Nile River History

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River Nile , History, Present and Future Prosperity Dr. Mary Ghobrial National Institute of Oceanography & Fisheries, Alexandria Egypt

description

Nile River History

Transcript of Nile River History

Page 1: Nile River History

River Nile, History, Present

and Future Prosperity

Dr. Mary Ghobrial

National Institute of

Oceanography &

Fisheries, Alexandria

Egypt

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River Nile Basin

ŠLongest river in the World (6,695

Km) ŠLocation: Africa latitude 40S to

310N

ŠTotal length of the river and its tributaries: 37,20505

KmKm22

ŠRiver catchment's area: 2,9 million Km2

ŠShared among ten countries: Burundi,

Democraticmocratic

Republic of Congo, Egypt, Ethiopia, Eritrea,,

Kenya,Kenya, Rwanda, Sudan, Tanzania and Uganda

ŠTotal population of these countries: about 280

millionmillion ŠCrosses several climatic regions of

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Africa: tropicalpical rainrain forest to desert

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NILE RIVER Watersheds

Watershed area : 3.3 million km2 (one tenthth

ofof Africa)

The Nile River gets its water from threethree

catchments :

1- The Plateau of Equatorial lakes (South)

2- Bahr EL Ghazal (Center)

3- Ethiopian high lands (East)

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Water Sources of River Nile

ŠThe Nile is a combination of three long rivers whose

sources are in central Africa: the White Nile, the Blue

Nile, and the Atbarah.

ŠThe White Nile, which begins at Lake Victoria in

Uganda, supplies about 28% of the Nile's waters in Egypt

ŠIn southern and central Sudan, the White Nile passes

through a wide, flat plain covered with swamp vegetation

and slows almost to stagnation.

ŠThe Blue Nile, which originates at Lake Tana in

Ethiopia, provides an average of 58% of the Nile's waters

in Egypt.

ŠThe much shorter Atbarah River, which also originates

in Ethiopia, and provides about 14% of the Nile's waters

in Egypt.

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Total budget off waterwater

sources

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Water flow to River Nile (Egypt)

(x106)

Egypt’s share of the Nile flow is 55.5 cubic kilometreses

perper year ( average flow is 84 cubic kilometres per

yearear atat Aswan )

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Delta Branches

ŠThe Nile Delta extends over approximatelyly

22,00022,000 square kilometers.

ŠThe Nile in Egypt extends for 1200 km betweenen

AswanAswan and the Mediterranean Sea .

ŠAt Cairo, the Nile spreads out over what wasas onceonce aa

broad estuary that has been filled by silt depositsposits toto form

a fertile, fan-shape delta about 250 kilometersters widewide..

ŠAccording to historical accounts from the firstst centurycentury

A.D., seven branches of the Nile once ran throughrough

thethe Delta.

ŠNature and man have closed all but two mainin

outletsoutlets:: the east branch, Damietta (240

kilometers long),), andand thethe west branch, Rosetta

(31.50°N, 30.35°E )(235 kilometersilometers long).

ŠA network of drainage and irrigation canalscanals

supplements these remaining outlets.

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Nile Valley Geology

ŠThe Nile Delta has strong geological similaritiesities withwith

the desert to the west and the Nile Valley to the southsouth..

ŠThe Nile Valley consists of the broad floodplainain

whichwhich flows between steep limestone or sandstone

hillsls..

ŠThe valley sediments have been formed byby thethe

deposition of over bank deposits (sands, silts, andnd

claysclays)) when the Nile flooded. Silt is 50 to 75 feet deep.

ŠMuch of the delta is dominated by similarr

alluvialalluvial sediments to those found in the Nile

Valley.

ŠRiver regulation has stopped this annual

sedimentsediment influx, and the flood plain is now

dissected by aa networknetwork of irrigation canals.

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ŠAt the coast there is a series of saline lagoons andand

saltsalt flats trapped behind coastal sand bars.

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Sources of Nile Sediment

ŠMost of the sedimentation of the Nile (~ 90%),),

flowsflows from the Ethiopian highlands through the

Blue NileNile andand the Atbara during the flood .

ŠThe White Nile and its tributaries lose mostst ofof

itsits sediment load by spilling and deposition overer

floodflood plains, lakes, and marshlands.

ŠMean annual sediment load to be approximatelytely

134134 million tons at Aswan.

ŠNorth of Aswan, the river has a gentle

gradient,gradient, dropping 1m in every 13 km.

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