Abstract |
The Cuvelai Etosha Basin is one of the densest populated areas in Namibia, a semi-arid sub-
Sahara African country. It is however also host to the least developed rural areas where
people still rely on the traditional hand dug wells that tap perched aquifers of the basin. There
is generally a lack of safe drinking water and sanitation in areas such as this and hence makes
it prune to water borne diseases such as Cholera. This study focuses on a) determination of
hydrochemical characteristics of the groundwater, b) determination of the water quality and
the production of a time series analysis of the substances of concern and c) production of
spatial and temporal variation maps of the substances of concern. The study aims to increase
the knowledge on the nature of groundwater quality of perched aquifers in the CEB,
especially those in the Ohangwena and Omusati regions. Groundwater samples from hand
dug wells in the Ohangwena and Omusati regions were collected and analyzed for physio-
chemical parameters. Sampling was carried out at four different times of the year i.e. in
February and March 2015 (wet season) and June and August 2015 (dry season). In addition to
the primary data collected for the project secondary data, 2014, available from the SASSCAL
project was used Hand dug wells samples in the Omusati Region are predominantly of the
Ca-SO₄-HCO₃ type in which strong acids (SO4 + Cl) exceed week acids (CO3 + HCO3)
while those of the Ohangwena region are Ca-HCO₃ water type for deep wells and Na-HCO₃
water type for shallow wells. The physiochemical parameters exceeding the Namibia Water
quality standards for the Omusati region have been identified as SO₄, Cl, F, Mg, EC and TDS
while the TDS, EC, turbidity, nitrate and iron were identified for Ohangwena region. Shallow
wells yield water of very poor quality than deeper wells. The Ohangwena region wells had
more fresh water while the Omusati region wells have brackish water. There is a general
increase of the substances of concern during the dry season. Hence the water quality is not
the same throughout the perched aquifer of the CEB. |
? |