Nile River

Nile
The River Nile in Egypt
Origin	Africa
Mouth	Mediterranean Sea +
Basin countries	Sudan, Burundi, Rwanda, Democratic Republic of the Congo, Tanzania, Kenya, Uganda, Ethiopia, Egypt +
Length	6,695 km (4,180 mi) +
Source elevation	1,134 m (3,721 ft) +
Avg. discharge	2,830 m³/s (99,956 ft³/s) +
Basin area	3,400,000 km² (1,312,740 mi²) +

The Nile is a major north-flowing river in Africa, generally regarded as the longest river in the world. The Nile has two major tributaries. The Blue Nile is the source of most of the Nile's water and fertile soil, but the White Nile is the longer of the two. The White Nile rises in the Great Lakes region of central Africa, with the most distant source in southern Rwanda, and flows north from there through Tanzania, Lake Victoria, Uganda, and southern Sudan. The Blue Nile starts at Lake Tana in Ethiopia and flows into Sudan from the southeast. The two rivers meet near the Sudanese capital, Khartoum.

The northern section of the river flows almost entirely through desert from Sudan into Egypt, a country whose civilization has depended on the river since ancient times. Most of the population of Egypt and all its cities, with the exception of those near the coast, lie along those parts of the Nile valley north of Aswan, and nearly all the cultural and historical sites of Ancient Egypt are found along its banks.

Etymology of the word Nile

The word "Nile" comes from the Greek word Neilos, meaning river valley. In the ancient Egyptian language, the Nile is called iteru, meaning "great river," represented by the hieroglyphs shown on the right (literally itrw). In Coptic, the words piaro (Sahidic) or phiaro (Bohairic) meaning "the river" (lit. p(h).iar-o "the.canal-great") come from the same ancient name.

Tributaries

East Africa, showing the course of the Nile River, with the "Blue" and "White" Niles marked in those colors.

The Nile ends in a large delta that empties into the Mediterranean Sea. The drainage basin of the Nile covers 3,254,555 km², about 10 percent of the area of Africa [1].

The Nile has two great tributaries: the White Nile, starting in equatorial East Africa, and the Blue Nile, beginning in Ethiopia. Both branches are on the western flanks of the East African Rift, the southern part of the Great Rift Valley. Another less important one is Atbara, which flows only while there is rain in Ethiopia and dries very fast.

White Nile

The source of the Nile is sometimes considered to be Lake Victoria, but the lake itself has feeder rivers of considerable size. The most distant stream emerges from Nyungwe Forest in Rwanda, via the Rukarara, Mwogo, Nyabarongo and Kagera rivers, before flowing into Lake Victoria in Tanzania near the town of Bukoba. -

-

The Blue Nile Falls fed by Lake Tana near the city of Bahar Dar, Ethiopia

forms the upstream of the Blue Nile. It is also known as Tis Issat Falls after the name of the nearby village. The Nile leaves Lake Victoria at Ripon Falls, near Jinja, Uganda, as the Victoria Nile. It flows for approximately 300 miles(500 km) farther, 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 ("River of the Mountain"). At the confluence of the Bahr al Jabal with the Bahr al Ghazal, itself 445 miles(720 km) long, the river becomes known as the Bahr al Abyad, or the White Nile, from the white-ish clay suspended in its waters. From there, the river flows to Khartoum. When the Nile flooded it left this rich material named silt. The Ancient Egyptians used this soil to farm.

- - ===Blue Nile=== - The Blue Nile to Ethiopians (Bahr al Azraq to Sudanese) springs from Lake Tana in the Ethiopian highlands. The Blue Nile flows about 850 miles(1,400 km) to Khartoum, where the Blue Nile and White Nile join to form the "Nile proper." 90 percent of the water and 96 percent of the transported sediment carried by the Nile originates in Ethiopia, with 59 percent of the water from the Blue nile alone (the rest being from the Tekezé, Atbarah, Sobat, and small tributaries). The erosion and transportation of silt only occurs during the Ethiopian rainy season in the summer, however, when rainfall is especially high on the Ethiopian Plateau; the rest of the year, the great rivers draining Ethiopia into the Nile (Sobat, Blue Nile, Tekezé, and Atbarah) flow weakly. -

-

Composite satellite image of the White Nile (see also the Nile delta)

