Application Of Remote Sensing And GIS Technique In Survey And Evaluation Of Geological Hazards In Changdu County, Tibet

Geological disaster has beening severe and has caused serious harm to people's production and life. It is urgent to need new technology and method to solve this problem. RS and GIS technique are superior to traditional method in survey and evaluation of geological hazards, which is currently a hot and direction research of geological hazards.Taking the Changdu county as study area and using remote sensing data, hazard information was extracted, and hazard factors were analyzed. Combing with GIS technique and AHP theory, geological hazard zoning has been divided and analyzed, and the technical routes and methods of system are explored by the application of remote sensing and GIS technique in carrying out regional geological hazard survey and evaluation. The main achievements were made as follows:(1) Through image processing and image feature analysis by using multi-platform, multi-temporal remote sensing data, based on the amendment and improvement of the field investigation, the collapse, landslide, debris flow interpretation signs were established. And a total of 136 sites of geological hazards were extracted.(2) Risk evaluation index system were set up, which contains 9 factors, such as lithology, geological structure, slope, human activities, geological hazards scale, distribution density etc. These factors weight were calculated by the AHP model. And hazard zoning map was gotten based on the platform of GIS software, which were divided into four grades:high-risk area(0.42%), in the danger area(3.43%), low-risk area(18.56%), risk-free area(77.59%).(3) Based on the RS and GIS technique, the work method of regional geological hazard investigation and analysis of risk assessment was summarized:data collection→analysis and processing of RS data→disaster information extraction→factors analysis of geological hazards→regional risk assessment and analysis.From practical application, research and analyzing, it was found that the RS and GIS technique combined with AHP model is better in the survey and evaluation of regional geological hazards, and the results have practical and scientific evaluation. It will be used to server as disaster prevention and reduction, and promote the development of economy and society stabilization in Changdu County.