Jump to content

Congo–Nile Divide

From Wikipedia, the free encyclopedia
(Redirected fromCongo-Nile Divide)
Congo Basinwith the divide between it and theNile Basinto the east highlighted in green.

TheCongo–Nile Divideor theNile–Congo Watershedis thecontinental dividethat separates thedrainage basinsof theCongoandNilerivers. It is about 2,000 kilometres (1,200 mi) long.

There are several geologically and geographically distinct sections between the point on the border between theCentral African RepublicandSouth Sudanwhere theCongoandNilebasins meet theChad Basin,and the southern point in Tanzania to the southwest ofLake Victoriawhere the boundaries of the Nile and Congo basins diverge and border severalendorheic basinsin theGregory Rift,of which the largest areLake Eyasiin the north andLake Rukwain the south.

The people who live along the divide are diverse, mainly speakingCentral Sudanic languagesin the northern parts andBantu languagesfurther south. The European colonialists used the Congo–Nile divide as a boundary between British-controlled territories to the east and territories controlled by the French and Belgians to the west. This was decided at a time when few Europeans had visited the area, which had yet to be mapped. It separated members of the ethnic groups that live on both sides of the divide.

Location

[edit]

Northern section: Sudan

[edit]
Azande peoplec. 1880. Their territory lay on either side of the northern section of the divide, which was made an international frontier at theBerlin Conferenceof 1884–85.

The Congo–Nile divide starts at thetriple dividewhere the Congo, Chad and Nile basins meet. This point is located on the boundary between theCentral African Republicand theSudan,at the limit between theVakagaandHaute-Kottoprefectures. From this triple point:

  1. the Umbelasha River flows to the North East into theNile,through theBahr al-Araband theBahr el Ghazal River.
  2. theKotto Riverflows to the South into theCongo River,through theUbangi River.
  3. the Yata River flows to the North West intoLake Chad,through the Bahr Oulou, theBahr Aouk Riverand theChari River.
The Congo–Nile divide (green line) starts at thetriple divide(orange dot) where the Congo, Chad and Nile basins meet. This point is located on the boundary theCentral African RepublicandSudan,at the limit between theVakagaandHaute-Kottoprefectures.

The Congo–Nile divide runs southeast and then south along the border betweenSouth SudanandUgandato the east and theCentral African RepublicandDemocratic Republic of the Congo(DRC) to the west.

TheIronstone Plateauregion between South Sudan and the DRC is cut by many streams that have formed steep and narrow valleys.[1] The vastSuddwetlands in South Sudan are fed by theBahr al Jabalriver that drainsLake AlbertandLake Victoriain the south, and also from ten smaller rivers flowing from the Congo–Nile divide which together provide 20 billion cubic meters of water annually.[2]

The easily traveled northern section of the divide may have been the main route for Bantu expansion to the east and south in theIron Age. The combination of deforestation due to seed agriculture, cattle ownership and changes in weapons technology with the introduction of iron may have allowedBantu-speakers to migrate south through the region intoBugandano more than 1,500 years ago. From there, they would have continued yet further south.[3]

The people who now live along the Congo–Nile divide in South Sudan speakCentral Sudanic languages,and include theKresh people. They once lived to the west of the divide in the region to the south ofLake Chad, but were forced east and south by expanding populations further to the west.[4] The Europeans knew little about the area in 1885, when they made the divide the boundary between Belgian and French spheres of influence to the west and the British sphere of influence to the east. The line ran through the territory of theZande people,who lived in the dense woodland in the extreme southwest of what is nowSouth Sudanand northeast of what is now theDemocratic Republic of the Congo.About 29% of them now lived in the Sudan, 68% in the Congo and the rest in the French colony ofUbangi-Shari,now theCentral African Republic.[1]

Central section: west of Albertine rift

[edit]
Ruwenzori Mountainsin the central part of the divide, to the west of the Albertine rift

In the central section, the divide runs along the mountains that form the west flank of theAlbertine RiftfromLake Albertin the north, pastLake Edwardand on towards the north end ofLake Kivu. The divide crosses the Albertine rift along the line of theVirunga Mountains,to the north of Lake Kivu.

The Virunga Massif along the border between Rwanda and the DRC consists of eight volcanoes. Two of these,NyamuragiraandNyiragongo,are still highly active.[5] South of the Virungas, Lake Kivu drains to the south into Lake Tanganyika through theRuzizi River.Lake Tanganyika then drains into theCongo Rivervia theLukuga River.[6] It seems likely that the present hydrological system was established quite recently when the Virunga volcanoes erupted and blocked the northward flow of water fromLake KivuintoLake Edward,causing it instead to discharge southward into Lake Tanganyika. Before that Lake Tanganyika, or separate sub-basins in what is now the lake, may have had no outlet other than evaporation.[7]

Southern section: east of Albertine rift

[edit]
Mountains in Rwanda. The volcanoes in the background are theVirunga Mountains,home of the critically endangeredmountain gorillas.
Main article:Congo-Nile Divide (Rwanda-Burundi)

In the south, the divide runs from a point near the southwest corner ofLake Victoriain a southwesterly direction throughTanzaniaandBurundito the mountains that form the eastern wall of theAlbertine Rift. The divide runs northward along the crest of these mountains to the east ofLake TanganyikaandLake Kivu.

