powerful tool to analyze spatial distribution of the surface objects,including treatment,management,query, analysis,input,output of spatial data and attribute data and so on.Using the spatial data management and analysis functions of GIS,it can extract spatial information of the large scale landslides in remote sensing images,set up the spatial database of landslide factors and assess landslide hazards combining quantitative factors and qualitative factors.Wulong county in Chongqing is a high incidence region for landslide disaster.In this paper there are two TM images as the main data source.The scanning graphic documents and statistical data are dealed with into digital forms based on RS&GIS technology.The landslide hazards in Wulong is evalued with these methods of overlay analysis,analytic hierarchy process,fuzzy comprehensive evaluation etc.in each cell of 30m~*30m.The conclusions are the following according to the research:(1) The basic information of seven large scale landslides in the image is obtained by the determined interpretation keys and the field research in Wulong county;(2) The database of landslide factors in the study area is built up;(3) Preparation of landslide hazard evaluation factors and their weights;(4) The final hazards assessment map tallied with landslide distribution.The most hazard regions mainly distribute in the lower slopes along the Wujiang River and its tributaries.The practice shows that RS&GIS technology has quite feasibility and practicality on remote sensing interpretation and risk assessment of landslide disaster.Of course,the landslide risk assessment is a very complex system with many changeable factors which come from many different sources.The paper is limited to the discussion of basic theories and methods of RS&GIS technology, just as an application reference of large-scale landslide hazard assessment.