Satellite observations confirm that groundwater levels in Europe are currently lower than normal. It has been going on for four years.
Europe has been permanently lacking rain since the summer of 2018. We were able to observe this on the surface, last summer, with a drought that affected 75% of the European continent. This groundwater deficit has also been confirmed from space, thanks to observations from two satellites located 490 km from the earth. In reality, these satellites do not directly see what is happening underground.
But they are able once a month to assess changes in the mass of water on the earth’s surface.
>> Faced with the lack of water, American researchers propose to capture the steam emitted by the oceans
Initially, it is an overall assessment of the water contained in seas, lakes or groundwater. And so you then have to do a bit of math and distinguish (still by satellite) the changes in the mass of water in the rivers, in the oceans, the evolution of the mass of snow or ice, then do the subtraction (for only the groundwater body remains). The map drawn up a few days ago by researchers from the University of Graz in Austria, using this method, shows a persistent deficit of groundwater throughout Europe for four years, with the exception of the Great -Brittany, and for France, the Atlantic coast and the Pyrenees.
Two-thirds of drinking water consumption in France
This is partly a consequence of climate change, partly with a lack of precipitation for several summers, but beyond the lack of rain, this state of the groundwater also testifies to excessive withdrawals compared to the recharge capacity, estimates Florence. Habets, hydroclimatologist and director of research at the National Center for Scientific Research (CNRS).
In mainland France, groundwater represents almost two thirds of drinking water consumption, more than a third of that of the agricultural world and this groundwater is also used by the industrial sector.
There is a risk of talk of drought again this summer in France. Everything will depend on the weather for the coming months. But according to the national geological office, in January three-quarters of groundwater tables were already below monthly norms. The rains will be welcome because in France, in the coming months.