Rain, rain and more rain. The situation in the flood areas is critical; weakened dikes are causing concern for the emergency services. Lower Saxony is particularly badly affected. An overview of important questions and answers.
Why is it raining so much at the moment?
In short, this is due to low pressure areas that move eastwards from the northeast Atlantic and have absorbed moisture over the sea, as a meteorologist from the German Weather Service (DWD) explains upon request. “Because the air masses are quite mild, they can absorb more moisture and therefore lead to greater amounts of precipitation.” It will be cooler in northern Germany next week and there will be less rainfall.
Climate researchers have long been warning that the risk of extreme weather events is increasing due to climate change. As a result of global warming, extreme precipitation is increasing worldwide and here too, Potsdam climate researcher Stefan Rahmstorf recently wrote on X, formerly Twitter. At the beginning of January he explained that extreme precipitation was becoming more frequent because warmer air could absorb more water vapor and therefore rain. According to a study in the journal “Climate and Atmospheric Science,” the number of precipitation records has risen sharply. On average, one in four record-high daily precipitation events can be attributed to climate change.
Will such floods happen more often in the future?
As a consequence of the flood, experts are calling for a rethink when it comes to protecting against flooding. “As a result of climate change, where the flood processes will change, we will certainly see other types of floods in the future,” said Ralf Merz, hydrologist at the Helmholtz Center for Environmental Research in Halle (Saale), recently on Deutschlandfunk. “Such long flood events will certainly occur more often in the future.”
When will it stop raining?
The continuous rain in parts of Germany is expected to last until Saturday. The German Weather Service originally issued its warnings until Thursday night – but they were extended on Wednesday. The situation in the flood areas is likely to worsen again as a result.
What does it depend on whether the dikes hold?
“So far we have not seen any dike breaches because the technical flood protection works well,” says Torsten Schlurmann, head of the Ludwig Franzius Institute for Hydraulic, Estuarine and Coastal Engineering at the Leibniz University in Hanover. “The dikes protect against flooding sufficiently well as long as water does not accumulate on them for a long period of time.” The stability of a dike then depends on what material the dike is made of and what ground it stands on. It is therefore important that the emergency services constantly monitor the dikes, for example with dike runners on the ground or with drones from the air.
There are entry bans in effect in Lilienthal in Lower Saxony, which was particularly hard hit by flooding. The general order states: “The dikes, the areas near the dikes and their access roads have become softened due to the heavy rainfall and the persistently high water levels.” If you enter, there is a risk that the dikes will break, the water will spread uncontrollably and vulnerable areas will be flooded, especially residential buildings.
How affected is agriculture?
According to the local farmers’ association, almost every farmer in Lower Saxony is currently affected by flooding of their fields or damage caused by moisture. The background was the large amounts of rainfall in the past few weeks, the rural population of Lower Saxony told the German Press Agency. “Several hundred thousand hectares of fields and grassland are flooded,” said Landvolk President Holger Hennies. Hundreds of farms were also affected by flooding, “but fortunately only a few farms were so badly affected that stables were also affected and livestock had to be evacuated.”
