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Encyclopedia > Aswan dam

Coordinates: 23.970589° N 32.877861° E Map of Earth showing lines of latitude (horizontally) and longitude (vertically), Eckert VI projection; large version (pdf, 1. ...

Map showing reservoir
Map showing reservoir
The hydroelectric power station of Aswan Dam
The hydroelectric power station of Aswan Dam

Aswan (Assuan) is a city on the first cataract of the Nile in Egypt. Two dams straddle the river at this point: the newer Aswan High Dam (Arabic: السد العالي; transliterated: as-Sad al-'Aly), and the older Aswan Dam or Aswan Low Dam. The aim of this water project was to prevent the river's flooding, generate electricity and provide water for agriculture. Map showing the location of Lake Nasser in Egypt and Sudan. ... Map showing the location of Lake Nasser in Egypt and Sudan. ... Hydroelectricity is electricity produced by hydropower. ... Egypt: Site of Aswan (bottom). ... The six cataracts of the Nile Fourth Cataract Sixth Cataract The six primary cataracts of the Nile are shallow stretches between Aswan and Khartoum where the waters surface is broken by numerous small boulders and stones lying on the river bed, as well as many small rocky islets. ... For other uses, see Nile (disambiguation). ... This article is about structures for water impoundment. ... Arabic redirects here. ... Due to the fact that the Arabic language has a number of phonemes that have no equivalent in English or other European languages, a number of different transliteration methods have been invented to represent certain Arabic characters, due to various conflicting goals: A desire to stay consistent with traditional usage... Electricity (from New Latin Ä“lectricus, amberlike) is a general term for a variety of phenomena resulting from the presence and flow of electric charge. ...


Without impoundment the River Nile would flood each year during summer, as waters from East Africa flowed down the river as they did in ancient times. These floods brought nutrients and minerals that made the soil around the Nile fertile and ideal for farming. As the population along the river grew, there came a need to control the flood waters to protect and support farmland and cotton fields. In a high-water year, the whole crop may be entirely wiped out, while in a low-water year there was widespread drought and famine. For other uses, see Nile (disambiguation). ... Flooding near Key West, Florida, United States from Hurricane Wilmas storm surge in October 2005 For other uses, see Flood (disambiguation). ... For other uses, see Summer (disambiguation). ...  Eastern Africa (UN subregion)  East African Community  Central African Federation (defunct)  Geographic East Africa, including the UN subregion and East African Community East Africa or Eastern Africa is the easternmost region of the African continent, variably defined by geography or geopolitics. ... A nutrient is a substance used in an organisms metabolism which must be taken in from the environment. ... For other uses, see Mineral (disambiguation). ... Loess field in Germany Surface-water-gley developed in glacial till, Northern Ireland For the American hard rock band, see SOiL. For the System of a Down song, see Soil (song). ... For other uses, see crop (disambiguation). ... Fields outside Benambra, Victoria, Australia suffering from drought conditions A drought is an extended period of months or years when a region notes a deficiency in its water supply. ... <nowiki>Insert non-formatted text hereBold text</nowiki>A famine is a social and economic crisis that is commonly accompanied by widespread malnutrition, starvation, epidemic and increased mortality. ...

Contents

Construction history

The British began construction of the first dam in 1889. Construction lasted until 1902. It was opened on December 10, 1902. The project was designed by Sir William Willcocks and involved several eminent engineers including Sir Benjamin Baker and Sir John Aird, whose firm, John Aird & Co., was the main contractor.[1] A gravity dam, it was 1,900 m long and 54 m high. The initial design was soon found to be inadequate and the height of the dam was raised in two phases, 1907–1912 and 1929–1933. is the 344th day of the year (345th in leap years) in the Gregorian calendar. ... Year 1902 (MCMII) was a common year starting on Wednesday (link will display calendar) of the Gregorian calendar (or a common year starting on Tuesday [1] of the 13-day-slower Julian calendar). ... Sir William Willcocks (September 27, 1852, India – July 28, 1932, Cairo, Egypt) was a British civil engineer. ... Sir Benjamin Baker (March 31, 1840 - May 19, 1907), English engineer, was born near Bath in 1840, and, after receiving his early training in a South Wales ironworks, became associated with Sir John Fowler in London. ... Sir John Aird (3 December 1833 - 6 January 1911) was a notable English civil engineering contractor of the late 19th and early 20th centuries. ... dam stands for dekametre. ...


