Zambezi

from Wikipedia, the free encyclopedia
Zambezi
Map of the course of the river

Map of the course of the river

Data
location Central and Southern Africa : Zambia Angola Namibia Botswana Zimbabwe Mozambique
ZambiaZambia 
AngolaAngola 
NamibiaNamibia 
BotswanaBotswana 
ZimbabweZimbabwe 
MozambiqueMozambique 
River system Zambezi
source near Mwinilunga , Zambia
11 ° 22 ′ 3 ″  S , 24 ° 18 ′ 32 ″  E
Source height 1500  m
muzzle Indian Ocean Coordinates: 18 ° 50 ′  S , 36 ° 17 ′  E 18 ° 50 ′  S , 36 ° 17 ′  E
Mouth height 0  m
Height difference 1386 m
Bottom slope 0.54 ‰
length 2574 km
Catchment area 1,333,000 km²
Outflow
A Eo : 1,333,000 km²
at the mouth 		MQ
Mq
 		4200 m³ / s
3.2 l / (s km²)
Discharge at the Muturara gauge (before the construction of the Kariba Reservoir)
A Eo : 1,035,900 km²
Location: 250 km above the mouth 		MNQ 1930–1958
MQ 1930–1958
Mq 1930–1958
 MHQ 1930–1958
HHQ 		620 m³ / s
3319 m³ / s
3.2 l / (s km²)
 7450 m³ / s
22,500 m³ / s
Discharge at the Muturara gauge (after the construction of the Cahora Bassa Reservoir)
A Eo : 1,035,900 km²
Location: 250 km above the mouth 		MNQ 1976-1999
MQ 1976-1999
Mq 1976-1999
 MHQ 1976-1999
 1580 m³ / s
2229 m³ / s
2.2 l / (s km²)
 3350 m³ / s
Left tributaries Kabompo , Luena (Zambia) , Kafue , Chongwe , Luangwa , Luia , Revuboe , Shire
Right tributaries Luena (Angola) , Lungwebungu , Luanginga , Linyanti , Gwayi , Sengwa , Hunyani , Sanyati , Luenha , Muira , Pompue
Reservoirs flowed through Kariba dam , Cahora-Bassa dam
Big cities Mongu , Katima Mulilo , Livingstone , Tete , Sena , Marromeu
Navigable From the Cahora Bassa dam
Victoria Falls; in the foreground the railway bridge between Zimbabwe (left) and Zambia (right)

Victoria Falls; in the foreground the railway bridge between
Zimbabwe (left) and Zambia (right)

The Zambezi (also Zambezi or Zambesi ) is the fourth longest river in Africa after the Nile , Congo and Niger with a stretch of 2574 km and the largest African river that flows into the Indian Ocean . The catchment area covers areas in eight states in southern Africa and covers approximately 1.33 million square kilometers (km²), which is about half that of the Nile. This makes it the fourth largest river system in Africa. He is known worldwide mainly for the Victoria Falls. It is located in southern Africa .

The source of the Zambezi is located in the Zambezi Source National Forest and is located on the Lunda wave in Zambia , on the border between the Democratic Republic of Congo and Angola . It flows through Angola, Zambia and Mozambique , where it flows into the Indian Ocean in an 880 km² delta. It also partially forms the border between Zambia and Namibia , as well as Zambia and Zimbabwe , where it forms the mightiest waterfall in Africa, the Victoria Falls, at the level of the cities of Livingstone (Zambia) and Victoria Falls , where it falls about 110 meters. Other waterfalls are the Chavuma Falls on the border between Zambia and Angola and the Ngonye Falls , which are located near Sioma in western Zambia. The river is spanned by just eleven bridges over its entire length (see below: Significance as a traffic route ).

The hydroelectric power stations of the Cahora Bassa dam supply South Africa with electricity via a 1,420 kilometer long direct current transmission line, the HVDC Cahora Bassa . The Zambezi is navigable in the lower reaches from Tete. Hippos can still be found in the Zambezi today .

course

source

The Zambezi rises in a swampy rainforest area of ​​the Mitumba Mountains in northwest Zambia at an altitude of about 1500  m , on the border with the Democratic Republic of the Congo . The headwaters are thus north of Mwinilunga near Kalene Hill in the Zambian tip between Angola and the DR Congo. To the east of its source lies the watershed between the catchment areas of the Zambezi and the Congo ( Lualaba ), which runs as a ridge almost from east to west. The river basin of the Western Lunga drains to the south .