- - ==Hydrology== - The flow rate of the Albert Nile at Mongalla is almost constant throughout the year and averages 1,048 cubic meters per second (36,980 cubic feet per second). After Mongalla, the Nile is known as the Bahr El Jebel, which enters the enormous swamps of the Sud region of the Sudan. More than half of the Nile’s water is lost in this swamp to evaporation and transpiration. The average flow rate in the Bahr El Jebel at the tails of the swamps is about 510 m³/s (18,000 ft³/s). From here it soon meets with the Sobat River and forms the White Nile. - - The average flow of the White Nile at Malakal is 924 m³/s (32,600 ft³/s), the peak flow is approximately 1218 m³/s (42,980 ft³/s) in early March and minimum flow is about 609 m³/s (21,490 ft³/s) in late August. The fluctuation there is due the substantial variation in the flow of the Sobat which has a minimum flow of about 99 m³/s (3,490 ft³/s) in August and a peak flow of over 680 m³/s (24,000 ft³/s) in early March. - - From here the White Nile flows to Khartoum where it merges with the Blue Nile to form the Nile River. Further upstream the Atbara River, the last significant Nile tributary, merges with the Nile.The White Nile contributes approximately 31 percent ^{[citation needed]} of the yearly Nile discharge. However, during the dry season (January to June) the White Nile contributes between 70 and 90 percent of the total discharge from the Nile. During this period of time the natural discharge of the Blue Nile can be as low as 113 m³/s (3,990 ft³/s), although upstream dams regulate the flow of the river. During the dry period, there will typically be no flow from the Atbara River.

The Blue Nile contributes approximately 80-90 percent of the Nile River discharge. The flow of the Blue Nile varies considerably over its yearly cycle and is the main contribution to the large natural variation of the Nile flow.

Before the placement of dams on the river, peak flows would occur during late August and early September and minimum flows would occur during late April and early May.

The Nile basin is complex and because of this the discharge at any given point along the river depends on many factors including weather, diversions, evaporation/evapotranspiration, and groundwater flow.

In 1958 radioisotope tracking led to the discovery of a subterranean river, also called a crypto-river, which flows beneath the Nile.

Tributaries and Distributaries

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 around 800 km (500 miles) long. It joins the Nile approximately 200 miles(300 km) north of Khartoum.

The Nile is unusual in that its last tributary (the Atbara) joins it roughly halfway to the sea. From that point north, the Nile diminishes because of evaporation.

The course of the Nile in Sudan is distinctive for two reasons: 1) it flows over 6 groups of cataracts, from the first at Aswan to the sixth at Sabaloka (just north of Khartoum); and 2) it turns to flow southward for a good portion of its course, before again returning to flow north to the sea. This is called the "Great Bend of the Nile."

North of Cairo, the Nile splits into two branches (or distributaries) that feed the Mediterranean: the Rosetta Branch to the west and the Damietta to the east, forming the Nile Delta.

History

The confluence of the Kagera and Ruvubu rivers near Rusumo Falls, part of the Nile's upper reaches.

The Nile was the lifeline of the ancient Egyptian civilization, with most of the population and all of the cities of Egypt resting along those parts of the Nile valley lying north of Aswan. The Nile has been the lifeline for Egyptian culture since the Stone Age. Climate change, or perhaps overgrazing, desiccated the pastoral lands of Egypt to form the Sahara Desert, possibly as long ago as 8000 B.C.E., and the inhabitants then presumably migrated to the river, where they developed a settled agricultural economy and a more centralized society.

The founding of Egyptian civilization

As an unending source of sustenance, The Nile played a crucial role in the founding of Egyptian civilization. The Nile made the land surrounding it extremely fertile when it flooded or was inundated annually. The Egyptians were able to cultivate wheat and other crops, providing food for the population. Also, the Nile’s water attracted game such as water buffalo and, after the Persians introduced them in the seventh century B.C.E., camels. These animals could be killed for meat or tamed and used for ploughing — or in the camels' case, traveling. The Nile itself was also a convenient and efficient way of transportation for people and goods.

Egypt’s stability was one of the best structured in history. In fact, it might easily have surpassed many modern societies. This stability was an immediate result of the Nile’s fertility. The Nile also provided flax for trade. Wheat was also traded, a crucial crop in the Middle East where famine was very common. This trading system secured the diplomatic relationship Egypt had with other countries, and often contributed to Egypt's economic stability. Also, the Nile provided the resources such as food or money, to quickly and efficiently raise an army. Whether the army was to take on a defensive or offensive role is unknown.