When the dam almost overflowed in 1946 it was decided that rather than raise the dam a third time, a second dam would be built 6 km upriver (about 4 miles). Proper planning began in 1952, just after the Egyptian Revolution led by the Free Officers, of whom Nasser was to become leader. At first the USA and Britain were to help finance construction with a loan of USD $270 million in return for Nasser's leadership on resolving the Arab-Israeli Conflict. However both nations cancelled the offer in July 1956 as part of the secret US-led 'OMEGA' policy to marginalize Nasser. A secret Egyptian arms agreement with Czechoslovakia (Eastern Bloc) and Egyptian recognition of the People's Republic of China are cited as possible reasons. The 1952 Revolution (Arabic:ثورة 23 يوليو 1952), in Egypt also known as the July 23 Revolution, began with a military coup détat that took place on July 23, 1952 by a group of young army officers who named themselves The Free Officers Movement. The revolution was initially aimed at overthrowing... Nasser redirects here. ... The United States dollar is the official currency of the United States. ... The OMEGA memorandum[1] of 21st March 1956 was a secret informal policy memo drafted by John Foster Dulles for President Eisenhower. ... A map of the Eastern Bloc 1948-1989. ...


In 1958, the Soviet Union stepped in and funded the dam project. The Soviets also provided technicians and heavy machinery. The enormous rock and clay dam was designed by the Soviet Hydroproject Institute.
This article is about structures for water impoundment. ...

A panorama of Aswan Dam
Aswan Low Dam
Aswan Low Dam

Construction began in 1960. The High Dam, as-Sad al-'Aali, an embankment dam, was completed on July 21, 1970, with the first stage finished in 1964. The reservoir began filling in 1964 while the dam was still under construction and first reached capacity in 1976. The reservoir raised concerns from archaeologists and a rescue operation was begun in 1960 under UNESCO. Sites were to be surveyed and excavated and 24 major monuments were moved to safer locations (see Abu Simbel) or granted to countries that helped with the works (such as the Debod temple in Madrid and the Temple of Dendur in New York). Image File history File links Size of this preview: 800 × 170 pixelsFull resolution (1024 × 218 pixel, file size: 46 KB, MIME type: image/jpeg) Stephen David Hunt, picture taken by myself on nov 2005 I, the creator of this work, hereby release it into the public domain. ... Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... San Luis Dam - Embankment dam An Embankment dam is a massive semi-plastic mound of earth and/or rock with a dense, waterproof core. ... is the 202nd day of the year (203rd in leap years) in the Gregorian calendar. ... Year 1970 (MCMLXX) was a common year starting on Thursday (link shows full calendar) of the Gregorian calendar. ... UNESCO (United Nations Educational, Scientific and Cultural Organization) is a specialized agency of the United Nations established in 1945. ... Model showing the relative positions of the Abu Simbel temples before and after relocation Categories: Ancient Egypt stubs | Wonders of the World ... Temple of Debod The Temple of Debod is an ancient Egyptian temple which has been rebuilt in Madrid, Spain. ... The Temple of Dendur is a Nubian temple built during the Roman period around 15 BC. It was dedicated to the goddess Isis, the gods Harpocrates and Osiris, as well as two deified sons of a local Nubian chieftain, Pedesi (he whom Isis has given) and Pihor (he who belongs...


On the Egyptian side, the project was led by Osman Ahmed Osman's Arab Contractors. The relatively young Osman underbid his only competitor by one-half [2]. Osman complained about the quality of the Soviet-supplied equipment and machinery, and successfully campaigned to have Soviet workers removed from the project. The project made the Arab Contractors, and Osman himself, national icons. Osman Ahmed Osman (Arabic: ) ‎ (1917-1999) was a famous and influential Egyptian engineer, contractor, entrepreneur, and politician. ... Al-Mokawloon al-Arab المقاولون العرب is an Egyptian football club based in Nasr City. ...


Specifications

The Aswan High Dam is 3,830 m in length, 980 m wide at the base, 40 m wide at the crest and 111 m tall. It contains 43 million m³ of material. At maximum, 11,000 m³ of water can pass through the dam every second. There are further emergency spillways for an extra 5000 m³ per second and the Toshka Canal links the reservoir to the Toshka Depression. The reservoir, named Lake Nasser, is 550 km long and 35 km at its widest with a surface area of 5,250 km² and holds 111 km³. To help compare different orders of magnitudes this page lists volumes between 10 million and 100 million ( to ) cubic metres. ... View of Lake Nasser from Abu Simbel Map showing the location of Lake Nasser Lake Nasser (Arabic: Buhayrat Nasir) is a vast artificial lake in southern Egypt and northern Sudan. ...


Benefits

The dam powers twelve generators each rated at 175 megawatts, producing a hydroelectric output of 2.1 gigawatts. Power generation began in 1967. When the dam first reached peak output it produced around half of Egypt's entire electricity production (about 15% by 1998) and allowed for the connection of most Egyptian villages to use electricity for the first time. The dam mitigated the effects of dangerous floods in 1964 and 1973 and of threatening droughts in 1972–73 and 1983–84. A new fishing industry has been created around Lake Nasser, though it is struggling due to its distance from any significant markets.


