Study On Geological Hazards Risk Zoning Base On GIS And Logistic

Geological hazards risk evaluation and zoning is a foundational work of reducing geological hazards risk effectively. It has become the hot spot of domestic related domain. The usual step of zoning is subdivide element with GIS client, extract the geological hazard indexs, grid calculate, make a unified dimension of indexs, then classified by risk. Fuzzy comprehensive evaluation, analytic hierarchy process, Logistic model, CF method are used widely in geological hazards risk evaluation and zoning. On the basis of summarized and study predecessors' achievements, using investigation data and 1:50000 DEM, this article extracted the geological hazard indexs and determined their weights quantitatively base on GIS and Logistic; Realized the geological hazard risk zoning of study area, and the result in accord with the actual situation.The main researches are following:(1)Set up, extracted and quantized geological hazard indexs system. Set up geological hazard indexs system of 7 factors include geological hazards points density, slope shape ,slope gradient, slope height, vegetation, human engineering activities and rainfall. Used the terrain feature extracte tools and the Hydrologic analysis tools of ArcGIS to extract and quantize the indexs. Then unitized them with the foldline or linear threshold, make a unified dimension.(2)Set up Logistic regression model. Take advantage of Logistic model to classification variables and nonlinear regression, fitted the relationship between geological hazard and the indexs, set up nonlinear Logistic regression model which fitting geological hazard probability well. Got the quantificational weights of indexs and the equation of geological hazard probability.(3) Geological hazards risk zoning. Finished the cluster analysis of geological hazard probability base on basin unit grid by using Spatial analysis module of ArcGIS. Then accomplished the geological hazard risk zoning.(4) The geological hazard risk zoning method and technique base on GIS and Logistic. Formed the technical route, methods and working flow of geographical hazard risk zoning base on GIS and Logistic, its step is data acquisition→data analysis→building index system→extracting and unitizing the indexs→Logistic analysis→geological hazard risk zoning.