120
A. M. Sharaky
treating the migrating dune belts is to avoid their directions. As to the main roads
between cities that are subject to sand encroachment, the sands are removed mechanically throughout the year. The easiest way, on the other hand, of reclaiming new
areas is to get out of the way of migrating dune belts.
6 Conclusions
The surface of African continent includes a gigantic plateau with shallow depressions.
More than one-third of the world’s arid lands is in Africa, namely Sahara, Kalahari,
and Namib deserts. Sand dunes which is Africa’s most distinctive aeolian feature
cover one-fifth of the African deserts. Among the major dune types in Africa that
are longitudinal and crescentic dunes, the longitudinal ones are the most common.
In Egypt, more than 17% of the land surface is covered by sand dunes. The Great
Sand Sea in the Western Desert constitutes about 80% of the Egyptian dunes.
As to Dakhla Oasis, the two main types of sand dunes are crescentic and longitudinal or linear dunes. The compound crescentic dunes called barchanoid ridges are
the most common type. The linear dunes are common in the southern part of the
eastern dune belt. Dakhla sand dunes continues to move from north to south. They
threaten highways, houses, cultivated lands, irrigated channels, and water wells. The
Dakhla dune movements follow the directional variability of the wind regime and
speed, distance from the northern plat-eau. The rate of Dakhla crescentic dune movement ranges between 0.5 and 14 m per year, and averages 5.8 m per year. The southern
extremity of linear dunes southwest of Mut ranges between few meters and 15 m/yr
with an average of 7.5 m/yr. The average rate of crescentic dune growth is 25 cm/yr
for width and 37 cm/yr for length. The drift potential (DP) varies significantly from
one direction to another according to the effective wind velocity. The average annual
DP at Dakhla is 787 VU, while it is 1882 VU at Farafra. Spring months showed the
highest RDP.
7 Recommendations
Controlling of dune movement in Dakhla Depression is very difficult and expensive.
Therefore, it is better to overcome threatening dunes by avoiding their way, and the
new reclamation land should be in between the dune belts. Laser stations are required
to monitor the movement of sand dunes in Dakhla Depression.
References
Ashri AH (1973) The movement of sand dunes at Kharga oasis. Geol Soc Egypt 17:37–46
Bagnall RS, Tallet G (eds) (2019) The great oasis of Egypt the Kharga and Dakhla Oases in antiquity.
Institute for the Study of the Ancient World, New York, 362 p
A. M. Sharaky
treating the migrating dune belts is to avoid their directions. As to the main roads
between cities that are subject to sand encroachment, the sands are removed mechanically throughout the year. The easiest way, on the other hand, of reclaiming new
areas is to get out of the way of migrating dune belts.
6 Conclusions
The surface of African continent includes a gigantic plateau with shallow depressions.
More than one-third of the world’s arid lands is in Africa, namely Sahara, Kalahari,
and Namib deserts. Sand dunes which is Africa’s most distinctive aeolian feature
cover one-fifth of the African deserts. Among the major dune types in Africa that
are longitudinal and crescentic dunes, the longitudinal ones are the most common.
In Egypt, more than 17% of the land surface is covered by sand dunes. The Great
Sand Sea in the Western Desert constitutes about 80% of the Egyptian dunes.
As to Dakhla Oasis, the two main types of sand dunes are crescentic and longitudinal or linear dunes. The compound crescentic dunes called barchanoid ridges are
the most common type. The linear dunes are common in the southern part of the
eastern dune belt. Dakhla sand dunes continues to move from north to south. They
threaten highways, houses, cultivated lands, irrigated channels, and water wells. The
Dakhla dune movements follow the directional variability of the wind regime and
speed, distance from the northern plat-eau. The rate of Dakhla crescentic dune movement ranges between 0.5 and 14 m per year, and averages 5.8 m per year. The southern
extremity of linear dunes southwest of Mut ranges between few meters and 15 m/yr
with an average of 7.5 m/yr. The average rate of crescentic dune growth is 25 cm/yr
for width and 37 cm/yr for length. The drift potential (DP) varies significantly from
one direction to another according to the effective wind velocity. The average annual
DP at Dakhla is 787 VU, while it is 1882 VU at Farafra. Spring months showed the
highest RDP.
7 Recommendations
Controlling of dune movement in Dakhla Depression is very difficult and expensive.
Therefore, it is better to overcome threatening dunes by avoiding their way, and the
new reclamation land should be in between the dune belts. Laser stations are required
to monitor the movement of sand dunes in Dakhla Depression.
References
Ashri AH (1973) The movement of sand dunes at Kharga oasis. Geol Soc Egypt 17:37–46
Bagnall RS, Tallet G (eds) (2019) The great oasis of Egypt the Kharga and Dakhla Oases in antiquity.
Institute for the Study of the Ancient World, New York, 362 p