Study On Geological Hazard Zonation In Yongdeng County

Geological hazard analysis is a probability of occurrence in geological hazard. Geological hazard risk evaluation and zoning is a foundational work of reducing geological hazard risk effectively. According to having calculated and graded the degree of risk, geological hazard zonation is divided into different risk levels in the study area, which has played an important role in disaster prevention and reduction. So it is necessary to study the regional geological hazard. Qualitative and quantitative analysis are two main research methods in geologic hazard evaluation.Qualitative analysis include filed landform analysis, empirical analysis and mapping methods with given index and parameters, Quantitative analytical methods include statistical analysis methods, Fuzzy level analytical method, Fuzzy Synthesis Estimate, principal component analysis, the method of neural network, information and GIS technology analysis, etc.This paper takes the Yongdeng county being study area. Based on the analysis of control factors and main influence factors of main sudden geologic disasters which include landslide, collapse, and mudslide, the paper discusses GIS application into the geologic hazard danger evaluation, and evaluation factors are demonstrated in form of several of figures and pictures by using principal component analysis. Finally, the geologic hazard evaluation of Yongdeng county is completed. Finally, the risk of Yongdeng was divided into four levels,in which are high risk areas, medium risk areas, low risk areas and geological disaster areas not occur.According to the statistical relationship between development characteristics of different types of geological disasters, control factors and influence factors in Yongdeng county, we chose the facts for the risk evaluation,such as slope, relative height, structure of rock and soil, geological structure, percentage of vegetation and human activities etc. Base on occurrence probability figures of signal hazard, the distribution map of geologic hazards of whole Yongdeng county was obtained. The risk of Yongdeng county geologic hazard was divided into three area, there are high risk area, medium risk area and low risk area.