The Online Encyclopedia and Dictionary







For alternative meanings of "Nile", see Nile (disambiguation)

The Nile (Arabic: النيل an-nīl), in Africa, is one of the two longest rivers on Earth. Whether the Nile is longer than South America's Amazon still remains the subject of much debate. This is, for the most part, due to two reasons: first, the lengths of rivers vary over time (especially in plains, where rivers often change course), and, second, the point from which the length of a river is measured is not always agreed upon. The Nile lost several miles of meanders in Nubia when Lake Nasser was formed.

Lake Victoria in Uganda is commonly considered to be the source of the Nile, although the lake itself has feeder rivers of considerable size from the other Great Lakes. In particular, the farthest headstream of the Nile is the Ruvyironza River in Burundi, which is an upper branch of the Kagera River. The Kagera flows for 690 km (429 miles) before reaching Lake Victoria.

Leaving Lake Victoria, the river is known as the Victoria Nile. It flows further for approximately 500 km (300 miles), through Lake Kyoga, until it reaches Lake Albert. After leaving Lake Albert, the river is known as the Albert Nile. It then flows into Sudan, where it becomes known as the Bahr al Jabal. At the confluence of the Bahr al Jabal with the Bahr el Ghazal, itself 720 km (445 miles) long, the river beomes known as the Bahr al Abyad, or the White Nile, from the clay suspended in its waters. From there, the river flows to Khartoum.

Meanwhile, the Blue Nile (or Bahr al Azraq) springs from Lake Tana in the Ethiopian Highlands . The Blue Nile flows about 1,400 km (850 miles) to Khartoum, where the Blue Nile and White Nile join to form "the Nile."

After the Blue and White Niles merge, the only remaining major tributary is the Atbara River, which originates in Ethiopia north of Lake Tana, and is approximately 800 km (500 miles) long. It joins the Nile approximately 300 km (200 miles) past Khartoum.

The Nile then reaches the man-made Lake Nasser, impounded behind the Aswan High Dam 270 km (170 miles) into Egypt from the Sudanese border. From there the main channel flows north through Egypt and into the Mediterranean Sea; a side channel, the Bahr Yussef , splits from the main channel downriver from the city of Asyut, and empties into the Fayum. Where the Nile meets the Mediterranean, the Nile Delta, is the eponym of all river deltas worldwide. Enrichment from Nile sediments carried eastward by currents nurture the fishing industries of the Eastern Mediterranean.

From its most remote headstream — the Ruvyironza — to the Mediterranean, the Nile is approximately 6695 km (4160 miles) long. Measuring instead from Lake Victoria gives a length of approximately 5584 km (3470 miles). It drains approximately 2.8 million to 3.4 million km² (1.1 million to 1.3 million mile²).

The Nile (iteru in Ancient Egyptian) was the lifeline of the ancient Egyptian civilization, with most of the population and all of the cities of Egypt in the Nile valley . It still supports much of the population of Egypt, living between otherwise inhospitable regions of the Sahara Desert. The river flooded every spring, depositing fertile soil on the fields. The flow of the river is disturbed at several points by cataracts , which are sections of faster flowing water with many small islands, shallow water, and rocks, forming an obstacle to navigation by boats. The first cataract, the closest to the mouth of the river, is at Aswan to the north of the Aswan Dams. The Nile north of Aswan is a regular tourist route, with cruise ships and traditional wooden sailing boats known as feluccas.

While most Egyptians still live in the Nile valley, the construction of the Aswan High Dam (finished in 1970) to provide hydroelectricity ended the spring floods and their renewal of the fertile soil.

Cities on the Nile include Khartoum, Aswan, Luxor (Thebes), and the GizaCairo conurbation.

Despite the attempts of the Greeks and Romans (who were unable to penetrate the Sudd), the source of the Nile was unknown until the 19th century, when John Hanning Speke was the first to identify it as Lake Victoria. Various earlier expeditions since ancient times had failed to determine the source, thus the classical Hellenistic and Roman representations of the river as a male river god with his head obscured in drapery.

The word "Nile" comes from the word Neilos (Νειλος), a Greek name for the Nile. Another Greek name for the Nile was Aigyptos (Αιγυπτος), which itself is the source of the name "Egypt".

The Nile has been the lifeline for Egyptian culture since the Stone Age. The annual flood was personified by the god Hapy, who was associated with fertility and regeneration.

The Nile was, and still is, used to transport goods to different places along its long path; the trade winds in this area happen to blow south, upriver, so ships could travel up and down the Nile with ease.

Ledyard, in his Travels, speaks thus contemptuously of this celebrated wonder:—"This is the mighty, the sovereign of rivers—the vast Nile that has been metamorphosed into one of the wonders of the world! Let me be careful how I read, and, above all, how I read ancient history. You have heard, and read too, much of its inundations. If the thousands of large and small canals from it, and the thousands of men and machines employed to transfer, by artificial means, the water of the Nile to the meadows on its banks—if this be the inundation that is meant, it is true; any other is false; it is not an inundating river."

On April 28, 2004, geologist Pasquale Scaturro and his partner, kayaker and documentary filmmaker Gordon Brown became the first people to navigate the entire Nile, from Lake Tana in Ethiopia to the beaches of Alexandria on the Mediterranean. Though their expedition included a number of others, Brown and Scaturro were the only ones to remain on the expedition for the entire journey. They chronicled their adventure with an IMAX camera and two handheld video cams, sharing their story in the IMAX film "Mystery of the Nile ," and in a book of the same title.

The Eonile

The present Nile is at least the fifth river that has flowed north from the Ethiopian Highands. Satellite imagery identified dry watercourses in the desert to the west of the Nile. An Eonile Canyon filled by surface drift represents an ancestral Nile, called the Eonile that flowed during the later Miocene, transporting clastics and light sediments to the Mediterranean, where several gas fields have been discovered. South of Cairo, the sand-filled canyon reaches 1400 meters.

When the Mediterranean Sea was a hot dry empty salt-floored sink in the late Miocene period, the Nile cut its course down to the new base level until it was several hundred feet below world ocean level at Aswan and 8000 feet below at Cairo. This huge canyon is now full of later sediment.

Formerly Lake Tanganyika drained northwards into the Nile, until the Virunga Volcanoes blocked its course in Rwanda. That would have made the Nile much longer, with its longest headwaters in northern Zambia.

External links

Last updated: 06-02-2005 00:10:13
The contents of this article are licensed from under the GNU Free Documentation License. How to see transparent copy