Pope Gregory defined the seven deadly sins in order to guide the Catholic Church in the 6th century. The past 20 odd years in the industry has shown that there are several mistakes that are repeatedly made by numerical modelers. Although we all acknowledge that any numerical model is a non-unique solution, and that there exists and infinite number of solutions, there are several sins that will prevent the model from giving an accurate representation.
Latest approaches and examples illustrating the key role of numerical modelling in sustainable groundwater use in South Africa
An investigation of the natural groundwater recharge and discharge of the Saldanha Bay Aquifer Systems, South Africa
Saldanha Bay is partially dependent on groundwater as part of their bulk water supply, as surface water resources in the area are extremely limited and fully allocated. Due to this, there is lots of pressure on the groundwater resources by industrial development and residential growth. Despite studies being conducted on these aquifer systems since 1976, they are still poorly understood especially with regards to their recharge and discharge processes.
Due to its location in a dry and arid part of South Africa, Beaufort West relies on groundwater as a crucial source of freshwater for the town. Although there have been fluctuations over the years, groundwater levels in the area have progressively dropped due to unsustainable abstraction from wellfields. The general flow of groundwater in the town, which is from the North where the Nuweveld mountains are situated to the town dyke in the South, is dictated by major dykes in the area.
In southern Africa, crystalline basement aquifers constitute approximately 55% of the land area and therefore it is important to understand these aquifers and the mechanisms that control them. These aquifers have been well documented in the northern parts of South Africa however the amount of research done on the central Namaqualand basement aquifers is severely lacking, especially in the area surrounding Kakamas in the Northern Cape (the study area).
The overexploitation of water resources has resulted in a global decline in groundwater levels. Managed aquifer recharge (MAR) is a globally acceptable practice to manage the depletion of water in overexploited aquifers in regions with limited water availability. The West Coast of South Africa experiences a semi-arid climate with predominantly dry summers. This study aims to identify potential areas suitable for MAR in the Saldanha Bay area to maximize the water available to these areas during the dry season.
An Investigation Of The Natural Groundwater Recharge And Discharge Of The West Coast Aquifer Systems
Groundwater in the West Coast has been utilised for many years as there are not many surface water resources in the area, and is therefore extremely important. Despite studies being conducted on the aquifer systems since 1976, they are still poorly understood especially with regards to their recharge and discharge processes. This means that the amount of water entering and leaving these systems are unknown, which may lead to over abstraction.
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.
The influence of land cover and vegetation on the hydrological balance and groundwater recharge in the Northern Cape Province South Africa
Groundwater water levels and the ability of aquifers to sustain water have been reportedly on the decline in specific areas in the Northern Cape Province in South Africa. The study area is located in an arid regional with mean annual precipitation of less than 400 mm/a, which is drought prone. The hydrological balances indicated that the required groundwater recharge to balance is at least 20 times less than the expected minimum natural recharge. Further investigation indicated that evapo-transpiration forms +95% of the hydrological balance.