byPiet-Louis Grundling
Southern Africa is at present experiencing one of the worst droughts in 40 years. Some areas, such as Pretoria in the interior of South Africa have received less than 20 % of its mean annual summer rainfall. The region is in general a dry area with rainfall varying from 1200 – 1500 mm per annum in the east to less than 200 mm per annum in the west.
The drought has resulted in huge pressures on already water stressed catchments and associated mires. Especially in areas where groundwater resources are exploited peatlands are in peril. The karst peatlands in the western part of South Africa (refer to article in IMCG Newsletter issue 2001/2, June 2001) are hit particularly hard. One of these peatlands, Bodibe, is currently one fire. The area is located in the midst of a rural community and the inhabitants are suffering from a overdose of acrid peat fire smoke, a fire hazard, and a lack of grazing and water of livestock. The fire has lead to the loss of at least two cattle and one man has sustained severe burns when trapped in the burning peat. Deep desiccation fissures along which the fire spreads also poses a health and safety risk.
Peat fires are part of the eco-system dynamics of the Okavango Delta in Botswana further towards the northwest. Ash layers within the peatland indicate that also in this part of the country fire is not an isolated incident. The peat fire was probably started when the peatland vegetation was deliberately burned to stimulate new growth for grazing.
The Working for Wetlands Programme has been requested by the government of the North West province to render support. The peat fire will be isolated by the digging of a trench after which a cut-off wall will be constructed within the peat to drown the fire with the remaining water within the peatland. Care will be taken to allow water to migrate downstream to maintain moisture levels in the wetland downstream of the peatfire.
Another peat fire is raging in the central part at the Rietvlei Nature Reserve near Pretoria. This is also a karst peatland and is one of sites that will be visited during the 2004 IMCG congress in Southern Africa (refer to 2nd Circular in IMCG Newsletter issue 2003/3, October 2003). The peat fire occurred in an area that has been on fire before due to a lowering in regional groundwater resources. This fire was a result of arson that originated outside the nature reserve. The fire is currently under control. A cut-off trench was dug around it and a feeder channel was dug by Working for Wetlands from the main channel to rewet this part of the wetland. Half of the water in this channel consists of controlled discharge from a sewage treatment plant up-stream of the peatland.
Two other peat fires are burning in the higher lying Steenkamsberg Plateau in the eastern part of the country. One is located in the Lakenvlei mire, which is also one of the sites that will be visited during the 2004 IMCG congress. This peatfire was caused by a run-away veld (grassland) fire. The mire is in a good condition and the fire did not burn very deeply into the substrate.
The other peat fire on this plateau occurred in an area that is afforested with exotic Pinus and Eucalyptus plantations. These plantations have a dramatic negative impact on regional watertables. The result is that peatlands dry out and it is ironic that it are usually management fires that result in the combustion of degraded peatlands within these plantations. Severe peat fires occur from time to time on the eastern seabord of South Africa where extensive plantations are found.
These fires do not only poses a health and safety risk to man and animal, result in the destruction of peatlands, but also pose an environmental disaster with the release of carbon gases into the atmosphere. More than anything else it is a reflection of a changing environment, not only on a global scale, but also on a local level – a monument of our failures as custodians of our environment.