Impacts of drought on European inland transportation – insights from the European Drought Impact Inventory 2.0

Drought is one of the most disastrous natural hazards in Europe, affecting a broad range of systems directly and indirectly, tangible and intangible. The complex nature of the hazard drought, its associated and cascading risks and the occurrence of compound hazards often hinder a precise assignment and quantification of drought impacts. Especially for the case of inland transportation, where different types of drought affect the strongly interconnected modes of transport, only little is known on the effects of drought. This contribution presents an analysis of the effects of drought on European inland navigation, road, and rail transport based on the European Drought Impact report Inventory 2.0 (EDII). The EDII is a standardised collection of drought impact information from a variety of sources. Impact information is classified to one of >100 drought impact types, referenced in space and time and complemented with additional reported impact information such as secondary impacts and response measures where applicable. The second public version of the EDII extends the initial database until 2021. The results show strong effects on inland navigation, in particular along major navigable European rivers. Especially cargo transport is impacted by drought, but impacts on public transport via ferries (rivers and lakes) have also been reported. For road and rail traffic, drought induced land degradation and soil shrinkage are reported as causes for damaged roads and deformation of rail tracks. Furthermore, heat waves associated with drought can lead to “melting of road surfaces” and road blow-ups, as well as track deformation and buckling. Moreover, forest and embankment fires are reported as short-term impacts on rail traffic, whereas information on secondary impacts and compound effects are generally scarce. Drought impacts on inland navigation (reduced cargo) are reported to raise market costs of goods and increase traffic on roads and rails. The results also highlight strong spatial disparity in the occurrence of drought impacts on inland transport, which either are a results of strong differences in national drought risks, reporting behaviour or information collection practice. In order to increase the resilience of transport systems to drought, a comprehensive overview on the direct and indirect impacts of the past is essential. Thus, there is a need for a common pan-European investigation of impacts on inland transportation to inform a central database.