Abstract:
A baseline study was conducted to gain a better understanding of the relationship between
groundwater, geology, and geography of the Greater Timbavati Area, to advance the knowledge of
hydrostratigraphical settings affected by various socioeconomic and environmental factors.
Samples were collected from both surface water and groundwater and were taken in both nature
reserves and rural communities for comparison. An Aquaread AP-5000 probe was used to measure
basic water chemistry parameters as well as nitrates, ammonium, and ammonia in the field.
Samples were also taken and analysed for radon using a Durridge RAD7. Rainwater samples were
also collected from two sites for hydrogen and oxygen isotope analysis using a Los Gatos Research
(LGR) Liquid Water Isotope Analyzer. There are noticeable differences between the surface water
and groundwater chemistry and isotopic signatures. Groundwater samples have a mean TDS of
1217 mg/l and pH of 7.5 while surface water samples have a mean TDS of 332 mg/l and pH of 8.3.
A close correlation between land use and nitrate concentrations is observed with higher values
being found in groundwater in the more developed areas, over 500 mg/l, suggesting human and
agricultural contamination. Unfortunately, there also appears to be no relationship between radon
concentration and the underlying geology with mean values in groundwater ranging from 188
Bq/m3
to 51400 Bq/m3
.
