Wars alter groundwater dynamics, says Swiss study

Thanks in particular to satellite observations, a doctoral student at the University of Neuchâtel (UniNE) has observed an unexpected recharge of water in an underground cavity in a river basin in Syria.

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This research could help to prioritise repairs, protect wells and networks and direct aid to the populations most affected by the loss of access to water.

“The hydrogeological changes observed in Syria are linked to the massive population displacements caused by the war since 2011,” observed doctoral student Saeed Mhanna. His thesis won first prize and the public prize in the Neuchâtel selection of the “My thesis in 180 seconds” competition on May 7, UniNE said on Monday.

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“Due to the invisible nature of aquifers, it is difficult in wartime to assess characteristics such as storage capacity, water recharge and the position of the water table, because it is impossible to visit the sites concerned. In order to overcome this difficulty, Saeed Mhanna has combined several indirect measurement and calculation tools that are rarely used together,” states the press release.

In particular, the researcher had to learn to master the complex processing of inSAR data provided by satellites. This study has enabled him to demonstrate that in places where the displaced population has had to abandon agricultural land, the cessation of irrigation has led to a partial recharging of the water table and a rise in the surface of the soil, of up to 4cm per year, as the pressure in the underlying geological layers increased.

Dam in Ukraine

Another major chapter in Mhanna’s thesis concerns the Kakhovka dam region, located in southern Ukraine along the Dnieper river. He found that the collapse of the dam in June 2023 turned the entire hydrological system upside down.

The researcher was surprised to find that two years after the dam’s destruction, the amount of water lost to the Black Sea from the continent corresponded approximately to the volume of Lake Geneva, with an uncertainty of around 40%.

The hydrogeologist’s work is opening up new perspectives by providing concrete information where data is lacking or arriving too late. Thanks to satellites, it is now possible to pinpoint areas where hydraulic infrastructures have been damaged, where water resources are dwindling or, on the contrary, where groundwater is being recharged.

Adapted from French by AI/ts