Etude du potentiel de contamination des eaux de la nappe phréatique de la région de Ouargla (Sahara septentrional Est Algérien)

Abstract

Ouargla’s basin (Southeast of Algeria), is currently suffering from natural and anthropogenic groundwater degradation. This work was carried out in order to study the vulnerability and risk of contamination through the aquifer mapping and chemical parameters.The hydro-chemical study showed that the waters of the aquifer have a chemical facies dominant sodium chloride and sodium sulfate. The water temperature varies between 17.2°C and 29.4°C, the pH ranges from 6.33 to 9.16 and the electrical conductivity oscillates between 1.91 and 263 dS.m-1. These results reflect a strong mineralization of water in the region.The results obtained of the indices of organic pollution (IPO) and contamination index (CI) show an organic pollution that affects more than 64% of the measurement points and a mineral pollution of 73 %. The degree of vulnerability recorded increase from upstream to downstream of the basin in the direction of groundwater flow toward the north (Sebkhet Safioune) and the other to the West (Sebkhet Bamendil)