Nile River Flow Bayesian Changepoint Detection

The Nile (also known as the Nile River or River Nile) is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa. It has historically been considered the longest river in the world,
though this has been contested by research suggesting that the Amazon River is slightly longer.Amazon Longer Than Nile River, Scientists Say

Of the world's major rivers, the Nile has one of the lowest average annual flow rates.
About long, its drainage basin covers eleven countries: the Democratic Republic of the Congo, Tanzania, Burundi, Rwanda, Uganda, Kenya, Ethiopia, Eritrea, South Sudan, Sudan, and Egypt.
In particular, the Nile is the primary water source of Egypt, Sudan and South Sudan.
In these countries it is an important economic factor in agriculture and fishing.

The Nile has two major tributaries: the White Nile and the Blue Nile. The White Nile, being the longer, is traditionally considered to be the headwaters stream, while the Blue Nile actually contributes 80% of the water and silt below the confluence of the two. The White Nile rises in the Great Lakes region. It begins at Lake Victoria and flows through Uganda and South Sudan. The Blue Nile begins at Lake Tana in Ethiopia and flows into Sudan from the southeast. The two rivers meet at the Sudanese capital of Khartoum.

After Khartoum the river flows north, almost entirely through the Nubian Desert, to Cairo and its large delta, joining the Mediterranean Sea at Alexandria. Egyptian civilization and Sudanese kingdoms have depended on the river and its annual flooding since ancient times. Most of the population and cities of Egypt lie along those parts of the Nile valley north of the Aswan Dam. Nearly all the cultural and historical sites of Ancient Egypt developed and are found along river banks. The Nile is, with the Rhône and Po, one of the three Mediterranean rivers with the largest water discharge.

Etymology

In the ancient Egyptian language, the Nile is called ''Ḥꜥpy'' (Hapy) or ''Jtrw'' (Iteru), meaning "river". In Coptic, the word ⲫⲓⲁⲣⲟ, pronounced ''piaro'' ( Sahidic) or ''phiaro'' ( Bohairic), means "the river" (lit. p(h).iar-o "the-canal-great"), and comes from the same ancient name. In Nobiin, the river is called ''Áman Dawū'', meaning "the great water". In Luganda, the river is called ''Kiira'' or ''Kiyira''. In Runyoro, it is called ''Kihiira''. In Egyptian Arabic, the Nile is called ''en-Nīl'', while in Standard Arabic it is called ''an-Nīl''. In Biblical Hebrew, it is , ''Ha-Ye'or'' or , ''Ha-Shiḥor''.

The English name ''Nile'' and the Arabic names ''en-Nîl'' and ''an-Nîl'' both derive from the Latin ' and the Ancient Greek . Beyond that, however, the etymology is disputed. Homer called the river , ''Aiguptos'', but in subsequent periods, Greek authors referred to its lower course as ''Neilos''; this term later became generalized for the entire river system. Thus, the name may derive from Ancient Egyptian expression ''n''ꜣ ''r''ꜣ''w-ḥ''ꜣ''w(t)'' (), which referred specifically to the branches of the Nile transversing the Delta, and would have been pronounced ''ni-lo-he'' in the area around Memphis in the 8th century BCE. Hesiod at his ''Theogony'' refers to Nilus (Νεῖλος) as one of the river gods, son of Oceanus and Tethys.

Another derivation of ''Nile'' might be related to the term ''Nil'' (; ), which refers to ''Indigofera tinctoria'', one of the original sources of indigo dye. Another possible etymology derives from the Semitic term ''Nahal'', meaning "river". Old Libyan has the term ''lilu'', meaning water (in modern Berber ''ilel'' ⵉⵍⴻⵍ means ''sea'').

Courses

With a total length of about between the region of Lake Victoria and the Mediterranean Sea, the Nile is among the longest rivers on Earth. The drainage basin of the Nile covers , about 10% of the area of Africa. Compared to other major rivers, though, the Nile carries little water (5% of that of the Congo River, for example). The Nile basin is complex, and because of this, the discharge at any given point along the main stem depends on many factors including weather, diversions, evaporation and evapotranspiration, and groundwater flow.

