Product Code Database
A dambo is a class of complex shallow wetlands in central, southern and eastern Africa, particularly in Zambia, Malawi and Zimbabwe. They are generally found in higher-rainfall flat plateau areas and have river-like branching forms which in themselves are not very large but combined add up to a large area. Dambos have been estimated to comprise 12.5% of the area of Zambia.Chidumayo, E.N.: "The utilisation status of dambos in southern Africa: a Zambian case study". In: Matiza, T. & Chabwela, H.N. (eds.) Wetlands conservation conference for southern Africa (pp. 105-108). International Union for Conservation of Nature and Natural Resources, Gland (1992). Similar African words include mbuga (commonly used in East Africa), matoro (Mashonaland), vlei (South Africa), fadama (Nigeria), and bolis (Sierra Leone); the French bas-fond and German Spültal have also been suggested as referring to similar grassy wetlands.Andrew S. Goudie, "The Geomorphology of the Seasonal Tropics" in William M. Adams, et al. (editors), The Physical geography of Africa (Oxford: University Press, 1996), p. 152
The name dambo is most frequently used for wetlands on flat plateaus which form the river source of streams. The definition for scientific purposes has been proposed as "seasonally waterlogged, predominantly grass covered, depressions bordering headwater drainage lines".Mackel, R. 1985. “Dambos and related landforms in Africa; an example for the ecological approach to tropical geomorphology”. Z. Geomorphol. N.F. Supplementband 52: 1–23.
A 1998 report of the Food and Agriculture Organization distinguishes between 'hydromorphic/Phreatic zone' dambos (associated with headwaters) and 'fluvial' dambos (associated with rivers), and also referred to five geomorphological types in Zambia's Luapula Province: upland, valley, hanging, sand dune and pan dambos. FAO: Wetland Characterization and Classification for Sustainable Agricultural Development 1998
There is a popular idea that dambos act like sponges to soak up the wet season rain which they release slowly into rivers during the dry season thus ensuring a year-round flow, but this is opposed by some research which suggests that in the middle to late dry season the water is actually released from .Von der Heyden, C.J. and New, M.G.: “The role of the dambo in the hydrology of a catchment and the river network downstream”. Hydrology and Earth Science, 7(3). 2003. Springs are seen in some dambos. Thus it may take a long time—perhaps several years—for water from a heavy rainy season to percolate through hills and emerge in a dambo, creating lagoons there or a flow in downstream rivers which cannot be explained by the previous year's rainfall. Dambos may be involved, for instance, in explaining puzzling variations in water level or flow in Lake Mweru Wantipa and Lake Chila in Mbala.
More recently, they have been used for fish farming and growing upland rice. Efforts to develop dambos agriculturally have been hampered by a lack of research on the hydrology and soils of dambos, which have proved to be variable and complex.
An example of a pan dambo can be seen at (102 km north-west of Mulobezi, Zambia). The water in the pan has dried out, and the grass has been burnt off giving the dark appearance at the centre of the dambo. To the east and west of the pan dambo a series of dambos can be seen along two river courses.
|
|
