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The Nile River: Basin, Course, Facts, and Risks Facing It

Eman is a writer and engineer. She loves to research and write about nature and geography.

The Nile River

The Nile Basin contains the longest river canal system in the world, nearly more than 6,500 km, which drains about one-tenth of the African continent. The river basin extends at a latitude of 35° (4° S to 31° N) and includes a variety of climates, river systems, biomes, and topography; from the plateau of equatorial lakes in the headwaters of the White Nile to the complex of delta in the eastern Mediterranean. The total catchment area of the Nile is about 3,000,000 square kilometers.

The Nile River covers eleven countries: Tanzania, Uganda, Rwanda, Burundi, the Democratic Republic of the Congo, Kenya, Ethiopia, Eritrea, South Sudan, the Republic of Sudan, and Egypt.

Currently, more than 180 million people live within the basin, and about half of that number depends almost completely on the Nile flows to meet economic and local needs.

Ancient Egyptian Gardens

Wall painting from the tomb of Sennedjen, Dayr al-Madinah, Thebes-West.

Wall painting from the tomb of Sennedjen, Dayr al-Madinah, Thebes-West.

The Nile River and the Ancient Egyptian Civilization

God granted the Nile to Egypt to run on its land, to be a reason to bring goodness to it. The Nile River was one of the most important factors in the emergence of the ancient Egyptian civilization. The river and fertile soil helped the Egyptians to build an empire based on great agricultural wealth. The Egyptians were the first to cultivate on a large scale and to develop irrigation methods. The Egyptians planted wheat, barley, and flax. They also excelled at gardening.

The Egyptians developed horticulture and gardens, as well as field agriculture in the flood plains. The Nile brought silt that naturally fertilized the valley. These gardens and orchards were generally used to grow vegetables, grapes, and fruit trees.

The Egyptians also planted dates, sorghum, beans, lentils, chickpeas, beans, and root crops, such as onions, garlic, and radish, along with lettuce and parsley.

The fruit was a popular component of Egyptian artwork, indicating that its growth was also a major focus of agricultural efforts as the agricultural technology of civilization developed.

The Basic Areas of the Nile Basin

The Nile Basin includes 5 main regions that differ from each other in characteristics:

1. Equatorial lake plateau in the vertical waters of the White Nile with dense forested tropical catchments with perpetual flow systems.

2. The dam area and central Sudan with rich, low-slope plains, wide swamps, wide channel belts, and low concentrations of suspended sediments.

3. The Ethiopian Highlands form the headwaters of the Blue Nile and Atbara with deep valleys, unstable slopes, and steep gravel bottom streams with high seasonal flows and high sediment loads.

4. Large bends and cataracts of the desert Nile, with systems of ephemeral tributary valleys and mud fans in the arid lands of Sudan and Egypt, cataracts, and extensive sedimentary tributaries of the main Nile with a highly modified flow and sediment system downstream of the Aswan High Dam.

5. The Egyptian zone including the low gradient delta complex with its large branches, outcrops, and lakes, highly modified drainage, and a dense network of irrigation canals.

Geomorphology of the Nile channel complex in the Dongola Reache in northern Sudan at low flow. (a) A large sand bar and thick channel margin flood deposits. (b) A flood channel to the east of the main Nile. View looking downstream in each case, 1997.

Geomorphology of the Nile channel complex in the Dongola Reache in northern Sudan at low flow. (a) A large sand bar and thick channel margin flood deposits. (b) A flood channel to the east of the main Nile. View looking downstream in each case, 1997.

A Brief History of the Nile

Opinions and theories varied about the history of the Nile.

According to an article on the geomorphology of the Nile by Woodward, Macklin, Krom, and Williams, at the end of the Miocene (around 6.5 million years BP), the evaporation of the Mediterranean Sea and the transfer to saline desert conditions across marine basins had deep impacts on the large river systems of the region including the Nile. The fall in the base standard in the Eastern Mediterranean led to large-scale fluvial silt, and the Nile carved a deep bedrock canyon to ca. 570 m below current sea level at Cairo and to 170 m at Aswan, some 1000 km upstream from the current coastline. This fall in elevation of about 400 meters between Aswan and Cairo for the Late Miocene Nile Valley compares with a fall of about 70 m for the current Nile over the same distance.

