Komma et al. (2026) The September 2024 Danube flood compared to the 1899, 2002, and 2013 events: a hydrometeorological analysis in a changing climate

Identification

• Journal: Hydrology and earth system sciences
• Year: 2026
• Date: 2026-06-30
• Authors: Jürgen Komma, Peter Valent, Miriam Bertola, Juraj Párajka, Klaus Haslinger, Benedikt Bica, Georg Pistotnik, Korbinian Breinl, Gabriele Müller, Lovrenc Pavlin, B Kahl, Achim Naderer, Günter Blöschl
• DOI: 10.5194/hess-30-4075-2026

Research Groups

• Institute of Hydraulic Engineering and Water Resources Management, TU Wien, Vienna, Austria
• Department for Climate-Impact Research, Geosphere Austria (GSA), Vienna, Austria
• Federal Ministry of Agriculture and Forestry, Climate and Environmental Protection, Regions and Water Management, Directorate Water Balance, Vienna, Austria
• Office of the Provincial Government of Lower Austria, Department of Water Management, St. Pölten, Austria
• viadonau – Österreichische Wasserstraßen-Gesellschaft mbH, Vienna, Austria

Short Summary

This study compares the September 2024 Danube flood with three historic floods (1899, 2002, and 2013) to identify similarities, differences, and emerging trends in flood generation. The analysis reveals a shift from Alpine-controlled, basin-wide events toward regionally concentrated, convectively enhanced floods.

Objective

• Investigate the causes of the September 2024 Danube flood and compare them with three historic floods (1899, 2002, and 2013)
• Identify similarities, differences, and emerging trends in flood generation

Study Configuration

• Spatial Scale: The Upper Danube Basin upstream of the Wildungsmauer gauge near Vienna, Austria
• Temporal Scale: Four flood events: September 2024, August 2002, June 2013, and September 1899

Methodology and Data

• Models used: Gridded rain-gauge analysis (INCA method combining gauges and radar; Haiden et al., 2011)
• Data sources: Historical rain-gauge data interpolated from about 600 stations (sources: Hydrographisches Zentralbüro, 1955; Lauda, 1900), national weather services and hydrographic services in Austria and Germany

Main Results

• The September 2024 flood was triggered by a quasi-stationary low-pressure system over the eastern Alps and western Hungary that produced two rainfall phases: a stratiform period in the west followed by convective extremes in the east.
• The event was characterized by exceptionally high rainfall accumulations over central Lower Austria, with local totals of up to 500 mm over five days.
• The flood response was intense and localized, with record flows in central Lower Austria, while western Austrian Alps (e.g., Tyrol and Vorarlberg) and Bavaria received only moderate precipitation and did not experience extreme flooding.

Contributions

• This study provides new insights into the generation mechanisms of specific extreme floods and compares them to past events.
• The analysis highlights the increasing importance of atmospheric persistence, antecedent saturation, and tributary synchronisation in shaping flood extremes.
• The results provide a basis for adaptive flood-risk management in a changing climate.

Funding

• This research was funded by the Austrian Science Fund (FWF) project P 31461-N27.

Citation

@article{Komma2026September,
  author = {Komma, Jürgen and Valent, Peter and Bertola, Miriam and Párajka, Juraj and Haslinger, Klaus and Bica, Benedikt and Pistotnik, Georg and Breinl, Korbinian and Müller, Gabriele and Pavlin, Lovrenc and Kahl, B and Naderer, Achim and Blöschl, Günter},
  title = {The September 2024 Danube flood compared to the 1899, 2002, and 2013 events: a hydrometeorological analysis in a changing climate},
  journal = {Hydrology and earth system sciences},
  year = {2026},
  doi = {10.5194/hess-30-4075-2026},
  url = {https://doi.org/10.5194/hess-30-4075-2026}
}