Atbara (river)

Atbara (river), also called the Black Nile, the only tributary of the River Nile north of Khartoum, Sudan. It is 1,120 km (695 mi) long, and rises in the Ethiopian Highlands west of Gonder, and not far from Lake Tana. It flows north-westwards into Sudan, where it joins the larger Tekeze tributary. The Atbara then joins the Nile at the town of Atbara. From June to August the river is swollen by the summer rains, and provides more than one-fifth of the Nile's total volume of water. It also brings down more than 10,000,000 tonnes of silt a year, which adds to the accumulations in Lake Nasser behind the Aswān High Dam. From November to May the Atbara dwindles to a mere trickle, and appears only as a series of pools.