High stopping of Aswan - SpeedyLook encyclopedia

History

It was built in supplement of the Ancien stopping of Aswan (he even elevated twice) which did not give satisfaction in term of effectiveness and safety. This last is however always under operation and continuous to produce hydroelectric energy.

Without this Stopping, the the Nile would flood each summer the fertile plains of the valley, because of the water multitude coming from all the East Africa. These floods brought Nutrient S and Mineral (silt) which returned Fertile the ground of the Vallée of the Nile, and allowed the Agriculture. But, the increase in the Population in the Vallée made necessary the control of water to protect the agricultural installations and the exploitations from Coton. Large years the “Raw S”, whole harvests was lost, whereas the years when the rising was less, the population suffered from the Sécheresse and Famine. The goal of this project was to control the risings, to produce electricity for the country, and to constitute a water tank for the Agriculture.

Design

In 1952, the Egyptian president Gamal Abdel Nasser amorça this project with for objectives making water available throughout the year, extending irrigated surfaces, to improve navigation on the river and to produce electricity. It will also make it possible to attenuate the damage generated by floods or drynesses.

Nasser required initially an financial aid and technique of the the United States and with the Great Britain which, initially, agreed to help with its construction, with the help of a loan of 270 million $ of their share. But, the project was cancelled in July 1956, for still obscure reasons. A contract of secret armament with the Czechoslovakia (Communist bloc) and the recognition by the Egypt of the Popular republic of China are the probable reasons, advanced by the historians. A little later Nasser nationalized the Suez Canal, in the objective to finance the stopping by the expenses of passage. This episode gave place to the Crise of Suez Canal, which ended in the order of UNO to the France, the Great Britain and Israel to evacuate the Egyptian territory, and thus with the victory of Nasser. Also to build this stopping, the Egypt sought to belong to the Soviet sphere of influence and Nasser turned to the Soviet Union, which will assume a third of construction and will provide approximately 400 technicians. Egypt then ceased belonging to the Nonaligned countries.

Construction

Its construction lasted approximately eleven years and mobilized some: 30000 workers. Built 6 km upstream of the Old stopping of Aswan, it is a gigantic work of 42,7, length m ³ million 3600 meters, thick of 980 meters at its base and 40 meters at its top and high of 111 meters. To the maximum: 11000 m ³ of water can spend each second through the valves of the stopping. Moreover, in the event of urgency: 5000 m ³ a second can be evacuated by the Toshka channel connecting the tank to the depression Toshka. The tank constituted the Lac Nasser, length of approximately 550 km on 10 km of broad on average (35 km to the maximum), on a surface of: 5250 km and of a capacity of reserve of 157 km of water.

The stopping contains twelve generating electric of 175 megawatts each one, producing 2,1 giga Watt S of energy hydroelectric. The electric exploitation started in 1967. When the stopping reached for the first time its maximum electric production, it produced half of Egyptian electricity then (and still 15% in 1998) and made it possible to connect the majority of the Egyptian villages to the electrical communication for the first time. The effects of dangerous believed of 1964 and 1973 and the drynesses menaçantes of 1972-73 and 1983-84 could be attenuated. A new industry related to fishing could be created around the Lac Nasser, although its distance of the markets poses some problems to him.

Benefit

High stopping of Aswan:

Feeds the water country.
babbit metal the Crue S of the the Nile what allows a system of irrigation during all the year (and thus the intensification of the Agriculture, which brings to final rise of the outputs) and improves navigation.
Provides all the country in electricity.

Environmental problems

It would seem that various problems appeared with the passing of years since the construction of this stopping:

the Temples of Abou Simbel of the Pharaon Ramsès {{II}} were moved in the Années 1960 at the edge of the Lac Nasser not to be flooded by water of the stopping of Assouan.
a Worm of the group of the acœlomates named bilharzie (the Bilharziose: highlighted by Theodore Bilharz) settles in stagnant water and causes diseases (|interference of bodies - Kidney S, Bladder, Liver, Spleen - causing Hemorrhage S).
the erosion and the contribution of the silt S is not balanced any more, involving the geological modification Delta of the Nile. The Nile runs more quickly than before and erodes its bed at a rate of 1,7 cm per annum.
the salt water penetrates in a more important way in the grounds close to the delta, and the Ground water goes up.
the flow of the Nile being less, there does not exist any more against current with the mouth of the Suez Canal which limited the exchanges of water and faunas between the Mediterranean and Red Sea. The appearance of new invasive species passing by Suez Canal thus increased significantly since the construction of the stopping.
Having water with profusion, the farmers pay attention to the quantities less and less that they use. That could be dangerous for the future of Egypt.

Photographs

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