Severe flooding sweeps through southern Germany
Torrential rain hit Bavaria and Baden-Württemberg in May causing extreme flooding in southern Germany at the beginning of June. At least four people are known to have died, and thousands were evacuated from their homes as flood defences failed (Al Jazeera, 2024). Whilst promising central government support to flood-stricken areas, German Chancellor Olaf Scholz said, “This shows how the situation has changed due to climate change” (Guardian, 2024). With floods damaging homes, infrastructure, farmlands and businesses, the German Insurance Association has predicted the insured losses to be around €2 billion (Reinsurance News, 2024).
Event Overview
Storm Orinoco brought extreme rainfall to the southern German states of Bavaria and Baden-Wuerttemberg on 31 May. Zeisertsweiler, Kisslegg and Bad Wörishofen recorded 135mm, 130mm and 129mm of rainfall respectively. There were reported dam breaks and river floods, resulting in a state of emergency being declared in several districts. Thousands of evacuations were carried out by the authorities. A firefighter lost his life during rescue operations in Pfaffenhofen an der Ilm (FloodList, 2024). Train services were affected between Munich and Stuttgart. Near Schwäbisch Gmünd, an express train carrying 185 passengers derailed after a landslide (DW News, 2024a).
Floods damaged 95,000 hectares of farmland in Baden-Württemberg. A range of crops including corn, potatoes, grain and strawberries were destroyed (DW News, 2024b). Meanwhile, the output of hydroelectric plants in the region was disrupted because of flooding, straining the national power supply (BNN Bloomberg, 2024). Bavaria has in recent years seen a reduction in flood protection initiatives. Opposition parties have criticised the government for the delays and inadequate funding for these projects (DW News, 2024c).
Event Causes
Heavy rain in this area is often brought about by low pressure systems that have taken a southerly trajectory due to cooler air masses in Western Europe, passing through the Mediterranean and pushing warm and humid air towards Scandinavia. Winds coming up from the Mediterranean pick up moisture along the way which resulted in heavy precipitation in this recent flooding event (DW News, 2024d).
This unusual trajectory is also known as the Vb cyclone pathway – a term only used by meteorologists nowadays. Vb is pronounced as ‘five-b’. The Vb system is an anomalous pressure system known to result in extreme precipitation, bringing large amounts of precipitation towards the south of Germany given its trajectory (DW News, 2024d; Ludwig et al., 2023). Despite being an abnormality, the Vb system does not occur randomly; the Vb cyclone is found to be in sync with both the Northern Atlantic and Arctic Oscillations. However, it is still considered a rare occurrence in the region as about 5% of Central European cyclones are associated with this system (Hofstätter nd Blöschl, 2019).
Extreme Value Analysis (EVT)
JBA conducted an Extreme Value Analysis on rainfall data in order to estimate the return period of the event. We fit a Generalised Pareto Distribution (GPD) curve to Deutscher Wetterdienst (DWD, 2024) precipitation data at various locations to produce rainfall exceedance probability curves.
The curves are shown by the solid orange lines in Figure 1, with the 95th percentiles given by the dashed lines and observed values by the blue lines. Floodlist (2024) mentions three locations with observed daily rainfall higher than 120mm on 31 May 2024, which are:
- Zeisertsweiler in Sigmarszell District - 135 mm
- Kißlegg in Baden-Württemberg - 130 mm
- Bad Wörishofen - 129mm
The analysis at all three locations suggests above 100-year precipitation with Zeisertsweiler having a 1-in-140-year rainfall event (Figure 1a).
Figure 1: Estimated extreme rainfall return periods for three sites in southern Germany. (a-c) Rainfall return period analysis for Zeisertsweiler (135mm), Kißlegg (130mm) and Bad Wörishofen (129mm) based on daily rainfall summaries from DWD (2024) and observed rainfall for 31 May 2024 from Floodlist (2024).
Notable historical events
This is the third flood event to hit Germany this year. The first occurred earlier in the year, affecting north-west Lower Saxony and resulting in €160 million in damages. The second flood struck the state of Saarland in May (Politico, 2024).
The most notable event in the country’s recent history happened only three years ago in July 2021 (read our report here). While the flood event was widespread across the entire European continent, Germany suffered particularly significant causalities and damages. In this flood event, Germany estimated a total damage of €32-33 billion or about 70% of the total losses faced by the region as a whole (Mohr et al., 2022). Over 180 people died in western Germany and the floods also caused significant damage and destruction to more than 10,000 buildings and public infrastructure like railways (Matandirotya, 2022; Mohr et al., 2022). This is thought to be the most catastrophic and costly flood that Germany has faced to date.
Going back to August 2002, large-scale flooding occurred and affected several European nations including Germany. Heavy rainfalls led to rivers bursting their banks, with Ulbrich et al. (2003) estimating streamflow in Dresden to be 1-in-200-years. In the span of three weeks, 20 people died in Germany and losses were estimated to be about €9.1 billion with only €1.8 billion covered by insurance (Mechler & Weichselgartner, 2003; Weichselgartner & Breviere, 2011). This event was also driven by the Vb cyclone pathway (DW News, 2024d).
Industry insight
Despite being vulnerable to floods, Germany has a relatively low insurance penetration rate with only 37-47% of residential buildings being insured. In 2021, the insured loss was only €8.2 billion which is less than 25% of total losses in Germany. This is lower than neighbouring countries which saw about €11 billion in insured losses (Mohr et al., 2022).
