The Nile In Egypt (1963)

[Music] have you ever imagined what a tree where it never rained at all it would probably look like this for without moisture nothing grows there are many deserts in the world this one is the great sahara desert in north africa and yet if we look at a map of this desert region we find surrounded by desert on three sides a country that lives by its agriculture egypt how does egypt exist in an area where there is almost no rain no more than a few showers and the answer is the river nile the nile brings water from distant regions where there is rainfall much of egypt is desert the cultivated part makes the green area that is shaped rather like a kite with a long tail the wider triangular portion to the north is formed by the nile delta where the river divides into a number of branches that carry its waters to a large area the narrow portion of the tail of the kite is very narrow indeed this is what it looks like you can see the cultivated strip beside the river and the yellow desert beyond the land can only be cultivated as far as the river water can be carried there is no rain here at all or not enough to make any difference ever since men began living in the nile valley they have had to find ways of lifting the river water onto their land before anything would grow some of their ancient methods of litigation a this man is working what is called a shadow a counterweight makes it easier for him to lift the bucket in its contents these men are using a double shadow another method later in origin but still very ancient is known as the secure an animal is harnessed to a shaft it walks round and round and by means of crude gears a kind of water wheel is revolved which scoops up the water and empties it into channels often it is the children's job to keep the animals walking round and round a little more recent is the archimedes screw which was invented by the greeks and introduced when they ruled egypt it is a most ingenious method of raising water inside the wooden battle is a helical screw up which the water runs as it is rotated it is possible to lift water about three feet by this method the water is directed down channels to each row of crops when that row has received its share the water is diverted by damning the channel with mud and opening another channel all the rows of crops have to be watered individually like this every day during the growing season when we look at the wide fields of the delta we realize the tremendous amount of patient toil that has gone into making this one of the fertile regions of the world for thousands of years ever since the days of the pharaohs men have used these same methods of mitigation in the nile valley the nile is in flood each year between june and august the water rushes down from the mountains of ethiopia and east africa red with the silt it carries this silt it deposits as its speed slackens in the lower reaches as the flood subsides it leaves the wet soil which the farmers immediately sow with crops which grow quickly in the hot sun it is this nile silt that has gradually formed the rich soil of egypt the floods vary year by year causing in days gone by the lean years and the years of plenty referred to in the bible it has always been man's dream to control this mighty river to store some of the flood water so that it can be released later in the year a large dam was built this is the asswam dam built by the british in 1902 and raised in height twice since it has created a reservoir capable of storing five thousand million cubic meters of water the azwan dam is only one of a number of irrigation works in egypt lower down the nile there are a number of barrages like this these barrages are like small dams they raise the height of the water behind them a few feet the purpose is to drive the water behind the barrage into irrigation channels that carry it to the farming areas a network of these irrigation canals some of them quite wide covers the cultivated parts of egypt carrying the water to the fields to make up for the rain they do not get the nile is not only a means of irrigation it is also egypt's greatest highway the sailing boats with their traditional single sails travel along it for 900 miles between the sedan and the mediterranean sea on the nile are the two largest cities of egypt cairo is the capital and it is a cosmopolitan city with a population of more than two millions the principal port of egypt is alexandria situated at the mouth of the nile delta at the eastern end of the mediterranean it is the main gateway through which goods enter and leave the country [Music] from alexandria goods can travel up a branch of the nile to cairo boats can travel south from cairo as far as the sudan passing the barrages and the aswan dam by means of locks only during the flood and just afterwards is the nile not navigable when the flood comes down the sluice gates at swan are open the volume of water is so great that the aswan dam cannot contain it the water is red with the silt it is carrying down to the delta and the fields of egypt another reason for opening the sluices is to allow the water to maintain its speed and so carried the silt on past the reservoir if the flow was checked it would deposit all this silt and fill up the reservoir as the flood nears its end the gates are shut down again so that the reservoir will fill up once more as the level of the water rises the ancient filet temple on an island in the reservoir is gradually submerged as it has been every year since the aswan dam was heightened in 1926 many more temples will be submerged when the work of building another dam known as the high dam is successfully completed if we proceed upstream from the old aswan dam we come to the site of this new one it will eventually be able to contain some of the annual flood but some experts consider that because it has no sluices like the old aswan dam the water will deposit its silt and fill up the reservoir and the fields of egypt may no longer receive additions of fertile soil in the meantime the power that has gone to waste through the sluices of the old dam has been harnessed by a great new hydroelectric power station that has been added to the old aswan dam already the generators are working and the power lines stretch away across the desert and so the nile has been harnessed to produce power in addition to the other benefits she bestows upon egypt what would the ancient pharaohs have given for this ability to harness and control the nile a power that they could only dream of but which man has at last achieved but still the greatest benefit that the nile bestows on egypt is the water to irrigate her fields the water that is fed to her crops patiently day by day row by row by the egyptian farmers as they have done through countless centuries the water that has changed a desert into a green and fertile land [Music] so next time you see it raining remember how precious that rainwater is [Music] 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