Upstream from Khartoum (to the south), the river is known as the White Nile, a term also used in a limited sense to describe the section between Lake No and Khartoum. At Khartoum, the river is joined by the Blue Nile. The White Nile starts in equatorial East Africa, and the Blue Nile begins in Ethiopia. Both branches are on the western flanks of the East African Rift.

Sources

The source of the Blue Nile is Lake Tana in the Gish Abay region in the Ethiopian Highlands.

The source of the White Nile, even after centuries of exploration, remains in dispute. The most remote source that is indisputably a source for the White Nile is of the Kagera River; however, the Kagera has multiple tributaries that are in contention for the farthest source of the White Nile. Two start in Burundi: the Ruvyironza River (also known as the Luvironza) and the Rurubu River. In addition, in 2010, an exploration party in Rwanda went to a place described as the source of the Rukarara tributary, and by hacking a path up steep jungle-choked mountain slopes in the Nyungwe Forest found (in the dry season) an appreciable incoming surface flow for many kilometres upstream, thence finding a new source, giving the Nile a length of .

In Uganda

The White Nile leaves Lake Victoria at Ripon Falls near Jinja, Uganda, as the "Victoria Nile." It flows north for some to Lake Kyoga. The last part of the approximately river section starts from the western shores of the lake and flows at first to the west until just south of Masindi Port, where the river turns north, then makes a great half circle to the east and north to Karuma Falls. For the remaining part, it flows westerly through the Murchison Falls until it reaches the northern shores of Lake Albert where it forms a significant river delta. Lake Albert is on the border of the Democratic Republic of the Congo, but the Nile is not a border river at this point. After leaving Lake Albert, the river continues north through Uganda and is known as the Albert Nile.

In South Sudan

The White Nile flows into South Sudan just south of Nimule, where it is known as the ''Bahr al Jabal'' ("Mountain River"). Just south of the town is the confluence with the Achwa River. The Bahr al Ghazal, long, joins the Bahr al Jabal at a small lagoon called Lake No, after which the Nile becomes known as the ''Bahr al Abyad'', or the White Nile, from the whitish clay suspended in its waters. When the Nile floods it leaves a rich silty deposit which fertilizes the soil. The Nile no longer floods in Egypt since the completion of the Aswan Dam in 1970. An anabranch river, the Bahr el Zeraf, flows out of the Nile's Bahr al Jabal section and rejoins the White Nile.

The flow rate of the Bahr al Jabal at Mongalla is almost constant throughout the year and averages . After Mongalla, the Bahr Al Jabal enters the enormous swamps of the Sudd region. More than half of the Nile's water is lost in this swamp to evaporation and transpiration. The average flow rate of the White Nile at the tails of the swamps is about . From here it meets with the Sobat River at Malakal. On an annual basis, the White Nile upstream of Malakal contributes about 15% of the total outflow of the Nile.

The average flow of the White Nile at Lake Kawaki Malakal, just below the Sobat River, is ; the peak flow is approximately in October and minimum flow is about in April. This fluctuation is caused by the substantial variation in the flow of the Sobat, which has a minimum flow of about in March and a peak flow of over in October. During the dry season (January to June) the White Nile contributes between 70% and 90% of the total discharge from the Nile.

In Sudan

Below Renk, the White Nile enters Sudan, it flows north to Khartoum and meets the Blue Nile.

The course of the Nile in Sudan is distinctive. It flows over six groups of cataracts, from the sixth at Sabaloka just north of Khartoum northward to Abu Hamad. The tectonic uplift of the Nubian Swell diverts the river south-west for over 300 km, following the structure of the Central African Shear Zone embracing the Bayuda Desert. At Al Dabbah it resumes its northward course towards the first cataract at Aswan forming the S-shaped Great Bend of the Nile mentioned by Eratosthenes.

In the north of Sudan, the river enters Lake Nasser (known in Sudan as Lake Nubia), the larger part of which is in Egypt.

In Egypt

Below the Aswan Dam, at the northern limit of Lake Nasser, the Nile resumes its historic course. North of Cairo, the Nile splits into two branches (or distributaries) that feed the Mediterranean: the Rosetta Branch (an anglicized version of the name Rashid) to the west and the Damietta to the east, forming the Nile Delta.

