Study On The Building Of The Geological Hazards Database And The Evaluation Of The Susceptibility Of Geological Hazards Of Yan Chang County Based On GIS

Landslides, collapses and mud-flows threaten human life and property seriously, and affect sustainable development of local economies in recent years. For preventing them, China Geological Survey projects thorough investigations of geological hazards, including the geological hazards investigation of Yan chang County. The project gets lots of data, concerning the geology, topography, meteorology, hydrology and human activities. In order to store and manage the data effectively, the paper researches the building of the geological hazards database of Yan chang County and the evaluation of the susceptibility of geological hazards based on GIS.On the basis of data collection and field investigation in the County, the paper researches geological environment and the county's geological hazard situation, builds the county's geological hazards database using the county's Geological Hazard Information System (GHIS). The database involve Geological Conditions, Geological Hazard, Risk Management, Weather warning, Physical Geography, Document. The data can be searched, browsed, made statistics and printed based on GHIS.The paper analyses the formed and induced reasons of the county's geological hazards, then selects seven factors to assess susceptibility of the County's geological hazards, including distribution density of hazards, gradient, slope curvature, height of slope, fluvial erosion, character of rock and soil mass, human actives. The factors'weight are counted by AHP. The factors'quantitative analysis are made using the spatial analysis of the software ArcGIS. Then all the maps are made overlay analysis using the spatial analysis of the software ArcGIS, forming the map about the susceptibility of the County's geological hazards based on ArcGIS. Based on the result, the paper draws up the the susceptibility zoning of the County's geological hazards, divides Yan chang County into four zones:the high susceptibility zoning, the middle susceptibility zoning, the low susceptibility zoning and non- susceptibility zoning.