Egyptian Rivers and Flooding Cycle of Nile

March 30, 2019

https://en.wikipedia.org/wiki/List_of_rivers_of_Egypt

This is a list of rivers in Egypt.

Nile (JEOR)

There is only one year-round river in Egypt, the Nile. It has no non-seasonal tributaries for its entire length in Egypt, though it has two further upstream, the Blue Nile and White Nile, which merge in central Sudan.

In the Nile Delta, the river splits into a number of distributaries and lesser channels. In ancient times there were seven distributaries, of which only two are extant today due to silting and flood relief schemes; from east to west, they were:

  • the Pelusiacas
  • the Taniticasa,
  • the Mendesian,
  • the Phatnitic (extant; now the Damietta or Damyat),
  • the Sebennyticana,
  • the Bolbitinicanadia,
  • the Canopicias (extant; now the Rosettasa or Rashida).

The Nile is intersected by a number of normally dry tributaries or wadis which traverse the Eastern Desert. The wadis drain run-off rainfall from the mountains along the Egyptian Red Sea coast, though it only rarely reaches the main trunk of the wadis to flow downstream to the Nile. The three principal wadis are:

  • Wadi Abbad (drainage area 7,000 km²)
  • Wadi Shait (length 200 km, drainage area 10,000 km²)
  • Wadi El-Kharit (length 260 km, drainage area 23,000 km²)

Sinai

Sinai haspe Mukattab]] (“The Valley of Writing”) and the Wadi Feiran (associated with the biblical Rephidim).

Sources

  • The Vegetation of Egypt, pp. 192, 253. M. A. Zahran, A. J. Willis. Springer, 2008. ISBN 978-1-4020-8755-4

Flooding Cycle of Nile

The flooding of the Nile is the result of the yearly monsoon between May and August causing enormous precipitations on the Ethiopian Highlands whose summits reach heights of up to 4550 m (14,928 ft). Most of this rainwater is taken by the Blue Nile and by the Atbarah River into the Nile, while a less important amount flows through the Sobat and the White Nile into the Nile. During this short period, those rivers contribute up to ninety percent of the water of the Nile and most of the sedimentation carried by it, but after the rainy season, dwindle to minor rivers.

These facts were unknown to the ancient Egyptians who could only observe the rise and fall of the Nile waters. The flooding as such was foreseeable, though its exact dates and levels could only be forecast on a short term basis by transmitting the gauge readings at Aswan to the lower parts of the kingdom where the data had to be converted to the local circumstances. What was not foreseeable, of course, was the extent of flooding and its total discharge.

The Egyptian year was divided into the three seasons of Akhet (Inundation), Peret (Growth), and Shemu (Harvest). Akhet covered the Egyptian flood cycle. This cycle was so consistent that the Egyptians timed its onset using the heliacal rising of Sirius, the key event used to set their calendar.

The first indications of the rise of the river could be seen at the first of the cataracts of the Nile (at Aswan) as early as the beginning of June, and a steady increase went on until the middle of July, when the increase of water became very great. The Nile continued to rise until the beginning of September, when the level remained stationary for a period of about three weeks, sometimes a little less. In October it often rose again, and reached its highest level. From this period it began to subside, and usually sank steadily until the month of June when it reached its lowest level, again. Flooding reached Aswan about a week earlier than Cairo, and Luxor 5 – 6 days earlier than Cairo. Typical heights of flood were 45 feet (13.7 metres) at Aswan, 38 feet (11.6 metres) at Luxor (and Thebes) and 25 feet (7.6 metres) at Cairo.[

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