Sediment transport

The annual sediment transport by the Nile in Egypt has been quantified.
* At Aswan: 0.14 million tonnes of suspended sediment and an additional 28% of bedload
* At Beni Sweif: 0.5 million tonnes of suspended sediment and an additional 20% of bedload
* At Qena: 0.27 million tonnes of suspended sediment and an additional 27% of bedload
* At Sohag: 1.5 million tonnes of suspended sediment and an additional 13% of bedload

Tributaries

Atbarah River

Below the confluence with the Blue Nile the only major tributary is the Atbarah River, also known as the Red Nile. Roughly halfway to the sea, it originates in Ethiopia north of Lake Tana, and is around long. The Atbarah flows only while there is rain in Ethiopia and dries very rapidly. During the dry period of January to June, it typically dries up north of Khartoum.

Blue Nile

The Blue Nile (, ''ʿĀbay'') springs from Lake Tana in the Ethiopian Highlands. The Blue Nile flows about 1,400 kilometres to Khartoum, where the Blue Nile and White Nile join to form the Nile. Ninety percent of the water and ninety-six percent of the transported sediment carried by the Nile come from the Atbarah and Blue Nile, both of which originate in Ethiopia, with fifty-nine percent of the water coming from the Blue Nile. The erosion and transportation of silt only occurs during the Ethiopian rainy season when rainfall is especially high in the Ethiopian Highlands; the rest of the year, the great rivers draining Ethiopia into the Nile have a weaker flow. In harsh and arid seasons and droughts, the Blue Nile dries out completely.

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. During the dry season the natural discharge of the Blue Nile can be as low as , although upstream dams regulate the flow of the river. During the wet season, the peak flow of the Blue Nile often exceeds in late August (a difference of a factor of 50).

Before the placement of dams on the river the yearly discharge varied by a factor of 15 at Aswan. Peak flows of over occurred during late August and early September, and minimum flows of about occurred during late April and early May.

Bahr el Ghazal and Sobat River

The Bahr al Ghazal and the Sobat River are the two most important tributaries of the White Nile in terms of discharge.

The Bahr al Ghazal's drainage basin is the largest of any of the Nile's sub-basins, measuring in size, but it contributes a relatively small amount of water, about annually, because tremendous volumes of water are lost in the Sudd wetlands.

The Sobat River, which joins the Nile a short distance below Lake No, drains about half as much land, , but contributes annually to the Nile. When in flood the Sobat carries a large amount of sediment, adding greatly to the White Nile's color.

Yellow Nile

The Yellow Nile is a former tributary that connected the Ouaddaï highlands of eastern Chad to the Nile River Valley to . Its remains are known as the Wadi Howar. The wadi passes through Gharb Darfur near the northern border with Chad and meets up with the Nile near the southern point of the Great Bend.

History

The Nile has been the lifeline of civilization in Egypt since the Stone Age, with most of the population and all of the cities of Egypt developing along those parts of the Nile valley lying north of Aswan. However, the Nile used to run much more westerly through what is now Wadi Hamim and Wadi al Maqar in Libya and flow into the Gulf of Sidra. As the sea level rose at the end of the most recent ice age, the stream which is now the northern Nile captured the ancestral Nile near Asyut. This change in climate also led to the current extents of the Sahara desert, around 3400 BCE.

Khufu branch

The Giza pyramid complex originally overlooked a branch of the Nile that no longer exists. This branch was highest during the African Humid Period.

Ancient Niles

The existing Nile has five earlier phases:
*i) the Upper Miocenian Eonile, of about 6 million years BP;
*ii) the Upper Pliocenian Paleonile, commencing about 3.32 million years BP, and during the Pleistocene;
*iii) The Nile phases, including the Proto-Nile, commencing about 600,000 years BP;
*iv) Pre-Nile;
*v) transitioning at about 400,000 years BP to the Neo-Nile.
Flowing north from the Ethiopian Highlands, satellite imagery was used to identify dry watercourses in the desert to the west of the Nile. A canyon, now filled by surface drift, represents the Eonile that flowed during 23–5.3 million years before present. The Eonile transported clastic sediments to the Mediterranean; several natural gas fields have been discovered within these sediments.

