Toshka Lakes

Location of the Toshka Lakes and Lake Nasser in Egypt.

Photograph of the Toshka Lakes taken Dec. 2002 from the International Space Station looking NE. Lake Nasser is the very long lake that lies east of the lakes. Wadi Toshka is the large bay in Lake Nasser directly east of the Toshka lakes. The Western Desert of Egypt can be seen east of Lake Nasser

Toshka Lakes (Arabic: بحيرات توشكى‎, Egyptian Arabic pronunciation: [boħeˈɾæːt ˈtoʃkæ]) is the name given to recently formed endorheic lakes in the Sahara Desert of Egypt.^[1]

History

The Aswan High Dam, constructed in Egypt in 1964-1968, created Lake Nasser, with a maximum water level of 183 metres (600 ft) above sea level. In 1978 Egypt began building the Sadat Canal NW from Lake Nasser through Wadi Toshka to allow water levels higher than 178 metres (584 ft) to be drained off into a depression at the south end of the Eocene limestone plateau. In the late 1990s, water began flowing through the Sadat Canal into the Western Desert. This feeder canal from Lake Nasser is concrete lined, to reduce seepage losses.

Formation

Astronauts began noticing the first, easternmost lake growing in November 1998. By late 1999, three additional lakes formed successively westward, and the westernmost lake started forming sometime between September 2000 and March 2001. These lakes are not yet named individually. In total, the Toshka Lakes cover approximately 1300 square kilometers (502 mi²). As of as of 2006 the levels of the lakes are lower than in 2001, and areas of wetlands and sand dunes have formed between the former and present shorelines. A minor lake downstream of the three larger lakes has completely dried out. The levels of the lakes vary between 175 metres (574 ft) for the one closest Lake Nasser to 144 metres (472 ft) for the one furthest downstreams.

Landsat mosaic of Toshka Lakes (April 2003). False-color image, with bands 7-4-2 assigned to R-G-B).

Geography

• The new lake system is endorheic, that is, the waters can never flow on to the sea. The Nile-sourced water creates the lakes and helps to recharge the underlying aquifer; but desert temperatures cause very high levels of evaporation. Although the new lakes already contain an impressive amount of fish, these high evaporation levels will make the waters become increasingly saline over time, reducing fish stocks and harming the newly established flora and fauna.
• The Toshka Depression lies within the seismically active Nubian Swell. The Egyptian government is developing the surrounding region, also known as the "New Valley Project". The plan is to extend the waterway to the Kharga oasis.
• Use of Nile resources is governed by the Nile Basin Initiative; but the Toshka project does not breach the agreement as water is diverted from Lake Nasser only after heavy water flows upstream have raised lake levels above 178 metres (584 ft) (see above).

Related Projects

• Sudan's Gezira Scheme, south of Khartoum, at the confluence of the Blue Nile and the White Nile.
• The Qattara Depression, north of the Kharga oasis and west of Cairo, is a large area of Egypt that lies below sea level. It has long been mooted to divert waters, either from the fresh Nile or from the saline Mediterranean Sea, to generate hydro-electric power. Much of this water would then evaporate. Ideally fresh Nile water would be used, to recharge the aquifer and to allow irrigation for agriculture; use of sea water would create a "second Dead Sea".
• In May 2009 Jordan announced its plans to construct the "Jordan National Red Sea Development Project" (JRSP). This is a plan to convey seawater from the Red Sea near Aqaba to the Dead Sea. Water would be desalinated along the route to provide freshwater to Jordan, with the brine discharge sent to the Dead Sea for replenishment.^[2]
• Further related projects include: (i) diverting and/or damming the River Niger to help irrigation and hydro-electric power in Mali and Niger; and (ii) diverting water from the Mediterranean Sea to form an inland sea in Tunisia's Chott Djerid salt pan, near Tozeur;

See also

• New Valley Project
• New Valley Governorate
• Lakes of Egypt

References

Further reading

• Chipman, J. W; T. M. Lillesand (2007). "Satellite‐based assessment of the dynamics of new lakes in southern Egypt". International Journal of Remote Sensing 28 (19): 4365–4379. doi:10.1080/01431160701241787. 

External links

• Astronaut photography of Sara Lake formation 1998-1999.
• March 2002 MODIS 'true color' image of Toshka Lakes and vicinity.
• Jan. 2003 MODIS false color image of the Toshka Lakes.
• This fly-through is of the area imaged by satellites before the lakes formed.
• Astronaut photography documenting the formation of the westernmost lake in 2001.
• Astronaut photography documenting shrinking of the lakes in late 2005.
• CEO (Crew Earth Observation) on the Gateway to Astronaut Photography of Earth (Toshka, Egypt)