The Urema Valley , also known as the Urema Graben , is a lowland valley in Sofala Province of central Mozambique .
80-475: The Urema Valley extends from the Zambezi River south to Sofala Bay . It is a typical graben valley, with a flat bottom and escarpments on either side. It forms a broad crescent which bends towards the west as it extends from north to south. The valley floor is 12-80 meters above sea level, and averages about 40 km wide. Escarpments 300 to 400 meters high lead to plateaus. The Cheringoma Plateau lies to
160-409: A defined barometric pressure . Generally, the pressure used to set the altimeter is the barometric pressure that would exist at MSL in the region being flown over. This pressure is referred to as either QNH or "altimeter" and is transmitted to the pilot by radio from air traffic control (ATC) or an automatic terminal information service (ATIS). Since the terrain elevation is also referenced to MSL,
240-591: A different impact on the ecosystems of the delta from today, as it brought nutrient-rich fresh water down to the Indian Ocean coastal wetlands. The lower Zambezi experienced a small flood surge early in the dry season as rain in the Gwembe catchment and north-eastern Zimbabwe rushed through while rain in the upper Zambezi, Kafue, and Lake Malawi basins, and Luangwa to a lesser extent, is held back by swamps and floodplains. The discharges of these systems contribute to
320-432: A few metres, in timeframes ranging from minutes to months: Between 1901 and 2018, the average sea level rose by 15–25 cm (6–10 in), with an increase of 2.3 mm (0.091 in) per year since the 1970s. This was faster than the sea level had ever risen over at least the past 3,000 years. The rate accelerated to 4.62 mm (0.182 in)/yr for the decade 2013–2022. Climate change due to human activities
400-416: A haven for migratory waterbirds, including pintails , garganey , African openbill ( Anastomus lamelligerus ), saddle-billed stork ( Ephippiorhynchus senegalensis ), wattled crane ( Bugeranus carunculatus ), and great white pelican ( Pelecanus onocrotalus ). Reptiles include Nile crocodile ( Crocodylus niloticus ), Nile monitor lizard ( Varanus niloticus ), African rock python ( Python sebae ),
480-826: A large area to the west, joins the Zambezi. A short distance higher up on the east, the main stream is joined in the rainy season by overflow of the Luampa / Luena system. A short distance downstream of the confluence with the Luanginga is Lealui , one of the capitals of the Lozi people , who populate the Zambian region of Barotseland in the Western Province. The chief of the Lozi maintains one of his two compounds at Lealui;
560-469: A much larger flood in March or April, with a mean monthly maximum for April of 6,700 m (240,000 cu ft) per second at the delta. The record flood was more than three times as big, 22,500 m (790,000 cu ft) per second being recorded in 1958. By contrast, the discharge at the end of the dry season averaged just 500 m (18,000 cu ft) per second. In the 1960s and 1970s,
640-438: A reference datum for mean sea level (MSL). It is also used in aviation, where some heights are recorded and reported with respect to mean sea level (contrast with flight level ), and in the atmospheric sciences , and in land surveying . An alternative is to base height measurements on a reference ellipsoid approximating the entire Earth, which is what systems such as GPS do. In aviation, the reference ellipsoid known as WGS84
720-549: A reputation as great cloth traders throughout the region. In a curious note, Goese-born Portuguese trader Manuel Caetano Pereira, who traveled to the Bisa homelands in 1796, was surprised to be shown a second, separate river referred to as the "Zambezi". This "other Zambezi" that puzzled Pereira is most likely what modern sources spell the Chambeshi River in northern Zambia. The Monomatapa notion (reported by Santos) that
800-470: A sharp reduction in greenhouse gas emissions, this may increase to hundreds of millions in the latter decades of the century. Local factors like tidal range or land subsidence will greatly affect the severity of impacts. For instance, sea level rise in the United States is likely to be two to three times greater than the global average by the end of the century. Yet, of the 20 countries with
