The water tables are at their lowest, after the exceptional drought of the summer of 2022. However, France is entering its fourth week without rain, and the underground water reserves have still not been replenished.
The days pass without a drop of rain or almost. Hexagonal France broke a new climatic record, Monday, February 13: that of the number of days without rain in winter. For 23 days, the cumulative daily rainfall across the country was less than one millimeter, according to Météo France. The previous winter record of 1989, with 22 days without rain, has been exceeded.
Because the water tables are at their lowest (and there is little time left to fill them)
2022 has been a terrible year for soils. An exceptional drought has affected all of France, with water restrictions in almost all departments and even cuts in some villages. July 2022 was even the driest July since 1959, the Minister for Ecological Transition, Christophe Béchu, announced on franceinfo. At the end of the summer, the farmers in particular hoped for a rainy winter, capable of recharging the water tables, completely dry.
But for the moment, the water reserves are not being replenished. At present, “25% of the French water tables are at an extremely low level, 25% at a low level, 25% slightly below average, and the last quarter at average and above”, details the doctor in agroclimatology Serge Zaka, interviewed by franceinfo. These levels are lower than those of 2022 at the same period, according to the specialist.
However, it is in winter that the water tables must absolutely fill up. The groundwater recharge period, from November to March, is “crucial”according to Serge Zaka. “It conditions what will happen all year round. If they do not recharge, the risk of drought is increased.” For the moment, the level of rain does not make it possible to compensate for the drought of 2022, according to the expert.
“It’s a time bomb: as soon as the small quantities of water in the soil are used by the plants, we will have to draw on the groundwater to water the crops, and we will have the same consequences as last year.”
Serge Zaka, doctor in agroclimatologyat franceinfo
The situation is all the more worrying as the groundwater recharge period is soon coming to an end. “From the beginning of April and budding, most of the water will be directly absorbed by the plants, and will no longer go down into the water tables”, explains Serge Zaka. If these nature reserves are too low in early spring, the consequences could become dramatic. There is therefore a month and a half to complete them.
Because France is entering its fourth week without rain (and it should continue)
The rain suddenly stopped falling on January 21 in mainland France. And since then, it has rained very, very little. The country enters its fourth week with little or no rainfall. “The soil moisture index is much lower than what should normally be observedlaments Serge Zaka. And the record of 23 days without rain is going to be extended, because it’s not going to rain in the next few days.”
The fault, according to Météo France, is an anticyclone that has been stagnating over Western Europe for more than three weeks. In addition to the absence of rain, the temperatures in the afternoon are already almost spring-like. “The maximum temperatures (…) are close to the average values for a month of March, even a month of April”, notes the weather institute. Moreover, there was no cold spell this winter, underlines Serge Zaka.
“It’s the same high pressure we had in 2022, notes the expert in agroclimatology, and the good weather will last at least until the end of February.” The next few days promise to be very dry. Météo France is still forecasting a little rain north of the Loire on Sunday, “but in miserable quantity”.
“Of course, if it rains a lot in spring and summer, we won’t have a problem. But otherwise, we will have to draw from the groundwater to irrigate, and drinking water will very quickly be limited, perhaps as early as the middle of spring.”
Serge Zaka, doctor in agroclimatologyat franceinfo
In the longer term, the seasonal forecasts of Météo France do not give a clear trend for the next three months. Indeed, according to the institute, France is as likely to see a drier spring, wetter or in line with seasonal norms.
Because meteorologists fear a rise in temperatures with the return of El Niño
Scientists fear the consequences of the end of La Niña and the return of its counterpart: El Niño. These climatic phenomena, which originate over the Pacific Ocean, influence the precipitation cycle and the climate of many regions of the world. Including in Europe. If La Nina causes cooling, El Niño causes warming, explains Météo France. “Statistically, that means that we are more likely to have a warmer year over the whole year, not just in summer”summarizes Serge Zaka.
“For the year [2023], our climate model indicates the end of three consecutive La Niña years, and a return to relatively warmer conditions in parts of the tropical Pacific. This change is expected to lead to the global temperature in 2023 being warmer than in 2022.” confirmed last December the Met Office, the British meteorological institute.
This warming of temperatures in 2023 therefore raises fears of an aggravation of the drought. In fact, high temperatures “promote evapotranspiration”that is to say theevaporation at ground level and through plant transpirationexplains Serge Zaka, “so we have a greater loss of water, especially on the first 40 centimeters of the ground”. All these factors are so many alarm signals, but the agroclimatology specialist would like to remind you that “the painting is not catastrophic”. “We’re off to a bad start, but an intense drought this summer is conditioned by what will happen in the spring”he concludes.