During the late-Miocene Messinian salinity crisis, when the Mediterranean Sea was a closed basin and evaporated to the point of being empty or nearly so, the Nile cut its course down to the new base level until it was several hundred metres below world ocean level at Aswan and below Cairo. This created a very long and deep canyon which was filled with sediment after the Mediterranean was recreated. At some point the sediments raised the riverbed sufficiently for the river to overflow westward into a depression to create Lake Moeris.

Lake Tanganyika drained northwards into the Nile until the Virunga Volcanoes blocked its course in Rwanda. The Nile was much longer at that time, with its furthest headwaters in northern Zambia. The currently existing Nile first flowed during the former parts of the Würm glaciation period.

Affad 23 is an archaeological site located in alluvial deposits formed by an ancient channel of the Nile in the Affad region of southern Dongola Reach, Sudan.

Integrated Nile

There are two theories about the age of the integrated Nile. One is that the integrated drainage of the Nile is of young age and that the Nile basin was formerly broken into series of separate basins, only the most northerly of which fed a river following the present course of the Nile in Egypt and Sudan. Rushdi Said postulates that Egypt supplied most of the waters of the Nile during the early part of its history.Said, R. (1981). ''The geological evolution of the River Nile''. Springer Verlag.

The other theory is that the drainage from Ethiopia via rivers equivalent to the Blue Nile, the Atbara and the Takazze flowed to the Mediterranean via the Egyptian Nile since well back into Tertiary times.Williams, M.A.J.; Williams, F. (1980). ''Evolution of Nile Basin''. In M.A.J. Williams and H. Faure (eds). ''The Sahara and the Nile''. Balkema, Rotterdam, pp. 207–224.

R. B. Salama suggests that a series of separate closed continental basins each occupied one of the major parts of the Sudanese Rift System that during the Paleogene and Neogene periods (66 million to 2.588 million years ago): Mellut rift, White Nile rift, Blue Nile rift, Atbara rift and Sag El Naam rift.
The Mellut Basin is nearly deep at its central part. This rift could possibly be still active, with reported tectonic activity in its northern and southern boundaries. The Sudd swamp which forms the central part of the basin may still be subsiding. The White Nile Rift system, although shallower than the Bahr el Arab rift, is about deep. Geophysical exploration of the Blue Nile Rift System estimated the depth of the sediments to be . These basins were not interconnected until their subsidence ceased, and the rate of sediment deposition was enough to fill and connect them.

The Egyptian Nile connected to the Sudanese Nile, which captures the Ethiopian and Equatorial headwaters during the current stages of tectonic activity in the Eastern, Central and Sudanese Rift systems.Salama, R.B. (1997). ''Rift Basins of Sudan. African Basins, Sedimentary Basins of the World. 3.'' Edited by R.C. Selley (Series Editor K.J. Hsu) pp. 105–149. ElSevier, Amsterdam. The connection of the different Niles occurred during cyclic wet periods. The Atbarah overflowed its closed basin during the wet periods that occurred about 100,000 to 120,000 years ago. The Blue Nile connected to the main Nile during the 70,000–80,000 years B.P. wet period. The White Nile system in Bahr El Arab and White Nile Rifts remained a closed lake until the connection of the Victoria Nile to the main system some 12,500 years ago during the African humid period.

Role in the founding of Egyptian civilization

The Greek historian Herodotus wrote that "Egypt was the gift of the Nile". An unending source of sustenance, it played a crucial role in the development of Egyptian civilization. Because the river overflowed its banks annually and deposited new layers of silt, the surrounding land was very fertile. The Ancient Egyptians cultivated and traded wheat, flax, papyrus and other crops around the Nile. Wheat was a crucial crop in the famine-plagued Middle East. This trading system secured Egypt's diplomatic relationships with other countries and contributed to economic stability. Far-reaching trade has been carried on along the Nile since ancient times. A tune, Hymn to the Nile, was created and sung by the ancient Egyptian peoples about the flooding of the Nile River and all of the miracles it brought to Ancient Egyptian civilization.

Water buffalo were introduced from Asia, and the Assyrians introduced camels in the 7th century BCE. These animals were raised for meat and were domesticated and used for ploughing—or in the camels' case, carriage. Water was vital to both people and livestock. The Nile was also a convenient and efficient means of transportation for people and goods.

