Impact of land use on water quality in the Likangala catchment, southern Malawi
In southern Malawi, the Likangala River, which is important for irrigation, domestic use and fishing, is affected by various land uses along its catchment. The impact of urbanisation and agriculture on the water quality of this river was investigated in 2013. Water samples, collected during dry and wet seasons at locations chosen on the basis of their dominant land use, were analysed for physical, chemical and biological contamination. Increased anions and cations were found downstream of urban areas, although most values were within acceptable levels. Total coliforms increased by 176.1% and Escherichia coli counts increased by 157% downstream of urban areas, these levels being above the permitted local and international standards. Water quality index computations showed that the overall river water quality in both wet and dry seasons were ‘medium’ and ‘bad’ at the sampled locations, showing that the water was unsuitable for human consumption without treatment. Waste management, the enforcement of buffer zones on river banks, urban land-use regulation for improving water quality, improved sanitation, the provision of civic education to communities and the employment of an ecosystem approach in management of the catchment are recommended.
Keywords: environment, urbanisation, waste management, water pollution, water quality index