Hydrochemical Characterization and Spatial Analysis of Groundwater Salinization in the Ghiss-Nekor Coastal Aquifer (Northern Morocco)

Laboratory of Research and Development in Applied Geosciences, Faculty of Science and Techniques of Al Hoceima, Abdelmalek Essaadi University, Tetouan, Morocco

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Abstract

Groundwater salinization has become one of the most critical environmental challenges threatening coastal aquifers in Mediterranean semi-arid regions. This study investigates the physicochemical characteristics and salinization mechanisms of the Ghiss-Nekor Aquifer through a hydrochemical survey conducted during January 2026. A total of 57 groundwater samples were collected and analyzed in situ for pH, electrical conductivity (EC), total dissolved solids (TDS), and salinity, combined with GIS-based spatial analysis to identify hydrochemical gradients and vulnerable zones.

The results reveal strong spatial variability in groundwater quality across the aquifer. Elevated EC, TDS, and salinity values are predominantly concentrated in the northeastern coastal sector near Trougout, indicating advanced groundwater mineralization and progressive seawater intrusion. Salinity values reached more than 5.30 g/L, while EC exceeded 9,283 μS/cm in highly affected areas. Conversely, southern and southwestern sectors exhibited lower mineralization levels due to stronger freshwater recharge conditions. The spatial coincidence of high salinity indicators confirms the dominant influence of marine intrusion, intensified by groundwater overexploitation, recurrent droughts, tectonic structures, and anthropogenic pressures. The study further demonstrates that lithological conditions and water-rock interactions contribute significantly to groundwater mineralization through evaporite and carbonate dissolution processes. Neutral to slightly alkaline pH conditions indicate stable hydrochemical environments dominated by carbonate buffering mechanisms. The integration of hydrochemical interpretation and spatial analysis provides new insights into the functioning of the Ghiss-Nekor coastal aquifer and highlights the urgent need for sustainable groundwater management strategies in northern Morocco.