The Zambezi initially runs a few kilometers to the north, then to the west, and after just under 100 kilometers of the river, about 90 km west of Kalene Hill, it reaches the territory of Angola.

Upper course

After the Zambezi flows about 240 kilometers in a southwesterly direction, it makes an arc to the south and enlarges through numerous tributaries . A few kilometers above Kakengi, the river bed widens from 100 to about 350 meters. Below Kakengi there are some rapids that lead to the Chavuma Falls, which are considered the upper limit of the 600-kilometer-long upper course, on which the current falls by only 180 meters. From then on, the Zambezi flows through a rocky gorge.

The first major tributary is the Kabompo River in northern Zambia, further south the Lungwebungu River flows into it. The savannah through which the river ran until now is being replaced by open scrubland overgrown with Borassus palms. Dense vegetation is limited to a strip of forest a few hundred meters narrow, which covers the area around the Zambezi and its tributaries for the first 160 kilometers of the river.

The following downhill section runs for about 350 kilometers from 1050 m above sea level. M. at the Chavuma falls up to 1000 m above sea level. M. at Kakengi . From there to the Victoria Falls the course is even and drops only a little further. 30 kilometers below the confluence of the Lungwebungu, the landscape becomes very flat and large areas are flooded during the rainy season. Another 80 kilometers downstream flow with the Luena and the Luanginga , which has a large catchment area in the west, two further tributaries.

Just below it is Lealui , one of the largest cities of the Lozi people, who populate the semi-autonomous region of Barotseland . The leader of the Lozi has two branches in Lealui and Limulunga , which, due to its high position, serves as the capital during the rainy season. The annual move from Lealui to Limulunga is a major event that is celebrated with one of Zambia's most famous festivals, the Kuomboka ceremony.

The Zambezi in northwestern Zambia

Below Lealui, the Zambezi turns to the southeast. Over the next 240 km stretch of river, only tributaries flow from the east, before the Cuando flows again from the west. The Ngonye Falls and other rapids are on this section . To the south of it, the river borders the Zambezi region , which belongs to Namibia and which, under the name of Caprivi Strip, enabled the former colony of German Southwest Africa to access the Zambezi.

Below the junction of the Zambezi and the Cuando, the current turns exactly to the east. Here it is very wide and flat, with a slow flow rate. In its further course to the east, the Zambezi merges into the large central African plateau , where it reaches a gorge that ends in the Victoria Falls. There the Zambezi falls at a width of 1708 meters over a 110-meter sloping rock face.

Middle course

Canyon below Victoria Falls

The Victoria Falls are seen as the border between the upper and middle reaches of the Zambezi. The course of the river to the east continues for another 200 km, cutting through vertical basalt walls up to 250 meters high. The current is fast in these ravines, occasionally interrupted by stone banks. These gorges are followed by a series of rapids that end 150 miles below Victoria Falls. In the course of this stretch the river falls 250 meters. Until bridges and dams were built, the Zambezi steep slopes of the middle course were considered insurmountable.

Zambezi in the Mana Pools National Park below the Kariba Dam

The Zambezi then flows into the Kariba Reservoir , which was created in 1959 after the Kariba Reservoir was built (1955–1959) . The lake is one of the largest man-made lakes in the world, and the dam's hydropower plants provide electricity for much of Zambia and Zimbabwe . The Zambezi River Authority as a bi-national authority is responsible for the complex.

The Luangwa and the Kafue are the two largest left-hand tributaries of the Zambezi. The Kafue flows into the Zambezi as a calmly flowing, deep stream with a width of 180 meters. From this point on, the course of the river, which deviates slightly to the north, changes its direction again directly to the east and crosses the border to Mozambique with the inflow of the Luangwa .

The middle Zambezi ends with the Cahora-Bassa reservoir . This lake, too, was created through the construction of a dam (1969–1979), previously the dangerous rapids of Kebrabassa were located in its place .

