Development And Application Of GIS Information System For Sichuan-Tibet Line

The Sichuan-Tibet highway from Chengdu to Lhasa passes through many geomorphic units, mountains, big rivers and seismic zones. This puts the highway in a high risk of natural disasters. Therefore, an information system for the digital management, searching and analysis of natural disasters for the Sichuan-Tibet highway is needed for the prevention and reduction of natural disasters. In addition, the Sichuan-Tibet railway enters Tibet from the Eastern margin of the Tibetan Plateau where the environmental and geological problems are more complex than other regions. The analysis on the characteristics of various natural disasters and the geomorphy along the road could provide a basis for the decision-making for the disaster prevention and the line selection.In this paper, a disaster management system for the Sichuan-Tibet highway is established by using GIS technique. The application of GIS technique in the decision-making of railway location is studied. The main contents include:1. All data collected from the investigation of the Sichuan-Tibet highway are classified and imput into the computer. Based on the analysis of the data, the disaster management system is established bv using GIS. The main functions of the disaster management system are the searching and management of highway information, geological and topographic information and disaster information for the whole Sichuan-Tibet highway.2. One feature of the disaster management system is the linking function. This function is conduct by using VBA, the inner programming tool of ArcGIS. By the linking function, the disaster information at a site, like graphic and literal data, can be shown by simply clicking the position of the site on the map. Then, an interface of the disaster management system is designed by using VB.3. The geomorphies of the regions near the Sichuan-Tibet highway are analylized by using the spatial analysis function of ArcGIS in terms of the gradient distribution, the relief amplitude and the surface cutting depth. The comparizon of the geomorphies along the south line and the north line is performed, from which the basis of the dicision-maiking for the Sichuan-Tibet railway location is proposed.