The triple tectonic events associated with the Rift of Africa and the secession of the Arabian Peninsula created high-altitude sub-basins for the Nile and determined its northern course towards the Mediterranean. The new research has shown that the lower White Nile is relatively young, and it is difficult to estimate the age of the Blue Nile.

Fluctuations in climate in tropical Africa during the Quaternary had an important influence on the behavior of the Nile sediment system as extended ice sheets cooled the global oceans and decreased the intensity of the monsoons. The effects of changes in sea level did not spread in the Quartet due to changes in the volume of ice downstream of the Nile in Egypt.

Then the so-called global LGM for stage 2 marine isotopes appeared. In general, during the global LGM, the main canals of the Blue Nile and the Desert Nile were characterized by clear freezing, and sediments were deposited on the valley floor. The increased sediment supply to the fluvial system at this time resulted from reduced vegetation in the Ethiopian highlands resulting in slope instability and valley and plate erosion. During that period, the White Nile system was seasonal and very low flows, with periods of complete dryness throughout or part of the year. This is a major contrast to the modern White Nile system. This flow system was a product of reduced tropical and an absence of connection with Lake Victoria. Thus, the White Nile in Sudan became isolated from its tropical sources in Uganda. Currently, the White Nile is responsible for maintaining the permanent flow of the main Nile, especially during drought years. With increased drought at that time, the White Nile Valley was characterized by extensive active Aeolian dune systems derived from the sandy bottom load, which were large enough to block the canal area in some areas.

The increase in regional humidity and the transfer to a perennial flow regime led to the stability of the dune systems on the White Nile valley floor by the plants. After that, the White and Blue Niles carried very large discharges from the floods that inundated a very large area in the Lower White Nile Valley. This submerged area was about 4 to 5 meters higher and 20 to 40 km wider from the present day and resulted in the deposition of new-grained sediments over a large area of the lower White Nile Valley. Then the climate became more humid in the Ethiopian highlands with an increase in the intensity of the summer monsoons and an increase in the flow of water from the headwaters of the Blue Nile. This has resulted in increased vegetation cover, slope stabilization, soil formation, and decreased sediment flow from the Blue Nile Basin.

After a transitional period that lasted at least two thousand years, the present Nile arrived in Egypt about ten thousand years ago. That transitional period witnessed severe climatic fluctuations in the lakes region, which caused a tremendous increase in the volume of the water of the new Nile (gamma New Nile), which was suffering from a steady shortage of its water. This short period of immense and unusual floods was followed by a period of sculpture that led to the emergence of the modern Nile. The Nile was receiving its water from the Ethiopian plateau and the equatorial plateau through the White Nile. Floods and river resources on the Ethiopian plateau raised the Nile level and deposited large amounts of silt. Thereafter, the wet period in the Neolithic era continued to be very rainy, decreased about 2.350 BC at the end of the Fifth Dynasty in ancient Egypt. The oldest layer of modern silt dates back 10.000 years and is located 12 meters above the floodplain in Wadi Halfa.

According to Nature Geoscience, the Nile took its current course 30,000,000 years ago. Researchers from the University of Texas, USA, in cooperation with researchers at other universities, said that they had found a link between the flow of the river and the movement of rocks in the mantle of the earth, which is the semi-solid mass in the ground that lies between the earth's dense core and its thin outer layer. The mantle is approximately 2,900 km thick and makes up 84% of the Earth's total size. This study demonstrates that the slow movement of the esoteric mantle is one of the major forces that shape the landscape and geological processes of the earth. In this study, the researchers traced the geological history of the Nile River by studying ancient volcanic rocks in the Ethiopian highlands and linking them with huge quantities of river sediments buried under the Nile Delta in Egypt, which led researchers to believe that the delta was higher than its current position by supporting mantle rocks from below, which gave it an elevation comparable to that of the Ethiopian plateau for millions of years.

