By Marlene McKay
Kormorant 12 April to 18 April 2012
The word desertification, no doubt, conjures up images of the Sahara, mirages and a sun scorched Indiana Jones look-alike crawling across hot sand in search of a sip of water. In reality, desertification occurs right here, in our backyard and, shockingly, because of our own actions.
Consider this: clearing natural vegetation to obtain a better panoramic view from your patio or air-conditioned living room, over the river, valley, seaside or mountain is a normal practice. This amounts to desertification, as does planting a lone tree amidst a sea of paving.
What has desertification to do with the polluted Hartbeespoort Dam?
“Everything” says Petrus Venter, the program leader of the Hartbeespoort Dam Integrated Biological Remediation Programme (Metsi a me – My water)
“The Hartbeespoort Dam is a symptom of our modern lifestyles. And,” he continues, “since the mid 70’s the dam has slowly turned into a water desert because of the aquatic diversity.”
Desertification is classified as the development of desert-like conditions in regions where human disturbance has taken place and refers to deforestation, overgrazing and poorly managed agriculture.
Mining, as well as urban and industrial development, similarly affect the natural biodiversity of the land. In short, the destruction of the earth’s natural resources by human activities is by far the greatest cause of desertification today.
Even small-scale activities such as replacing vegetation with paving influence the natural water cycle. These ever-expanding hard surfaces and infrastructure add to the reduction of groundwater, drying up of wetlands and disappearance of flowing rivers.
Water quickly runs off these hard surfaces, leaving dried out land behind.Veld fires have the same effect in naturally vegetated areas. “These factors reduce the sponge effect prevalent in vegetated land and this inability to retain water and nutrients degrades the soil.
Water runs off land without vegetation at a much faster rate and erodes minerals and nutrients,” said Venter.
Land alterations modify local and global climates. It is little wonder then that the planet is busy dying.
Desertification, and the accompanying loss of water from land, is the number one cause of global warming and climate change.In non-technical language: the earth is no longer kept cool by vegetation (ground covered by plants acts as the skin of the earth, retaining moisture). The remaining sand and rock responds like an oven heating the once cooler landscape. Water sources evaporate and the planet heats up.
Taking measures to counteract deserts will not only create a cooler climate, but will also save water.
“A good place to start is to compost all your organic material (kitchen and garden waste) and to work it back into your soil” said Petrus Venter. “Re-vegetate every square inch of land you can, even if this means replacing paving, and re-use your urine and grey water (nutrients). You will be amazed at how much bigger and healthier your plants will grow.”