Hydrochemical and isotopic characteristics of groundwater in the Continental Intercalaire aquifer system: Insights from Mzab Ridge and surrounding regions, North of the Algerian Sahara
| Autor: | Hakimi, Youcef, Orban, Philippe, Deschamps, Pierre, Brouyere, Serge |
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| Přispěvatelé: | Departement Architecture, Géologie, Environnement et Constructions - ArGEnCo (Liège, Belgium), Université de Liège, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Journal of Hydrology: Regional Studies Journal of Hydrology: Regional Studies, 2021, 34 (4), ⟨10.1016/j.ejrh.2021.100791⟩ Journal of Hydrology: Regional Studies, Vol 34, Iss, Pp 100791-(2021) Journal of Hydrology: Regional Studies, Elsevier, 2021, 34 (4), ⟨10.1016/j.ejrh.2021.100791⟩ |
| ISSN: | 2214-5818 |
| Popis: | International audience; Study region : North of Sahara, Algeria.Study focus : The effects of water/rock interactions and hydrodynamic conditions on the characteristics of groundwater in the Continental Intercalaire aquifer (CI) are demonstrated using hydrochemical and isotopic data from the Mzab Ridge.New hydrological insights : The results confirm that CI groundwater in the oriental basin is highly mineralized (1010 > EC > 3500 μS/cm) and is of the SO4-Cl-Na type. However, it is poorly mineralized (340 > EC > 960) in the occidental basin and predominantly belongs to the HCO3-Ca type. The important contribution of evaporite minerals has been deduced using saturation indices and minor element ratios of Sr/Ca and Br/Cl. This is explained by lithological heterogeneities within the CI aquifer and corroborates the observations from regional piezometric features which suggest a groundwater divide located between 31.55° and 31.57 °N latitude. δ18O-NO3 and δ15N-NO3 analyses show that NO3 has a predominantly natural origin, which is soil nitrification even for the high concentrations exceeding 50 mg/L. CI groundwaters are highly depleted in both δ18O and δ2H compared to modern rainfall isotopic signatures. The most depleted ones are those situated in the Great Oriental Erg sub-basin. Isotopic values as low as δ18O=−6‰ can be taken as the limit for groundwater that is typically old. In the El Golea region, isotopic enrichment seems to indicate mixing between old groundwater and evaporation-affected groundwater infiltrating through the dunes of the Great Occidental Erg. |
| Databáze: | OpenAIRE |
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