The Nile played a major role in politics and social life. The Pharaoh would supposedly flood the Nile, and in return for the life-giving water and crops, the peasants would cultivate the fertile soil and send a portion of the resources they had reaped to the Pharaoh.

The Nile was so significant to the lifestyle of the Egyptians that they created a god dedicated to the welfare of the Nile’s annual inundation. His name was Hapi, and both he and the Pharaoh were thought to control the flooding of the Nile River. Also, the Nile was considered as a causeway from life to death and afterlife. The east was thought of as a place of birth and growth, and the west was considered the place of death, as the god Ra, the sun, underwent birth, death, and resurrection each time he crossed the sky. Thus, all tombs were located west of the Nile, because the Egyptians believed that to enter the afterlife, they must be buried on the side that symbolized death.

The Greek historian Herodotus wrote that ‘Egypt was the gift of the Nile’, and in a sense that is correct. Without the waters of the Nile River for irrigation, Egyptian civilization would probably have been short-lived. The Nile provided the elements that make a vigorous civilization, and contributed much to its lasting three thousand years.

That far-reaching trade has been carried on along the Nile since ancient times can be seen from the Ishango bone, possibly the earliest known indication of [Ancient Egyptian multiplication]], which was discovered along the headwaters of the Nile River (near Lake Edward, in northeastern Democratic Republic of Congo) and was carbon-dated to 20,000 B.C.E.

The search for the source

The Great Bend of the Nile in Sudan, looking north across the Sahara Desert towards Northern Sudan.

Despite the attempts of the Greeks and Romans (who were unable to penetrate the Sudd), the upper reaches of the Nile remained largely unknown. Various expeditions had failed to determine the river's source, thus yielding classical Hellenistic and Roman representations of the river as a male god with his face and head obscured in drapery. Agatharcides records that in the time of Ptolemy II Philadelphus, a military expedition had penetrated far enough along the course of the Blue Nile to determine that the summer floods were caused by heavy seasonal rainstorms in the Ethiopian highlands, but no European in Antiquity is known to have reached Lake Tana, let alone retraced the steps of this expedition farther than Meroe.

Europeans learned little new information about the origins of the Nile until the fifteenth and sixteenth centuries, when travelers to Ethiopia visited not only Lake Tana, but the source of the Blue Nile in the mountains south of the lake. Although James Bruce claimed to have been the first European to have visited the headwaters, and modern writers with better knowledge give the credit to the Jesuit Pedro Páez, Europeans had been resident in the country since the late fifteenth century, and it is entirely possible one of them had visited the headwaters but was unable to send a report of his discoveries out of Ethiopia.

The White Nile was even less understood, and the ancients mistakenly believed that the Niger River represented the upper reaches of the White Nile; for example, Pliny the Elder wrote that the Nile had its origins "in a mountain of lower Mauretania," flowed above ground for "many days" distance, then went underground, reappeared as a large lake in the territories of the Masaesyles, then sank again below the desert to flow underground "for a distance of 20 days' journey till it reaches the nearest Ethiopians" (N.H. 5.10). A merchant named Diogenes reported the Nile’s water attracted game such as water buffalo; and after the Persians introduced them in the 7th century B.C.E., camels.

Lake Victoria was first sighted by Europeans in 1858 when the British explorer John Hanning Speke reached its southern shore while on his journey with Richard Francis Burton to explore central Africa and locate the Great Lakes. Believing he had found the source of the Nile on seeing this "vast expanse of open water" for the first time, Speke named the lake after the then Queen of the United Kingdom. Burton, who had been recovering from illness at the time and resting farther south on the shores of Lake Tanganyika, was outraged that Speke claimed to have proved his discovery to have been the true source of the Nile when Burton regarded this as still unsettled. A very public quarrel ensued, which not only sparked a great deal of intense debate within the scientific community of the day but much interest by other explorers keen to either confirm or refute Speke's discovery. The well-known British explorer and missionary David Livingstone failed in his attempt to verify Speke's discovery, instead pushing too far west and entering the Congo River system instead. It was ultimately the American explorer Henry Morton Stanley who confirmed the truth of Speke's discovery, circumnavigating Lake Victoria and reporting the great outflow at Rippon Falls on the lake's northern shore.

The White Nile Expedition, led by South African national Hendri Coetzee, was to become the first to navigate the Nile in its entire length. The expedition took off from Uganda in January 2004 and arrived safely at the Mediterranean four and a half months later.

