A Study On GIS-Based Hazard Assessment About Landslide Of Beibei In ChongQing

This paper focuses on the core problem of the research of geographical hazards, hazard assessment, taking geological hazards of landslide in Beibei as an example. In the process of researching, this paper constructs a workflow based on ArcGIS to have the hazard assessment of landslide. On the basis of mapping unit of 35m×35m the paper makes use of Nonlinear-model (Information content model) and Quantitative-model (Two dimensional statistical model) to have a hazard assessment of Landslide. The research in this paper makes the following achievements:1. Based on the following routes and flow : data collection and problemanalysis------ evaluation Model Selection ------ establishment of aindex-system------building database of hazard assessment------GIS and mathematicalmodel combining analysis of hazard assessment ------confirmation of the results ofhazard assessment and GIS presentation------test of reasonableness of results. TheHazard Assessment about Landslide of Beibei was completed. Finally, the Hazard map is got by two kinds of models of hazard assessment after the analysis, we find, the results agree with the actual distribution of landslide, which proves that the index-system and assessment results are effective. And through comparative analysis of the results of two models, we know, in the evaluation about Landslide hazard, the information content model is better than two dimensional statistical model; 2. According to the characteristics and contributing factors of Landslide hazards in Beibei, and basing on the expert opinions, comprehensive literature search, we establish the index-system, which contains 9 factors, such as , aspect, slope, relative heights, the engineering rock-group, the interface of annual rainfall, building lot, the distance of thoroughfare ,fault and surface water, etc. It was proved by practice that the system is scientific, reasonable, laconic and operational;3. The distribution of Landslide hazard has been educed:(1) There are obvious regularity of the high risk and sky-high risk area. It extends mainly along the anticlinal low-mountain;(2) Two rainfall gush centre(Jinyun , Huaying Mountain) and the surrounding region, which is mostly distributing the high and sky-high hazard area pattern. It shows that rainfall gush is the main factor which induces the Landslide;4. Based on the expert opinions and literature search, we defined the weight synthetically. The weighting method is also more reasonable than pure experience or pure mathematical methods.