Integrating microbiological and physico-chemical parameters for enhanced spatial prediction of groundwater quality in Harare

Publication date: Available online 11 March 2019Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Mhosisi Masocha, Timothy Dube, Thokozani DubeAbstractWe predict groundwater quality to ascertain suitability for drinking purposes in the City of Harare using a geostatistical approach. Forty-four (44) groundwater samples collected across different parts of the City of Harare were used. The samples were analyzed for twelve physico-chemical and microbiological parameters (i.e., pH, conductivity, calcium, magnesium, hardness, sodium, iron, potassium, nitrates, sulphates, turbidity, and total coliforms). Then, an aggregate groundwater quality index (GWQI) was calculated for each sampling site. Ordinary kriging based on the spherical model was then applied to predict GWQI in unsampled areas resulting in the generation of the first integrated groundwater quality map for the City of Harare. The results indicate that approximately 57% of the groundwater in the city is below the acceptable standard for human consumption based on World Health Organization guidelines. The approach described here can be replicated in other cities to generate groundwater quality thematic maps that incorporate microbiological properties of the water to safeguard public health.

Source: Physics and Chemistry of the Earth, Parts ABC - March 13, 2019 Category: Science Source Type: research