Transport Network Vulnerability Assessment Methodology, Based on the Cost-Distance Method and GIS Integration

Abstract

Considering the various effects of natural disasters, and the need for a fast intervention and recovery time, before facing the associated problems it is needed to mitigate the risks. A basic and initial step is to assess the vulnerability in high risk areas. The importance of a transport network is major, whether it is a road, railway (for access) or pipe (for resources) network. Various methods were described for analyzing their behavior to disastrous events (like earthquakes, landslides, flooding). The methodology proposed in this study integrates all related input data within a GIS software, adding by so the spatial dimension, and adapt the cost-distance method to obtain fictive costs that translate into vulnerability states for each point of a network. Also, the hot-points that can determine detour costs are taken into consideration, by means of random “What if?” scenarios that are generated by an automation model. The fact that the cost-distance method requires origins to which the costs will refer it is important, because the vulnerability values will also be related to how hard it is for an emergency intervention team to reach a certain segment of the network. Because of the various degrees of freedom in the methodology, different methods can be also added to the actual core, in order to serve the purpose, whether it is emergency route analysis, road planning or loss estimation assessment. In order to test and exemplify the methodology and the results, a road network seismic vulnerability assessment example is presented, for a Romanian County right on top of the Vrancea Seismic Area. Specific details are given about the possibilities to implement the methodology.