The Nile was also an important part of ancient Egyptian spiritual life. Hapi was the god of the annual floods, and both he and the pharaoh were thought to control the flooding. The Nile was considered to be a causeway from life to death and the 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 day as he crossed the sky. Thus, all tombs were west of the Nile, because the Egyptians believed that in order to enter the afterlife, they had to be buried on the side that symbolized death.

As the Nile was such an important factor in Egyptian life, the ancient calendar was even based on the three cycles of the Nile. These seasons, each consisting of four months of thirty days each, were called Akhet, Peret, and Shemu. Akhet, which means inundation, was the time of the year when the Nile flooded, leaving several layers of fertile soil behind, aiding in agricultural growth. Peret was the growing season, and Shemu, the last season, was the harvest season when there were no rains.

European search for the source

To the ancient Greeks and Romans, the upper reaches of the White Nile remained largely unknown, as they failed to penetrate the ''Sudd'' wetlands of South Sudan. Vitruvius thought that source of the Nile was in Mauritania, on the "other" (south) side of the Atlas Mountains. Various expeditions failed to determine the river's source. Agatharchides 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 of antiquity is known to have reached Lake Tana. The '' Tabula Rogeriana'' depicted the source as three lakes in 1154.

Europeans began to learn about the origins of the Nile in the 14th century when the Pope sent monks as emissaries to Mongolia who passed India, the Middle East and Africa, and described being told of the source of the Nile in Abyssinia (Ethiopia). Later in the 15th and 16th centuries, travelers to Ethiopia visited Lake Tana and the source of the Blue Nile in the mountains south of the lake. Supposedly, Paolo Trevisani (–1483), a Venetian traveller in Ethiopia, wrote a journal of his travels to the ''origin of the Nile'' that has since been lost.
James Bruce claimed to be the first European to have visited the headwaters.
Modern writers give the credit to the Jesuit Pedro Páez. Páez's account of the source of the Nile is a long and vivid account of Ethiopia. It was published in full only in the early 20th century, but was featured in works of Páez's contemporaries, like Baltazar Téllez, Athanasius Kircher and Johann Michael Vansleb.

Europeans had been resident in Ethiopia since the late 15th century, and one of them may have visited the headwaters even earlier without leaving a written trace. The Portuguese João Bermudes published the first description of the Tis Issat Falls in his 1565 memoirs, compared them to the Nile Falls alluded to in Cicero's ''De Republica''. Jerónimo Lobo describes the source of the Blue Nile, visiting shortly after Pedro Páez. Telles also uses his account.

The White Nile was even less understood. The ancients mistakenly believed that the Niger River represented the upper reaches of the White Nile. For example, Pliny the Elder writes 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 Masaesyli, then sank again below the desert to flow underground "for a distance of 20 days' journey till it reaches the nearest Ethiopians."

Modern exploration of the Nile basin began with the conquest of the northern and central Sudan by the Ottoman viceroy of Egypt, Muhammad Ali, and his sons from 1821 onward. As a result of this, the Blue Nile was known as far as its exit from the Ethiopian foothills and the White Nile as far as the mouth of the Sobat River. Three expeditions under a Turkish officer, Selim Bimbashi, were made between 1839 and 1842, and two got to the point about beyond the present port of Juba, where the country rises and rapids make navigation very difficult.

Lake Victoria was first sighted by Europeans in 1858 when British explorer John Hanning Speke reached its southern shore while traveling 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 Queen Victoria. Burton, recovering from illness and resting further south on the shores of Lake Tanganyika, was outraged that Speke claimed to have proven his discovery to be the true source of the Nile when Burton regarded this as still unsettled. A quarrel ensued which sparked intense debate within the scientific community and interest by other explorers keen to either confirm or refute Speke's discovery. British explorer and missionary David Livingstone pushed too far west and entered the Congo River system instead. It was ultimately Welsh-American explorer Henry Morton Stanley who confirmed Speke's discovery, circumnavigating Lake Victoria and reporting the great outflow at Ripon Falls on the lake's northern shore.

