Study On Major Geological Hazard Risk Assessment Based On GIS Technology In The Eastern Himalayas

With constant improvement of the theories of Geography Information System (GIS) and rapid development of technology, the GIS has been widely applied to all the current fields related to spatial information beyond the initial limited field. In particular, since the new century come, the GIS theory has ripened relatively,and becomes the major tool of analysis of spatial information gradually. In recent years, along with the fast development of the economy of our country, especially with the thorough of west development, human project campaign gradually strengthened the influence of environment. In the loess area of west China, the geographical hazards show the tendency of growing. In order to solve this problem, the paper tries to apply the latest technology of GIS to assess the geological hazards in the eastern Himalayas.This paper against the core study of the area mail hazards—the risk of hazard assessment, takes the hazards in the eastern Himalayas belonging to the area of Milin and the area of Shannan in Tibet for example. First of all, the paper connects the regional environmental geological conditions, including the survey of natural geographic situation, the engineering geological conditions, the hydrogeological conditions, the human activity for socio-economic and so on. Secondly, the paper describes the geological hazards status quo , its formation mechanism, development mechanism and distribution about the research aera.This paper studies the geological hazards including landslide, collapse, debris flow and dangerous glacial lake and so on.Against the peculiar geological environment at the eastern Himalayas, the paper establishes a hazard evaluation system, instructs its developing principles and how to choice the evaluation factors in detail. The paper also gives a lot of facts to describe the Analytical Hierarchy Process (AHP) which is used. The contents include its basic principles and basic steps.focuses on the core problem of the geological hazards assessment in the eastern Himalayas, the paper attempts to use the technology of GIS in geological hazards so as to solve such problems in past as low efficiency, bad accuracy, and waste of time. Try to make the course informed and scientific. This paper constructs a workflow based on GIS to have the significant geological hazards assessment in the eastern Himalayas with AHP.This paper takes the catchment unit generated by ARCGIS as the assessment unit. The eight evaluation factors choosed includes the mountain slope, the mountain aspect, land use patterns, height distribution, formation lithology, the distance from the tectonic line, The average rainfall from June to September and human activity and so on. Through assessing the geological hazards for research area, gets the comprehensive risk zoning map matching with the geological hazards distribution map.The study in this paper makes the following major achievements(1) A set of complete technological route and work process of loess assessment based on GIS is set up specially for the geological hazards area of the eastern Himalayas. The system includes problem analysis→establishment of standards→preparation of assessment factors→building landslides database→building model→confirmation of results.(2) Based on GIS, built the database of geographical hazards in research area.(3) Based on GIS, confirmed the standards of geographical hazards assessment.(4) Based on GIS, confirmed the model of geographical hazards assessment.(5) Finally got the map of geographical hazards assessment of research area.