The salinity origin and hydrogeochemical evolution of groundwater in the Oued Kert basin, north‐eastern of Morocco

Abstract

Water scarcity in the Rif region of northwestern Morocco, particularly in the Kert plain, has resulted in significant groundwater exploitation to achieve human and socioeconomic objectives. These methods helped in identification of the source of dissolved elements and the mechanism that increased groundwater salinization. Current study is the part of groundwater's salinity sources and hydrogeochemical development in the Oued Kert basin (Mediterranean zone, Driouch province, eastern Morocco); 46 samples (45 wells and one spring) were collected in June 2021. Using the Cl-/Br- ratio, which appears to be a good tracer for detecting non-atmospheric Cl- contributions to groundwater provided chemical analyses are accurate since its variability is limited. To achieve this goal, processes that increase groundwater salinization was studied. The results indicate that the groundwater samples studied had medium to high conductivity electric, which can attain 9500 S/cm. The regional distribution of physicochemical parameters is consistent with the distribution of alluvial and evaporate rocks. The high molar ratio values of Sr2+/SO42− and Sr2+/Ca2+ imply an extra input of strontium, likely through carbonate precipitation/dissolution processes as well as adsorption reactions. The varied Bromide concentrations (1-7 mg/L) detected in groundwater samples were evaluated against the binary mixing model to determine the salinization mechanisms responsible for the analyzed system. It suggests that evaporate rocks dissolution was the predominant source of groundwater mineralization in the studied region. However, irrigation of water inflows and local saltwater intrusion seems to alter aquifer quality dramatically.

Keywords

• Mineralization
• Bromide
• Kert aquifer
• Hydrogeochemistry
• Evaporate rocks