The water deficit in Germany and Europe as a whole has worsened in recent months, according to joint studies conducted by Potsdam-based geoscientists working with the US space agency NASA and the German Aerospace Center (DLR).
The findings support fears that "water reserves will not recover by the end of the year, even if more rain than usual falls in the autumn," said a spokesman for the Helmholtz Centre for Geosciences (GFZ) in the city by Berlin.
The situation is likely to be even worse because the current data up to June did not reflect the heatwaves in Germany, said the GFZ, which on Thursday published some conclusions from the satellite imaging conducted with partners.
The effects of the heatwaves that wracked Germany and other countries in Europe this summer will only become apparent in the data from the coming months. This data is not expected until autumn.
The researchers are monitoring the total water content on and below the Earth's surface. According to the GFZ, this data allows them to calculate the extent to which water storage capacity is changing.
"Since 2015, we have been seeing increasingly drier conditions in Germany than in the 15 years prior to that," said Annette Eicker, head of the Global Geomonitoring and Gravity Field section at GFZ.
Although the above-average wet year of 2024 brought about some recovery in water storage, this was immediately followed by another sharp decline, according to the institute.
"The decline in groundwater storage accounts for the majority of the long-term decline in water storage in Germany," said Andreas Güntner, hydrology research group leader.
According to the studies, heat, in particular, reduces water storage. A comparison with precipitation data shows no long-term negative trend in precipitation amounts.
However, an increase in potential evaporation due to rising air temperatures is observed - "that is, the amount of water that can be transported from the ground into the atmosphere," said the GFZ spokesman.