Cape Town's winds threaten fruit exports, scientists step in

Source: Wikimedia Commons

Cape Town’s notorious southeasterly wind, the Cape Doctor, is a seasonal phenomenon that sweeps down from Table Mountain and Devil’s Peak, often intensifying around the port. While these winds have long been part of the region’s climate, concerns are growing over their increasing intensity and frequency, which could pose greater challenges for trade and shipping logistics.

Disruptions to port operations

Extreme winds at the Port of Cape Town are becoming more frequent and intense, posing growing challenges for shipping and trade. "This is our concern, especially when demand for marine services in the port is increasing,” says Dr Neville Sweijd, the director of the Access programme.

When wind speeds exceed 80 km/h, port operations must shut down to prevent safety hazards, such as swinging containers and crane collapses. These disruptions have significant financial implications, particularly for fruit exporters, with the port losing an average of 1,200 operational hours per year due to extreme winds.

"Occasionally, fruit companies have to put their fruit on a truck and get it to Durban so that they can get it to their market on time,” says Sweijd.

"We provide them essentially with weather parameters that inform their port operations,” says CSIR engineer, Vuyo Ndayi, who specialises in ocean monitoring in ports. He says the CSIR’s wind anemometers and sensors provide wind speed, wind direction and wind gust data that allow for hourly and daily operational decision-making.

"We need to get a good handle on understanding the wind, how it will trend going forward, and what measures we can then put in place to try to reduce the effects on port operations," says Magenthran Ruthenavelu, technical director at TNPA.

Ruthenavelu adds that the research will inform potential changes or additions to the port layout and structures to divert wind away from the operational area of the terminals.

Impact on the fruit export industry

Zelde Kennedy, spokesperson for major fruit exporter Fruitways, says the data will also help exporters plan around anticipated wind delays. “It will have an impact on our cost, and I think it will be better for the whole industry,” she says.

Sweijd says extreme wind disruption of fruit exports is an example of how the negative impacts of climate variability and change manifest in day-to-day life.

“Climate change is not some phenomenon of the future and it's not something that happens on average – it impacts people at the weather scale, not just at the long-term climate scale. It impacts them with extreme weather events, not as an average,” he says.

“We’re seeing a trend in the extreme events that are happening more frequently and that are happening with longer duration. They are more intense with bigger magnitude,” says Sweijd.

For the windy Cape Town port, Ndayi says long-term predictions and climate modelling will try to answer the question of how the wind will change. “Is it going to become worse? Is it going to become better? Are we going to see it outside of the spring and summer months, and how is that going to affect how things are run in the port?”

The project is supported by the National Research Foundation and the Belmont Forum."

More information here.