Rockfall Hazard Assessment Using A GIS-based Method

With constant improvement of the theory and technology, GIS has been widely applied to all the fields related to spatial information. Particularly, since 1990s, with the avalanche of commercial softwares of GIS, GIS technique has been widely applied to all physical fields. At the other hand, geological hazards in China, such as landslide and rockfall, are becoming more and more serious. Therefor, it is emergent to apply the latest technology of GIS to the researches on the geological hazards.This paper focuses on the core problem of the research of geological hazards-hazard assessment, taking geological hazards of rockfall in Isahaya, Japan as an example, working in a procedure of problem analysis-establishment of standards-preparation of assessment factors in GIS environment-building data base of hazard assessment-model analysis of hazard assessment-confirmation of results of hazard assessment and GIS presentation", attempting to use the technology of GIS in hazard assessment of rockfall so as to solve problems existing in former geological hazard assessment such as low efficiency, without enough accuracy, time consuming and so on. Some achievements have been made in this paper are listed as follows:1. Using lasted ESRI and GIS9.0, coupling GIS with modern information techniques for study of rockfall hazard assessment.2. Combining GIS with statistic methords as a space analyzing tool, a risk-zooning map of rockfall hazard of Isahaya, Japan has been made.3. Results show that, in Isahaya, Japan, more than 85% of the high risk area locates at mountainous areas with grading angle more than 30°slopes.Results show that, compare to traditional methods, GIS-based hazard assessment technique for rockfall is much more effective. The efficiency and the accuracy have been greatly improved during the quantification and modeling of hazard assessment.