Since 1950

The Nile has long been used to transport goods along its length. Winter winds blow south, up river, so ships could sail up river using sails and down river using the flow of the river. While most Egyptians still live in the Nile valley, the 1970 completion of the Aswan Dam ended the summer floods and their renewal of the fertile soil, fundamentally changing farming practices. The Nile supports much of the population living along its banks, enabling Egyptians to live in otherwise inhospitable regions of the Sahara. The river's flow is disturbed at several points by the Cataracts of the Nile which form an obstacle to navigation by boats. The Sudd also forms a formidable navigation obstacle and impedes water flow, to the extent that Sudan had once attempted to build the Jonglei Canal to bypass the swamp.

Nile cities include Khartoum, Aswan, Luxor (Thebes), and the GizaCairo conurbation. The first cataract, the closest to the mouth of the river, is at Aswan, north of the Aswan Dam. This part of the river is a regular tourist route, with cruise ships and traditional wooden sailing boats known as feluccas. Many cruise ships ply the route between Luxor and Aswan, stopping at Edfu and Kom Ombo along the way. Security concerns have limited cruising on the northernmost portion for many years.

A computer simulation study to plan the economic development of the Nile was directed by H.A.W. Morrice and W.N. Allan, for the Ministry of Hydro-power of Sudan, during 1955–57 Morrice was their hydrological adviser, and Allan his predecessor. The calculations were enabled by accurate monthly inflow data collected for 50 years. The underlying principle was the use of over-year storage, to conserve water from rainy years for use in dry years. Irrigation, navigation and other needs were considered. Each computer run postulated a set of reservoirs and operating equations for the release of water as a function of the month and the levels upstream. The behavior that would have resulted given the inflow data was modeled. Over 600 models were run. Recommendations were made to the Sudanese authorities. The calculations were run on an IBM 650 computer. Simulation studies to design water resources are discussed further in the article on hydrology transport models, which have been used since the 1980s to analyze water quality.

Despite the development of many reservoirs, drought during the 1980s led to widespread starvation in Ethiopia and Sudan, but Egypt was nourished by water impounded in Lake Nasser. Drought has proven to be a major cause of fatality in the Nile river basin. According to a report by the Strategic Foresight Group, droughts in the last century have affected around 170 million people and killed half a million people.Blue Peace for the Nile, 2009
; Report by Strategic Foresight Group From the 70 incidents of drought which took place between 1900 and 2012, 55 incidents took place in Ethiopia, Sudan, South Sudan, Kenya and Tanzania.

Water sharing dispute

The Nile waters have affected the populations, cultures, economies, and politics of Northeast Africa and the Nile Basin for many decades. The most recent water sharing dispute is the dispute between Egypt and Ethiopia over the $4.5 billion Grand Ethiopian Renaissance Dam, which has become a national preoccupation in both countries, stoking patriotism, deep-seated fears and even murmurs of war. In both Egypt and Ethiopia the Nile and the Grand Ethiopian Renaisance Dam are parts of the national identity. In Ethiopia it is seen as a path towards increased development, whereas in Egypt fears of drought and water shortage prevail. For Egypt, to justify its excessive access to Nile waters, three treaties signed in 1902, 1929, and 1959 are used, which are however criticized. The 1902 and 1929 treaties were heavily influenced by colonialism as the British Empire made African colonies make concessions on Nile waters to the benefit of British Egypt. With the end of colonialism and the emergence of postcolonialism, these treaties are seen as colonial products, which have lost their validity. The distribution of Nile waters in the treaties also sets the foundation for the alliance of Sudan and Egypt in the Nile Basin. Both states distributed practically all Nile waters between them in the 1959 agreement and still align their politics regarding the Nile waters. After the announcement of the Grand Ethiopian Renaissance Dam, Sudan and Egypt conducted three military exercises together.

