Modelling the risk of road networks in mountainous areas exposed to volcanic hazard

In countries with high exposure to natural hazards, it is important to consider physical risk assessment mechanisms for road networks. The lack of a methodology to model road networks exposed to natural hazards produces high social, environmental and physical costs. A methodology that models road networks and measures physical risk in road networks, is essential for timely decision making. This article presents a methodology that incorporates the integrated analysis of physical risk for road networks in mountainous areas and social vulnerability of a territory exposed to volcanic hazard in the south of Chile.
The physical risk evaluation model considers the effect of the hazard in terms of travel time in the road network due to the physical vulnerability, exposure of the assets and the simulated hazard. For the analysis of social dimension, a composite vulnerability index based on sociodemographic variables has been developed considering the dependence of society on the road network and other critical infrastructures. The research proposes a scientific tool, with a technical basis, to manage road assets by evaluating the effect of volcanic events. The results obtained show that the incorporation of social vulnerability in the management of road assets modifies the physical risk estimation of the elements of the network. The proposed methodology allows decision makers to incorporate multidimensional risk. Other aspects may be incorporated such as ecological, economical or environmental dimensions.