Approche hydrogéologique et caractérisation hydrochimique des eaux souterraines de l’aquifère superficielle de la plaine chott Gadaïne-Lazrou, Wilaya de Batna, Est Algérien

Abstract

Agriculture is considered to be the fundamental socio-economic activity in the Gadaïne-Lazrou plain region. As a result, the quality of surface groundwater is negatively affected by anthropogenic activity. In the course of this work, we have attempted to study the physico-chemical characterization of groundwater in the plain through the following stages: Firstly, a de limitation of the study area in order to describe its geographical position. The study area lies to the north-east of the Batna willaya, in the northern high plains. We have described the positioning of the convergence zones of the hydrographic network, the geomorphology of the region where we have placed the low zones (Chott Gadaïne…) and the high zones (Dj. Guedmane…). In the background, an interpretation of the geometric structure of the aquifers using geological and geophysical methods, showing the superficial Mio-Plio-Quartenaire aquifer made up of conglomerates, la custrine limestones, clays and marls; and the deep Cretaceous-Jurassic aquifer. Resistivity measurements show low values in the chotts. A characterization of the climate in the study region over the period (1989-2018), showing it to be semi-arid with an average rainfall of 319.7mm; then an interpretation of the water balance for the Gadaïne-Lazrou region, showing a deficit of 335mm and zero infiltration. A critical study based on the work carried out in the four seasons of “2002, 2009, 2015 and 2016” aims to determine: The hydro geological study explains the fluctuating piezometric level. The hydro-chemical study defines the most widespread facies (sodium chloride and agnesium chloride); The physico-chemical characterization of the waters has highlighted deterioration in their quality and the predominance of chlorides, calcium and magnesium, which seem to be linked to the geological nature.