Lower course

The lower 640 kilometers of the Zambezi from Cahora Bassa to the Indian Ocean are navigable, although the river is very shallow in many places in the dry season . This is facilitated by the fact that the Zambezi merges into a wide valley and is divided over a large area. Only at one point, in the Lupata Gorge , is the river limited by hills to a width of 200 meters. Otherwise it extends in many individual rivers over a width of five to eight kilometers. The river bed is sandy, the embankment is low and lined with reefs. Sometimes the individual runs merge into a single broad, fast-flowing stream, especially in the rainy season .

The Zambezi Delta

About 260 kilometers from the sea, the Zambezi receives the Shire tributary from Lake Malawi . Closer to the coast, it forms a widespread river delta that consists of numerous branches. Each of the four main estuaries Milambe, Kongone, Luabo and Timbwe is surrounded by sandbanks. A more northerly junction that ends in the Chinde estuary is two to four meters deep and is used for navigation. The Quelimane River , which is called like the city of the same name at its mouth, runs 100 kilometers further north . This silted up river receives water from the flooded Zambezi in the rainy season. The Zambezi delta is now only half as wide as it was before the construction of the Kariba and Cahora-Bassa dams, which regulate the seasonal variations in water levels.

The slope of the Zambezi represented as a graph

Catchment area

The catchment area of ​​the Zambezi is the fourth largest on the African continent with around 1,351,000 km². It extends over a total of eight states. Zambia (43%) has the largest share , followed by Angola (17%), Zimbabwe (16%), Mozambique (12%), Malawi (8%), Tanzania (2%), Botswana (1%) and Namibia ( 1 %). Malawi and Tanzania are not directly adjacent to the Zambezi, they are connected to the Zambezi via Lake Malawi and the Shire .

The catchment area of the Zambezi is divided as follows (based on 1,351 million km²):

States Catchment area of ​​the state in [km²] Percent of the area of ​​the catchment area Percent of the country's area
Angola 235.423 17.4 18.9
Namibia 17,426 1.3 2.1
Botswana 12,401 0.9 2.1
Zimbabwe 213.036 15.8 54.5
Zambia 574,875 42.5 76.4
Tanzania 27,840 2.1 2.9
Malawi 108,360 8.0 91.5
Mozambique 162.004 12.0 20.2
total 1,351,365 100
The Zambezi catchment area is climate-classified according to Köppen-Geiger.

The center of the catchment area is a huge plateau bounded by a jagged edge, which in the remote interior consists of multi-shaped stone beds and is lined by the rocks of the Victoria Falls. At Shupanga on the lower Zambezi there are layers of gray and yellow sandstone in the dry season , with strips of limestone in between . These can be found as far as behind Tete, where they are associated with larger coal deposits also below the Victoria Falls. Rocks containing gold appear in various places.

The southern part of the catchment area is predominantly in arid areas. Therefore, the Zambezi gets most of its water from the northern tributaries. This can be observed particularly in the runoff behavior of the Cundo, whose catchment area is comparable in size to that of the Kafue, but which has only a tenth of its runoff.

Tributaries

Course of the upper Samesi with its tributaries

The Kabompo rises in the highlands that form the watershed between the catchment area of ​​the Zambezi and the Congo. It is formed by the Upper Kabompo itself and the Western Lunga . It flows into the Zambezi north of the city of Lukulu , on the border of the Western Province and the Northwest Province . The Lungwebungu , a large tributary from the west, meets the Zambezi directly below the Kabompo. It has a width of up to 200 meters and flows through a valley made of white sand overgrown with sparse forest, where it sometimes floods areas several kilometers wide. The smaller Luanginga follows from the west .

Association with the Cuando

In relation to its catchment area, the Cuando is the largest of the western tributaries. It rises in Angola and forms the border between Zambia and Angola in its course , before turning south and east through the Caprivi Strip to the Zambezi. In the eastern part it flows over a distance of 110 kilometers through a reed swamp with alluvial islands, before it receives a tributary in the south from the Magwekwana , from which it receives excess water when the Okavango floods . The lower reaches of the Cuando, where it bears the name Chobe, flow into the Zambezi near Kazungula , which lies exactly in the four-country corner of Botswana-Namibia-Zambia-Zimbabwe. The ruins of the capital of the historical Kololo people are on its lower reaches.

