Multivariate statistical-based approach to the physical-chemical behavior of shallow groundwater in a semiarid dry climate: The case study of the Gadaïne-Ain Yaghout plain NE Algeria

Abstract

Purpose. Several natural and anthropogenic factors control the hydro-geochemical behavior of groundwater. These factors influence on the quality, even the suitability of this resource for drinking. The main purpose of our study is the application of multivariate statistical methods to compile the mechanisms of mineralization acquisition in confined aquifers. Methods. The adopted method measures the chemical evolution of Ca+2, Mg+2, Na+, K+, HCO-3, Cl-, SO4-2, NO-3, NO-2, NH+4, and PO4-3 using an atomic-absorption spectrometer. The content of nitrogen and dissolved oxygen is measured using a spectrophotometer. Temperature (T°), electrical conductivity (EC), pH and dissolved oxygen are determined using a multi-parameter system. Findings. The main results show that 28 water samples from the Mio-Plio-Quaternary aquifer of the Gadaïne-Ain Yaghout plain have chemical facies of chloride, sulfate-calcium and chloride-magnesium types. Originality. The originality of the study is in the demonstration that water acquires its carbonate mineralization at the supply limits. Whereas it acquires its chloride, sodium and sulfate mineralization in contact with terrigenous saliferous formations, as well as in its interaction with the salt chotts formations. The results show a significant variation in the concentrations of chemical elements, in some cases exceeding drinkability standards. Mineralization is mainly caused by the dissolution of evaporitic minerals such as gypsum, halite and epsomite. Practical implications. The practical implications of this study could be resumed in terms of the convenience of multiva-riate statistical evaluation of complex physical-chemical databases in identifying pollution sources and understanding temporal variations for effective groundwater quality management in semiarid regions.