The Sua Pan or Sowa Pan is a large natural topographic depression within the Makgadikgadi region of Botswana. It is located near the village of Sowa, whose name means salt in the language of the San.[1][2] The Sua salt pan is one of three large pans within the Makgadikgadi, the other two being Nxai Pan and Nwetwe Pan.[3]
The Sua Pan was first described to the European world by David Livingstone, pursuant to his explorations in this region.[4] Significant archaeological recoveries have been made within the Nwetwe Pan, featuring Stone-Age tools from peoples who lived in this area[5] when a large year-round lake occupied the Sua and Nwetwe Pans.[6]
Currently, Sua Pan is a seasonal lake; it fills with water during the Summer rainy season and retains water until April or May.[8] Among the more successful wildlife conservation projects in Botswana was the community-initiated Nata Bird Sanctuary in the northeast of this area. It opened in 1993 and was awarded that year the "Tourism for Tomorrow Award" for the Southern Hemisphere.[9] It is supported by members of four nearby villages, who have helped make it a success.
One of the tributaries of the Sua Pan is the Mosetse River. The village of Mosetse is named for it and lies along the river.
Industry
Pans used for sodium carbonate mining
Sua Pan is also the site of sodium carbonate (soda ash) mining company Botash. The company is half owned by the Botswana government and produces over 300,000 tonnes of soda ash and 450,000 tonnes of salt per year.[10]
David Livingstone (1868) Missionary Travels and Researches in South Africa: Including a Sketch of Sixteen Years' Residence in the Interior of Africa, Harper Publishers.
↑ Burrough, Sallie L.; Thomas, David S.G.; Bailey, Richard M. (July 2009). "Mega-Lake in the Kalahari: A Late Pleistocene record of the Palaeolake Makgadikgadi system". Quaternary Science Reviews. 28 (15–16): 1392–1411. Bibcode:2009QSRv...28.1392B. doi:10.1016/j.quascirev.2009.02.007.
↑ Frank D.Eckardt; Robert G.Bryant; Graham McCulloch; Baruch Spiro; Warren W.Wood (2008). "The hydrochemistry of a semi-arid pan basin case study: Sua Pan, Makgadikgadi, Botswana". Applied Geochemistry. 23 (6): 1563–1580. Bibcode:2008ApGC...23.1563E. doi:10.1016/j.apgeochem.2007.12.033.
Natron is a naturally occurring mixture of sodium carbonate decahydrate (Na2CO3·10H2O, a kind of soda ash) and around 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate. Natron is white to colourless when pure, varying to gray or yellow with impurities. Natron deposits are sometimes found in saline lake beds which arose in arid environments. Throughout history natron has had many practical applications that continue today in the wide range of modern uses of its constituent mineral components.
Sodium carbonate, Na2CO3, (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions in water. Historically, it was extracted from the ashes of plants growing in sodium-rich soils. Because the ashes of these sodium-rich plants were noticeably different from ashes of wood (once used to produce potash), sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process.
Lake Makgadikgadi was a paleolake that existed in what is now the Kalahari Desert in Botswana from 2,000,000 years BP to 10,000 years BP. It may have once covered an area of from 80,000 to 275,000 km2 and was 30 m deep. The Okavango, Upper Zambezi, and Cuando rivers once all emptied into the lake. Its remains are seen in the Makgadikgadi salt pans, one of the largest salt pans in the world.
The Leblanc process was an early industrial process for making soda ash used throughout the 19th century, named after its inventor, Nicolas Leblanc. It involved two stages: making sodium sulfate from sodium chloride, followed by reacting the sodium sulfate with coal and calcium carbonate to make sodium carbonate. The process gradually became obsolete after the development of the Solvay process.
The Solvay process or ammonia-soda process is the major industrial process for the production of sodium carbonate (soda ash, Na2CO3). The ammonia-soda process was developed into its modern form by the Belgian chemist Ernest Solvay during the 1860s. The ingredients for this are readily available and inexpensive: salt brine (from inland sources or from the sea) and limestone (from quarries). The worldwide production of soda ash in 2005 was estimated at 42 million tonnes, which is more than six kilograms (13 lb) per year for each person on Earth. Solvay-based chemical plants now produce roughly three-quarters of this supply, with the remaining being mined from natural deposits. This method superseded the Leblanc process.
Sodium sulfate (also known as sodium sulphate or sulfate of soda) is the inorganic compound with formula Na2SO4 as well as several related hydrates. All forms are white solids that are highly soluble in water. With an annual production of 6 million tonnes, the decahydrate is a major commodity chemical product. It is mainly used as a filler in the manufacture of powdered home laundry detergents and in the Kraft process of paper pulping for making highly alkaline sulfides.
A salt lake or saline lake is a landlocked body of water that has a concentration of salts and other dissolved minerals significantly higher than most lakes. In some cases, salt lakes have a higher concentration of salt than sea water; such lakes can also be termed hypersaline lakes, and may also be pink lakes on account of their colour. An alkalic salt lake that has a high content of carbonate is sometimes termed a soda lake.
Barium carbonate is the inorganic compound with the formula BaCO3. Like most alkaline earth metal carbonates, it is a white salt that is poorly soluble in water. It occurs as the mineral known as witherite. In a commercial sense, it is one of the most important barium compounds.
Lake Magadi is the southernmost lake in the Kenyan Rift Valley, lying in a catchment of faulted volcanic rocks, north of Tanzania's Lake Natron. During the dry season, it is 80% covered by soda and is well known for its wading birds, including flamingos.
