Our Burning Planet

SEA CHANGE

As climate change bites, South Africa’s ports need to adapt and evolve — CSIR

As climate change bites, South Africa’s ports need to adapt and evolve — CSIR
The CSIR’s Coastal and Hydraulics Laboratory in Stellenbosch can measure wave amplitudes, direction and force as well as propagation and agitation; vessel motions and response; mooring forces; wave run-up and overtopping; slope and breakwater stability; and force and pressure measurements. (Photo: Kristin Engel)

The long-term sustainability of South Africa’s ports is critical, especially in the face of climate change and rising sea levels. And important work is under way at the Coastal and Hydraulics Laboratory in Stellenbosch, the largest facility of its kind in the southern hemisphere.

Serving as the key points of exit and entry for goods and commodities, ports across South Africa play a crucial role in the economy. But congestion, delays, labour disputes, infrastructure constraints and the growing need for sustainable upgrades continue to hamper operations.

In a bid to address these issues, the Council for Scientific and Industrial Research (CSIR) is assisting the maritime sector to operate safe and efficient ports for the future at its Coastal and Hydraulics Laboratory in Stellenbosch, the largest facility in the southern hemisphere.

The team collects data for decision-making by port authorities, conducts physical modelling to optimise marine structures, and undertakes numerical modelling for port layout and ship simulation. 

Researchers also undertake studies to contribute to environmentally sustainable ports and guide port expansions and port development.

CSIR engineers and scientists have built small-scale versions of planned coastal infrastructure and their surrounding areas. The coastal processes and wave conditions are then simulated to test the performance of the planned port infrastructure and the unintended impact such structures may have on the surrounding coastline and coastal processes. 

Ports can no longer be what they used to be 50 years ago… we’re moving beyond fifth-generation ports, where ports need to – and are held accountable to – look after wider ecosystem services, not only in areas where they have a footprint but also up and down the coast.

The 11,000-square-metre hydraulics laboratory comprises various wave flumes and wave basins for both 2D and 3D tests to provide decision-makers with access to specialised infrastructure to test marine structures and port design.

CSIR senior researcher Carl Welitz says: “The big thing we are trying to do is replicate the environment and the structure, put them all together and almost simulate storm-like and overload conditions to simulate almost worst-case scenarios that we might find ourselves in.”

ports CSIR

The CSIR’s Coastal and Hydraulics Laboratory in Stellenbosch. (Photo: Kristin Engel)

The CSIR’s Coastal and Hydraulics Laboratory in Stellenbosch conducts physical modelling to optimise marine structures, and undertakes numerical modelling for port layout and ship simulation. (Photo: Kristin Engel)

CSIR engineer Lukhanyo Somlota specialises in marine and coastal engineering research, focusing on optimising international and national port developments through 2D and 3D physical modelling. 

Somlota explained that in 2D and 3D physical modelling of ports and harbours, they take real-life scenarios of ports or harbours along the coastline experiencing severe storm events which are simulated in basins and flumes, but on a much smaller scale, to see whether the design of the engineer would stand in future.

“In the 2D hydraulic flume, we fill it up with water and you put a trunk of breakwaters, just a section of the breakwater, in it and simulate waves on it to see how the slope of the structure will behave – whether it will experience overtopping, or if it’s stable. We analyse to see how stable it is and how it will behave in reality.

“Usually, the type of projects that we do get are new designs, or there could also be an existing breakwater where they rehabilitate it and retrofit it to that design,” she said.

Ports still do hold a natural ecological value that needs to be considered in development and operation.

Steven Weerts, CSIR senior scientist and research group leader for the Coastal Systems and Earth Observation research group, said: 

“Ports can no longer be what they used to be 50 years ago… we’re moving beyond fifth-generation ports, where ports need to – and are held accountable to – look after wider ecosystem services, not only in areas where they have a footprint but also up and down the coast.”

Weerts told Daily Maverick that the work they did as a research group focused specifically on the environmental side. 

A lot of the research was done with partners like Transnet to try to ensure that ports were managed, developed and operated sustainably. Also taken into account are wider ecosystem services and the benefits that people along the coast derive from ports. 

ports CSIR wave flume

A wave flume for 2D modelling at the CSIR’s Coastal and Hydraulics Laboratory in Stellenbosch, which uses a single paddle wave maker that is capable of producing both regular and irregular wave shapes. (Photo: Kristin Engel)

“Ports still do hold a natural ecological value that needs to be considered in development and operation. On the pollution side of things, we do pollution monitoring in all of South Africa’s main ports continually, and this work is for Transnet. They are concerned about pollution levels, and that information is important. 

“What we’re learning from it is where the pollution hotspots are in the ports… that in itself, and the types of pollution that are occurring, gives us some insight into the sources of that pollution,” he said.

Weerts said pollution levels were not always related to port operations or activities. Operations do have the potential to result in pollution, but quite often in ports with catchment inflows, especially where that catchment is strongly urban, pollution comes from those sources. 

In Durban, for example, the team was increasingly starting to see microbiological pollution as well as other contaminants. 

South Africa is a signatory to the London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter and is obligated to make sure that operations are conducted in a sustainable manner.

In the case of some of our older ports like Durban, Cape Town, Port Elizabeth and East London, the ports are constrained in their ability to grow around the cities, so they can’t really expand.

Weerts said one component of this is that South Africa must make informed decisions about how the country disposes of sediment that is dredged out of ports. 

“If that sediment is too contaminated, the implications are that we shouldn’t be disposing of it in the open sea, which is traditionally what we have done.