880-517: Is a national monument, forest reserve, and important bird area . Eastward of the source, the watershed between the Congo and Zambezi Basins is a well-marked belt of high ground, running nearly east–west and falling abruptly to the north and south. This distinctly cuts off the basin of the Lualaba (the main branch of the upper Congo) from the Zambezi. In the neighborhood of the source, the watershed
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#1732779772816960-405: Is a type of vertical datum – a standardised geodetic datum – that is used, for example, as a chart datum in cartography and marine navigation , or, in aviation, as the standard sea level at which atmospheric pressure is measured to calibrate altitude and, consequently, aircraft flight levels . A common and relatively straightforward mean sea-level standard
1040-488: Is because the sea is in constant motion, affected by the tides, wind , atmospheric pressure, local gravitational differences, temperature, salinity , and so forth. The mean sea level at a particular location may be calculated over an extended time period and used as a datum . For example, hourly measurements may be averaged over a full Metonic 19-year lunar cycle to determine the mean sea level at an official tide gauge . Still-water level or still-water sea level (SWL)
1120-427: Is due to change in either the volume of water in the world's oceans or the volume of the oceanic basins . Two major mechanisms are currently causing eustatic sea level rise. First, shrinking land ice, such as mountain glaciers and polar ice sheets, is releasing water into the oceans. Second, as ocean temperatures rise, the warmer water expands. Many factors can produce short-term changes in sea level, typically within
1200-549: Is home to coastal forest mosaic . Zambezi River (Period: 1971–2000)4,256.1 m /s (150,300 cu ft/s) The Zambezi (also spelled Zambeze and Zambesi ) is the fourth-longest river in Africa, the longest east-flowing river in Africa and the largest flowing into the Indian Ocean from Africa. Its drainage basin covers 1,390,000 km (540,000 sq mi), slightly less than half of
1280-483: Is increasingly used to define heights; however, differences up to 100 metres (328 feet) exist between this ellipsoid height and local mean sea level. Another alternative is to use a geoid -based vertical datum such as NAVD88 and the global EGM96 (part of WGS84). Details vary in different countries. When referring to geographic features such as mountains, on a topographic map variations in elevation are shown by contour lines . A mountain's highest point or summit
1360-408: Is instead a long-term average of tide gauge readings at a particular reference location. Sea levels can be affected by many factors and are known to have varied greatly over geological time scales . Current sea level rise is mainly caused by human-induced climate change . When temperatures rise, mountain glaciers and polar ice sheets melt, increasing the amount of water in the oceans, while
1440-601: Is lost through evaporation in its swamp systems. The 1940s and 1950s were particularly wet decades in the basin. Since 1975, it has been drier, the average discharge being only 70% of that for the years 1930 to 1958. Up to the Late Pliocene or Pleistocene (more than two million years ago), the upper Zambezi flowed south through what is now the Makgadikgadi Pan to the Limpopo River . The change of
1520-467: Is not as clearly defined, but the two river systems do not connect. The region drained by the Zambezi is a vast, broken-edged plateau 900–1,200 m high, composed in the remote interior of metamorphic beds and fringed with the igneous rocks of the Victoria Falls. At Chupanga , on the lower Zambezi, thin strata of grey and yellow sandstones , with an occasional band of limestone , crop out on
1600-463: Is not included in the figures because it only occasionally overflows to any extent into the Zambezi. Because of the rainfall distribution, northern tributaries contribute much more water than southern ones; for example: The Northern Highlands catchment of the upper Zambezi contributes 25%, Kafue 8%, Luangwa and Shire Rivers 16% each, total 65% of Zambezi discharge. The large Cuando basin in the south-west, though, contributes only about 2 m /s because most
1680-521: Is obstructed by a sand bar . A more northerly branch, called the Chinde mouth, has a minimum depth at low water of 2 metres (6 ft 7 in) at the entrance and 4 metres (13 ft) further in, and is the branch used for navigation. About 100 kilometres (62 mi) further north is a river called the Quelimane , after the town at its mouth. This stream, which is silting up, receives the overflow of
