Middies join Swiss professor on field-visit
Justin du Toit
MIDDELBURG — Students from Middelburg High School joined Klaus Kuhn and other researchers from Switzerland earlier this year for a field-visit to their research site near Compassberg to investigate cutting-edge research into how global warming is changing the Karoo. Researchers from University of Basil, headed by Klaus Kuhn have come to Middelburg to look for answers on how vegetation and veld are changing. They chose Middelburg because the veld in this area is delicately balanced between two very different vegetation types – grasslands to the east, and dry Karoo to the west.
Brigitte Kuhn uses drone technology to take high-resolution photographs of landscapes. She programs in a flight-path, fine-tunes the instructions, and off it goes, flying within a few seconds to a height of about fifty meters. Zigzagging across the sky, it takes the photos then, at the push of a button, lands itself back on the ground at her feet.
She explains that these are just vertical photos, and that the camera angles and photo locations can be adjusted to produce a Digital Elevation Model of the area, where the exact features of the landscape – slope, rocks, trees, gullies, and termite mounds – can be produced as a 3-D record of the precise terrain.
Nearby, on Alf and Brenda James’s farm, other researchers are investigating soil erosion. They simulate a heavy downpour onto eroded earth using water pumped from a drum through a specialised shower-headlooking nozzle. They take various careful measurements of how much water runs off, and how much seeps into the soil. Amazingly, on these hard, capped soils, almost all the water has just run off the surface – dig down a centimetre and the dry ground is revealed.
Klaus points out: “You think you’ve had a good rainfall, but how much of that water is in the soil? How much has just run off the top and been lost?”
This valuable research is ongoing – the researchers return each year, usually with a new group of students, to continue to build up their understanding of the Karoo, and what the future holds for it.