Rivers

Kwando River

April 27, 2012, 12:03 pm
Content Cover Image

Aerial photo of the Kwando Linyanti Swamp between Botswana and the Caprivi Strip. Source: C.Michael Hogan

The Kwando River, rising on the central Angolan plateau, is a significant tributary of the Zambezi River.


Source: Adapted from U.S.Geological Survey data.

After leaving Angola, the Kwando flows into an eastern panhandle of Namibia known as the Caprivi Strip. Then the Kwando, often spelled Cuando, forms an element of the border between northern Botswana and the Caprivi Strip; moreover, that border portion of the river is sometimes termed the Linyanti Swamp.

The Kwando course flows through miombo, baikiaea and mopane woodlands, beginning with steeper gradients descending from the Angolan plateau to the meanders of the Linyanti Marshes, lined with extensive papyrus beds.

Geologic history

Much like the geologic history of the trapped Okavango River, the Kwando origins indicate an early pattern of siltation, especially in the locale of the Linyanti Marshes, causing an elaborate braided swampy area that is apparent today. Additionally, there is evidence of an ancient river channel called the Magwegqana that split much earler from the Okavango, and leading to the Linyanti region near the present Zibadianja Lagoon.

Hydrology and water quality

caption Low lying topography along the middle reaches of the Kwando River. @ C.Michael Hogan Ion concentrations jgenerally in the rapid flowing river mainstem tends to be low in ionic content; however, swampy areas often contain higher concentrations of nitrate and other ionic components. Correspondingly, planktonic content is only appreciable at these slackwater portions of the river, notably in the Linyanti Swamp. The Kwando waters generally exhibit a lower pH level than the neighboring Okavango River, but have a slightly higher sulfate concentration.

Aquatic biota

The largest native demersal fish species in the Kwando is the 117 centimeter (cm) long tiger fish (Hydrocynus vittatus). Other large demersal native species are the 73 cm blunt-toothed African catfish (Clarias ngamensis), the 70 cm Kafue pike (Hepsetus odoe), and the 50 cm western bottlenose mormyrid (Mormyrus lacerda} . Each of these demersal vertebrate species are assigned a high trophic level (in the vicinity of level four).

The 170 cm long north African catfish (Clarias gariepinus) is the largest benthopelagic fish species in the Kwando River. The 61 cm three spotted tilapia (Oreochromis andersonii) is another large benthopelagic species occurring in the Kwando waters. The 15 cm long benthopelagic thicklipped happy (Thoracochromis albolabris) is the sole endemic fish recorded in this river basin.

Many mammalian species utilize the waters of the Kwando, not only for drinking but for bathing and partial or full immersion, notably including the endangered African painted hunting dogs and hippopotami.

Terrestrial ecoregions

 

1. Angolan miombo woodlands

2. Zambezian Baikiaea woodlands

3. Zambezian Flooded grasslands

4. Zambezian and mopane woodlands

In the headwaters reaches the Angolan miombo woodlands dominate native land cover. The more widespread large tree species in the Angolan miombo ecoregion are Brachystegia spiciformis, Julbernardia paniculata, and Copaifera baumiana, while Brachystegia floribunda, B. boehmii, B. gossweilerii, B. wangermeeana, B. longifolia, B. bakerana, Guibourtea coleosperma, and Isoberlinia angolensis are locally dominant. The grass layer is up to two meters high and several species of Loudetia, Hyparrhenia, Tristachya, and Monocymbium ceresiiforme predominate. Most of the miombo tree and shrub species shed their leaves in the late dry season, and the miombo vegetation is bare for a short time, usually for fewer than three months.


Source: World Wildlife Fund

The Zambezian and mopane woodlands ecoregion occupies much of the flanking area of the Kwando River in its lower reaches. Much of the northeastern potions of theis ecoregion contain White’s north Zambezian undifferentiated woodlands and wooded grasslands. Along the Kwando, drier riparian woodlands grow on alluvium with large trees frequently exceeding 20 meters, and plant communities of chiefly secondary woodland grow on fertile, well-drained, and slightly high pH soils at elevations intermediate to the river valleys and uplands. This floristically diverse community is distinguished by a paucity of dominant species representative of mopane woodland types, as well as the various miombo communities. Characteristic woody plants present are Acacia spp., Albizia spp., Combretum spp., Adansonia digitata, Diospyros mespiliformes, Ficus sycomorus, Kigelia africana, Lonchocarpus capassa, Trichilia emetica, Xanthocercis zambesiaca, and Xeroderris stuhlmannii.