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#17327797728161760-450: Is the level of the sea with motions such as wind waves averaged out. Then MSL implies the SWL further averaged over a period of time such that changes due to, e.g., the tides , also have zero mean. Global MSL refers to a spatial average over the entire ocean area, typically using large sets of tide gauges and/or satellite measurements. One often measures the values of MSL with respect to
1840-727: Is the main cause. Between 1993 and 2018, melting ice sheets and glaciers accounted for 44% of sea level rise , with another 42% resulting from thermal expansion of water . Sea level rise lags behind changes in the Earth 's temperature by many decades, and sea level rise will therefore continue to accelerate between now and 2050 in response to warming that has already happened. What happens after that depends on human greenhouse gas emissions . If there are very deep cuts in emissions, sea level rise would slow between 2050 and 2100. It could then reach by 2100 slightly over 30 cm (1 ft) from now and approximately 60 cm (2 ft) from
1920-531: Is typically illustrated with the AMSL height in metres, feet or both. In unusual cases where a land location is below sea level, such as Death Valley, California , the elevation AMSL is negative. It is often necessary to compare the local height of the mean sea surface with a "level" reference surface, or geodetic datum, called the geoid . In the absence of external forces, the local mean sea level would coincide with this geoid surface, being an equipotential surface of
2000-805: The Chavuma Falls at the border between Zambia and Angola, and Ngonye Falls near Sioma in western Zambia. The two main sources of hydroelectric power on the river are the Kariba Dam , which provides power to Zambia and Zimbabwe, and the Cahora Bassa Dam in Mozambique, which provides power to Mozambique and South Africa . Additionally, two smaller power stations are along the Zambezi River in Zambia, one at Victoria Falls and
2080-677: The Itezhi-Tezhi Dam 's deleterious effects on the Kafue Flats, this has these effects: The Zambezi Delta has extensive seasonally and permanently flooded grasslands, savannas, and swamp forests. Together with the floodplains of the Buzi , Pungwe , and Save Rivers, the Zambezi's floodplains make up the World Wildlife Fund 's Zambezian coastal flooded savanna ecoregion in Mozambique. The flooded savannas lie close to
2160-519: The Ngonye Falls and subsequent rapids interrupt navigation. South of Ngonye Falls, the river briefly borders Namibia's Caprivi Strip . Below the junction of the Cuando River and the Zambezi, the river bends almost due east. Here, the river is broad and shallow and flows slowly, but as it flows eastward towards the border of the great central plateau of Africa, it reaches a chasm into which
2240-504: The Nile 's. The 2,574 km (1,599 mi) river rises in Zambia and flows through eastern Angola , along the north-eastern border of Namibia and the northern border of Botswana , then along the border between Zambia and Zimbabwe to Mozambique , where it crosses the country to empty into the Indian Ocean. The Zambezi's most noted feature is Victoria Falls . Its other falls include
2320-465: The Quelimane or Quá-Qua, a small river on the northern end of the delta, which at that time was connected by navigable channels to the Zambezi River proper (the connection silted up by the 1830s). In a few of the oldest maps, the entire river is denoted as such. By the 16th century, a new name emerged, the Cuama River (sometimes "Quama" or "Zuama"). Cuama was the local name given by the dwellers of
2400-679: The Swahili coast for an outpost located on one of the southerly islands of the delta (near the Luabo channel). Most old nautical maps denote the Luabo entry as Cuama, the entire delta as the "rivers of Cuama", and the Zambezi proper as the "Cuama River". In 1552, Portuguese chronicler João de Barros noted that the same Cuama River was called Zembere by the inland people of Monomatapa . The Portuguese Dominican friar João dos Santos , visiting Monomatapa in 1597 reported it as Zambeze (Bantu languages frequently shifts between z and r) and inquired into