The largest tributary of the central Zambezi is the Kafue , which rises in northern Zambia in a densely forested area. It later unites with the lunga . The Itezhi-Tezhi Dam is on the Kafue dam an important energy source for Zambia, which makes the country virtually self-sufficient energy. The area of ​​the river harbors a great variety of animals, which are protected in Zambia's largest national park, the Kafue National Park. At the lower Kafue there are several waterfalls and rapids that drop the river over a short distance over several hundred meters.

The upper reaches of the Luangwa runs parallel to the west bank of Lake Malawi. With two tributaries, the Lunsemfwa and the Lukasashi, its catchment area covers a large part of the western plateau of Zambia. The Luangwa is generally flat and quite wide, but its flow rate is rapid. It forms a wide valley that is bordered by steep rock climbs. This is an important wildlife sanctuary and contains the northern and southern Luangwa National Park . The Luangwa, with its lower course, forms the border with Mozambique for more than 75 kilometers before it, coming from the east, unites with the Zambezi above Zumbo .

The Shire is next to the Kafue and Cuando one of the three rivers with the largest catchment area. Its northernmost sources are in Tanzania. It drains almost all of Malawi and Lake Malawi. Together with the Ruhuhu , the longest headwaters of the Shire, and the stretch of river that its water needs to cross Lake Malawi, the course of the river is around 1,200 km long. In its lower reaches it forms part of the border between Mozambique and Malawi.

From the south, the Zambezi receives numerous tributaries that come from northern Zimbabwe. In addition to numerous small bodies of water, these are above all the Shangani , the Hunyani and the Sanyati . The Luenha , which rises in Mashonaland , flows below the Cahora Bassa dam.

Hydrometry

The total discharge of the Zambezi is given with values ​​between 4,200 and 3,251 m³ / s.

Due to its length and extensive use for energy generation, an extensive amount of flow data of the Zambezi is available. In contrast to other rivers, the runoff over the course sometimes decreases and increases again. In particular, evaporation in the reservoirs and irrigation reduce the amount of water that eventually reaches the Indian Ocean. The last level before the mouth is in Muturara , about 250 km before the mouth and with a catchment area of ​​1,035,900 km². The following diagram shows the average flow of the Zambezi before the construction of the Kariba Reservoir (1930–1958) and after the construction of the Cahora Bassa Reservoir (1976–1999).

Exploring the river

Satellite image of Victoria Falls and the following zigzag canyons

The region around the Zambezi was known to medieval geographers as the Empire of Monomotapa and the course of the river, like the location of Lake Ngami (located in the Okavango Basin) and Lake Malawi, was marked quite accurately on early maps. These were possibly made according to the knowledge of the Arabs.

The first European to visit the Upper Zambezi was David Livingstone on his exploration of the Bechuanaland from 1851 to 1853. Two or three years later he followed the Zambezi down to the mouth, during this trip he discovered the Victoria Falls. Between 1858 and 1860, Livingstone traveled from the Congone Estuary to the Falls with John Kirk . He also followed the course of the Shire and reached Lake Malawi.

Little exploration of the river took place over the next 35 years, but in 1889 the Chinde Canal was discovered north of the main estuaries. Two expeditions under Major A. St Hill Gibbons from 1895 to 1896 and 1898 to 1900 continued the exploration that Livingstone had begun in the upper and main course of the river. The Portuguese explorer Alexandre Alberto da Rocha de Serpa Pinto examined some of the western tributaries and measured the Victoria Falls in 1878.

economy

Kariba dam
Map of the cross-border Kavango-Zambezi Transfrontier Conservation Area

The population in the Zambezi Valley is around 32 million people, 80% of whom live from agriculture . The floodplains of the upper river provide fertile land that is well suited for cultivation.

The Zambezi is fished intensively and many people travel long distances for it. Some cities on the roads to the Zambezi levy unofficial fish taxes on fishers from other parts of the country. Sport fishing, especially between Mongu and Livingstone, where exotic fish species can be caught, and various safari tours in the national parks form the basis for tourism . The Victoria Falls are visited by 1.5 million visitors annually, the Kariba Lake attracts more tourists.

The river valley is rich in mineral deposits and fossil fuels . Coal mines are an important economic factor in some areas. The dams in the course of the river are important sources of energy and provide work for many people.

