Africa is an arid continent with the lowest river flow per unit area of any continental landmass. Most African countries outside of the rainforest zone receive little rain for most of the year. Seasonal wetlands, such as dambos therefore serve as important water sources, storing water during the wet season and making it accessible during the dry season. Furthermore, seasonal floodplains also provide food and biodiversity habitat to last from one wet period to the next.
Across the dry regions of Africa, including the Sahel, rivers bring the necessary water flowing from wet, upland areas that receive large parts of the continental precipitation. These flat, downstream dry areas flood annually, forming extensive floodplains that turn green and full of life.
For example, in the Inner Niger Delta in Mali the water flowing from the Guinean highlands flood an area the size of Belgium each year. These floodplains provide the 1.5 million people with fish and water for agriculture and household uses. The annually revived ecosystems of flood forest and marshes provide habitat to millions of waterbirds, many of which migrate all the way from Europe. We work with communities, governments and Niger River basin organisation to protect this precious water flow and maintain the annual flooding. Read more
Dambos are seasonally saturated wetlands common in the headwaters of rivers, found throughout the elevated plateaus of Central and Southern Africa. They are also called Banis, Matoro or Vleis (South Africa). Dambos constitute cover a potentially 135 million hectares of land area throughout the African continent (FAO, 1998). In Zimbabwe dambos cover an estimated 1.28 million hectares, (~3.6%), of the land area (Whitlow, 1985)
These dambos are important sources of water in these drought stricken countries. Rainwater infiltrates in the soil of adjacent hills and through underground streams flow into the dambos. Prior to European colonisation, the use of the water resources of dambos for the cultivation of crops was a long established traditional indigenous land-use practice. Traditional systems of dambo cultivation were based on ridge and furrow and basin-like structures to control drainage, runoff and soil erosion.
In recent times deforestation of the adjacent hills strongly diminished this infiltration and causes the water to run on the surface, thereby taking away top soil layers. This muddy water then flows into the dambo and fills it with sediment. Through our ‘Functional Landscape Approach’, we helped to reforest, plant grass and demarcate the upland, and balance the water use for agriculture around the dambos, thereby maintaining the important services that they provide. Watch the video