2480-561: The geoid of the Earth, which approximates the local mean sea level for locations in the open ocean. The geoid includes a significant depression in the Indian Ocean , whose surface dips as much as 106 m (348 ft) below the global mean sea level (excluding minor effects such as tides and currents). Precise determination of a "mean sea level" is difficult because of the many factors that affect sea level. Instantaneous sea level varies substantially on several scales of time and space. This
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2560-418: The height above mean sea level (AMSL). The term APSL means above present sea level, comparing sea levels in the past with the level today. Earth's radius at sea level is 6,378.137 km (3,963.191 mi) at the equator. It is 6,356.752 km (3,949.903 mi) at the poles and 6,371.001 km (3,958.756 mi) on average. This flattened spheroid , combined with local gravity anomalies , defines
2640-515: The "Espirito Santo" Rivers converging deep in the interior, at the same lake. However, the Bisa-derived etymology is not without dispute. In 1845, W.D. Cooley, examining Pereira's notes, concluded the term "Zambezi" derives not from the Bisa people, but rather from the Bantu term "mbege"/"mbeze" ("fish"), and consequently it probably means merely "river of fish". David Livingstone , who reached
2720-562: The 1690s. Satellite altimeters have been making precise measurements of sea level since the launch of TOPEX/Poseidon in 1992. A joint mission of NASA and CNES , TOPEX/Poseidon was followed by Jason-1 in 2001 and the Ocean Surface Topography Mission on the Jason-2 satellite in 2008. Height above mean sea level ( AMSL ) is the elevation (on the ground) or altitude (in the air) of an object, relative to
2800-973: The 19th century. With high emissions it would instead accelerate further, and could rise by 1.0 m ( 3 + 1 ⁄ 3 ft) or even 1.6 m ( 5 + 1 ⁄ 3 ft) by 2100. In the long run, sea level rise would amount to 2–3 m (7–10 ft) over the next 2000 years if warming stays to its current 1.5 °C (2.7 °F) over the pre-industrial past. It would be 19–22 metres (62–72 ft) if warming peaks at 5 °C (9.0 °F). Rising seas affect every coastal and island population on Earth. This can be through flooding, higher storm surges , king tides , and tsunamis . There are many knock-on effects. They lead to loss of coastal ecosystems like mangroves . Crop yields may reduce because of increasing salt levels in irrigation water. Damage to ports disrupts sea trade. The sea level rise projected by 2050 will expose places currently inhabited by tens of millions of people to annual flooding. Without
2880-583: The Barue Plateau. The northern end of the graben is drained by the Zangue River , which flows north to join the Zambezi. The Urema River flows south into the lower Pungwe , and forms a large but shallow seasonal lake called Lake Urema. Gorongosa National Park occupies the central portion of the Graben, including Lake Urema. The southernmost portion of the valley is occupied by the large estuary of
2960-448: The Earth's gravitational field which, in itself, does not conform to a simple sphere or ellipsoid and exhibits gravity anomalies such as those measured by NASA's GRACE satellites . In reality, the geoid surface is not directly observed, even as a long-term average, due to ocean currents, air pressure variations, temperature and salinity variations, etc. The location-dependent but time-persistent separation between local mean sea level and
3040-455: The Indian Ocean coast. Mangroves fringe the delta's shoreline. Although the dams have stemmed some of the annual flooding of the lower Zambezi and caused the area of floodplain to be greatly reduced, they have not removed flooding completely. They cannot control extreme floods, and they have only made medium-level floods less frequent. When heavy rain in the lower Zambezi combines with significant runoff upstream, massive floods still happen, and
3120-705: The Marégraphe in Marseilles measures continuously the sea level since 1883 and offers the longest collated data about the sea level. It is used for a part of continental Europe and the main part of Africa as the official sea level. Spain uses the reference to measure heights below or above sea level at Alicante , while the European Vertical Reference System is calibrated to the Amsterdam Peil elevation, which dates back to
