The map collection shows the average terrestrial water storage as measured by GRACE and GRACE-FO for each year since 2002. Regions in which less water was stored on average in the respective year than in the reference period 2002–2020 are shown in red; a water surplus is shown in blue.

The collection can be used to recognize events in individual years as well as long-term changes. For example, a water surplus is visible in the flood years 2002 and 2013, as well as in the extremely snowy year 2010. However, only large-scale floods can be seen in the yearly mean, which is why the Ahrtal flood in 2021 is not visible.

On the other hand, Germany has been in drought since 2018, which only eased slightly in 2021. However, a water shortage was already apparent from 2015 onwards. The massive rainfalls at the end of 2023 are not visible in the yearly average for this year. It remains to be seen if and how the terrestrial water storage in Germany will recover in the next months and years.

Text and maps: Eva Boergens, GFZ