Hydrochemical characterization of Gareat-El-Tarf plain groundwaters, northeastern, Algeria

Abstract

A hydrochemical study has been conducted on groundwaters of Gareat-El- Tarf plain in order to discriminate the salinity
origin. Achieved findings indicate that waters are of medium salinity, with a conductivity of 1618μ
S/cm. A spatial variation in
chemical facies suggests that waters chemistry is influenced by a number of factors such as geology, climate and
anthropogenic activity. Waters are bicarbonate-calcic type upstream of the basin and near calcareous outcrops, sulfate-calcic
type in the Mio-Plio-Quaternary filling and ultimately become chloride-sodic type on the borders of the Sebkha. Chloride
ion crossing with major ions on binary diagrams suggests that waters salinity would be attributed to water-rock interaction
characterized by mineral dissolution and precipitation, as well as cation exchange. Chemical tracing by trace elements such
as strontium suggests that evaporites dissolution contributes to waters salinity of Gareat-El-Tarf plain. Statistical approach is
another tool allowing to classify processes responsible for hydrochemical variability, in function of their significance. The
increase in salinity is mainly due to climate aridity