Importance as a traffic route

The Zambezi, which is interrupted many times by rapids, has never been of great importance as a route over long distances. However, many small places along the river can only be reached by boat and the often poor condition of the unpaved roads, which are also temporarily flooded, makes shipping traffic a suitable way of getting around over shorter distances .

Transitions

In many places, ferries transport people and vehicles across the river.

In its entire course, the Zambezi is spanned by only eleven bridges , one of which is a pedestrian bridge. In addition, the river can be crossed on two dams:

  • The Kariba Dam serves as a cross-border crossing from Zimbabwe to Zambia
  • The Cahora Bassa dam in Mozambique can be crossed by pedestrians.

The Victoria Falls Bridge at Victoria Falls was the first Zambezi bridge; it was completed in April 1905. According to Cecil Rhodes ' plans, it was to be part of a railway line from Cairo to Cape Town . The bridge spans 250 meters, of which the main arch alone 150 meters. It is 125 meters above the water level of the river.

In addition to the Victoria Falls Bridge, the following bridges exist in Zambia:

The following bridges were later built in Mozambique:

Photos of the bridges over the Zambezi

River history

The assumed maximum extent of the Paleo- Makgadikgadisees in the early Pleistocene and the course of the rivers in the early to middle Cenozoic.

The Zambezi did not flow into the Mozambique Strait about 65 million years ago . It flowed parallel to the Cuando and Okavango and, like these, emptied into the Limpopo . The Zambezi used the river bed of the Shashe , and the Cuando that of the Motloutse . Although the Luangwa and the Kafue were tributaries of the Zambezi back then, the Kafue was extended by the Chambeshi and it flowed over the Machili valley. Although the Luangwa had a course like today, it did not flow to the east at the current mouth, but flowed to the west, up the current river bed of the Zambezi and flows into the Paleo Zambezi in the border area between Zimbabwe and Botswana.

The Mambove Fault with the breakthrough of the Zambezi and the Chobe (Cuando)

The uplift of the Ovambo-Kalahari-Zimbabwe Fault (OKZ) created a new watershed that cut off the Zambezi from the Limpopo. As a result, a lake was formed in the Makgadikgadi Basin, the highest shoreline of which was 995 m and which was comparable in extent to today's Lake Victoria , or in some cases significantly larger. A total of 5 different shorelines have been found so far. The lake on today's Zambezi was dammed by the Chobe or Mambova fault . In the further course of the Luangwa changed its course to the east. After that, the Chambeshi, which has been part of the Congo catchment area since then, is gone . Then the Kafue shifted its course over the Kafue floodplains to its current bed. And finally the Zambezi broke through the faults above the Victoria Falls, so that it no longer flowed into the Makgadikgadi Basin either. As the last, the course of the Cuando was diverted by a sand dune to the Zambezi, although it still has some contact with the Okavango via the Savuti and Magwekwana .

Trivia

The film comedy “ King Ralph ” (1991) features an African fantasy state called “Zambezi”, whose King Mulambon (Rudolph Walker) wants to establish diplomatic relations with Great Britain.

In Hanover Zoo there is an African-inspired part called "Zambezi", which you can cross by boat on a watercourse also called "Zambezi".

See also

Web links

Commons : Zambezi  - collection of pictures, videos and audio files

Individual evidence

  1. ^ Hydropower Production in Future Climate Scenarios; the Case for the Zambezi River
  2. ↑ a b c Patterns of Hydrological Change in the Zambezi Delta, Mozambique
  3. ^ FAO - The Zambezi River basin
  4. ↑ Hydraulic-hydrologic model for the Zambezi River using satellite data and artificial intelligence techniques
  5. ↑ [1]
  6. ↑ [2]
  7. ^ Zambia Daily Mail (April 29, 2016): President launches k108m Sioma Bridge
  8. ↑ A proposed drainage evolution model for Central Africa — Did the Congo flow east?
  9. ^ A b The evolution and ages of Makgadikgadi paleo-lakes: consilient evidence from Kalahari drainage evolution south-central Africa
  10. ^ The Zambezi River - Andy E. Moore, Fenton PD (Woody) Cotterill, Mike PL Main and Hugh B. Williams