IN PHOTOS – Drought seen from space: what do the satellites say about the situation in Lorraine?

Satellite images comparing and illustrating the effects of drought and forest fires in France have been widely circulated in recent weeks. But what do they actually say about the climate crisis? We took out more pictures of Lorraine seen from spacemade comparisons and interviewed specialists.

First observation: If the comparison between the months of August 2021 and 2022 is spectacular, it must be remembered that last summer was particularly wet with floods and floods, especially in eastern France, mid-July. Comparison 2021 to 2022 is “compare two extremes” points out Météo France.

But it is a fact the rainfall totals for this summer 2022 are well below average (see map + further). Just as your lawn is very green when you water it or yellow when you stop watering it, our landscapes, seen from space, are parched.

In order to progress in the analysis, it is necessary to work in the long term. This is the role of the European Copernicus programme, which processes data from the satellites of the European Space Agency (ESA). Satellites provide detailed images, over long periods and with regularity.

Heat episodes are intense and repeated – Clément Albergel, European Space Agency

You need to know if you are dealing with one “extreme weather phenomenon” but punctually or by a “long-term climatic phenomenon” explains Clément Albergel, researcher at the climate office of the European Space Agency. However, we see that “heat episodes are intense and repeated” adds the scientist, “This is a clear sign of climate change caused by our human activity. We even see an acceleration of these extreme events”.

In the video below (source Sentinel-Hub) we see the evolution of the level of Lake Bouzey every August since 2017: 2021 is actually an exception, the level of the lake drops every summer.

The climatic upheaval on earth is clearly visible from space. And must encourage us to adjust our behavior.

The images below come from the Sentinel -2 satellite. They were all taken in August 2021 and August 2022, but not necessarily from date to date, for example due to the availability of images or cloud cover. Drag the slider to compare the same landscape from 2021 to 2022.

The Vosges: le Thillot, Gérardmer

Since 8 August, the Vosges department has been partly on drought crisis alert.

Moselle: Metz

Since the end of July, the Mosel Furen has been put on heightened alert.

Meurthe-et-Moselle: Nancy and Baccarat

Since August 12, most of Meurthe-et-Moselle has entered the “crisis stage”. The level of the rivers is at its lowest: of the 38 stations that monitor the flow of rivers in the department, 50% report a completely dry river.

Verdun and Meuse

About “the ward’s situation is generally less worrying than that of its neighbours”according to Maas prefecture, “the condition of the water bodies is worsening and the drought situation seems to be stuck for a long time”. Part of the territory has reached the elevated alert threshold since the end of July.

Map: precipitation in July 2021 and 2022 in Lorraine

These maps compare the rainfall in July 2022 and 2021 with normal rainfall in Lorraine. “The maps show relationships with normals” explains Meteo France, “when the ratios shown are greater than 100, the period considered is surplus (or rainier than normal); when the ratio is less than 100, the period is drier than normal.”

Graphically, the more intense the blue, the more we are above normal in terms of rain, the more we are in the red, the more we are in the deficit.

The comparison of precipitation for the months of July 2021 and 2022 compared to normal.
Meteo France

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