Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

HYDRODYNAMIC AND HYDROCHEMICAL CHARACTERIZATION OF THE LIASIC GROUNDWATER IN ATLASSIC ZONE (KSOUR OF NORTH, BECHAR, ALGERIA)

ALOUI RAFIQA, NABOU MOHAMED AND MEKKAOUI ABDERRAHMANE

Abstract

The strategy for the rational exploitation of a groundwater requires knowledge of hydrodynamic and hydrochemical properties of this resource. The volume withdrawn from a groundwater is a function of its hydrodynamic parameters. In addition, water quality is primarily related to the properties of aquifers and soils that filter water by adding dissolved materials. This study consists of a geological, hydrodynamic, and hydrochemical characterization of the Mougheul liasic aquifer. This aquifer belongs in the Atlas domain. It is located on the Algerian-Moroccan borders in the South West of Algeria, exactly in the extreme south west of the Algerian Saharan Atlas energetically shaken by the alpine orogeny. This area includes a Precambrian base in Cambrian-Ordovician and a Triassic-Jurassic cover, structured in syncline dislocated by faults. The Lias is composed of dolomitic limestones and bioclastic limestones housing a circulating groundwater, free at the edges, semi-captive to captive toward the center. The hydrodynamic characteristics are determined by the interpretation of the pumping tests according to the logarithmic approximation of Jacob C. E. 1947. The transmissivity of this aquifer is 3.09×10-4 m2/s at 8.13×10-3 m2/s, and the storage coefficient “s” is estimated at 2.83×10-4. This groundwater exhibits convergent flows towards the main source. The hydrochemical study suggests that the waters of this aquifer occupy the facies of the calcicmagnesian- bicarbonated and slightly overlapping the calcic-magnesian-chlorinated and the calcicmagnesian- sulphated waters. These waters are relatively hard, and the concentrations of the other elements remain within the intervals tolerated by the World Health Organization. On the other hand, it shows pollution indices (NO3 -> 50 mg/L) at some points.