Evaluation of seasonal patterns of water quality in the Zambezi River Basin, using Zambezi River Authority (ZRA) data of 2011 <Article>

The study reports the seasonal variation of the water quality, along Lake Kariba, Zambezi River and its tributaries in 2011. To evaluate the water pollution quality, the following ten parameters were analysed: water temperature, pH, Electroconductivity (EC), Dissolved Oxygen (DO), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), alkalinity as CaCO3, turbidity, Total Phosphorus (TP), and ammonia-nitrogen (NH3-N). The study found that water quality along the Zambezi River and its tributaries was most polluted in the Late Rain Season (LRS), that is, January to March, with a Water Pollution Index (WPI) of 4.02. The water quality was least polluted during the Late Dry Season (July to September) with a WPI of 0.44. It is also made clear that the water exiting Lake Kariba is generally free of any significant pollution across all seasons.