The researchers linked the nature of the course of the Nile River from the south to the north where its mouth is in the Mediterranean Sea, through the delta in Egypt, and the moving belt of mantle rocks that represent a thrust against the Ethiopian highlands in the south, as these rocks pull the river basin down; which was the reason of the gentle gradient of the Nile has kept it steady northward over all these millions of years. The research team made a computer simulation to recreate 40 million years of Earth's tectonic activity; the model showed that a warming mantle may have led to the pyroclastic flow and the formation of the Ethiopian highlands 30 million years ago.

Another study published in 2018 indicated that the age of the Nile River is estimated at more than 30 million years, and the results of the study show this through the similarity of minerals in river sediments in the Nile Delta in Egypt, with rocks upstream in Ethiopia.

Nile River Map

The Course of the Nile

The Ruvironza is the furthest source of the Nile, which flows into Lake Victoria through the Rovubo and Kagera rivers. Other rivers converge at Lake Victoria, the largest tropical lake in the Nile, includes Simeo-Duma, Grumeti-Rawana, Mara, Gucha-Meguri, Sundo, Yala, Nzoia, Seo, Katonga, and Ruizi.

Lake Victoria has an area of ​​about 66,7002 kilometers. The lake occupies a large proportion of the entire sub-basin. Three countries Kenya 6%, Tanzania 51%, and Uganda 43% share the lakeshore. Six countries share the basin: Burundi, the Democratic Republic of the Congo, Kenya, Rwanda, Tanzania, and Uganda.

The confluence of the White Nile and the Blue Nile rivers.

The confluence of the White Nile and the Blue Nile rivers.

From Jinja in Uganda, the White Nile emerges from Lake Victoria, as the Victoria River, and travels north, passing through two other tropical lakes, Kyoga and Albert. Through these two lakes, the Nile captures runoff from two mountainous and high-rainfall regions, Mts Rwenzori and Elgon, on the southwestern and southeastern ends of the basin.

The river appears again from Lake Albert as the Albert River and travels north to Nimule near the border, between South Sudan and Uganda. From this point, Bahr al-Jabal River (the mountain river) flows over the Fula slopes and crosses the dam before it meets Bahr Al-Ghazal (Deer River) in Lake No in southern Sudan. Bahr al-Ghazal drains high rainfall regions of western South Sudan.

From Lake No, the river turns east to join with the Sobat River, which carries high and seasonally variable flows originating in the Ethiopian highlands. The Bahr al-Jabal and the Saubat River together form the White Nile, which continues its northward descent to meet with the Blue Nile at Khartoum, Sudan.

The Blue Nile is the second major stream of the Nile River. The Blue Nile originates from Lake Tana in Ethiopia. Before the Blue Nile meets the White Nile, it joins with some rivers such as the Rahad and Dinder rivers, which originate in the Ethiopian highlands

Satellite Picture of the Nile Delta, Egypt.

Satellite Picture of the Nile Delta, Egypt.

From Khartoum, the common rivers of the Nile are joined by Atbara, which originates from the Ethiopian highlands.

The main Nile continues to journey north and flows into Lake Nasser, a major man-made dam on the border between Sudan and Egypt.

The Nile River eventually discharges into the Mediterranean Sea through the delta. In this region, the meeting of the river’s water with the sea, where neither one overwhelms the other, is one of the natural phenomena that deserve contemplation and which God told about in the Holy Qur’an more than 14 centuries ago according to verses 19 and 20 of Surah Ar-Rahman (The Beneficent). As in the Qur'an, the English translation of these verses is: “In the Name of Allah, the Most Gracious, and the Most Merciful.

