The impacts of land use changes on the water quality of the Okavango River in Namibia

Kavango region in Namibia has experienced massive population increase over the past year which resulted in increase of settlements and agricultural activities along Okavango River. This increase in settlements and agriculture pose a serious threat to a river. Landsat TM images for years 1990 and 2011 were classified using unsupervised classification process to determine the land use/cover changes. Water quality parameters were measured once for three months at six sampling points along the river. Observed data was statistically analyzed using Microsoft Excel for significance and linear regression was performed at 0.05% confidence level to observe if there is any correlation between the distance from Namibia/Angola border and water quality parameters. The classification shows increase in cultivated land and bare land and settlements along the Namibian side of Okavango River by 2 and 9% while. Forest and Grass and shrubs have decreased by 3 and 9% between 1990 and 2011 respectively. The results show that there is no spatial and temporal significance between the water quality parameters apart from Electrical Conductivity, pH and Temperature. Comparison between current and past water quality show no significant change in water quality of Okavango River, hence the study concluded that land use/cover changes has little effects on the water quality of Okavango River. However, even though the effects are minimum or negligible, consideration should be taken in terms of good agricultural practice on fertilizers applications. And good land management practices should also be encouraged especially to rural people in order to reduce land clearance.