MODFLOW

The City of Windhoek in Namibia has developed wellfields and a managed aquifer recharge scheme within the fractured Windhoek Aquifer to ensure a sustainable potable water supply to the city during drought. A three-dimensional numerical groundwater model of the aquifer was developed using the finite-difference code MODFLOW to determine the potential impacts of varying pump inlet depth elevations and varying production borehole abstraction rates for optimal wellfield and aquifer management.

This paper presents the results of groundwater flow modelling studies that were conducted within the scope of the PRIMA RESERVOIR project. The project’s main goal is to develop an innovative methodology to mitigate land subsidence due to excessive groundwater exploitation in water-stressed Mediterranean watersheds. This objective is achieved by integrating earth-observation-derived land subsidence rates with a coupled implementation of numerical groundwater flow and geomechanical modelling.

Underground mine water rebound prediction in its simplest form can be simulated linearly by comparing the volume of the mined ore with long-term average recharge rate to obtain an estimate of the time which will elapse before the workings are full to their decant elevation.

Water stress is frequently experienced in many parts of South Africa. To ensure the longevity of the country’s water resources, particularly groundwater, accurate quantification of the resource and prediction of the responses of each water resource unit to natural and anthropogenic stresses are necessary. To this endeavour, Simbithi Eco-Estate, located at Shaka’s Rock, KwaZulu-Natal requires the implementation of a Water Management Plan that includes a hydrogeological investigation.

A cycle of research is under way to investigate sustainable farming practices and business development on emerging farms in the lowveld of the Limpopo Province of South Africa. One of the main limiting factors for intensive agricultural production in this region is water availability. The objectives of this study were: i) to determine the spatial extent of occurrence of shallow groundwater (<20 m deep), in particular along dry river beds; and ii) to determine the sustainability of shallow groundwater abstraction for irrigation on emerging farms.

Monitoring groundwater storage is conducted in the study. World Health Organisation estimates, about 55 million people affected by drought yearly. However, Surface water holds 0.3 percent of the freshwater, and groundwater holds 30.1 percent of the freshwater. Hence, monitoring groundwater storage is vital.