Risk zoning for highway alignment in disaster-prone mountainous areas using GIS

Improper highway alignment leads to disasters that threaten the safe operation of the highway, people´s lives and property, and even the sustainable development of the regional economy. Highway alignment in the mountainous areas is especially important for its complicated topographical, geological and ecological conditions. The disaster-prone Polongzangbu River Basin was taken for risk zoning of the highway alignment by using Geographic Information Systems (GIS). Guided by the principles of relative uniformity, dominant characteristics and comprehensive study, topography, geological structure, lithology, rainfall, vegetation and temperature were selected as risk zoning factors and the weight of each factor was determined by analytic hierarchy process(AHP), then a GIS zoning model was established by spatial analysis. Comparison of GIS risk zoning results with real disasters proves that GIS is reliable for risk zoning of highway alignment. The above research helps to curb the highway disasters before its occurrence and to ensure more scientific design, construction and safe operation of highway in the disaster-prone mountainous areas.