Already before the plans for the Grand Ethiopian Renaissance Dam were published in 2014, several attempts have been made to establish new agreements between the countries sharing the Nile waters. Countries including Uganda, Sudan, Ethiopia and Kenya have complained about Egyptian domination of its water resources and the 1999 Nile Basin Initiative promoted a peaceful cooperation among those states. On 14 May 2010 at Entebbe, Uganda, Ethiopia, Rwanda, and Tanzania signed a new agreement on sharing the Nile waters even though this agreement raised strong opposition from Egypt and Sudan. Ideally, such international agreements should promote equitable and efficient usage of the Nile basin's water resources. Without a better understanding about the availability of the future water resources of the Nile, it is possible that conflicts could arise between these countries relying on the Nile for their water supply, economic and social developments. The conflicting priorities of the Nile riparian countries according to different domestic factors such as socioeconomic status, level of development, or climatic conditions severely affect the stance of Egypt and Ethiopia in negotiations. In the several rounds of negotiations since 2014 especially the filling and operation of the Grand Ethiopian Renaissance Dam in times of water scarcity appeared to be a critical topic where no consensus was found. The talks about the Grand Ethiopian Renaissance Dam are almost exclusively between Egypt, Sudan, and Ethiopia, however some rounds of negotiations were accompanied and led by other actors such as the United States, the African Union, or the European Union. The failure of the several rounds of negotiations has led some to argue that the Grand Ethiopian Renaissance Dam dispute might develop into a water war. Especially after the failed negotiations led by the United States, this risk was discussed as president Trump threatened that Egypt might “blow up the dam”. Nevertheless, a water war is thus far considered unlikely, given the serious consequences this would have for the countries involved and the region. Also, given the high protection of the Grand Ethiopian Renaissance Dam it is unclear if the Egyptian military would be successful in an attack.

Modern achievements and exploration

White Nile

In 1951, American John Goddard together with two French explorers became the first to successfully navigate the entire Nile from its source in Burundi at the potential headsprings of the Kagera River in Burundi to its mouth on the Mediterranean Sea, a journey of approximately . Their 9-month journey is described in the book ''Kayaks down the Nile''.

The White Nile Expedition, led by South African national Hendrik Coetzee, navigated the White Nile's entire length of approximately . The expedition began at the White Nile's beginning at Lake Victoria in Uganda, on 17 January 2004 and arrived at the Mediterranean in Rosetta, four and a half months later.

Blue Nile

The Blue Nile Expedition, led by geologist Pasquale Scaturro and his partner, kayaker and documentary filmmaker Gordon Brown became the first known people to descend the entire Blue Nile, from Lake Tana in Ethiopia to the beaches of Alexandria on the Mediterranean. Their approximately journey took 114 days, from 25 December 2003 to 28 April 2004. Though their expedition included others, Brown and Scaturro were the only ones to complete the entire journey. Although they descended whitewater manually, the team used outboard motors for much of their journey.

On 29 January 2005, Canadian Les Jickling and New Zealander Mark Tanner completed the first human-powered transit of Ethiopia's Blue Nile. Their journey of over took five months. They recount that they paddled through two war zones, regions notorious for bandits, and were arrested at gunpoint.

Dangers

Inland flood events cause the highest number of casualties among all natural catastrophes - including the devastation of harvest, starvation, sickness and famine in the aftermath of floods. Millions of people have died in consequence of single flood events before. An estimated 2- 4 million people perished in consequence of the Yangtze–Huai River flood of 1931 including famine and epidemics in the following years.
A flood in Egypt, caused by overtopping of AHD and the subsequent eroding of the dam, can be 20 times worse than the historic flood in China. Nasser Lake contains a water-volume that defies imagination and it would increase to 209 cubic kilometers
during the events described in this study. Moreover, the flood caused by a dam breach is concentrated to plus/minus one day, instead of a seasonal flood distributed over 4 months. The short flood is much more violent. Millions of homes would be destroyed. Nationwide irrigation infrastructure would be covered by a layer of contaminated sediment that becomes hard as stone after a short while. After Nasser lake has disappeared (emptied), agricultural production would fall back to pre-AHD levels causing widespread famine for years. "Nicol-André Berdellé (2024) Breach of Aswan Dam - a realistic worst case scenario

Crossings

Crossings from Khartoum to the Mediterranean Sea

The following bridges cross the Blue Nile and connect Khartoum to Khartoum North:
* Mac Nimir Bridge
* Blue Nile Road & Railway Bridge
* Burri Bridge
* Elmansheya Bridge
* Soba Bridge

