Characterising the Soils of the Karoo: Implications for Groundwater Resource Management

The aim of the following study was to characterise the soils of Sutherland, located in the Northern Cape of South Africa. This was completed in order to shed light on possible pathways for infiltration and understand the ultimate impact on groundwater resources. Therefore, the relationship between the soil characteristics and infiltration was explored. To achieve this, field work was conducted whereby soil profiles were exposed in order to examine the subsurface characteristics of the soil and map the soil types. Thereafter, infiltration tests were taken randomly across the terrain in order to determine the in-situ properties of the soils in the region. Dye tracer tests were conducted on two plots of 1m2 within the study area, to determine the preferential flow paths and heterogeneities within the area. Field observations, as well as dye tracer tests, indicate a low clay content at the surface. This could be attributed to high wind velocity. Finally, it is shown that local river beds are hydraulically conductive due to the coarse nature of the underlying gravel. Therefore these strips of land need to be protected in order to avoid possible contamination of the already limited groundwater supplies in the region.