Sécheresses en Méditerranée : comment l’agriculture est-elle impactée ?

The Mediterranean region is a climate change hotspot. It is warming 20 times faster than the rest of the planet. Droughts are expected to intensify and become more frequent.[1]They will affect producers/livestock farmers, production conditions, and cultivable areas. Although contrasting across the Mediterranean, these consequences are already widely visible today. The FARM Foundation takes stock of current droughts and also provides insights from Serge Zaka, a researcher and modeler in agro-climatology.

Mediterranean: early drought and late rains

In 2022, the Western Mediterranean was already experiencing a very severe summer drought that continued into 2023 with a significant winter drought and limited recharge of water reserves. According to the European Drought Observatory, at the beginning of June 2023, the Western Mediterranean was still in a state of drought alert, with temperature and precipitation anomalies.[2]This alert particularly concerns Spain, southern Portugal, southern France, northwestern Italy and the Maghreb.

The Eastern Mediterranean has not experienced any significant drought episodes. On the contrary, some areas have been affected by heavy rainfall. These excessively humid conditions have degraded cereal production in some places, particularly in Turkey, Italy, and Greece. Nevertheless, according to MED-Amin, growing conditions are much more favorable in the East than in the West.[3].

The western Mediterranean was also subjected to severe storms between May and June. According to Serge Zaka, a researcher and modeler in agro-climatology, "The rains that fell in this region fell too late, outside the period of groundwater recharge. […] Of all the water that fell, 20 % infiltrates into the water tables, 80 % is runoff, surface capture or essentially capture by plants via their roots for their growth. These localized storms may have given vegetation some respite in places with recharged agricultural soils, but they did not improve the situation in a lasting way. This can be seen on the drought monitoring map, with a return to normal (blue zone) in certain areas of the Maghreb countries and Portugal, but a majority of areas remaining on drought alert.

Water reserves remain a concern in most of the countries affected by the alert. In Tunisia, although the filling rate is increasing, reaching nearly 38,000 tonnes,[4], restrictive measures limiting the use of drinking water from the distribution network, particularly for agriculture and irrigation, are maintained until September. In Algeria, the average filling rate of dams has also increased nationally, but with significant regional disparities. Dams with a good filling rate are mainly located in the east of the country.

In the center, the Taksebt dam in Kabylie received nearly two months of rain in a few days, reaching a filling rate of 33%. On the other hand, the other dams in the center and especially in the West remain at very low levels, limiting the use of irrigation for this summer. In Morocco, there has been a significant drop in the filling of dams in recent years. According to the available data[5], this occupancy rate has been falling since 2015 with a peak at 35 % in 2023, compared to 85 % in 2015. At the end of June, the national rate only reached 32 %.

In the face of droughts, farmers can also resort to groundwater. There is little up-to-date data on this resource in the Maghreb. However, it represents a significant proportion of the water used for irrigation: 42,100 tonnes of irrigated land is irrigated by groundwater in Morocco, 641,000 tonnes in Tunisia, and 881,000 tonnes in Algeria.[6]A significant part of the water tables would be overexploited (withdrawals exceeding recharge[7]). Over the period 2007-2011, 57 % of Moroccan aquifers were overexploited, 26% in Tunisia[8] and up to 100 % from the aquifers of the South and 60 % from those of the North of Algeria.

On the other side of the Mediterranean, in Spain, despite recent rains, the situation has not improved much. Water reserves – both surface and groundwater – remain low. or even lower in some places than in June 2022, especially for Andalusia^[9]In Portugal, reserves are relatively high except in the South.[10]In France, two-thirds of the water tables are below normal. Those in the Mediterranean regions of Provence and the Côte d'Azur are at very low, even historically low, levels.[11] – involving in places orders limiting or prohibiting irrigation.

According to the French Ministry of Ecological Transition, the departments around the Mediterranean are at high risk of drought by the end of summer 2023.[12]Serge Zaka, who relies on data from Météo-France, also fears a summer hotter than normal with “increased evaporation and transpiration phenomena”. 

Spring crops affected by water and heat stress

The agro-climatology researcher explains that the crops most affected by water stress induced by droughts will mainly be spring crops (corn, sunflower, sorghum), "since these are the crops that will grow all summer", at a time when water reserves are low and demand is highest. Arboriculture could also be impacted. The problem is less of a problem for trees whose fruit will be harvested earlier, such as apricots. Species harvested a little later, such as peaches, olives, and vines, will be more impacted. As for market gardening, sunny vegetables, zucchini, cucumbers, melons, and watermelons need a lot of water and will be mainly affected by heatwaves during flowering. For example, in 2022, in France, harvests of fresh summer vegetables were particularly affected by drought and the summer heatwave, as the High Council for Climate points out in its latest report.[13].

Indeed, heat stress due to high temperatures can impact crops. “Above 35°C, during the flowering period, the flowers abort. During the fruit ripening period, this causes problems with burns […], smaller fruits, which may be undersized when put on the market.”, says Serge Zaka. For some sectors, the consequences of repeated periods of drought are already being felt. "We are seeing an increase in alcohol content in wine across the entire Mediterranean region. […] We have gained 2°C of alcohol in 50 years in the French region Mediterranean. The organoleptic properties of certain foods will therefore most certainly continue to evolve.

Maghreb and Iberian Peninsula: degraded winter crops

This year, early drought and heat waves also impacted winter crops, a phenomenon not necessarily expected with climate change, but Serge Zaka confirms it: "Some years will still have winter droughts that could affect winter crops."

