NILE, river, E Africa, the longest river in the world. From Lake Victoria in E central Africa, it flows generally N through Uganda, Sudan, and Egypt to the Mediterranean Sea, for a distance of 5584 km (3470 mi).
From its remotest headstream, the Luvironza R. in Burundi, the river is 6671 km (4145 mi) long. The river basin has an area of more than 2,590,000 km (1,000,000 sq mi).
The source of the Nile is one of the upper branches of the Kagera R. in Tanzania. The Kagera follows the boundary of Rwanda northward, turns along the boundary of Uganda, and drains into Lake Victoria. On leaving Lake Victoria at the site of the now-submerged Ripon Falls, the Nile rushes for 483 km (300 mi) between high rocky walls and over rapids and cataracts, at first NW and then W, until it enters Lake Albert.
The section between the two lakes is called the Victoria Nile. The river leaves the N end of Lake Albert as the Albert Nile, flows through N Uganda, and at the Sudan border becomes the Bahr al-Jabal.
At its junction with the Bahr al-Ghazal, the river becomes the Bahr al-Abyad, or the White Nile. Various tributaries flow through the Bahr al-Ghazal district. At Khartoum the White Nile is joined by the Blue Nile, or Bahr al-Azraq.
These are so named because of the color of the water. The Blue Nile, 1529 km (950 mi) long, gathers its volume mainly from Lake Tana, in the Ethiopian Highlands; it is known here as the Abbai.
The Nile enters the Mediterranean Sea by a delta that separates into the Rosetta and Damietta distributaries.
Noted Western explorers of the Nile include the British explorers John Hanning Speke, who reached Lake Victoria in 1858 and Ripon Falls in 1862, and Sir Samuel White, who sighted Lake Albert in 1864; a German, Georg August Schweinfurth (1836-1925), who explored (1868-71) the W feeders of the White Nile; and a British-American, Sir Henry Morton Stanley.
In 1875 Stanley sailed around Lake Victoria; in 1889 he traced the Semliki R. and reached Lake Edward and the Ruwenzori Range. The first dam on the Nile, the Aswan dam, was built in 1902 and heightened in 1936. The Aswan High Dam (q.v.) was dedicated in 1971; it impounds one of the world's largest reservoirs, Lake Nasser. The Makwar Dam, now called the Sennar Dam, was built across the Blue Nile S of Khartoum following World War I to provide storage water for cotton plantations in the Sudan.
A dam at Jabal Awliya was constructed on the White Nile S of Khartoum in 1937.For further information on this topic, see ~BIBLIO. WATER, ~BIBLIO. NORTHERN AFRICA.