Groundwater is an increasingly important source of water supply for agriculture, households, and industry. With population growth and increasing climate variability, this water resource plays an increasingly important role in South Africa (RSA) to enhance water and food security. However, with increasing pressure on groundwater and intensive landuse, the resource is vulnerable to depletion and degradation. This is compounded by limited capacity and inadequate resources allocated to its protection and sustainable management.
Managing groundwater resources for sustained uses requires knowledge of the aquifer systems, their replenishment and interactions with rivers, wetlands and terrestrial systems. It also requires knowledge of the human interaction with the resource to ensure a sustainable exploitation.
The replenishment, or recharge, of groundwater occurs as diffuse and focused fluxes. Diffuse recharge is recharge that occurs distributed over the catchment. Focused recharge, on the other hand, occurs from localized accumulation of water on the land surface such as ponds and from river segments. It varies much more in space and time than diffuse recharge, especially for ephemeral rivers, which are common in arid and semi-arid areas. Large uncertainties are related to focused recharge and this component can potentially be the major contributor to recharge in such environments. In this project, a suite of field experiments and data collection in conjunction with hydrological modeling will be carried out to investigate and quantify focussed recharge.
Sustainable groundwater exploitation requires consideration of the environmental, agronomic, and socio-economic conditions in the linked groundwater-surface water system. Integrated hydrological models in combination with resource sustainability indicators will be used for making such assessments. Citizen science has been documented as an efficient manner to involve stakeholders in the management of their water and environmental resources. In this project the citizen science approach will be further developed and adapted for integrated surface-groundwater systems.
(1) To improve the understanding of the hydrogeological conditions in typical geological settings and farming communities in SA, exemplified by the Hout/Sand river catchment in Limpopo Province.
(2) To develop an integrated model for the Hout/River catchment making innovative use of new satellite data types and state-of-the-art field investigations and monitoring.
(3) To estimate the spatial and temporal variation in groundwater recharge and with particular emphasis on focused recharge from the ephemeral river system and episodic recharge events generated by extreme rainfall events.
(4) To improve the basis for development of sustainable groundwater management plans.
(5) To involve of local stakeholders via new developments of citizen science and hereby help securing the implementation of management plans.