Caliche is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions, including in central and western Australia, in the Kalahari Desert, in the High Plains of the western United States, in the Sonoran Desert, Chihuahuan Desert and Mojave Desert of North America, and in eastern Saudi Arabia at Al-Hasa. Caliche is also known as calcrete or kankar. It belongs to the duricrusts. The term caliche is Spanish and is originally from the Latin calx, meaning lime.
Sowa is a town which lies in the Central District of Botswana, but constitutes a separate administrative district. The Sowa Township was established in 1991 by an act of Parliament, Statutory Instrument No.26 of 1991 and governed by Sowa Township Regulations, 1991 under the Township Act. The population was of 2,879 inhabitants, according to 2001 Census, and had grown to 3,598 according to the 2011 census.
The Makgadikgadi Pan, a salt pan situated in the middle of the dry savanna of north-eastern Botswana, is one of the largest salt flats in the world. The pan is all that remains of the formerly enormous Lake Makgadikgadi, which once covered an area larger than Switzerland, but dried up tens of thousands of years ago. Recent studies of human mitochondrial DNA suggest that modern Homo sapiens first began to evolve in this region some 200,000 years ago, when it was a vast, exceptionally fertile area of lakes, rivers, marshes, woodlands and grasslands especially favorable for habitation by evolving hominins and other mammals.
The Kalahari Basin, also known as the Kalahari Depression, Okavango Basin or the Makgadikgadi basin, is an endorheic basin and large lowland area covering approximately 725,293 km2 covering most of Botswana and Namibia, as well as parts of Angola, South Africa, Zambia, and Zimbabwe. The outstanding physical feature in the basin, and occupying the centre, is the large Kalahari Desert.
Alkali, or Alkaline, soils are clay soils with high pH, a poor soil structure and a low infiltration capacity. Often they have a hard calcareous layer at 0.5 to 1 metre depth. Alkali soils owe their unfavorable physico-chemical properties mainly to the dominating presence of sodium carbonate, which causes the soil to swell and difficult to clarify/settle. They derive their name from the alkali metal group of elements, to which sodium belongs, and which can induce basicity. Sometimes these soils are also referred to as alkaline sodic soils. Alkaline soils are basic, but not all basic soils are alkaline.
The Ntwetwe Pan is a large salt pan within the Makgadikgadi region of Botswana. The Ntwetwe is one of three large pans within the Makgadikgadi, the other two being Nxai Pan and Sua Pan. Ntwetwe Pan is now a seasonal lake with filling occurring in the rainy season. Ntwetwe was first described to the European world by David Livingstone, pursuant to his explorations in this region. Significant archaeological recoveries have occurred within the Nwetwe Pan, including Stone Age tools from people who lived in this area, in an earlier time of prehistory when a large year round lake occupied the Nwetwe Pan area within the Makgadikgadi.
The Nata River or Manzamnyama River is a natural watercourse in Southern Africa. It is an ephemeral river flowing in Zimbabwe and Botswana. It has a length of 330 km from its source to mouth, 210 km in Zimbabwe and 120 km in Botswana. Its total catchment area is 24,585 km2. The river originates in Sandown, a small farming town located on the Zimbabwean central watershed 50 km south west of Bulawayo and ends in the Makgadikgadi Pans in Botswana. There is no outlet from the salt pans which can be considered as the “dead sea” of the south. The upper reaches of the river are located in a commercial farming area where good environmental and farming practices have resulted in the river experiencing very little siltation/sedimentation. Impressive sedimentation starts occurring about 65 km along the river course marking the beginning of a 90 km stretch in Zimbabwe where the river passes through communal farming areas. It is on this stretch where the sand-abstraction potential of the river is realised and communities rely on the sand river water for domestic, farming and livestock purposes. Within the country of Botswana the Nata River is a source of water to the ephemeral wetlands of the Makgadikgadi Pans, where a number of species of limited distribution thrive. Specifically the Nata River discharges to Sua Pan, draining parts of eastern Botswana and southwestern Zimbabwe.
Sua Pan Airport or Sowa Airport is an airport 11 kilometres (6.8 mi) west of Sowa, a town in the Central District of Botswana.
American Natural Soda Ash Corporation (ANSAC) operates as the international distribution arm for three US manufacturers of natural soda ash produced from trona deposits in Green River, Wyoming, the trade name for sodium carbonate Na2CO3, is an essential raw material used in the manufacture of glass, detergents, and several sodium-based chemicals.
The Nata Bird Sanctuary, the only protected reserve in the northeastern periphery of Sowa Pan in Botswana, is a community-managed project, with assistance from the Nata Conservation Committee and national and international organizations. Founded in 1988, it opened for operations in 1993; it encompasses an area of 230 square kilometres (89 sq mi), with the objective of conservation of wildlife. The community project is managed by a Trust titled the "Kalahari Conservation Society", which has members drawn from the four villages of Nata, Sepako, Maposa and Manxotae in the vicinity of the sanctuary.
Lekhubu Island is a rock outcrop in Botswana. It is located in the Southern campus of the large natural topographic depression within the Makgadikgadi region of Botswana called the Sua Pan, which is the largest pan in Botswana. It is a two billion year old granite rock island, crescent shaped and is about one kilometre long, its slopes are littered with fossil beaches of rounded pebbles, an indication of the prehistoric lake's former water levels. Lukhubu is referred to as an island because it is surrounded by a sea of white salt.
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