Hazard zoning of trunk highway slope disasters: a case study in northern Shaanxi, China

Abstract

The fragile natural environment of the northern Shaanxi Province in China is susceptible to ambient conditions. Highway slope disasters and the frequent occurrence of highway hazards that different in type, possible outcomes, and scale by region cause severe adverse effects on the construction and operation of trunk highways in the province. Therefore, conducting hazard zoning of highway slope disasters is essential in order to mitigate and manage highway slope disasters and to analyze the distribution regularities of hazards in northern Shaanxi. In this study, a hazard assessment model based on the principle of disaster-causing factor superposition was established. Five hazard assessment indexes, namely terrain gradient, ravine density, annual average days with precipitation more than 25 mm, geotechnical types, and vegetation coverage, were selected to analyze the types of highway slope disasters and disaster-causing factors. The distribution of assessment indexes and the degree of the highway slope disaster hazard were presented using an assessment model and geographic information system (GIS). The hazard zoning of highway slope disasters in northern Shaanxi is classified into slight, moderate, and severe according to hazard characteristics and trunk highway network distribution. Results show that the hazard zoning of highway slope disasters in northern Shaanxi is consistent with the actual distribution.