Environmental and cultural issues

A view from the vantage point in the middle of High Dam towards the "Lotus Flower" tower by the sculptor Ernst Neizvestny.
A view from the vantage point in the middle of High Dam towards the "Lotus Flower" tower by the sculptor Ernst Neizvestny.

Damming the Nile has caused a number of environmental and cultural issues. It flooded much of lower Nubia and over 90,000 people were displaced. Lake Nasser flooded valuable archaeological sites such as the fort at Buhen. The silt which was deposited in the yearly floods, and made the Nile floodplain fertile, is now held behind the dam. Silt deposited in the reservoir is lowering the water storage capacity of Lake Nasser. Poor irrigation practices are waterlogging soils and bringing salt to the surface. Mediterranean fishing declined after the dam was finished because nutrients that used to flow down the Nile to the Mediterranean were trapped behind the dam.[citation needed] Image File history File links This is a lossless scalable vector image. ... Download high resolution version (1280x658, 258 KB) Aswan High Dam, Egypt. ... Download high resolution version (1280x658, 258 KB) Aswan High Dam, Egypt. ... Khrushchevs tomb at the Novodevichy Cemetery was sculpted by Neizvestny. ... Nubia (not to be confused with Nuba, a collective term used for the peoples who inhabit the Nuba Mountains, in Kordofan province, Sudan, Africa) is the region in the south of Egypt, along the Nile and in northern Sudan. ... For other uses, see Silt (disambiguation). ...

Aswan High Dam (NASA satellite photo)
Aswan High Dam (NASA satellite photo)

There is some erosion of farmland down-river as the river replenishes its sediment load. Erosion of coastline barriers due to lack of new sediments from floods will eventually cause loss of the brackish water lake fishery that is currently the largest source of fish for Egypt, and the subsidence of the Nile Delta will lead to inundation of the northern portion of the delta with seawater, in areas which are now used for rice crops.[citation needed] The delta itself, no longer renewed by Nile silt, has lost much of its fertility. The red-brick construction industry, which used delta mud, is also severely affected. There is significant erosion of coastlines (due to lack of sand, which was once brought by the Nile) all along the eastern Mediterranean. For morphological image processing operations, see Erosion (morphology). ... NASA satellite photograph of the Nile Delta (shown in false colour) The Nile Delta (Arabic:دلتا النيل) is the delta formed in Northern Egypt where the Nile River spreads out and drains into the Mediterranean Sea. ... Nile River delta, as seen from Earth orbit. ...


The increased use of artificial fertilizers in farmland below the dam has caused chemical pollution which the traditional river silt did not. Indifferent irrigation control has also caused some farmland to be damaged by waterlogging and increased salinity, a problem complicated by the reduced flow of the river, which allows salt water to encroach further into the delta. Spreading manure, an organic fertilizer Fertilizers (also spelled fertilisers) are compounds given to plants to promote growth; they are usually applied either through the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... Annual mean sea surface salinity for the World Ocean. ... Nile River delta, as seen from Earth orbit. ...

A wall commemorating the completion of Aswan High Dam. Coat of arms of the Soviet Union is on the left and Coat of arms of Egypt is on the right.
A wall commemorating the completion of Aswan High Dam. Coat of arms of the Soviet Union is on the left and Coat of arms of Egypt is on the right.

Mediterranean fish stocks are also negatively affected by the dam. The eastern basin of the Mediterranean is low in fertility, and traditionally the marine ecosystem depended on the rich flow of phosphate and silicates from the Nile outflow. Mediterranean catches decreased by almost half after the dam was constructed.[citation needed] The dam has been implicated in a rise in cases of schistosomiasis (bilharzia), due to the thick plant life that has grown up in Lake Nasser, which hosts the snails who carry the disease. Download high resolution version (1280x813, 361 KB) A memorial wall, on the inside of the the Lotus Flower tower, located at Aswan High Dam, Egypt. ... Download high resolution version (1280x813, 361 KB) A memorial wall, on the inside of the the Lotus Flower tower, located at Aswan High Dam, Egypt. ... The state coat of arms of the Soviet Union, from 1958-1991 The state coat of arms of the Soviet Union (Russian: ) was adopted in 1924 and was used until the collapse of the Soviet Union in 1991. ... The Egyptian coat of arms is a golden eagle looking towards the left. ... Schistosomiasis or bilharzia is a parasitic disease caused by several species of flatworm. ...


