| The thesis relies on the project—"geology hazard investigation and preventing and curing project of Ludian" .In this paper, it systematically discusses the characteristics of development and distribution, and the forming conditions and mechanisms of the geological hazards in Ludian County with methods such as geological field investigation, data processing and GIS model calculating. On this basis, the major indexes affecting the forming of the geological hazards are selected, and zoning of the occurrence probability of the geological hazards is made by the comprehensive information model in MAPGIS. According to the distribution characteristics of towns, important engineering constructions, and local sustainable development plans, constructing a model for zoning of geological hazards. The main conclusions of this research are drawn as following:(1)The main types of geological hazards in Ludian County include landslide, mud-rock flow, unstable slope and ground fissure, of which landslide is the most serious one.Each hazard has its characters and spatial laws.(2)The scale of landslips relies mainly on the fact that medium-sizednd small-scale in the district; Landslip destroy the mode and rely mainly on compounding type; Landslip bed material is mainly soil; It's thickness layer not shallow for being getting more middle-level mainly;They strongly effected by topographical geological condition,most landslips lay on the escarpment; The form type of debris flow is mainly valley type,secondly is slope type;the unstable slope distribute abroadly in the county,the total number is 58.(3)The results of information value calculation show that, among the factors affecting the forming of landslides, the following attributes are gained: intense degree of conformation, soft-rock such as argillaceous rock mass, slope angle, raining and human engineering activities, which are dominant. Combined with the development characteristics of other geological hazards, the occurrence possibility of them can be divided into four grades: the most high probability, high probability, medium probability.(4) According to the people-oriented principle, based on zoning of the geological hazard risks, combined with the development characteristics of the geological hazard and the danger degree, it zones Ludian County in some aspects of geological hazard prevention and control, and it divides the Ludian County into three-grade areas including the key preventing areas, the secondary preventing areas and the general preventing areas. |
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