3200-522: The Pungwe and Buzi rivers, with extensive mangrove swamps . The port of Beira lies on the eastern shore of the estuary where it meets Sofala Bay. In addition to the seasonally-flooded grasslands, the valley floor is occupied by warm and dry mopane woodland . Miombo woodlands occupy the more humid Barue Plateau. The climate of the Cheringoma Plateau is influenced by the Indian Ocean, and
3280-592: The Swahili (and later Portuguese) upriver trade station at Sena . In 1752, the Zambezi Delta, under the name "Rivers of Sena" ( Rios de Sena ) formed a colonial administrative district of Portuguese Mozambique , but common usage of "Zambezi" led eventually to a royal decree in 1858 officially renaming the district " Zambézia ". The Zambezi region was known to medieval geographers as the Empire of Monomotapa , and
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3360-540: The Victoria Falls plunge. The Victoria Falls are considered the boundary between the upper and middle Zambezi. Below them, the river continues to flow due east for about 200 km (120 mi), cutting through perpendicular walls of basalt 20 to 60 m (66 to 197 ft) apart in hills 200 to 250 m (660 to 820 ft) high. The river flows swiftly through the Batoka Gorge, the current being continually interrupted by reefs. It has been described as one of
3440-471: The Zambezi in the rainy season. Average, minimum and maximum discharge of the Zambezi River at Marromeu (Lower Zambezi). Period from 1998 to 2022. The delta of the Zambezi is today about half as broad as it was before the construction of the Kariba and Cahora Bassa dams controlled the seasonal variations in the flow rate of the river. Before the dams were built, seasonal flooding of the Zambezi had quite
3520-719: The Zambezi is the Kabompo River in the North-Western Province of Zambia. The savanna through which the river flows gives way to a wide floodplain, studded with Borassus fan palms . A little farther south is the confluence with the Lungwebungu River . This is the beginning of the Barotse Floodplain , the most notable feature of the upper Zambezi, but this northern part does not flood so much and includes islands of higher land in
3600-543: The Zambezi was sourced from a great internal lake might be a reference to one of the African Great Lakes . One of the names reported by early explorers for Lake Malawi was "Lake Zambre" (probably a corruption of "Zambezi"), possibly because Lake Malawi is connected to the lower Zambezi via the Shire River. The Monomatapa story resonated with the old European notion, drawn from classical antiquity, that all
3680-467: The banks are low and reed-fringed. At places, however, and especially in the rainy season, the streams unite into one broad, fast-flowing river. About 160 kilometres (99 mi) from the sea, the Zambezi receives the drainage of Lake Malawi through the Shire River . On approaching the Indian Ocean, the river splits up into a delta . Each of the primary distributaries, Kongone, Luabo, and Timbwe,
3760-532: The bed of the river in the dry season, and these persist beyond Tete , where they are associated with extensive seams of coal. Coal is also found in the district just below Victoria Falls. Gold-bearing rocks occur in several places. The river flows to the southwest into Angola for about 240 km (150 mi), then is joined by sizeable tributaries such as the Luena and the Chifumage flowing from highlands to
3840-406: The building of dams changed that pattern completely. Downstream, the mean monthly minimum–maximum was 500 to 6,000 m (18,000 to 212,000 cu ft) per second; now it is 1,000 to 3,900 m (35,000 to 138,000 cu ft) per second. Medium-level floods especially, of the kind to which the ecology of the lower Zambezi was adapted, happen less often and have a shorter duration. As with
3920-445: The calm stretches of the river, as well as Nile crocodiles. Monitor lizards are found in many places. Birds are abundant, with species including heron , pelican , egret , lesser flamingo , and African fish eagle present in large numbers. Riverine woodland also supports many large animals, such as buffalo, zebras , giraffes , and elephants . The Zambezi also supports several hundred species of fish, some of which are endemic to
4000-546: The confluence of the Luangwa (15°37' S), it enters Mozambique. The middle Zambezi ends where the river enters Lake Cahora Bassa , formerly the site of dangerous rapids known as Kebrabassa; the lake was created in 1974 by the construction of the Cahora Bassa Dam. The lower Zambezi's 650 kilometres (400 mi) from Cahora Bassa to the Indian Ocean is navigable, although the river is shallow in many places during
