© Prof. Dr. Margreth Keiler (Universität Innsbruck und Österreichische Akademie der Wissenschaften)

© Prof. Dr. Margreth Keiler (Universität Innsbruck und Österreichische Akademie der Wissenschaften)

A working group of the Institute of Mountain Risk Engineering at BOKU Vienna evaluated two methods to determine how susceptible buildings are to damage from floods and mudflows. Together, they enable data-based risk analyses and provide a basis for cost-benefit considerations in terms of protective measures.

Floods caused by torrents and debris flows repeatedly cause major damage, both financial and humanitarian. Due to stones and tree trunks carried along, the extent of destruction is often much higher than in conventional floods. In order to predict the vulnerability of buildings to these highly variable natural disasters, a research team from BOKU Vienna, in cooperation with the University of Padua, the University of Innsbruck and the Austrian Academy of Sciences, developed vulnerability curves and vulnerability indices. The working group around Maria Papathoma-Köhle and Sven Fuchs now evaluated and refined these using two case studies from Austria and Italy.

Vulnerability curves show financial damage, vulnerability indices show weaknesses of the building

The vulnerability curves map how strongly the extent of damage depends on the flood level. "In this way, they allow forecasts of the amount of financial damage," Papathoma-Köhle explains. For the vulnerability indices, the team analyzed parameters that make a building susceptible to torrent processes, such as window heights, its location in the terrain or possible shading effects from other buildings. Weighted by their influence on the extent of damage, the researchers developed a vulnerability indicator from these factors. According to Papathoma-Köhle, vulnerability curves and indicators can be used to construct buildings in a way that makes them less susceptible to damage in the event of an incident.

Comprehensive documentation essential

In the specific study, the team evaluated two natural disasters: In the Austrian community of See in the Paznaun Valley in Tyrol, heavy rainfall on June 8, 2015, led to fluvial sediment transport that damaged 30 buildings and caused property damage of 6.21 million euros. The second case study concerns the extreme rainfall in Dimaro, a small mountain village in the Italian Alps, on October 27-29, 2018, which triggered three debris flows. One woman was killed, 26 buildings were damaged and about 200 people had to be evacuated from their homes. "Events like these should be recorded in a standardized way in the future," Papathoma-Köhle says, "both the damage itself and the processes that triggered the damage. This is the only way to further improve methods and reduce uncertainties in predicting damage, she adds.

Maria Papathoma-Köhle received funding for this study from the Elise Richter Fellowship of the Austrian Science Fund FWF.

The study has just been published in the Journal of Hydrology:

https://doi.org/10.1016/j.jhydrol.2022.127501

Contact

Dr. Maria Papathoma-Köhle
University of Natural Resources and Applied Life Sciences
Institute for Alpine Natural Hazards
E-Mail: maria.papathoma-koehle(at)boku.ac.at
Phone: +43 1 47654 87121

Priv.-Doz. Dr. Sven Fuchs
University of Natural Resources and Applied Life Sciences
Institute for Alpine Natural Hazards
E-Mail: sven.fuchs(at)boku.ac.at
Phone: + 43 1 47654 87117

Copyright Photos

Prof. Dr. Margreth Keiler
University of Innsbruck and Austrian Academy of Sciences
E-mail: margreth.keiler(at)uibk.ac.at