Farther upriver along the Kwando are the Zambezian Baikiaea woodlands. There is considerable floristic spatial variation in Baikiaea vegetation within the ecoregion. Nearly all the woody plant species are deciduous, but there is major variation in this leaf loss from year to year. Baikiaea plurijuga is the dominant tree species typifying the ecoregion, slash-and-burn agricultural practises have destroyed habitat in many areas and boundaris with surrounding woodlands and savannas are often difficult to discern. In well-developed Baikiaea communities, species of Brachystegia and Julbernardia and Colophospermum mopane (species typical of miombo and mopane woodlands) are totally absent. Baikiaea plurijuga is the sole dominant, forming a dense, dry, semi-deciduous forest with trees up to 20 meters in height.

caption Endangered African painted hunting dogs in the Linyanti Marshes. @ C.Michael Hogan In thse Zambezian Baikiaea woodlands, there is a dense and shrubby lower story of Combretum engleri, Pteleopsis anisoptera, Pterocarpus antunesii, Guibourtea coleosperma, Dialium engleranum, Strychnos spp., Parinari curatellifolia, Ochna pulchra, Baphia massaiensis subsp. obovata, Diplorhynchus condylocarpon, Terminalia brachystemma, Burkea africana, Copaifera baumiana and Bauhinia petersiana serpae. Lianas and climbers are also common in the understory, including Combretum elaeagnoides, C. celastroides, Dalbergia martinii, Acacia ataxacantha, Friesodielsia obovata, and Strophanthus kombe. Smaller shrubs are scattered beneath the thicket. The herb layer is only conspicuous during the rainy season. Grasses vary from sparse to dense and include Leptochloa uniflora, Oplismenus hirtellus, Panicum heterostachyum, and Setaria homonyma. Other conspicuous herbs are Aneilema johnstonii and Kaempferia rosa. Epiphytes and mosses are virtually absent.

 

caption Biomes along the middle and lower Kwando/Chobe. Source: Barbara Paterson

Prehistory and history

caption Traditional style fishing boats on the middle Kwando at the Botswana/Caprivi border, supporting ecotourists. @ C.Michael Hogant Research on the prehistory of the Kwando Basin lags detail found in some of the other Southern African sub-regions. This outcome derives from three chief reasons: (a) this interior region was not among the early explored parts of Southern Africa when explorers first visited the general area in the nineteenth century; (b) meandering and successive flooding on the Linyanti portion may have inundated and over-silted considerable remains of early human settlement; and (c) Angolan conflicts in the latter 20th century driven by large numbers of armed Soviet funded Cuban mercenaries have deterred modern exploration.

Nevertheless, the basin as a whole is northward of remarkable evidence of Early Stone Age settlements in the Makgadikgadi Pans, where not only Homo sapiens, but Homo habilis has left thousands of artefacts of primitive tools scattered aournd the desiccated beds of the ancient lake there.

Iron age fishing cultures have persisted into relatvely recent times in the Kwando Basin, with vestiges of these tribal cultures thriving today. Thus only a thin timeline separates traditional tribal fishing cultures in the basin, from the current times where there is a mixture of subsistence fishing alongside tribal support of ecotourism.

References

  • G.Cronberg, A.Gieske, E.Martins, J.Prince Nengu and I-M.Stenstrom. Hydrobiological Studies of the Okavango Delta and Kwando/Linyanti/Chobe River, Botswana. I. Surface Water Quality Analysis. Botswana Notes and Records, Vol.27
  • C. Michael Hogan. 2008. Makgadikgadi, The Megalithic Portal, ed. A. Burnham
  • Fishbase. 2011. Species in the Chobe River.
  • Chris McIntyre. 2010. Botswana: Okavango Delta, Chobe, Northern Kalahari. 512 pages.  google.ebook
  • World Wildlife Fund. 2002. Zambezian and mopane woodlands ecoregion
Glossary

Citation

Hogan, C. (2012). Kwando River. Retrieved from http://www.eoearth.org/view/article/51cbf3087896bb431f6ab982