Evaluation of Souss-Massa Daraa Region Irrigation Groundwater Hydrogeochemical Characteristics and Quality: A Multivariate Statistical Approach

Abstract

The quality of the Souss-Massa Daraa (S-MD) aquifer is influenced by natural and anthropogenic contaminations. Indeed, geological formations are the main sources of mineralization in the aquifer, which compromises the potential irrigation, and threatens the sustainability of agricultural activities. In this context, hydrochemical and statistical studies were carried out on the major and secondary elements of water, based on different physico-chemical parameters, such as T °C, pH, EC (electric conductivity), NO 3- (nitrate), Cl - (chloride), HCO 3- (bicarbonate), SO 42- (sulfate), Ca 2+ (calcium ions), Mg 2+ (magnesium ions), K+ (potassium ion), Na + (sodium), Na%, Mg% and SAR ( sodium adsorption ratio ). The sampling was carried out in 2018, over two seasons (winter and summer), by analyzing 26 wells distributed over the studied plain. the water classification based on EC, it was found that 80% of the samples show very high mineralization, and 96.66% are very hard and unfit for human consumption. Also, Cl - values of most of the samples were within limits inappropriate for irrigation, but some estimated parameters, such as Na% and SAR, were within appropriate levels. In addition, according to the piper diagram, the waters are characterized by a geochemical facies of 86.66% NaCl (sodium chloride), 13.33% CaSO 4 (sulphated calcium) and Mg. Thus, the principal component analysis (PCA) shows that the region waters mineralization is of natural origin.