Author(s)

Richard Ayuk Akoachere¹, Sonia Ebot Egbe¹, Thomson Areapkoh Eyong¹, Sophie Ngomune Edimo², Simon Ngomba Longonje³, Diana Besem Tambe⁴, Nji Bihmimihney Nelly¹

¹Department of Geology, University of Buea, Cameroon.
²Department of Environmental Mines and Geology (CEA-MEM), Felix Houphuoet-Boigny National Polytectnic Institute, Cote D’Ivoire.
³Department of Environmental Science, University of Buea, Cameroon.
⁴Advanced School of Public Works Yaounde, Cameroon.

This study was to determine the seasonal variations of groundwater, the influence of the rock formations on the groundwater solute chemistry and groundwater domestic-agro-industrial quality using hydrogeochemical tools and physicochemical parameters; Ionic ratios, Gibbs diagrams, Piper diagrams, Durov diagrams and water quality indices. From physicochemical parameters; in the rainy season, pH ranged from, 4.6-7.1; EC, 0.023-1.63 mS/cm; Temperature, 26.3-29⁰C andTDS, 0.015-1.09 mg/L and in the dry season pH ranged from 5-7.2; EC, 0.01-1.61 mS/cm; Temperature, 24.4-29.5⁰C andTDS, 0.01-1.08 mg/L. Forty groundwater samples; 20 per season, wet and dry were analysed. Themajor ions fell below WHO acceptable limits for both seasons. The sequences of abundance of major ions were, Ca² >K >Mg² >NH₄ >Na , HCO₃^->Cl^->SO₄^2->NO₃^->HPO₄^2- in wet season and Ca² >Mg² >K >Na >NH₄ , HCO₃^->Cl^->SO₄^2->HPO₄^2->NO₃^- in dry season. Ion-exchange, simple dissolution and uncommon dissolution processes determined groundwater character. Groundwater ionic content was as a result of ion exchange from rock-weathering. Water types are; MgCl and MgHCO₃ in both seasons. Hydrogeochemical facies are; Ca-Mg-Cl-SO₄, characteristic of groundwater some distance along its flow path and Ca-Mg-HCO₃, characteristic of freshly recharged groundwater from precipitation. The groundwater indices of; Sodium Percent (% Na), Residual Sodium Carbonate (RSC) , Kelley’s ratio (KR), Sodium Adsorption Ratio (SAR), Electrical Conductivity (EC), Total Dissolved Solid (TDS), USSL  and Wilcox index were determined, evaluated and found to be suitable for agro-industrial uses in all seasons. Permeability Index (PI) , Water quality index (WQI) and Magnesium Adsorption Ratio (MAR) were not suitable in some areas and in some seasons.

Groundwater, Hydrogeochemistry, Seasonal Variations, Water Quality, Douala-Cameroon

Akoachere, R. , Egbe, S. , Eyong, T. , Edimo, S. , Longonje, S. , Tambe, D. and Nelly, N. (2019) Seasonal Variations in Groundwater of the Phreatic Aquiferous Formations in Douala City-Cameroon: Hydrogeochemistry and Water Quality. Open Access Library Journal, 6, 1-26. doi: 10.4236/oalib.1105328.