The Evaluation Of Geological Hazard Susceptibility In The Southeast Coastal Area

Fujian is located in the southeastern coast of China, which characterized by perfectly developed strata, frequent magmatic activities, complex geological structures. This area is more likely to suffer from geologic hazard such as landslip, collapse, debris flow and surface subsidence because of the large precipitation with typhoon, the vigorous land development while the mountains area is far more than plains, and the big slope, thick residual soil layer of mountain. Based on the geological disaster investigation of Fujian, the paper carried out the research on the susceptibility of geological hazards of Fujian. The study of this paper can give a reference to disaster-inducing factors selection of evaluation of geological hazard probability. It is meaningful for exploiting, utilizing land resource and reducing losses by the natural disaster.The main research contents and results are as follows:(1) Based on the investigation of geological hazards of Fujian, to be compiled and analyzed the spatial data of collapses, landslides, mudslides and other geological disasters of Fujian,to establish a geological disasters database of Fujian Fujian by the MAPGIS(2) When study the influence factors of the study area which the geological disasters maybe take place, selecting the rainfall, lithology, hydrological conditions, and other human activities as an evaluation factor, by using MAPGIS to analyze the influencing factors, the spatial intersection of various influencing factors and the three types of disaster types, to know the distribution of disasters in Fujian, and it’s relationship with the influencing factors.(3) Using entropy method Intuitive analysis the nine kinds of influencing factors impact on the various types of geological hazards. By calculating the distribution of various types of disasters in the corresponding impact factor divisions within the range, calculate the entropy of all influencing factors, then determine the weight of all kinds of influencing factors. Analysis shows that for different types of disasters, the main impact factors are also different. The main factors affecting the collapse disaster are the degree of hydraulic erosion, and the main impact factors of the landslide and debris flow disaster are hydrological conditions.(4) In order to get the geological disasters in fujian area chart, assigned the calculated weights to the regional unit grid data layer, and comparison and analysis the various types of geological hazards prone. The collected data were used to verify the susceptibility of geological hazards, verified the prone zoning is correct. Most of the disaster occurred in the most and middle prone areas, a small amount occurred in low prone areas, coastal areas are not prone to sporadic distribution. The use of entropy method for geological hazard assessment is feasible.