Articles | Volume 23, issue 3
https://doi.org/10.5194/nhess-23-1227-2023
https://doi.org/10.5194/nhess-23-1227-2023
Brief communication
 | Highlight paper
 | 
29 Mar 2023
Brief communication | Highlight paper |  | 29 Mar 2023

Brief communication: On the extremeness of the July 2021 precipitation event in western Germany

Katharina Lengfeld, Paul Voit, Frank Kaspar, and Maik Heistermann

Related authors

Hail events in Germany, rare or frequent natural hazards?
Tabea Wilke, Katharina Lengfeld, and Markus Schultze
EGUsphere, https://doi.org/10.5194/egusphere-2024-2507,https://doi.org/10.5194/egusphere-2024-2507, 2024
Short summary
A novel approach for absolute radar calibration: formulation and theoretical validation
C. Merker, G. Peters, M. Clemens, K. Lengfeld, and F. Ament
Atmos. Meas. Tech., 8, 2521–2530, https://doi.org/10.5194/amt-8-2521-2015,https://doi.org/10.5194/amt-8-2521-2015, 2015
Short summary
Performance of high-resolution X-band weather radar networks – the PATTERN example
K. Lengfeld, M. Clemens, H. Münster, and F. Ament
Atmos. Meas. Tech., 7, 4151–4166, https://doi.org/10.5194/amt-7-4151-2014,https://doi.org/10.5194/amt-7-4151-2014, 2014
Short summary

Related subject area

Hydrological Hazards
Post-wildfire sediment source and transport modeling, empirical observations, and applied mitigation: an Arizona, USA, case study
Edward R. Schenk, Alex Wood, Allen Haden, Gabriel Baca, Jake Fleishman, and Joe Loverich
Nat. Hazards Earth Syst. Sci., 25, 727–745, https://doi.org/10.5194/nhess-25-727-2025,https://doi.org/10.5194/nhess-25-727-2025, 2025
Short summary
Causes of the exceptionally high number of fatalities in the Ahr valley, Germany, during the 2021 flood
Belinda Rhein and Heidi Kreibich
Nat. Hazards Earth Syst. Sci., 25, 581–589, https://doi.org/10.5194/nhess-25-581-2025,https://doi.org/10.5194/nhess-25-581-2025, 2025
Short summary
Large-scale flood risk assessment in data-scarce areas: an application to Central Asia
Paola Ceresa, Gianbattista Bussi, Simona Denaro, Gabriele Coccia, Paolo Bazzurro, Mario Martina, Ettore Fagà, Carlos Avelar, Mario Ordaz, Benjamin Huerta, Osvaldo Garay, Zhanar Raimbekova, Kanatbek Abdrakhmatov, Sitora Mirzokhonova, Vakhitkhan Ismailov, and Vladimir Belikov
Nat. Hazards Earth Syst. Sci., 25, 403–428, https://doi.org/10.5194/nhess-25-403-2025,https://doi.org/10.5194/nhess-25-403-2025, 2025
Short summary
Multi-scale hydraulic graph neural networks for flood modelling
Roberto Bentivoglio, Elvin Isufi, Sebastiaan Nicolas Jonkman, and Riccardo Taormina
Nat. Hazards Earth Syst. Sci., 25, 335–351, https://doi.org/10.5194/nhess-25-335-2025,https://doi.org/10.5194/nhess-25-335-2025, 2025
Short summary
The role of antecedent conditions in translating precipitation events into extreme floods at the catchment scale and in a large-basin context
Maria Staudinger, Martina Kauzlaric, Alexandre Mas, Guillaume Evin, Benoit Hingray, and Daniel Viviroli
Nat. Hazards Earth Syst. Sci., 25, 247–265, https://doi.org/10.5194/nhess-25-247-2025,https://doi.org/10.5194/nhess-25-247-2025, 2025
Short summary

Cited articles

Dietze, M., Bell, R., Ozturk, U., Cook, K. L., Andermann, C., Beer, A. R., Damm, B., Lucia, A., Fauer, F. S., Nissen, K. M., Sieg, T., and Thieken, A. H.: More than heavy rain turning into fast-flowing water – a landscape perspective on the 2021 Eifel floods, Nat. Hazards Earth Syst. Sci., 22, 1845–1856, https://doi.org/10.5194/nhess-22-1845-2022, 2022. a, b
Fekete, A. and Sandholz, S.: Here Comes the Flood, but Not Failure? Lessons to Learn after the Heavy Rain and Pluvial Floods in Germany 2021, Water, 13, 3016, https://doi.org/10.3390/w13213016, 2021. a
GDV: 2021 teuerstes Naturgefahrenjahr für die Versicherer, https://www.gdv.de/de/medien/aktuell/2021-teuerstes- naturgefahrenjahr-fuer-die-versicherer-74092 (last access: 22 September 2022), 2021 (in German). a
Gvoždíková, B., Müller, M., and Kašpar, M.: Spatial patterns and time distribution of central European extreme precipitation events between 1961 and 2013, Int. J. Climatol., 39, 3282–3297, https://doi.org/10.1002/joc.6019, 2019. a
Junghänel, T., Bisolli, P., Daßler, J., Fleckenstein, R., Imbery, F., Janssen, W., Kaspar, F., Lengfeld, K., Leppelt, T., Rauthe, M., Rauthe-Schöch, A., Rocek, M., Walawender, E., and Weigl, E.: Hydro-klimatologische Einordnung der Stark- und Dauerniederschläge in Teilen Deutschlands im Zusammenhang mit dem Tiefdruckgebiet “Bernd” vom 12. bis 19. Juli 2021, Deutscher Wetterdienst, https://www.dwd.de/DE/leistungen/besondereereignisse/niederschlag/20210721_bericht_starkniederschlaege_tief_bernd.pdf (last access: 17 March 2023), 2021. a, b
Download

The requested paper has a corresponding corrigendum published. Please read the corrigendum first before downloading the article.

Executive editor
Here approaches to rank precipitation events according to their hazard characteristics are presented, while their impacts depend on many other factors as well like the orography, hydrological situation, exposure and vulnerability. Determining the severity of a precipitation event is not straight forward, as it depends on both the intensity on different time scales and the spatial extent. The weather extremity index (WEI) and the cross-scale WEI (xWEI) are used to determine the extremeness of precipitation events. The devastating event in the Ahr valley in Germany in July 2021 is shown to rank No 1 or 4 for Germany, dependent on the measure used. This emphasizes that it was extreme across multiple spatial and temporal scales, and the importance of considering different scales to determine the extremeness of rainfall events.
Short summary
Estimating the severity of a rainfall event based on the damage caused is easy but highly depends on the affected region. A less biased measure for the extremeness of an event is its rarity combined with its spatial extent. In this brief communication, we investigate the sensitivity of such measures to the underlying dataset and highlight the importance of considering multiple spatial and temporal scales using the devastating rainfall event in July 2021 in central Europe as an example.
Share
Altmetrics
Final-revised paper
Preprint