Mapping groundwater recharge zones (GWRZs) is essential for planning artificial recharge programs to mitigate groundwater decline and saltwater intrusion into coastal aquifers. We applied two multi-criteria decision-making approaches, namely the analytical hierarchy process (AHP) and the multi-influencing factors (MIF), to map GWRZs in the Korba aquifer in northeastern Tunisia. GWRZ results from the AHP indicate that the majority (69%) of the area can be classified as very good and good for groundwater recharge. The MIF results suggest larger (80.7%) very good and good GWRZs. The GWRZ maps improve groundwater balance calculations by providing estimates of recharge-precipitation ratios to quantify percolation. Lithology, land use/cover and slope were the most sensitive parameters followed by geomorphology, lineament density, rainfall, drainage density and soil type. The AHP approach produced relatively more accurate results than the MIF technique based on correlation of the obtained GWRZs with groundwater well discharge data from 20 wells across the study area. The accuracy of the approaches ultimately depends on the classification criteria, mean rating score and weights assigned to the thematic layers. Nonetheless, the GWRZ maps suggest that there is ample opportunity to implement aquifer recharge programs to reduce groundwater stress in the Korba aquifer.

The Korba region in northwestern Tunisia has a coastal aquifer that is impacted by intensive irrigation, urban expansion, and sensitivity to SWI. We assessed the vulnerability extent of Korba’s GW to SWI. We utilized a parametric model for GW vulnerability assessment, the GALDIT, which considers six parameters to determine SWI effects. The GALDIT map has four rating categories (≥7.5, 7.5–5, 5–2.5, and <2.5), representing very high, high, moderate, and low vulnerability, respectively. Most of the region was found to be highly vulnerable (44.2% of the surface area), followed by areas characterized by very high (20.3%) and moderate (19.3%) vulnerability. Only 16.2% was found to have low vulnerability. A parameter sensitivity analysis showed that distance from shore and depth of GW represent the determining factors for SWI with variation index values of 24.12 and 18.02%, respectively. Inland advancement of seawater is causing GW salinity to rise, as indicated by a strong Pearson correlation coefficient of 0.75 between SWI indices and the electrical conductivity. Suitable areas for artificial recharge were mainly distributed in the alluvial plains, with a total area of 32.85 km². Inhibiting SWI requires about 11.31 MCM of artificial recharge in the two most suitable recharge zones in the region.

L'analyse fréquentielle des pluies mensuelles réalisée à partir des données recueillies sur un réseau de 102 stations reparties sur tout le territoire tunisien, a permis l'identification de la loi statistique la plus adéquate pour représenter la variable des pluies mensuelles en Tunisie. Différentes techniques statistiques ont été utilisées pour identifier la distribution la plus appropriée pour l'ajustement de cette variable pour différentes régions de la Tunisie. Deux lois sont retenues pour l'ajustement de la pluviométrie mensuelle en Tunisie: la loi des fuites et la loi log-normale mixte. Le poids de ces deux lois varie en fonction du temps et de l'espace. Editor Z.W. Kundzewicz Citation Merzougui, A. et Slimani, M., 2012. Régionalisation des lois de distribution des pluies mensuelles en Tunisie. Hydrological Sciences Journal, 57 (4), 668–;685.

Coastal aquifers are usually the main source of water supply for irrigation, drinkingand industrial purposes in coastal regions. They are often subject to overexploitation andconsequent quantitative and qualitative degradation. The groundwater flow system of the Chibawatershed in the CapBon peninsula (NE of Tunisia) is a typical case of an overexploited aquifer,where a piezometric depression exceeding -10 m (a.m.s.l) appeared has developed over the twolast decades. Among the numerous remediation tentatives, the SMART-WATER project aimedto propose a remediation plan based on a smart monitoring and water-energy nexus solutionthrough the installation of smart energy and water meters (SEWM). This technology aims tooptimize groundwater pumping at a set of selected representative farming systems in thewatershed. In this context, a first coupled surface water-groundwater flow model has beendeveloped and applied, coupled with energy nexus for the irrigated Chiba plain. The model isimplemented using a dynamic coupling between MODFLOW WEAP and LEAP in order toassess the SEWM system efficiency in reducing aquifer exploitation and electrical energyconsumption at farm level. Multi-objective calibration of the model using river discharge andGW level data has yielded accurate simulation of historical conditions, and resulted in better-constrained parameters compared to using either data source alone. Model simulations show thatcrop water demand cannot be met during droughts due to limited GW pumping capacity, and thatincreased GW pumping has a relatively strong impact on GW levels due to the small specificyield of the aquifer. Groundwater and energy models have also revealed that, under differentmanagement and climatic scenarios, electric energy consumption and groundwater table declineare intricately connected. Despite the short monitoring period and the intermittence of thereceived data, SEWMs have shown a promising role in monitoring groundwater pumping andengaging farmers in energy saving and aquifer sustainability.