Groundwater potential recharge assessment in Southern Mediterranean basin using GIS and remote sensing tools: case of Khalled- Teboursouk basin, karst aquifer

In the Khaled-Teboursouk basin (Southern Mediterranean Basin), karstic aquifers are the main sources of drinking and irrigation water. They play a crucial role in the socio-economic development of the region. Therefore, the estimation of groundwater recharge is necessary for a good management of water resources, while considering the impacts of climate change. The present study utilizes the application of APLIS method integrated with Geographic Information System (GIS) as a remote sensing technique for geospatial analysis to explore groundwater recharge areas along Khalled-Teboursouk basin, expressed as a percentage of precipitation combined with numerous parameters. The morphology of earth surface features such as Altitude (A), Slope (P), Lithology (L), infiltration (I), and Soil (S) influence the groundwater recharge rate in carbonate aquifers, from the infiltration of rainfall in aquifers in either direct or indirect way. The results revealed that 60–80% of precipitation is identified as high potential for groundwater recharge and it is associated with karstified limestones of Eocene lower age. The gentle slope areas in the Middle-East and Central parts have been moderate potential for groundwater recharge 40–60% of precipitation and they are associated with karstified limestone of Campanian-Maastrichtian age (Abiod Fm.). Hilly terrains with low and very low recharge are the most represented for groundwater recharge processes. They are associated with areas of non-karstified rocks and Quaternary deposits. The dominant water type of the groundwater in this area is Ca–Mg–Cl–SO₄ water type. The Total Dissolved Solids (TDS) of these waters (0.37 to 3.58 g/l) are slow in the recharge area and high in the discharge area. This is caused by rapid circulation of water from the recharge areas to the discharge points. The aquifers have been recharged by rainfall originating from a mixture of Atlantic and Mediterranean vapor masses. The isotope analyses, δ¹⁸O and δ²H ranged from − 6.8 to -5.3‰ (vs. SMOW) and from − 42 to -4‰ (vs. SMOW) respectively, confirm the recent recharge of these carbonate aquifers.