Assessing Groundwater Suitability for Irrigation of Thirteen Shallow and Deep Tunisian Aquifers

The main objective of the research is to evaluate the quality of Tunisia’s groundwater for irrigation. For this purpose, a total of 576 sample wells distributed over seven shallow aquifers (Grombalia; Kef, Sfax, Sidi Bouzid, Gafsa, Chott Jerid, and Maritime Djeffara) and six deep aquifers (Grombalia; Sfax, Sidi Bouzid, Gafsa, Djeffara, and Continental Intercalaire) have been extracted, and eleven hydro-chemical parameters including pH, EC, TDS, HCO₃⁻, Cl⁻, SO₄²⁻, NO₃^–, Ca²⁺, Mg²⁺, Na⁺, and K⁺ have been collected through twelve literature reviews. The selected aquifers have been assessed based on various qualitative parameters including EC (or TDS) to study the salinity problem of the water for irrigation, sodium adsorption ratio (SAR), permeability index (PI), and magnesium adsorption ratio (MH) for water infiltration problem; and sodium and chloride for toxicity problem. USSL diagram and FAO guidelines are used to classify the aquifers according to their suitability to irrigation. The results reveal that the shallow aquifers (S.As) of Grombalia and Gafsa; the deep aquifer (D.A) of Gafsa have the best water quality for irrigation, followed by Grombalia, Kef, Sfax and Sidi Bouzid S.As and Sidi Bouzid and Continental Intercalaire D.A. Djeffara S.A and D.A, Chott Jerid S.A and Sfax D.A have the worst quality.