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20 July 2020 | Story Leonie Bolleurs | Photo Supplied
The view from one of the offices in the Marion Island research station, with fresh snowfall in the interior of the island in the background.

Liezel Rudolph, lecturer and researcher in the Department of Geography at the University of the Free State (UFS), is strongly convinced that the Southern Hemisphere’s past glacial cycles will provide valuable insights to help predict and prepare for future climate change. Climate is changing fast and the magnitude of change we have seen over the last 30 years has taken a hundred or several hundred years to occur in the past. 

It is not only temperatures that are rising, but changes in wind patterns, rain cycles, oceanic circulation, etc., are also observed. As we do not know how the earth will respond or adapt to such rapid and drastic changes in climatic patterns, this poses various threats.

Link between landscape responses and climate change

Rudolph focuses her research on reconstructing the past climate of Marion Island. 

She had the wonderful opportunity to visit the island for the past three years with study and project leaders, Profs Werner Nel from the University of Fort Hare and David Hedding from UNISA, she departed on a ship to Marion Island to conduct fieldwork.They published their research findings of fieldwork conducted in 2017 and 2018.  

According to Rudolph, research in Antarctica, the Southern Ocean, and islands such as Marion Island is very important. South Africa is the only African country with research stations that have the ability to explore these regions.

“Marion Island has many landforms that could only have been created by glacial erosional or depositional processes, with glaciers currently absent from the island. To determine when the island was last in a full glacial period, we date the formation ages of these landforms.”

“In the short time we have been visiting the island, it was impossible to notice any drastic changes in the island climate. That is why we use these very old landforms to tell us more about periods before humans visited the island,” she says. 

Rudolph believes that understanding the link between landscape responses and climate change of the past can help to better predict some of the climate change processes that are currently threatening the planet.

“There’s a principle in geography called ‘uniformitarianism’, whereby we assume that the earth-surface processes we observe today, are the same as those that have been active in the past,” says Rudolph.

As scientists, they thus look at evidence of past geomorphic processes (which remain in the landscape in various forms, e.g. residual landforms, stratigraphic sequences, etc.) to piece together what the past climate was like. In the same way, they also use this principle to predict how certain earth processes will change in the future, along with climate changes.

“In return, we understand how the climate and the earth’s surface interact, and we can better predict how the earth will respond to climate change,” Rudolph adds. 

Society to play its part in climate change

In the long run, we as the public should play our part in readying society for the effects of climate change. 

Rudolph says society can play a positive role in terms of climate change by educating themselves with unbiased, scientifically sound information on the true state of climate change and by responding within their own spheres of influence.

“Don’t leave everything up to politicians and policy. As the public, you can start to make progress by assessing the effects that climate change may have on your industry, business or society, and strategise on how to adapt your processes to deal with these changes.”

“Be responsible with our natural resources, reduce your waste, support local businesses that are sustainable, and volunteer at a local environmental protection/clean-up organisation. All the small efforts will eventually add up to substantial change,” she says. 

News Archive

Water erosion research help determine future of dams
2017-03-07

Description: Dr Jay le Roux Tags: Dr Jay le Roux

Dr Jay le Roux, one of 31 new NRF-rated
researchers at the University of the Free State,
aims for a higher rating from the NRF.
Photo: Rulanzen Martin

“This rating will motivate me to do more research, to improve outcomes, and to aim for a higher C-rating.” This was the response of Dr Jay le Roux, who was recently graded as an Y2-rated researcher by the National Research Foundation (NRF).

Dr Le Roux, senior lecturer in the Department of Geography at the University of the Free State (UFS), is one of 31 new NRF-rated researchers at the UFS. “This grading will make it possible to focus on more specific research during field research and to come in contact with other experts. Researchers are graded on their potential or contribution in their respective fields,” he said.

Research assess different techniques
His research on water erosion risk in South Africa (SA) is a methodological framework with three hierarchal levels presented. It was done in collaboration with the University of Pretoria (UP), Water Research Commission, Department of Agriculture, Forestry and Fisheries, and recently Rhodes University and the Department of Environmental Affairs. Dr Le Roux was registered for 5 years at UP, while working full-time for the Agricultural Research Council – Institute for Soil, Climate and Water (ARC-ISCW).

Water erosion risk assessment in South Africa: towards a methodological framework
, illustrates the most feasible erosion assessment techniques and input datasets that can be used to map water erosion features in SA. It also emphasises the simplicity required for application at a regional scale, with proper incorporation of the most important erosion-causal factors.

The main feature that distinguishes this approach from previous studies is the fact that this study interprets erosion features as individual sediment sources. Modelling the sediment yield contribution from gully erosion (also known as dongas) with emphasis on connectivity and sediment transport, can be considered as an important step towards the assessment of sediment produce at regional scale. 
 
Dams a pivotal element in river networks

Soil is an important, but limited natural resource in SA. Soil erosion not only involves loss of fertile topsoil and reduction of soil productivity, but is also coupled with serious off-site impacts related to increased mobilisation of sediment and delivery to rivers.

The siltation of dams is a big problem in SA, especially dams that are located in eroded catchment areas. Dr Le Roux recently developed a model to assess sediment yield contribution from gully erosion at a large catchment scale. “The Mzimvubu River Catchment is the only large river network in SA on record without a dam.” The flow and sediment yield in the catchment made it possible to estimate dam life expectancies on between 43 and 55 years for future dams in the area.
 
Future model to assess soil erosion
“I plan to finalise a soil erosion model that will determine the sediment yield of gully erosion on a bigger scale.” It will be useful to determine the lifespan of dams where gully erosion is a big problem. Two of his PhD students are currently working on project proposals to assess soil erosion with the help of remote sensing techniques.

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