This region includes theNyungwe Forestin Rwanda and theKibira National Parkin Burundi. The parks provide a refuge for various primates of conservation concern, and also for rare bird and plant species. Around these parks the land is heavily populated, and agriculture is practiced intensively.[8] Farming is difficult in this area, where peaks can be over 3,000 metres (10,000 ft) high.[9] The parks are under pressure from the people that live near them.[8] TheRukarara Riverrises in forested country in southern Rwanda to the east of the divide.[10] The source of the Rukarara is now known to be the overall source of theNile– the point at the furthest distance upstream from the river's mouth.[11][12]

European exploration and boundary setting

[edit]
An 1827 map, where the Congo basin was thought to be much smaller, and the Nile to originate in theMountains of the Moon,to the west of today's South Sudan. The coastline is depicted accurately, but the interior and theGreat Lakeswere unknown.

The East African great lakes plateau was difficult for the nineteenth-century European explorers to access, with inhospitable arid or semi-arid land to the north, east and southeast, and the difficult Congo Basin forests to the west. The route from the south via the rift valley lakes,NyasaandTanganyika,was easier, and the Congo–Nile divide from the northwest provided the easiest route.[13]

The Ruzizi River, flowing south into Lake Tanganyika, is part of the upper watershed of theCongo River.Nineteenth-century British explorers such asRichard Francis BurtonandJohn Hanning Speke,uncertain of the direction of flow of the Ruzizi, thought that it might flow north out of the lake toward theWhite Nile.Their research and follow-up explorations byDavid LivingstoneandHenry Morton Stanleyestablished among Europeans that this was not the case. The Ruzizi flows into Lake Tanganyika, which overflows into theLukuga Riverabout 120 kilometres (75 mi) south ofUjiji.The Lukuga flows west into theLualaba River,a major tributary of the Congo.[14]

Other European explorers who helped map out the region includedPanayotis Potagos(1839–1903),Georg August Schweinfurth(1836–1925), who discovered theUele River,although he mistakenly thought it flowed into the Chad Basin rather than the Congo, Wilhelm Junker (1840–1892), who corrected Schweinfurth's hydrographical theories, andOskar Lenz1848–1925).

The Berlin Conference of 1885 agreed that the Nile–Congo watershed would form the boundary between the British Sudan and the Congo State.[1] Under an agreement of 12 May 1894 between Britain and KingLeopold II of Belgium,the sphere of influence of Leopold's Congo Free State was limited to "a frontier following the 30th meridian east of Greenwich up to its intersection by the watershed between the Nile and the Congo, and thence following the watershed in a northerly and north-westerly direction."[15]

In 1907 D.C.E. Comyn published a survey,Western Sources of the Nile,in theGeographical Journal. He claimed to be the only living "white man who had crossed the headwaters of all the rivers from river Wau to Bahr al-Arab." In 1911 Comyn, in hisService and Sport in the Sudan,described the tributaries of the Nile that came from the Congo–Nile divide to the east of the Central African Republic.[16]

In 1915–16, when the divide defined part of the western frontier of theAnglo-Egyptian Sudan,Cuthbert Christyexplored the area. He opined that it was a suitable place to build a railway.

France and Britain made a friendly agreement in 1919 to define the boundary between the Anglo-Egyptian Sudan and French Equatorial Africa. The boundary was to run along the Nile–Congo divide until the 11th parallel of northern latitude, and then along the boundary betweenDarfurandWadai.Most of this area had not previously been explored by Europeans. A joint Anglo-French surveying party left Khartoum at the end of 1921.[17] The section along the divide from the 11th to 5th parallel, where French Equatorial Africa met the Belgian Congo, was densely wooded and uninhabited. The expedition could not buy food locally, but had to carry all they needed.[18] Pinning down the location of the divide was extremely difficult. The technique was to march along a compass bearing until a stream was reached, then to follow it up to its ultimate source, which was often a marsh, and to determine its location. The surveyors suffered from poor food, although there was abundant game, from malaria and from torrential rainfall. It took eighteen months to complete the task.[19]

References

[edit]
  1. ^abcBarbour 1961,p. 319.
  2. ^Okbazghi 2008,p. 73.
  3. ^McMaster 2013,p. 26.
  4. ^Collins 2006,p. 11.
  5. ^Erfurt-Cooper & Cooper 2010,p. 36.
  6. ^Erfurt-Cooper & Cooper 2010,pp. 35–36.
  7. ^Clark 1969,p. 35.
  8. ^abCongo-Nile Divide Landscape: WCS.
  9. ^Streissguth 2008,p. 11.
  10. ^Hughes, Hughes & Bernacsek 1992,p. 203.
  11. ^Brakspear 2008,p. 20.
  12. ^Dumont 2009,p. 2.
  13. ^McMaster 2013,p. 26ff.
  14. ^Ondaatje 1998,p. 166.
  15. ^The Expansion of Egypt,p. 413.
  16. ^Tvedt 2004,p. 338.
  17. ^Sykes 1949,p. 384.
  18. ^Sykes 1949,p. 385.
  19. ^Sykes 1949,p. 386.

Sources

[edit]

Further reading

Retrieved from "https://en.wikipedia.org/w/index.php?title=Congo–Nile_Divide&oldid=1216016934"