Environmental Isotopes

The response of an alluvial and estuarine deposit aquifer, locally known as the Harbour Beds Formation, located in the coastal area of the Durban Metropolitan District to 48 hours of group well pumping is studied to understand its potential for groundwater supply and consequent seawater intrusion. Groundwater levels were monitored from the three pumped boreholes and piezometers. Similarly, EC, TDS and pH were monitored every hour from the boreholes and piezometers.

The Cedarville Flats aquifer located in the Upper Umzimvubu River Basin, Eastern Cape Province is a source of water supply for an important agricultural region in South Africa. The hydrogeology of this important aquifer is investigated to understand the occurrence, circulation, recharge and quality of groundwater.

The natural CO2 springs at the Bongwana area emanates from a number of sites along an 80 km long N-S trending fault known as Bongwana fault. CO2 rich groundwater is observed at a shallow depth in a borehole drilled for water supply parallel to the main fault. The geology along the entire fault length is characterized mainly by Dwyka Group sediments. The objectives of this study are to characterize the CO2 springs and assess their impacts on groundwater and surface water quality.

An integrated approach involving multivariate statistical analysis combined with graphical methods (Piper trilinear diagram and δ18O-δ 2H plots), and environmental isotope analyses were successfully applied to characterise the spatial distribution of hydrogeochemical parameters and their controlling factors within the Lake Sibayi catchment located in north-eastern South Africa.

Continued population growth, economic development and climatic change have increased the demand for water supply in South Africa. As a result, most surface water systems have been exhaustively developed, increasing dependency on groundwater, including on meager aquifers during dry spells. This study aims to characterize the hydrogeology of the Pietermaritzburg Formation, a poorly productive aquifer that has been targeted for borehole sitting during drought years though with poor success rate.

Hydrogeochemical and environmental isotope investigation of the Thyspunt area, located in Eastern Cape South Africa, has been undertaken to understand the hydrogeological conditions in the area. Fifty-nine water samples from springs, wells, streams and ocean were collected for major ions, metals, and environmental isotope analyses. The hydrogeochemical and environmental isotope signatures were used to identify the interaction between various waters bodies, major hydrogeochemical processes, and possible sources of moisture in the Thyspunt area.