Photo courtesy of ÖBB
The railway transportation system of the Austrian Alps plays an important role in the European transit of passengers and goods. In total, 11.7 million tons of goods were transported across the Austrian Alps in 2013, which is 28% of the total volume recorded for the inner Alpine Arc. 1 In addition, railway lines are essential for the accessibility of lateral alpine valleys and thus contribute to their economic and societal welfare. If traffic networks are (temporarily) disrupted, alternative options for transportation are rarely available.
Meteorological extreme events have great potential for damaging railway infrastructure and threatening the safety of train passengers while climate change is expected to have serious implications on meteorological hazards in the region. Hence, it is crucial to attain insights on future frequencies of meteorological extremes with relevance for the railway operation in Austria.
To support decision-makers in the comprehensive and sustainable natural hazard management, the ENHANCE project has studied the possible changes in the frequencies of so-called Critical Meteorological Conditions (CMCs) due to climate change and future implications for railway transportation in Austria.
The study 2 analysed the periods 1961-1990 (reference period) and 2011-2040 (projection period). A Regional Climate Model (RCM) ensemble was used to investigate changes in the frequency of CMCs. The thresholds for CMCs were directly drawn from the Infra: Wetter weather monitoring and early warning system of the Austrian railway operator ÖBB and applied to the RCM simulation runs.
All-season climate change impacts
The results of the study give robust indications for an all-season air temperature rise, but show no clear tendency in average precipitation. The frequency analyses reveal an increase in intense rainfall events and heat waves, whereas heavy snowfall and cold days are likely to decrease.
ÖBB natural hazards management
Extreme rainfall events rank among the most important meteorological hazards for risk management of railway transportation in Austria. Besides considerable potential of this event type itself, (very) intensive rainfall triggers other natural hazards such as (flash) floods, torrential processes, and debris flows. The projected significant increase of extreme rainfall events leads to new challenges for the ÖBB natural hazards management. If no action is taken, the costs due to extreme weather events must be expected to rise in the future.
Standardised documentation of damaging events
Importantly, the results indicate that frequencies of CMCs are rather sensitive to changes of thresholds. The findings thus emphasise the importance to carefully define, validate, and – if needed – to adapt the thresholds that are used in the weather monitoring and warning system of the railway operator. For this, continuous and standardised documentation of damaging events and near-misses is a pre-requisite.
While the ÖBB already collects detailed damage data due to natural hazards, and currently further elaborates this system, no such reporting exists in many other European member states or at the European level. The existence of a European damage database for natural hazards could, however, significantly contribute to improving the understanding of damaging processes to railway infrastructure, the proportional share of different natural hazards to overall losses, and thus to the development of strategic risk management.
1 Eidgenössisches Departement für Umwelt, Verkehr, Energie un Kommunikation UVEK. Alpinfo 2013: Alpenquerender Güterverkehr auf Strasse und Schiene. Bern, Switzerland, 2013.
2 Kellermann P, Bubeck P, Kundela G, Dosio A, Thieken AH. Frequency Analysis of Critical Meteorological Conditions in a Changing Climate—Assessing Future Implications for Railway Transportation in Austria. Climate. 2016; 4(2):25. Available at: http://www.mdpi.com/2225-1154/4/2/25
Note to readers:
Building railway transport resilience to alpine hazards is one of the 10 participatory case studies of the ENHANCE project.
Interested in other research from the case study? To support strategic decision-making of the Austrian railway operator ÖBB, the ENHANCE partners from the University of Potsdam developed an empirical modelling approach for estimating direct structural flood damage to railway infrastructure and associated financial losses. The study uses the March River flood in 2006 at the Austrian Northern Railway as a case study.