4080-412: The course of the river, as well as the position of lakes Ngami and Nyasa , were generally accurate in early maps. These were probably constructed from Arab information. Sea level Mean sea level ( MSL , often shortened to sea level ) is an average surface level of one or more among Earth 's coastal bodies of water from which heights such as elevation may be measured. The global MSL
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#17327797728164160-469: The dry season. This shallowness arises as the river enters a broad valley and spreads out over a large area. Only at one point, the Lupata Gorge , 320 kilometres (200 mi) from its mouth, is the river confined between high hills. Here, it is scarcely 200 metres (660 ft) wide. Elsewhere it is from 5 to 8 kilometres (3 to 5 mi) wide, flowing gently in many streams. The river bed is sandy, and
4240-481: The east, and the Barue Plateau to the west. Mount Gorongosa lies on the Barue Plateau near the western escarpment. The Urema Valley is the southernmost portion of the East African Rift , a continuation of the southern rift segment contains the Shire River valley and Lake Malawi . Much of the valley floor is covered with seasonal wetlands, which are filled during the rainy season by rivers flowing off
4320-442: The endemic Pungwe worm snake ( Leptotyphlops pungwensis ), and three other snakes that are nearly endemic - floodplain water snake ( Lycodonomorphus whytei obscuriventris ), dwarf wolf snake ( Lycophidion nanus ), and swamp viper ( Proatheris ). Several butterfly species are endemic. The north of the Zambezi basin has mean annual rainfall of 1100 to 1400 mm, which declines towards the south, reaching about half that figure in
4400-415: The existing seawater also expands with heat. Because most of human settlement and infrastructure was built in response to a more-normalized sea level with limited expected change, populations affected by sea level rise will need to invest in climate adaptation to mitigate the worst effects or, when populations are at extreme risk, a process of managed retreat . The term above sea level generally refers to
4480-482: The geoid is referred to as (mean) ocean surface topography . It varies globally in a typical range of ±1 m (3 ft). Several terms are used to describe the changing relationships between sea level and dry land. The melting of glaciers at the end of ice ages results in isostatic post-glacial rebound , when land rises after the weight of ice is removed. Conversely, older volcanic islands experience relative sea level rise, due to isostatic subsidence from
4560-751: The great African rivers—the Nile, the Senegal , the Congo, and the Zambezi—were all sourced from the same great internal lake. The Portuguese were also told that the Mozambican Espirito Santo "river" (actually an estuary formed by the Umbeluzi , Matola , and Tembe Rivers) was sourced from a lake (hence its outlet became known as Delagoa Bay ). As a result, several old maps depict the Zambezi and
4640-634: The greatest exposure to sea level rise, twelve are in Asia , including Indonesia , Bangladesh and the Philippines. The resilience and adaptive capacity of ecosystems and countries also varies, which will result in more or less pronounced impacts. The greatest impact on human populations in the near term will occur in the low-lying Caribbean and Pacific islands . Sea level rise will make many of them uninhabitable later this century. Pilots can estimate height above sea level with an altimeter set to
4720-555: The height of planetary features. Local mean sea level (LMSL) is defined as the height of the sea with respect to a land benchmark, averaged over a period of time long enough that fluctuations caused by waves and tides are smoothed out, typically a year or more. One must adjust perceived changes in LMSL to account for vertical movements of the land, which can occur at rates similar to sea level changes (millimetres per year). Some land movements occur because of isostatic adjustment to
4800-591: The land; hence a change in relative MSL or ( relative sea level ) can result from a real change in sea level, or from a change in the height of the land on which the tide gauge operates, or both. In the UK, the ordnance datum (the 0 metres height on UK maps) is the mean sea level measured at Newlyn in Cornwall between 1915 and 1921. Before 1921, the vertical datum was MSL at the Victoria Dock, Liverpool . Since