Breakwater armour units at the CSIR’s Coastal and Hydraulics Laboratory in Stellenbosch. These small-scale versions of large quarried stones or specially shaped concrete blocks are used as primary protection against wave action. (Photo: Kristin Engel)

“A lot of the work we do is trying to ascertain how polluted sediments are and whether or not they can be disposed of safely at sea in open water disposal sites or not. That’s a space that’s also changing,” Weerts said.

Traditionally, South Africa, together with other countries, has disposed of dredge sediments at sea, but now dredgers are being asked to consider alternatives.

“There’s a conflicting need for development. Ships are getting bigger, ports need to have wider and deeper channels, and we want to grow our imports and export facilities, which inevitably is going to mean developments and expansions.

“In the case of some of our older ports like Durban, Cape Town, Port Elizabeth and East London, the ports are constrained in their ability to grow around the cities, so they can’t really expand,” Weerts said. 

In a lot of cases, Weerts said, ports were starting to move down deeper, but also inwards and outwards – which had implications as ports don’t have a vested interest in further developing areas they’ve already developed. Increasingly, they’re going to have to look at the remaining natural areas they have. 

“This puts them in conflict from an environmental and ecological perspective. We need to look after wider ecosystem benefits… this is something that needs to be resolved,” Weerts said.

Climate change impacts on ports

Weerts told Daily Maverick that “in terms of climate change, from an infrastructure point of view, it is a real threat. We’ve seen increased storms up and down the coast… we’ve seen the impacts of climate change on ports and port operations.

“Those (impacts) are going to become increasingly more common and more severe. We’re going to have to develop [new] infrastructure, increase our maintenance of infrastructure and improve existing infrastructure, to deal with that. This again provides an opportunity where we are renewing… it involves ecological inputs into our new engineering designs.”

In new port developments, CSIR teams said they have to start implementing bio tools and ecological advancement methods, and while more difficult, they also need to think about ways to retrofit old infrastructure technologies. 

We can have all these beautiful designs, but if the leadership and the maintenance are not effectively done, everything falls through the cracks.

“Climate change impacts on ports are going to be the same as the climate change impacts outside of ports. Our animals have to learn to deal with slightly increased temperatures, sea level rise, etc,” Weerts said.

Not only do designs and modelling bolstering South Africa’s ports need to protect against sea level rise, increased storms and increased flooding, but also soil erosion – Weerts said there is a history of soil erosion up and down the South African coast. 

A 3D Breakwater Optimisation model at the CSIR’s Coastal and Hydraulics Laboratory in Stellenbosch. (Photo: Kristin Engel)

“South Africa is not alone, it’s happening all across the world where shorelines are eroding and retreating to the extent that a lot of our infrastructure is now threatened by sea level rise, and the relationship between that and ports is that ports often have significant impacts on natural sediment dynamics because ports need breakwaters.

“Breakwaters disturb natural sediment movement up and down the coast. So those erosion impacts are often exacerbated in places where ports are. In all of the ports where that is an issue in South Africa, there are engineering interventions, there are sand bypass systems in place where sediment is either pumped or dredged from downstream and taken upstream of the breakwater to try to replenish the coast on the other side of the port.”

Weerts said South Africa was also losing sediments naturally, not necessarily because of port development, but because of changes in river courses, dams and sand mining. 

What is lacking?

Recent events demonstrate that South Africa is struggling with failing infrastructure, on top of congestion, delays, labour disputes and the growing need for upgrades. But Somlota said their teams, along with Transnet, the CSIR and other stakeholders, were working hard to make sure that SA was in a better position in the event of severe storms. 

Somlota said that better management and maintenance were crucial: “We can have all these beautiful designs, but if the leadership and the maintenance are not effectively done, everything falls through the cracks.

Read more in Daily Maverick: Our Burning Planet

“I’ve recently worked on a strategic programme that is making the integration of our transport logistics work better to be more efficient. We see who the key stakeholders are, what the challenges are, why these issues are being faced… If we have the solution and all these tools, then why are they not being implemented? Where is it failing?

“We are working closely with the port in Cape Town because of our location. There are quite a lot of issues when it comes to the functionality and the operation there. We have a big issue here specifically with wind, and our infrastructure is not necessarily able to handle what’s coming or what has been happening,” she said.

Somlota said the solutions were there, but because of the current state of South Africa, they were difficult to implement. DM

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Comments - Please in order to comment.

  • Allrite Jack says:

    Where exactly are you seeing evidence of sea water rise? There are lots of photos arround showing sea level in different places the same as it was 30 years ago and such. Environmental officials warned 30 years ago the Maldives could be completely covered by water due to global warming-induced sea level rise.

    That didn’t happen. The Indian Ocean did not swallow the Maldives island chain as predicted by government officials in the 1980s. Its the same story everywhere, except South Africa? Where’s the evidence?

  • Allrite Jack says:

    From Burning Planet: Warmer water and more carbon dioxide are sending phytoplankton into overdrive – study
    Reality strikes: The key to dissolving carbon dioxide is temperature. Cold water is better at dissolving and absorbing gasses like CO2 compared to warmer water, which is why a large amount of it gets dissolved in the ocean’s chilliest waters, according to the report. When that heavy water sinks to the deep sea, large portions of that CO2 can be stored for a long time.

    But as the ocean continues to warm like the rest of the planet, its waters are projected to become less efficient at taking in carbon dioxide, and can even release it back into the atmosphere more rapidly.

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