The following bridges cross the White Nile and connect Khartoum to Omdurman:
* White Nile Bridge
* Victory Bridge, also known as El Fitihab Bridge

The following bridges cross from Omdurman to Khartoum North:
* Hafaya Bridge

The following bridges cross to Tuti from Khartoum state's three cities:
* Tuti Bridge (previously known as the Khartoum North-Tuti bridge)

Other bridges:
* Shandi Bridge, Shendi
* Atbarah Bridge, Atbarah
* Merowe Dam, Merowe
* Merowe Bridge, Merowe
* Aswan Bridge, Aswan
* Luxor Bridge, Luxor
* Suhag Bridge, Suhag
* Assiut Bridge, Assiut
* Al Minya Bridge, Minya
* Al Marazeek Bridge, Helwan
* First Ring Road Bridge (Moneeb Crossing), Cairo
* Abbas Bridge, Cairo
* University Bridge, Cairo
* Qasr al-Nil Bridge, Cairo
* 6th October Bridge, Cairo
* Abu El Ela Bridge, Cairo (removed in 1998)
* New Abu El Ela Bridge, Cairo
* Imbaba Bridge, Cairo
* Rod Elfarag Bridge, Cairo
* Second Ring Road Bridge, Cairo
* Banha Bridge, Banha
* Samanoud Bridge, Samanoud
* Mansoura 2 Bridges, Mansoura
* Talkha Bridge, Talkha
* Shirbine high Bridge
* Shirbine Bridge
* Kafr Sad – Farscor Bridge
* International Coastal Road Bridge
* Damietta high Bridge, Damietta
* Damietta Bridge, Damietta
* Kafr El Zayat Bridges, Kafr El Zayat
* Zefta Bridge, Zefta

Crossings from Jinja, Uganda to Khartoum

* Source of the Nile Bridge, Jinja, Uganda
* River Nile Railway Bridge, Jinja, Uganda
* Nalubaale Bridge, Jinja, Uganda (Formerly Owen Falls Bridge)
* Karuma Bridge, Karuma, Uganda
* Pakwach Bridge, Uganda

See also

* Bujagali Hydroelectric Power Station
* Egyptian Public Works
* Kiira Hydroelectric Power Station
* Water politics in the Nile Basin
* Merowe Dam
* Nalubaale Hydroelectric Power Station
* Orders of magnitude
* Vid Flumina, a river of liquid methane and ethane on Saturn's moon Titan
* ''The River War'' (1899), Winston Churchill's second book, an account of steaming up the Nile to the Battle of Omdurman, Sudan, in 1898

Notes and references

;Notes

;References

;Sources
*

Further reading

*
* Jeal, Tim (2011). ''Explorers of the Nile: The Triumph and Tragedy of a Great Victorian Adventure''.
* Moorehead, Alan, "The White Nile" (Hamish Hamilton, 1960; revised and illustrated edition, 1971). Abridged illustrated edition, as The Story of the White Nile (Harper & Row, 1967)
* Moorehead, Alan, "The Blue Nile" (Hamish Hamilton, 1962; revised and illustrated edition, 1972). Abridged illustrated edition, as The Story of the Blue Nile (Harper & Row, 1966)
* Tvedt, Terje, ed. ''The River Nile in the Post-Colonial Age: Conflict and Cooperation Among the Nile Basin Countries'' (I.B. Tauris, 2010) 293 pages; studies of the river's finite resources as shared by multiple nations in the post-colonial era; includes research by scholars from Burundi, Congo, Egypt, Ethiopia, Kenya, Rwanda, Sudan, Tanzania, and Uganda.
* Tvedt, Terje, (2004) "The Nile: An Annotated Bibliography", London/New York,

External links

A Struggle Over the Nile
– slideshow by ''The New York Times''

Thesis Analyzing Nile River Negotiations
(archived 10 January 2016)
*
Old maps of the Nile
from the Eran Laor Cartographic Collection, The National Library of Israel

{{Authority control

International rivers of Africa
*
Rivers of Egypt
Rivers of Sudan
Rivers of South Sudan
Rivers of Uganda
Geography of ancient Egypt
Hebrew Bible rivers
National parks of Egypt
Water transport in Egypt
Articles containing video clips