4880-481: The melting of ice sheets at the end of the last ice age . The weight of the ice sheet depresses the underlying land, and when the ice melts away the land slowly rebounds . Changes in ground-based ice volume also affect local and regional sea levels by the readjustment of the geoid and true polar wander . Atmospheric pressure , ocean currents and local ocean temperature changes can affect LMSL as well. Eustatic sea level change (global as opposed to local change)
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#17327797728164960-556: The middle. About 30 km below the confluence of the Lungwebungu, the country becomes very flat, and the typical Barotse Floodplain landscape unfolds, with the flood reaching a width of 25 km in the rainy season. For more than 200 km downstream, the annual flood cycle dominates the natural environment and human life, society, and culture. About 80 km further down, the Luanginga , which with its tributaries drains
5040-459: The native idea of this magnificent stream being the main drain of the country". Other historical records show that the river was called Kasambabezi by the Tonga people, which means “only those who know the river can bath in it.” a name which is still in use to this day. In Portuguese records, the "Cuama River" term disappeared and gave way to the term "Sena River" ( Rio de Sena ), a reference to
5120-413: The north-west. It turns south and develops a floodplain , with extreme width variation between the dry and rainy seasons. It enters dense evergreen Cryptosepalum dry forest , though on its western side, Western Zambezian grasslands also occur. Where it re-enters Zambia, it is nearly 400 m (1,300 ft) wide in the rainy season and flows rapidly, with rapids ending in the Chavuma Falls , where
5200-576: The origins of the name; he was told it was named after a people. "The River Cuama is by them called Zambeze; the head whereof is so farre within Land that none of them know it, but by tradition of their Progenitors say it comes from a Lake in the midst of the continent which yeelds also other great Rivers, divers ways visiting the Sea. They call it Zambeze, of a Nation of Cafres dwelling neere that Lake which are so called." —J. Santos Ethiopia Oriental , 1609 Thus,
5280-522: The other in Zengamina , near Kalene Hill in the Ikelenge District . The river rises in a black, marshy dambo in dense, undulating miombo woodland 50 km (31 mi) north of Mwinilunga and 20 km (12 mi) south of Ikelenge in the Ikelenge District of North-Western Province , Zambia, at about 1,524 metres (5,000 ft) above sea level . The area around the source
5360-476: The other is at Limulunga , which is on high ground and serves as the capital during the rainy season. The annual move from Lealui to Limulunga is a major event, celebrated as one of Zambia's best-known festivals, the Kuomboka . After Lealui, the river turns south-southeast. From the east, it continues to receive numerous small streams, but on the west, it is without major tributaries for 240 km. Before this,
5440-422: The river course is the result of epeirogenic movements that lifted up the surface at the present-day water divide between both rivers. Meanwhile, 1,000 km (620 mi) east, a western tributary of the Shire River in the East African Rift 's southern extension through Malawi eroded a deep valley on its western escarpment. At a slow rate, the middle Zambezi started cutting back the bed of its river towards
5520-551: The river flows through a rocky fissure. The river drops about 400 m (1,300 ft) in elevation from its source at 1,500 m (4,900 ft) to the Chavuma Falls at 1,100 m (3,600 ft), over a distance of about 400 km (250 mi). From this point to the Victoria Falls, the level of the basin is very uniform, dropping only by another 180 m (590 ft) across a distance of around 800 km (500 mi). The first of its large tributaries to enter
5600-743: The river. Important species include cichlids , which are fished heavily for food, as well as catfish, tigerfish, yellowfish , and other large species. The bull shark is sometimes known as the Zambezi shark after the river, not to be mistaken with Glyphis freshwater shark genus that inhabit the river, as well. Upper Zambezi: 507,200 km , discharges 1044 m /s at Victoria Falls, comprising: Middle Zambezi cumulatively 1,050,000 km , 2442 m /s, measured at Cahora Bassa Gorge Lower Zambezi cumulatively, 1,378,000 km , 3424 m /s, measured at Marromeu Total Zambezi river basin : 1,390,000 km , 3424 m /s discharged into delta Source: Beilfuss & Dos Santos (2001) The Okavango Basin
