Study On Geological Hazard Risk Assessment In The Railway Line From Lhasa To Shigatse By The Method Of GIS

Lhasa to Shigatse railway as the first extension section of Qinghai Tibet railwayline have an important significance, and the project has not yet completed.What’smore, the relevant research is really less, so according to the geological hazardassessment of the significance of the correspondingly larger. In addition,compared tothe point of work, using the macro GIS does at work, planning the alignment of therailway (to avoid the high risk area), railway engineering maintenance andmaintenance of the latter (prevention of potential hazards) are particularly importantrole. In this site on the Lhasa to Shigatse railway based on the investigation, the fullcollection of research area geology, environment,remote sensing and otherbackground information.(1) The consolidation of pre field survey results (analysis of experimental data,finishing the scene photos), extracting useful information, and combining with theexisting data and information as well as the results of previous research, summarizesthe development characteristics of geological environment and geological disasters,the statistics of landslide, debris flow, landslide spatial development.(2) Establishing the system of geological disasters in the study area of riskassessment, the risk assessment factors, choose eight evaluation factors, respectivelyis the distance from the river valley landform, engineering geological rock group, thedegree of geological hazard, crust stability, micro landform units, human engineeringactivities, precipitation and railway.(3) Using the analytic hierarchy process modeling, based on the GIS technologyevaluation and prediction of geological hazard, which focuses on the generalprinciples and modeling steps of AHP, according to the geological environment ofLhasa endemic to Shigatse railway, the expert score comparison matrix, and then theweight coefficient of evaluation factors, determine the degree an evaluation of variousfactors. Using spatial data analysis and processing the powerful function of Arcgissoftware, to calculate the grid of each evaluation factor, the study area is divided into30×30m cells, each cell as an independent factor superposition calculation, geological disaster rectangular key research area and the railway buffer risk zoningmap finally, and further application of Arcgis two development function, the picture.Finally, show that the study area of geological disaster risk zoning map.(4) The data were analyzed by the zoning map, the corresponding measures ofprevention and treatment of division, for the construction of the next step plan toprovide reference. In addition, through this study, adverse geological disaster type hasgreat influence on the railway construction, to have foresight further details andlargely, to focus for protection and renovation, will effectively improve workefficiency.