19. He merges the two bodies of ˹fresh and salt˺ water,

20. Yet between them is a barrier they never cross. (Surah 55: Ar-Rahman).

The first to notice a water barrier between fresh groundwater and salt seawater was the Dutch scientist Willem Badon-Gibben in 1888 and the German scientist Alexander Herzberg in 1901. The two scientists derived a relationship that determines the depth of the barrier above the sea level called (the Ghyben–Herzberg relation). The relationship depends on its derivation on the fact that the density of salt water is higher than the density of freshwater, where the density of salt water is 1.025 grams per cubic centimeter, while the density of fresh water is one gram per cubic centimeter. Based on this fact, the two scientists found that the depth of the barrier between the two bodies below the sea level is 40 times the height of the freshwater level above sea level, which means that the barrier will not arise if the freshwater level equals the saltwater level. This water barrier is a water wall that surrounds the groundwater from the salt waterside. The barrier begins at the top of the salty sea surface and extends downward in a curve until it reaches the bottom of the freshwater. The barrier is an area of a certain thickness in which the salt concentration gradually decreases from its level in the saltwater side to its level in the freshwater side. Scientists have given the name saltwater-freshwater interface to this water barrier that separates the two bodies of water.

Ethiopian Dam

The Grand Ethiopian Renaissance Dam, a 1.1-mile-long.

The Grand Ethiopian Renaissance Dam, a 1.1-mile-long.

Risks That Faces the Nile River

The Nile River faces three main risks:

1. Dam Crisis

All the basin countries depend on the Nile, but to varying degrees. Egypt totally depends on the Nile. Currently, 98% of Egypt's freshwater comes from the Nile River. Egypt is ranked among the top ten countries in the world that will be most vulnerable to the threat of water shortages in the future.

Every year Ethiopia has 123 billion cubic meters of surface water, which is 1.5 times the annual water of the Nile, but the country rarely uses any of this water. Only 3% of the water remains in Ethiopia, and the rest flows to neighboring countries. Ethiopia is one of the poorest countries in the world, with only 5% of the land suitable for irrigation is developed, and its prosperity depends on the use of more water resources.

More than 3,000 kilometers (2,000 miles) upstream on the Blue Nile, the major tributary, thousands of workers have worked for nearly a decade to build the Grand Ethiopian Renaissance Dam, set to be Africa's largest. Downstream countries, mainly Egypt and Sudan, fright that the dam's 145-meter (475-foot) high wall will trap their main water supplies.

2. Climate Change

Warming will affect the Nile Basin region. The impacts of climate change on the Nile flow will vary depending on the location of the different sub-basins, with more serious consequences later in some areas compared to others.

3. Pollution

The waters of the Nile River suffer from increasing pollution. Water pollution is a major issue that threatens human health and economic development. Polluted water affects human health directly when consumed. It also affects indirectly when used to irrigate crops. A high level of pollutants in irrigation water; increases the concentration of pollutants in the soil and thus in fruits and vegetables.

The severity of the water pollution problem varies between different water bodies according to flow, usage patterns, the extent of industrialization, population density, and availability of sewage systems. Discharge of treated or untreated industrial and domestic wastewater, fertilizer residues, pesticide filtration, solid waste, and navigation are sources of pollution.


© 2021 Eman Abdallah Kamel


Eman Abdallah Kamel (author) from Egypt on May 31, 2021:

Thank you, Linda, for reading the article and the comment. The Nile River deserves research and study because of its great importance. It is also worth making an effort to preserve it.

Linda Crampton from British Columbia, Canada on May 30, 2021:

Thank you for sharing so much information in this article. It’s very educational.

Eman Abdallah Kamel (author) from Egypt on May 30, 2021:

Thank you, Linda Chechar, for reading the article and the comment. Indeed, Nile cruises are popular with travelers, especially in Luxor and Aswan due to the beautiful landscapes on both sides of the river.

Eman Abdallah Kamel (author) from Egypt on May 30, 2021:

Thank you, Liz, for reading the article and the comment. You are right, the Nile cruises are loved by many travelers. The Nile is also a very important trade route, as well as being economically important to many countries of the basin.

Linda Chechar from Arizona on May 30, 2021:

This is an excellent and well-article. We have about the Nile. The river cruise is on the Nile that is popular with travelers!

Liz Westwood from UK on May 30, 2021:

This is an excellent and well-researched article. We have watched several programmes about the Nile. River cruises on the Nile used to be popular with British travellers. It is also an important trade route. The recent blockage for several days by a container ship has been blamed for a shortage of garden furniture in the UK.

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