An assessment of groundwater from semi-arid environment of Morocco for drinking and agricultural uses with reference to water quality indices technique

Abstract

The suitability of groundwater for domestic and agricultural uses was assessed in the Essaouira basin (Morocco) using the water quality indices technique. The Essaouira basin is one of Morocco’s developing basins characterized by the dominance of rural areas. A total of 61 groundwater samples collected in July 2020 were analyzed for major ions (Ca 2+ , Mg 2+ , Na + , K + , HCO 3 -, SO 4 2− , Cl − , and NO 3 − ). The adequacy of groundwater for drinking use was made by comparing the Electrical conductivity (EC) and the concentrations of Cl − and NO 3 − with the standards set by Morocco and the World Health Organization (WHO). The results obtained show that more than 50% of the groundwater from the Cenomano-Turonian aquifer is fit for domestic consumption. The groundwater quality for irrigation has been evaluated based on the indices: permeability index (PI), Kelly Ratio (KR), magnesium hazard (MH), sodium percent (Na%), residual sodium carbonate (RSC), and sodium adsorption ratio (SAR). The results show that the majority of the samples are suitable/excellent for agricultural purposes. The SAR vs Salinity (EC) diagram shows that the groundwater in the study area is suitable for plants resistant to high-salinity concentrations. The results of this investigation could be used for better and sustainable management of groundwater in the Cenomano-Turonian aquifer of the Essaouira basin.