Latest News Archive

Please select Category, Year, and then Month to display items
Previous Archive
12 October 2020 | Story Leonie Bolleurs | Photo Supplied
Adriaan van der Walt
Although several international studies have used temperature metrics to statistically classify their seasonal divisions, a study in which Adriaan van der Walt was involved, would be the first known publication in a South African context using temperature as classification metric.

Gone are the days when we as South Africans would experience a three-month spring season, easing into summer, and then cooling off for three months before we hit winter.

Adriaan van der Walt, Lecturer in the Department of Geography at the University of the Free State (UFS), focuses his research on biometeorology (a specialist discipline exploring the role and climate change in physical and human environments) as well as climatology and geographic information systems.

He recently published an article: ‘Statistical classification of South African seasonal divisions on the basis of daily temperature data’ in the South African Journal of Science.

In this study, which Van der Walt undertook with Jennifer Fitchett, a colleague from the University of the Witwatersrand, data on daily maximum and minimum temperatures was collected from 35 meteorological stations of the South African Weather Service, covering the period between 1980 and 2015.

They went to great lengths to ensure that they had a complete set of data before presenting it to demonstrate seasonal brackets.

First for South Africa

Their statistical seasonal brackets indicate that South Africans now experience longer summers (from October to March), autumn in April and May, winter from June to August, and spring in September.

Although considerable work has been done using rainfall to determine seasonality in Southern Africa, Van der Walt believes that these methods did not work well as there are too many inconsistencies in this approach, as identified by Roffe et al. (2019, South African Geographical Journal). To make matters more complicated – as a semi-arid region, and with desert conditions along the west coast – some regions do not have enough rainfall to use as a classifier.

Temperature, on the other hand, worked well in this study. “Temperature, by contrast, is a continuous variable, and in Southern Africa has sufficient seasonal variation to allow for successful classification,” says Van der Walt.

He continues: “Although several international studies used temperature metrics to statistically classify their seasonal divisions, this study would be the first known publication in a South African context using temperature as classification metric.”

Van der Walt says what we understand as seasons largely relates to phenology – the appearance of blossoms in spring, the colouration and fall of leaves in autumn, and the migration of birds as a few examples. “These phenological shifts are more sensitive to temperature than other climatic variables.”

Seasonal brackets

According to Van der Walt, they believe that a clearly defined and communicated method should be used in defining seasons, rather than just assigning months to seasons.

“One of the most important arguments of our work is that one needs to critically consider breaks in seasons, rather than arbitrarily placing months into seasons, and so we welcome any alternate approaches,” he says.

A number of sectors apply the temperature-based division to their benefit. “For example, in the tourism sector it is becoming increasingly important to align advertising with the season most climatically suitable for tourism,” says Van der Walt.

Temperature-based division is also used to develop adaptive strategies to monitor seasonal changes in temperature under climate change. However, Van der Walt points out that each sector will have its own way of defining seasons. “Seasonal boundaries should nevertheless be clearly communicated with the logic behind them,” he says.

News Archive

Fun and camaraderie key to Vishuis rugby success
2017-09-27

Description: TEDxUFS   Tags: TEDxUFS

The forwards of Vishuis laid a strong foundation in
the K1 rugby final against Kagiso. This helped them
to secure a win of 38-16.
Photo: Marelize van Niekerk

They have not only been dominating the residence rugby scene at the University of the Free State over the past few years, but also nationally. Although they might experience added pressure as favourites, a key ingredient to Vishuis’ success story is their enjoyment of the game and their camaraderie.

According to Henco Posthumus, the Vishuis captain, they realise that it still remains residence rugby. “The guys pitch up at practice because they want to play, not because somebody begged them to.”

Comfortable triumph in final

Vishuis claimed their fifth Varsity Cup Koshuis title earlier this year, and will defend their national title after being crowned Kovsie residence champions on 8 September 2017. They beat Kagiso comfortably 38-16 in the K1 final, after leading by 31-9 at half-time.

Posthumus says the fun element is often forgotten, but not at Vishuis. He says it is not just about the first team either. “Almost every house member, no matter if he studies medicine or if he hasn’t played rugby before, is playing a bit of rugby on a Friday evening. That is also why we, as a fairly small residence, can field five teams.”

More than just a game

Although their proud record serves as motivation, it is about more than just rugby. “The guys grow together in different ways. It is an honour to see how they grow during a season, also spiritually.”

They have been lucky not to suffer many serious injuries over a number of seasons, Posthumus says. “We are privileged to have 110 years of history behind our residence, and people from within and outside buy into who we are.”

“Our (new) coach, Zane Botha, is also a valuable acquisition. He has taken our rugby to the next level.”

We use cookies to make interactions with our websites and services easy and meaningful. To better understand how they are used, read more about the UFS cookie policy. By continuing to use this site you are giving us your consent to do this.

Accept