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THE BLUE NILE
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Path of Nile River
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In 1858, explorer John Hanning Speke discovered Lake Victoria in
Central Africa.
This discovery answered the question that had been asked in Europe
for centuries:
Where is the source of the Nile?
The White Nile flows from Lake Victoria to Khartoum in Sudan,
where it joins the Blue Nile.
The Blue Nile originates in Lake Tana at an altitude of about 6,000 feet
(1,800 meters) and many small streams
in the mountains of Ethiopia.
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Ptolemy's Map of Egypt
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Since the Blue Nile is longer and is the origin of 66% of the water that
eventually empties into the Mediterranean at Alexandria after a trip of
about 3,000 miles (4,750 km),
it is now considered the source of the Nile.
Most of this water flows during the rainy season from June to September
each year.
On the Blue Nile are many dams that allow the irrigation of
over a million acres of land previously barely able to be used for farming.
The Landsat image to the left shows the White Nile on the left and the Blue
Nile on the right. The textured region between is farmland divided up into
many narrow plots so that the image looks like a log jam. These farms
are sustained by water from the Blue Nile.
As many know, the Nile has sustained a remarkable civilization for many
centuries. However, the Nile's water flow has experienced dramatic changes.
For example, in 2150 BC, a drought reduced the flow for so long that
the rule of Pepy II, the fourth king of the 6th Dynasty of the Old Kingdom
was ended and the country thrown into anarchy. The writings of Ipuwer attest
to the extreme conditions. "…the desert claims the land Towns are ravaged,
Upper Egypt became a wasteland…children of nobles are dashed against
walls…Infants are put on high ground……those who were entombed are
cast on high grounds…"
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Landsat Image of White
and Blue Nile Rivers
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In the last 30 years, almost all the trees in Ethiopia have been cut down,
especially those along the banks of the rivers.
Indeed, in the late nineteenth century, about 30 percent of the country was
covered with forest.
Today, less than four percent of Ethiopia is forested.
This massive deforestation was not done to provide land for growing crops
but to provide wood for making charcoal.
The deforestation has led to very significant changes in the Nile.
It is now more acidic, contains more silt and carries fewer of the nutrients
that have fed the farms of Egypt for centuries.
The difference in flow between the wet season and dry season is also greater,
although the Aswan Dam now controls the flow below the dam.
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Confluence of White and Blue Nile
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Were not for the fact that there has been less change along the banks of
the White Nile the situation in Egypt would be much worse.
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Contents copyright 2005 by Dr. A. V. Persson and ParaComp, Inc.
All rights reserved.
Disclaimer
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Vol 4, No 8
