Assessment of anthropogenic sources of pollution along Mazai and Matsheumhlope streams in Bulawayo, Zimbabwe using GIS and Remote Sensing tools

Abstract

In recent years, global water pollution has been largely attributed to anthropogenic activities such as mining, agriculture, industrial activities and domestic effluent. In the case of Mazai and Matsheumhlope streams in Bulawayo, Zimbabwe, manufacturing industries in the surrounding areas are known to discharge partially treated effluent into the two streams. These two streams are tributaries to Umguza River, which is used by local communities for irrigation and domestic purposes. Pollutants carried by these two streams negatively affect the quality of the streams causing a deterioration in the health of Umguza River and Dam. This study aimed at investigating anthropogenic sources of pollution along the two streams. Water samples were collected from May 2016 to April 2017 and tested for permanganate value, chemical oxygen demand, nitrates, ammonia, phosphates, electrical conductivity, pH, total dissolved solids and suspended solids. The results were compared to EMA SI 6 Regulations on Effluent and Solid Waste Disposal. Results were divided into the wet and dry season. The physico-chemical parameters of the two streams were analysed for Analysis of Variance. The results showed that the streams had no significant influence on all the parameters except for pH (p<0.05). The seasons had a significant influence on the levels of ammonia, suspended solids, nitrates and pH. A GIS application QGIS, was used to generate maps using the selected parameters to display levels of pollution. The results showed that the industrial and sewage effluent significantly affect the water quality of the two streams. The study recommends that pollution hotspots indicated by the study be further investigated and given more attention to curb the release of pollutants in the two streams.

Keywords

• Urban streams
• anthropogenic activities
• pollution
• GIS

References

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