Floods caused by climate change could wreck Kruger National Park‚ scientists warn

17 May 2018 - 09:50 By Dave Chambers
Flooding in the Kruger National Park on 9 March 2016.
Flooding in the Kruger National Park on 9 March 2016.
Image: South African National Parks

Climate change could cause a catastrophic loss of species in the Kruger National Park.

That is the warning from scientists whose work in the park as shown that some of the world's most sensitive and valuable river habitats are being destroyed by increasingly frequent extreme floods driven by cyclones.

Airborne laser surveys that measured the impacts on Kruger’s rivers of extreme floods in 2000 and 2012 found they needed more than a decade to recover.

David Milan‚ from the University of Hull in the UK‚ said the 2012 flood removed almost 1.25 million tons of sediment from the bed of the Sabie River.

“We also found that patches of mature riparian forest that survived larger floods in 2000 were removed by the 2012 floods‚” he said.

“There is a suggestion that the frequency of large flood events is increasing due to climate change‚ and our analysis of river channel morphology for a 50km length of the Sabie river shows us that these rivers need timespans longer than a decade to recover.”

High-resolution data from the laser surveys was used to create accurate digital models of river beds after the 2012 flood‚ enabling scientists funded by the Natural Environmental Research Council in the UK to map detailed patterns of erosion and deposition.

Like two-thirds of Africa‚ Kruger is a dryland area‚ making it particularly vulnerable to climate change‚ and some climate model predictions predict more cyclones over South Africa.

“More frequent floods will continue to strip out sediment and vegetation from the river channel‚ leaving a more barren environment with less habitat value‚” said Milan.

“Continued progressive loss of habitat diversity will fundamentally‚ and for all intents and purposes irreversibly‚ alter our riverine landscapes and this will be accompanied by a catastrophic loss of species unable to adapt to the new environments.

“Conservationists need to work alongside geomorphologists to look at ways in which dryland river habitats can be best managed into the future.”

Writing in the Geological Society of America Bulletin‚ Milan said Kruger has global significance for its habitats and associated species‚ and the rivers flowing through the park provide essential ecosystem services‚ including water and habitat.