Deforestation has affected the water cycle in one of Zambia's largest charcoal-producing regions, forcing residents to adopt unsustainable farming practices in the wetlands, say experts.
Since the 1990s, several perennial streams in the Kaoma district of Western Province have become seasonal and some have even dried up, while the water level in the Luena River, which flows through the town of Kaoma, has dropped, say residents.
Morris Muchinda, director of the Zambia Meteorological Department, said there was a correlation between the streams drying up and charcoal production, which began in the district on a fairly large scale in the 1990s.
Zambia is one of the Food and Agriculture Organisation's top ten countries with the highest annual deforestation rates. Most of the trees are used as firewood or to produce charcoal.
Trees draw ground water up through their roots and release it into the atmosphere, so when forests are removed the region cannot hold as much water, which could lead to a drier climate, said Muchinda.
Deforestation also affects the carbon cycle warming up the atmosphere, and is responsible for 1.6 billion tonnes of carbon emissions every year, amounting to one-fifth of the global total.
According to the Indonesia-based Centre for International Forestry Research, this is more than the combined total contributed by the world's energy-intensive transport sectors. Some estimates put the contribution of deforestation to climate change at almost the same level as fossil fuel use in the United States.
Rainfall in Kaoma town has declined over the past three decades. Between 1960 and 1970 the town recorded an average rainfall of 945mm; from 1971 to 1980 this declined slightly to 943mm, before slumping to 839mm between 1981 and 1990. By 2000, the figure had fallen to 823mm.
|Judging by these trends, we are able to see that the rainfall pattern really got worse in the 1990s, and that's the time when Kaoma town started doing a lot of charcoal burning. It was a few years before the streams and tributaries started drying up|
"Judging by these trends, we are able to see that the rainfall pattern really got worse in the 1990s, and that's the time when Kaoma town started doing a lot of charcoal burning. It was a few years before the streams and tributaries started drying up," Muchinda said.
However, deforestation is not the only culprit, said Martin Mbewe, a project manager for the global environmental watchdog, World Wide Fund for Nature [WWF] in Zambia. "The practice of cultivating around spring water systems, and clearing riverine vegetation in general, disturbs the water-holding capacity of the river systems and predisposes them to drying."
Adapting with consequences
The district's residents, who depend on farming and fishing as their main source of livelihood, have been forced into coping with these changes. Kaoma is a large maize-producing district in the province.
Farmers have resorted to growing crops in the mainly seasonal wetlands, which are usually created by semi-perennial streams, said Mbewe. Communities grow winter maize or set up barricades of waterlogged grass across shallow streams, making temporary ponds in which fish become trapped.
Mcleana Tolosi, a housewife in the area, told IRIN: "Whenever we see a drying stream, we go and make barricades using some grass, then after a day we go as a village to stamp all over the waters so that the fish begins to surface up.
"My children come with me - they forget about going to school sometimes - so that as a family we can catch more fish. They know that food comes before school ... we catch everything, small and big fish, even snails sometimes," Tolosi said.
There is growing concern over this unsustainable use of the wetlands, said the WWF's Mbewe. "The use of inappropriate fishing methods, such as chemicals and mosquito nets, which remove all types of fishes, deplete the fish resources in the wetlands," he said. The continuous use of the same piece of land for agriculture also predisposes it to soil degradation."
Mubita Nyambe, a subsistence farmer who cultivates a stretch of wetland on the outskirts of Kaoma town, told IRIN: "We grow crops like maize, beans, cabbage, and the harvests are quite good because the soil is fertile; it is able to support crops. But after one or two seasons it also becomes infertile, sometimes it becomes completely dry, then we have to move to another area."
The development of sustainable aquaculture practices and inland agro-forestry systems that would help increase the fertility of the wetlands and enhance the water-holding capacity could help the farmers, Mbewe said.
Photo: Nebert Mulenga/IRIN
|Temporary ponds to trap fish|
In 2007, the Zambian government launched the National Adaptation Plan of Action (NAPA), which outlines the measures required to cope with climate change in all critical sectors of the economy, such as health, agriculture and water.
Michael Kaingu, Zambia's minister of tourism and environment, noted that "At the moment, each ministry is doing some ad hoc activities in line with how climate change has impacted on their sectors; for example, in agriculture they are encouraging people to practice conservation farming."
In the meantime, the residents of Kaoma keep moving from one stretch of a wetland to another. Chief Mwene Kahare, a traditional leader, commented: "The quality of life has reduced very much for my people. Water is drying up everywhere, and in some cases fish is just being eaten up as the rivers dry up."