Course of the Atbara as a right tributary of the Nile
, Called The Atbara (Arabic نهر عطبرة, DMG Nahr Atbara ʿ ) also Black Nile, is a right tributary of the Nile in Ethiopia and Sudan.
The Atbara is some 1,120 km long and originates in the Ethiopian highlands in the southwestern Simen Mountains. The source of the river is located about 50 km north of Lake Tana and 30 km west of Gondar. From there it flows predominantly to the northwest by Sudan. From June to August the river swells in the summer rainy season. During this flood period, he is navigable. The Atbara is more than one fifth of the total amount of water of the Nile and more than 10 million tons of dark particulate matter per year with it, by which it gets its name, " Black River ". The average discharge flow of the Atbara is in the long -term average at 360 m³ / s
Because of the characteristic climatic rainfall conditions in the Ethiopian highlands plateau of the Atbara reached its maximum in August, water management and shall, together with the Blue Nile a large part of the main flood of the Nile at. During the dry season from January until May, the amount of water of the Atbara usually reduced to a small trickle, which consists only of a series of small shallow lakes and no longer reached the Nile.
The Atbara has a catchment area of about 112,000 km ². The largest tributary is the Setit, which also has its source in the Ethiopian highlands, where it is known Tekeze. Since the commissioning of the Tekeze dam end of 2009 Setit has a more balanced water management.
In its lower reaches the water of Atbaras is dammed by the Khashm el- Girba dam to allow irrigation in the otherwise dry environment.
In the town of Atbara Atbara flows 325 km below the confluence of the Blue Nile in the Nile, whose last tributary he is in front of the Mediterranean Sea.
Average monthly flow of the Atbara measured at the hydrological station 3 kilos, about 25 km upstream of the mouth, in m³ / s ( 1912-1982 ).