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08 April 2025 | Story Andre Damons | Photo Andre Damons
DrSophie-Biskop_ProfFrancois-Engelbrecht
Dr Sophie Biskop from the Department of Geography at the Schiller University Jena, Germany, and Prof Francois Engelbrecht, a Professor of Climatology at the Global Change Institute (GCI), University of the Witwatersrand, at the Southern African Mountain Conference (SAMC).

The severe El Niño drought of 2015/16, which culminated in the Vaal dam reaching an alarming low water level (~25%), prompted scientists to try and predict whether climate change could bring a drought so severe and long lasting that Gauteng could run out of water. 

Prof Francois Engelbrecht, a Professor of Climatology at the Global Change Institute (GCI), University of the Witwatersrand, is one of the scientists working on this project and says though they cannot predict a Day Zero drought with certainty, he thinks it is possible that Gauteng might run out of water in the 2030s or 2040s.

 “This is the biggest climate change risk South Africa faces”, he said.  

Prof Engelbrecht and Dr Sophie Biskop from the Institute of Geography at the Friedrich Schiller University Jena, Germany, together with other scientists are working on a project involving hydrological modelling to predict and prevent a Day Zero from happening. Dr Biskop presented their research paper titled ‘Projected hydrological futures of South Africa's mega-dam region’ at the second Southern African Mountain Conference (SAMC2025) in March, indicating there is a high risk that the water demand in Gauteng will exceed available water resources within the Integrated Vaal River System (IVRS) under future climate change.

 

Gauteng may be severely compromised

The IVRS, a large, complex water system comprising water resources of different river basins, and several mega-dams within, has been constructed to secure the water supply of the Gauteng province, the economic hub in South Africa. 

According to the researchers, Southern Africa is a water-stress hot spot and is projected to become significantly warmer and likely also drier under global climate change, increasing the risk of devastating hydrological droughts. The IVRS, Dr Biskop told the attendees, is vulnerable to the occurrence of multi-year droughts as experienced between 2012 and in 2016. The alarming low water level of the Vaal dam after a period of drought of 2015/16 provided early warning that water security of Gauteng may be directly and severely compromised in a changing climate. Potential evapotranspiration will increase as a consequence of strong regional warming.

 

Answering questions

“There is consequently a high risk that the water demand in the Gauteng province will exceed available water resources within the IVRS under future climate change. This raises the question if under ongoing climate change the natural hydrological system (without considering water transfers between dam catchments) can maintain dam levels in South Africa’s eastern mega-dam region, and particularly within the Lesotho Highlands,” explained Dr Biskop. 

 “To answer this question, the aim of our study is to quantify future water balance changes of several dams under changing climate conditions using the Jena Adaptable Modelling System (JAMS), a software framework for component-based development of environmental models. For this purpose, we build process-based hydrological models for several dam catchments.”

She said an ensemble of high-resolution regional climate change projections is subsequently used as forcing, to generate future hydrological projections. The analysis of projected changes in hydrological system components (precipitation, evapotranspiration, run-off) provides probabilistic estimates of the occurrence of a regional climate change tipping point - when the natural water supply can no longer achieve the full storage capacity of the mega-dams which supply the Gauteng region.

 

Working to prevent Day Zero 

According to Prof Engelbrecht, they are working with the City of Johannesburg, the National Department of Water and Sanitation and Rand Water on this project. Their hope for this research is to create awareness in order to try and prevent Day Zero from happening. They also hope to assist these role players in building resilience and help them prepare for Day Zero. Their work with the City of Johannesburg also includes helping the city to reduce water wastage and change water users’ behaviour as well as formulating a disaster management plan should Day Zero happen. 

The Southern African Mountain Conference (SAMC) series is unique as it seeks to integrate science, policy and practitioner sectors for sustainable interventions in southern African mountains. SAMC events are conceptualised by the Afromontane Research Unit (ARU) of the University of the Free State (UFS), the African Mountain Research Foundation (AMRF) and Global Mountain Safeguard Research (GLOMOS), a joint initiative between Eurac Research and the UNU Institute for Environment and Human Security. These three organisations form the Primary Partners, with the SAMC series being implemented by The Peaks Foundation (a non-profit company). SAMC2025 is being held under the patronage of UNESCO.

News Archive

Discovery in Scorpius constellation may signify clean energy for Earth
2017-01-23

 Description: Discovery in Scorpius constellation may signify clean energy for Earth Tags: Discovery in Scorpius constellation may signify clean energy for Earth

Earlier this year, a group of international astronomers
announced the discovery of an exotic binary star system,
AR Scorpii. The system is in the Scorpius constellation.
Photos: Supplied

See article on Nature’s website 

In future, stargazers and astronomers will look at the Scorpius constellation near the Milky Way with new eyes. Earlier this year, a group of international astronomers announced the discovery of an exotic binary star system, AR Scorpii. The system is in the Scorpius constellation.

Prof Pieter Meintjes, researcher in the Department of Physics at the University of the Free State (UFS), worked with four colleagues on what he describes as a “wonderful discovery”. This sensational discovery, which could lead to the production of cleaner energy on Earth, will be published in the research journal, Nature, early in 2017.

Model developed to interpret new set of measurements
The exotic binary star which was discovered consists of a red dwarf and a white dwarf revolving around each other every 3,5 hours. The binary system showed very prominent pulsations of 117 and 118 seconds respectively. The pulsations can be explained by a bundle radiation produced by the white dwarf star.

“These new observations have shown that the radiation is strongly polarised, a sign that we are dealing with synchrotron radiation here. Synchrotron radiation is produced by electrons accelerated to extremely high energy levels in the magnetic field of the white dwarf star,” says Prof Meintjes.

He developed a theoretical model to interpret a new set of measurements that was taken by the 1,9 m telescope and the 10 m SALT telescope at the South African Astronomical Observatory (SAA0).

Totally unique phenomenon could contribute to energy production on Earth
“I further indicated that the interaction between the magnetic fields of the white dwarf star and the red dwarf star induces secondary processes that specifically describe the behaviour of the radiation in the radio band and infrared band accurately. AR Sco is the first white-red dwarf binary system of which all the pulsated radiation could be explained by the synchrotron process, which is totally unique,” says Prof Meintjes.

According to Prof Meintjes, the value of the model lies in the fact that the processes which produce the radiation in AR Sco, can also be applied to produce energy on Earth.

 

Plasma reactors are based on roughly the same processes which apply in AR Sco, and with refining, it could be utilised to generate electricity in future. This will be much cleaner than nuclear energy.

 

The model developed by Prof Meintjes explains all the radiation in the system – from radio waves to X-rays – in terms of electrons accelerated to extremely high energy levels by electric fields in the system, which then produce synchrotron radiation over a very wide band of the electromagnetic spectrum.

Prof Meintjes is currently working on a follow-up article examining the evolution of the AR Sco, in other words, the origin of such a unique system and the final state towards which it is evolving. “My vision for the immediate future is therefore to develop a model for the evolution of the source concerned,” he says.

 

 

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