On April 28, 2004, geologist Pasquale Scaturro and his partner, kayaker and documentary filmmaker Gordon Brown became the first people to navigate the Blue Nile, from Lake Tana in Ethiopia to 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. However, the team was forced to use outboard motors for most of their journey, and it was not until January 29, 2005, when Canadian Les Jickling and New Zealander Mark Tanner reached the Mediterranean Sea, that the river had been paddled for the first time under human power.

On April 30, 2005, a team led by South Africans Peter Meredith and Hendri Coetzee became the first to navigate the most remote headstream, the true source of the Nile — the Akagera river which starts as the Rukarara in Nyungwe forest in Rwanda.

On March 31, 2006, three explorers from Britain and New Zealand led by Neil McGrigor claimed to have been the first to travel the river from its mouth to a new "true source" deep in Rwanda's Nyungwe rainforest. {{#invoke:Coordinates|coord}}{{#coordinates:2|16|55.92|S|29|19|52.32|E| | |name= }}. [2]

The river today

View of the Nile from a cruiseboat, between Luxor and Aswan in Egypt

The Eternal Nile

The Nile in Uganda

A river boat crossing the Nile in Uganda

The Nile still supports much of the population living along its banks, with the Egyptians living in otherwise inhospitable regions of the Sahara Desert. The river flooded every summer, depositing fertile silt on the plains. 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 sudd in the Sudan also forms a formidable obstacle for navigation and flow of water, to the extent that Egypt had once attempted to dig a canal (the Jongeli Canal) to improve the flow of this stagnant mass of water (also known as Lake No).

The Nile was, and still is, used to transport goods to different places along its long path; especially since winter winds in this area blow up river, the ships could travel up with no work by using the sail, and down using the flow of the river. While most Egyptians still live in the Nile valley, the construction of the Aswan High Dam (finished in 1970) to provide hydroelectricity ended the summer floods and their renewal of the fertile soil.

Cities on the Nile include Khartoum, Aswan, Luxor (Thebes), and the Giza–Cairo conurbation. 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. In addition, many "floating hotel" cruise boats ply the route between Luxor and Aswan, stopping in at Edfu and Kom Ombo along the way. It used to be possible to sail on these boats all the way from Cairo to Aswan, but security concerns have shut down the northernmost portion for many years.

Flooding of the Nile

The annual cycles of the Nile were very important to the lives of ancient Egyptians. Egypt’s stability was an immediate result of the Nile’s fertility. The Nile also provided flax and wheat for trade. This trading system secured the diplomatic relationship Egypt had with other countries and contributed to Egypt's economic stability. Also, the Nile provided the resources such as food or money to quickly and efficiently raise an army.

The Nile also played a major role in political and social life. The Pharaoh would supposedly flood the Nile, and in return for the life-giving water and crops, the peasants would cultivate the fertile soil and send a portion of the resources they had reaped to the Pharaoh.

The Eonile

The present Nile is at least the fifth river that has flowed north from the Ethiopian highlands. Satellite imagery was used to identify dry watercourses in the desert to the west of the Nile. An Eonile canyon, now filled by surface drift, represents an ancestral Nile called the Eonile that flowed during the later Miocene (23-5.3 million years before the present). The Eonile transported clastic sediments to the Mediterranean, where several gas fields have been discovered within these sediments.

During the late-Miocene Messinian Salinity Crisis, when the Mediterranean was a closed basin and evaporated empty or nearly so, 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 deep under 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

• Images of Uganda. Uganda. Retrieved March 22, 2007.
• Bibliography on Water. Peace Palace Libray. Retrieved March 22, 2007.
• Watersheds of the World: Africa - Nile Watershed. World Resources Institute. Retrieved March 22, 2007.
• The River Nile. The University of Texas at Dallas. Retrieved March 22, 2007.
• Watersheds of Africa. Water Resources eAtlas. Retrieved March 22, 2007.
• Nile Delta. Earth from Space. Retrieved March 22, 2007.
• Nile River Boat Cruise, Egypt. IanandWendy. Retrieved March 22, 2007.
• The Inscrutable Nile at the Beginning of the New Millennium. Department of History. Retrieved March 22, 2007.
• Geology. Aberystwyth. Retrieved March 22, 2007.
• September 21, 2006 . Vast "Grand Canyon" Lurks 8,200 Feet BENEATH Cairo, Egypt. Suburban Emergency Management Project. Retrieved March 22, 2007.

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