On the nexus between landslide susceptibility and transport infrastructure – agent-based vulnerability assessment of rural road networks in the Eastern European Alps

Abstract

Abstract. Road networks are complex interconnected systems. Any sudden disruption can result in debilitating impacts on human life or the economy. Interruptions of the transport flow may lead to potentially severe consequences in terms of both direct and indirect losses. In particular, road systems in mountainous areas do not feature redundant elements at comparable economic efficiency. Therefore, assessment of network vulnerability is of major importance for guaranteeing the smooth functioning of societies, especially in those regions. Among various menacing hazards, landslides protrude as particularly destructive events jeopardizing the integrity of land transport systems by causing structural damage and network interruptions. The aim of this paper is to present how road infrastructure is vulnerable towards landslides events, with emphasis on the consequences for the affected road users. This is addressed on the Austrian region Vorarlberg, which allows cross-learning and cross-comparison of, for example, rural and urban areas, also at different scales. The focus of this case study is on resilience issues and support for decision making in the context of a large scale sectoral approach. By taking into account derivates of a high-resolution digital terrain model as well as geological properties, a landslide susceptibility map of the test region is derived by means of the weight of evidence method. This susceptibility map is concatenated with historic data of landslide inventories and a digital road graph in order to identify critical sections of the road network. Subsequently, effects of interruptions of the road network at these critical links are analyzed by applying a mesoscopic multi-agent transport simulation model. Results show the merits of using agent-based traffic modeling for assessing the impacts of road network interruptions on rural communities by providing insight into the characteristics of the population affected, as well as the effects on its daily routine in terms of detour costs.