The Aswan Dam tends to increase the salinity of the Mediterranean Sea, and this affects the Mediterranean's outflow current into the Atlantic Ocean (see Strait of Gibraltar). This current can be traced thousands of kilometers into the Atlantic. The Strait of Gibraltar as seen from space (on the left: Spain) A view across the Strait of Gibraltar taken from the hills over Tarifa, Spain The Strait of Gibraltar (Arabic: مضيق جبل طارق, Spanish: Estrecho de Gibraltar) is the strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Spain...


Irrigation for agriculture

Water balances
Water balances
Main irrigation system
Main irrigation system

Due to the absence of appreciable rainfall, Egypt's agriculture depends entirely on irrigation. With irrigation, two crops per year can be produced, except for sugar cane that has a growing period of almost one year. The high dam at Aswan releases on average 55 billion m³ water per year of which some 46 billion m³ are diverted into the irrigation canals. In Nile valley and delta, almost 8 million feddan (1 feddan is about 1 acre or 0.42 ha) benefit from these waters producing on average 1.8 crop per year. The annual crop consumptive use is about 38 billion m³. Hence, the overall irrigation efficiency is 38/46 = 0.82 or 82%.
Compared to the efficiency elsewhere in the world this is a high value. The field irrigation efficiencies are much less, but the losses are re-used downstream. This continuous re-use accounts for the high overall efficiency. The equal distribution of irrigation water over the branch canals taking off from the main irrigation canals leaves to be desired.[3] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Image File history File links Size of this preview: 789 × 600 pixelsFull resolution (818 × 622 pixel, file size: 46 KB, MIME type: image/jpeg)R.J.Oosterbaan self made File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Size of this preview: 789 × 600 pixelsFull resolution (818 × 622 pixel, file size: 46 KB, MIME type: image/jpeg)R.J.Oosterbaan self made File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Irrigation is the artificial application of water to the soil usually for assisting in growing crops. ... Species Ref: ITIS 42058 as of 2004-05-05 Sugarcane is one of six species of a tall tropical southeast Asian grass (Family Poaceae) having stout fibrous jointed stalks whose sap at one time was the primary source of sugar. ... A feddan (Arabic: , faddān) is a unit of area. ...

Branch canal Water delivery in m³/feddan*
Kafret Nasser 4700
Beni Magdul 3500
El Mansuria 3300
El Hammami upstream 2800
El Hammami downstream 1800
El Shimi 1200

* Period 1 March to 31 July. 1 feddan is about 1 acre or 0.42 ha. Data from Egyptian Water Use Management Project (EWUP)


The salt concentration of the water in the Aswan reservoir is about 0.25 kg/m³. This is very "sweet" water. At an annual inflow of 55 billion m³, the annual salt import reaches 14 million ton. The average salt concentration of the drainage water evacuated into the sea and the coastal lakes is 2.7 kg/m³ (Egyptian Drainage Research Institute, yearbook 1995/1996). At an annual discharge of 10 billion m³ (not counting the 2 billion m³ of salt intrusion from the sea and the lakes, see figure "Water balances"), the annual salt export reaches 27 million ton. In 1995, the salt export was higher than the import, and Egypt's agricultural lands were desalinizing. Part of this could be due to the large number of subsurface drainage projects executed in the last decades to control the water table and soil salinity. Cross section showing the water table varying with surface topography as well as a perched water table The water table or phreatic surface is the surface where the water pressure is equal to atmospheric pressure. ... It has been suggested that this article or section be merged with soil salination. ...


See also

A megaproject is an extremely large-scale investment project. ... Megaprojects and Risk: An Anatomy of Ambition is a book by Bent Flyvbjerg, Nils Bruzelius, and Werner Rothengatter dealing with the risks and legalities of promotion, policy, planning, and construction of megaprojects. ...

External links

Wikisource has original text related to this article:
an account of early plans to construct the Aswan Dam
Wikimedia Commons has media related to:
Image File history File links Wikisource-logo. ... The original Wikisource logo. ...

  Results from FactBites:
 
The Aswan Dam (426 words)
The High dam was actually the second dam at Aswan, the first one having been built in 1889.
Due to the irregular flooding pattern of the Nile river and increased water demands, the dam had to be raised on 2 occasions (1912 and 1933) in order to ensure its continued usefulness and safety.
Dams, like any other technical "advancement", need to be analyzed not only on the basis of their perceived economic benefits and their dollar cost, but also on their environmental, and social impacts as well.
Wikipedia search result (1161 words)
Aswan is a city on the first cataract of the Nile in Egypt.
The Aswan High Dam is 3,600 m in length, 980 m wide at the base, 40 m wide at the crest and 111 m tall.
The Aswan dam tends to increase the salinity of the Mediterranean Sea, and thus affects the Mediterranean's outflow current into the Atlantic ocean (see Strait of Gibraltar).
  More results at FactBites »

 
 

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