5680-517: The south-west. The rain falls in a 4-to-6-month summer rainy season when the Intertropical Convergence Zone moves over the basin from the north between October and March. Evaporation rates are high (1600 mm-2300 mm), and much water is lost this way in swamps and floodplains, especially in the south-west of the basin. The river supports large populations of many animals. Hippopotamuses are abundant along most of
5760-514: The term "Zambezi" is after a people who live by a great lake to the north. The most likely candidates are the "M'biza", or Bisa people (in older texts given as Muisa, Movisa, Abisa, Ambios, and other variations), a Bantu people who live in what is now central-eastern Zambia, between the Zambezi River and Lake Bangweolo (at the time, before the Lunda invasion, the Bisa would have likely stretched further north, possibly to Lake Tanganyika ). The Bisa had
5840-518: The times of the Russian Empire , in Russia and its other former parts, now independent states, the sea level is measured from the zero level of Kronstadt Sea-Gauge. In Hong Kong, "mPD" is a surveying term meaning "metres above Principal Datum" and refers to height of 0.146 m (5.7 in) above chart datum and 1.304 m (4 ft 3.3 in) below the average sea level. In France,
5920-458: The upper Zambezi in 1853, refers to it as "Zambesi", but also makes note of the local name "Leeambye" used by the Lozi people , which he says means "large river or river par excellence". Livingstone records other names for the Zambezi—Luambeji, Luambesi, Ambezi, Ojimbesi, and Zambesi—applied by different peoples along its course, and asserts they "all possess a similar signification and express
6000-411: The weight of cooling volcanos. The subsidence of land due to the withdrawal of groundwater is another isostatic cause of relative sea level rise. On planets that lack a liquid ocean, planetologists can calculate a "mean altitude" by averaging the heights of all points on the surface. This altitude, sometimes referred to as a "sea level" or zero-level elevation , serves equivalently as a reference for
6080-399: The west, aided by grabens ( rift valleys ) forming along its course in an east–west axis. As it did so, it captured several south-flowing rivers such as the Luangwa and Kafue. Eventually, the large lake trapped at Makgadikgadi (or a tributary of it) was captured by the middle Zambezi cutting back towards it, and emptied eastwards. The upper Zambezi was captured, as well. The middle Zambezi
6160-644: The wetlands are still an important habitat. The shrinking of the wetlands, though, resulted in uncontrolled hunting of animals such as buffalo and waterbuck during the Mozambican Civil War . Although the region has had a reduction in the populations of the large mammals, it is still home to some, including the reedbuck and migrating eland . Carnivores found here include lion ( Panthera leo ), leopard ( Panthera pardus ), cheetah ( Acinonyx jubatus ), spotted hyena ( Crocuta crocuta ), and side-striped jackal ( Canis adustus ). The floodplains are
6240-426: The world's most spectacular whitewater trips, a tremendous challenge for kayakers and rafters alike. Beyond the gorge are a succession of rapids that end 240 km (150 mi) below Victoria Falls. Over this distance, the river drops 250 m (820 ft). At this point, the river enters Lake Kariba , created in 1959 following the completion of the Kariba Dam . The lake is one of the largest man-made lakes in
6320-409: The world, and the hydroelectric power-generating facilities at the dam provide electricity to much of Zambia and Zimbabwe. The Luangwa and Kafue rivers are the two largest left-hand tributaries of the Zambezi. The Kafue joins the main river in a quiet, deep stream about 180 m (590 ft) wide. From this point, the northward bend of the Zambezi is checked, and the stream continues due east. At
6400-487: Was about 300 m (980 ft) lower than the upper Zambezi, and a high waterfall formed at the edge of the basalt plateau across which the upper river flows. This was the first Victoria Falls, somewhere down the Batoka Gorge near where Lake Kariba is now. The first European to come across the Zambezi River was Vasco da Gama in January 1498, who anchored at what he called Rio dos Bons Sinais (River of Good Omens), now
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