KÉBILI — Tunisia has just harvested the largest date crop in its history — 404,000 tonnes, up 16.3 percent on the previous season and the first time the country has crossed the 400,000-tonne line. A study published on 1 August in the journal Agricultural Water Management sets out what that record cost underground.
The paper, by Tarek Gasmi, Ramzi Guesmi, Slim Abdelbari, Soura Boulaares and Sajeda Albarghati, combines agricultural, climate and satellite data for Kébili, Tozeur, Gabès and Gafsa between 2002 and 2024. Over those 22 years, output from the main southern oases nearly tripled. The water that made the tripling possible came largely from deep aquifers that do not refill on a human timescale.
The arithmetic of Kébili
Kébili accounts for roughly 70 percent of the production studied. Citing bulletins from the regional agricultural development commissions, the researchers put abstraction from the governorate's deep aquifers at 229 percent of renewable resources — meaning the volume pumped in a year is about 2.29 times the estimated annual recharge. It does not mean that 229 percent of the aquifer's total stock has been consumed; it means the deficit compounds every season.
The pumping infrastructure grew accordingly. The study counts about 3,700 wells recorded in 2008 against more than 10,600 in 2023, while noting that some boreholes still escape official statistics — a gap that makes the real figure higher, not lower.
Measurements from the GRACE and GRACE-FO satellites, which detect changes in terrestrial water storage through variations in the gravity field, point the same way. Regionally, stored water has fallen by the equivalent of 16.6 centimetres of water since 2002 — a total loss across an area wider than the four governorates, not a uniform 16.6-centimetre drop in water tables. After relative stability in the mid-2000s, the decline has run at close to one centimetre a year.
Why the yields have not warned anyone yet
Irrigation has so far insulated the palms from climate variability. Larger planted areas, new boreholes and investment allowed average yields per hectare in Kébili to more than double over the study period. That is the trap: the indicator farmers and ministries watch most closely is the one the pumping keeps looking healthy.
The researchers do report a possible weakening of that insulation — yields per hectare appear to be growing more sensitive to atmospheric dryness during the hottest spells, a signal most visible in Kébili. They present it as exploratory. It demonstrates neither a current fall in yields nor a proven causal link to aquifer depletion.
The economic stakes are large. Date exports reached roughly 705 million dinars by 10 April in the 2025-26 campaign, with Deglet Nour supplying about 84 percent of exported volumes.
What the authors propose
The study reads as an early warning rather than a verdict of collapse, and its authors have published their data and code openly so the analysis can be checked and repeated. The implication they draw is procedural: monitoring should track water drawn per tonne of dates, not tonnage alone; unregistered boreholes need to be brought into the official count before any allocation rule can work; and the sensitivity of yields to heat should be watched as a leading indicator. On the evidence they assemble, a record harvest is not proof that the system producing it is sound.