According to MED-Amin bulletins on the evolution of cereal crops in the Mediterranean, the Maghreb and the Iberian Peninsula are experiencing one of the worst seasonal droughts in recent decades.[14]With recent rains arriving too late to reverse the trend, MED-Amin reports a collapse of crops in Morocco, Algeria, Tunisia and Spain, particularly for barley and durum wheat – “winter crop most impacted by adverse weather conditions this year”[15].

In Morocco, according to remote sensing analyses, crops appear to have suffered damage related to hot and dry conditions during the flowering period. According to the latest FAO forecasts[16], the country is expected to import up to 8.8 million tonnes of cereals in the 2023-2024 season, but production, although poor, should be better than last year according to MED-Amin. In Tunisia, wheat and barley also seem to be affected, the probabilities of“crop collapse or crop loss” are strong. In Algeria, cereal crops (barley and wheat) have suffered from delayed growth, flower sterility and accelerated senescence leading to degraded grain quality.

In Southern Europe, the situation is also alarming. In Portugal, cereal production and livestock farming are the most affected sectors. The cereal season is poor, with a decline in crop area and productivity. Harvest estimates are well below the 5-year average for Spain, and farmers are resorting to using fields as fodder or pasture for animals rather than harvesting them. In France, cereal production forecasts are considered by analysts to be good to exceptional. However, localized storms may have damaged some crops. In early June 2022, however, French farmers were reporting visible consequences of droughts on certain spring crops such as: the orchards, but the The situation has also been able to improve in some places.

Let's not forget that livestock farming is also impacted, particularly by heat stress, which can cause problems with gestation, growth, and production, adding to animal distress. Serge Zaka remains concerned about dairy farming. which “will probably no longer be possible in the Mediterranean region” in the future.

These growing conditions are set to become the norm as the Mediterranean basin warms. "Over the rolling year 2022-2023, in certain Mediterranean regions, particularly in the Pyrénées-Orientales region, we fell below 200mm, meaning we were occasionally in an arid climate, which is quite rare in France. But this probability of moving into this semi-arid to arid climate increases over time. By 2050, we will see a decrease in precipitation over the year.", explains Serge Zaka. “All climates will move north. […] We will have greater aridification.”At the same time, biogeographies – the distribution areas of species, including agricultural species – will also move north. Mediterranean agriculture will therefore evolve in parallel with the climate, bringing with it both opportunities and major difficulties.

This article is part of a series on droughts in the Mediterranean. In a future publication, Researchers and professionals will share the potential for adapting Mediterranean agriculture to climate change.

[1] Ali, E. et al. (2022) Cross-Chapter Paper 4: Mediterranean Region. In: Climate Change 2022: Impacts, Adaptation and Vulnerability. URL: https://www.ipcc.ch/report/ar6/wg2/chapter/ccp4/

[2] European Drought Observatory – JRC European Commission (2023) Map of Current Droughts in Europe. URL: https://edo.jrc.ec.europa.eu/edov2/php/index.php?id=1052

[3] MED-Amin is a network for monitoring agricultural markets and food systems in the Mediterranean, created by CIHEAM in June 2014.

[4] Ministry of Agriculture (2023) Dam inputs and releases from 25-06-23. URL: http://www.onagri.nat.tn/uploads/barrages/BARRAGES-26-6-2023.pdf

[5] Nechfate (2023) Evolution of the filling rate of all Moroccan dams. URL: https://nechfate.ma/taux-de-remplissage-des-barrages-marocains/

[6] Data from 2012 from Kuper et al. (2016) Liberation or Anarchy? The Janus Nature of Groundwater Use on North Africa's New Irrigation Frontiers. https://link.springer.com/chapter/10.1007/978-3-319-23576-9_23

[7] Definition of overexploitation of aquifers commonly used by national policies in the Maghreb. This definition is, however, controversial since it does not take into account "natural discharges" and use of the resource by ecosystems dependent on groundwater. For more information on this debate, see Molle (2023) "Aquifer Recharge and Overexploitation: The Need for a New Storyline". URL: https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2023-04/010087445.pdf

[8] Tunisia has identified more aquifers than its neighbors, this ratio represents 71 overexploited aquifers out of 273 identified.

[9] Embalses.net (2023) Estado de los embalses, pantanos y presas de España. URL: https://www.embalses.net/

[10] DGADR (2023) Albufeira water reserve. URL: https://sir.dgadr.gov.pt/reservas

[11] BRGM (2023) Groundwater tables at 1^er June 2023. URL: https://www.brgm.fr/fr/actualite/communique-presse/nappes-eau-souterraine-au-1er-juin-2023

[12] Ministère de la Transition Ecologique et de la Cohésion des Territoires (2023) Mise en œuvre des mesures de restriction des usages de l’eau en période de sécheresse. URL : https://www.ecologie.gouv.fr/sites/default/files/MM23087_Synthese_usages%20eau%20secheresse_BATweb.pdf

[13] High Council for the Climate (June 2023) 2023 Annual Report – Acknowledging the urgency. Committing the resources. URL: https://medias.vie-publique.fr/data_storage_s3/rapport/pdf/290091.pdf

[14] MED-Amin (05/2023) Contrasting cereal campaign in the Mediterranean. URL: https://www.med-amin.org/en/ressources-2/bulletinforecast/459-med-amin-bulletin-de-prevision-2023-2-mai/file

[15] MED-Amin (06/2023) Unexpected degradation at the end of season in some Western Mediterranean areas. https://www.med-amin.org/fr/ressources/bulletinprev/460-med-amin-forecasting-bulletin-2023-3-june/file

[16] FAO (2023) Food Outlook – Biannual report on global food markets. Food Outlook, June 2023. URL: https://doi.org/10.4060/cc3020en