Another key factor to Germany’s flood vulnerability is the number of properties built in flood-prone areas. According to FloodList (2023), the German Insurance Association estimates at least 32,000 out of 2.7 million homes built since 2000 have been constructed in high flood risk areas. It is only in the recent past that Germany is reviewing building integrity and improving existing infrastructure to adapt to catastrophic hazards in future.
JBA offers 5m resolution river, surface and coastal water flood hazard maps for Germany. This report is accompanied by a flood footprint for the event - detailing extents and depths of the flooding in areas affected. Download it via our Client Portal or request a copy by emailing eventresponse@jbarisk.com.
References
Al Jazeera, 2024. Four dead as floods sweep southern Germany. [Online]. Available at: https://www.aljazeera.com/gallery/2024/6/4/four-dead-as-floods-sweep-southern-germany [Accessed 12 June 2024]
BNN Bloomberg, 2024. Flooding Disrupts Hydro Power in Germany as Rivers Overflow. [Online]. Available at: https://www.bnnbloomberg.ca/flooding-disrupts-hydro-power-in-germany-as-rivers-overflow-1.2080468 [Accessed 12 June 2024]
Deutscher Wetterdienst (DWD), 2024. Climate data for direct download. [Online]. Available at: https://www.dwd.de/EN/ourservices/cdc/cdc_ueberblick-klimadaten_en.html [Accessed on 24 June 2024]
DW News, 2024a. Germany: Trains canceled amid southern storms and flooding. [Online]. Available at: https://www.dw.com/en/germany-trains-canceled-amid-southern-storms-and-flooding/a-69243774 [Accessed 12 June 2024]
DW News, 2024b. German insured flood damage estimated at €2 billion. [Online]. Available at: https://www.dw.com/en/german-insured-flood-damage-estimated-at-2-billion/a-69306995 [Accessed 12 June 2024]
DW News, 2024c. Germany floods: Blame game begins as waters recede. [Online]. Available at: https://www.dw.com/en/germany-floods-blame-game-begins-as-waters-recede/a-69292617 [Accessed 12 June 2024]
DW News, 2024d. Germany floods caused by rate ‘Vb’ weather conditions. [Online]. Available at: https://www.dw.com/en/germany-floods-caused-by-rare-vb-weather-conditions/a-69264729 [Accessed 20 June 2024]
FloodList, 2023. Germany – Insurers Demand a Stop to Building New Homes in Flood-Risk Areas. [Online]. Available at: https://floodlist.com/europe/germany-stop-building-houses-flood-risk-areas [Accessed on 21 June 2024]
FloodList, 2024. Germany – Thousands Evacuate Floods in Bavaria and Baden-Wuerttemberg. [Online]. Available at: https://floodlist.com/europe/germany-bavaria-baden-wuerttemberg-floods-june-2024 [Accessed 12 June 2024]
Guardian, 2022. After the floods: Germany’s Ahr valley then and now - in pictures. [Online]. Available at: https://www.theguardian.com/world/2022/jul/13/floods-then-and-now-photographs-germany-ahr-valley-flooding-disaster-july-2021 [Accessed on 21 June 2024]
Guardian, 2024. Scholz visits flood-hit region in southern Germany as death toll rises. [Online]. Available at: https://www.theguardian.com/world/article/2024/jun/03/two-killed-in-floods-and-scores-missing-in-southern-germany [Accessed 12 June 2024]
Hofstätter, M. and Blöschl, G., 2019. ‘Vb cyclones synchronized with the Arctic‐/North Atlantic Oscillation’, Journal of Geophysical Research: Atmospheres, 124(6), pp. 3259–3278. doi:10.1029/2018jd029420
Ludwig, P. et al., 2023. ‘A multi-disciplinary analysis of the exceptional flood event of July 2021 in Central Europe – part 2: Historical context and relation to climate change’, Natural Hazards and Earth System Sciences, 23(4), pp. 1287–1311. doi:10.5194/nhess-23-1287-2023
Matandirotya N., 2022. The 2021 Western Germany flood event: The value of flood risk dissemination strategies and social media. Jamba (Potchefstroom, South Africa), 14(1), 1322. https://doi.org/10.4102/jamba.v14i1.1322
Mechler, R. & Weichselgartner, J., 2003. Disaster Loss Financing in Germany - The Case of the Elbe River Floods 2002. IIASA Interim Report. IIASA, Laxenburg, Austria: IR-03-021
Mohr, S. et al., 2022. A multi-disciplinary analysis of the exceptional flood event of July 2021 in Central Europe. part 1: Event description and analysis [Preprint]. doi:10.5194/nhess-2022-137
Politico, 2024. Southern Germany battles floods as experts say Berlin will miss climate targets. [Online]. Available at: https://www.politico.eu/article/southern-germany-battles-floods-as-experts-say-berlin-will-miss-climate-targets/ [Accessed 20 June 2024]
Reinsurance News, 2024. German Insurance Association expects recent flooding to cost insurers around €2bn. [Online]. Available at: https://www.reinsurancene.ws/german-insurance-association-expects-recent-flooding-to-cost-insurers-around-e2bn/ [Accessed 12 June 2024]
Ulbrich, U. et al., 2003. ‘The Central European floods of August 2002: Part 1 – Rainfall Periods and flood development’, Weather, 58(10), pp. 371–377. doi:10.1256/wea.61.03a
Weichselgartner, J. & Breviere, E., 2011. The 2002 flood disaster in the Elbe region, Germany: A lack of context-sensitive knowledge
