Geochemical and multivariate statistical study to assess the salinization origin of the Remila plain groundwater, Khenchela Algeria
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Date
2020
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JOURNAL OF WATER AND LAND DEVELOPMENT
Abstract
The aquifer system of the Remila plain 250 km2 (Khenchela, Algeria) is one of the semiarid regions
where groundwater is heavily exploited for urban supply and irrigation. An integrated
hydrogeochemical and statistical approach was performed by 70 water samples to identify the main
processes and the origin of our waters’ salinization. Chemical analyses indicate salinity values (TDS)
ranging from 568 to 1586 mg.l-1 with an average of 869 mg.l-1, sulphate is the dominant ions,
especially in the north and northeast part. While the identified chemical facies are : SO4-Cl-Ca in the
northeastern part, SO4-Cl-Ca-Mg presents most waters and HCO3-Ca-Mg in the southeastern part.
The statistical approach, which allowed us to group the waters into three groups using PCA and
HCA; 1) saline waters (23%) (TDS > 1000 mg.l-1 and SO42- dominance), 2) moderately saline
waters (51%) with HCO3- dominance, 3) moderately saline waters (26%) with a mixed facies. The
binary ion diagrams used suggest that the most hydrochemical processes are: evaporites dissolution
and/or precipitation, accompanied by an exchange and/or reverse exchange of ions. Additionally,
another process was detected in the northeastern part of the area; the saline intrusion of Sabkha
waters, favored by intensive aquifer exploitation.