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Algeria
The Sahara
The Algerian portion of the Sahara extends south of the Saharan
Atlas for 1,500 kilometers to the Niger and Mali frontiers. The
desert is an otherworldly place, scarcely considered an integral
part of the country. Far from being covered wholly by sweeps of
sand, however, it is a region of great diversity. Immense areas
of sand dunes called areg (sing., erg) occupy
about one-quarter of the territory. The largest such region is
the Grand Erg Oriental (Great Eastern Erg), where enormous dunes
two to five meters high are spaced about forty meters apart. Much
of the remainder of the desert is covered by rocky platforms called
humud (sing., hamada), and almost the entire
southeastern quarter is taken up by the high, complex mass of
the Ahaggar and Tassili-n- Ajjer highlands, some parts of which
reach more than 2,000 meters. Surrounding the Ahaggar are sandstone
plateaus, cut into deep gorges by ancient rivers, and to the west
a desert of pebbles stretches to the Mali frontier.
The desert consists of readily distinguishable northern and southern
sectors, the northern sector extending southward a little less
than half the distance to the Niger and Mali frontiers. The north,
less arid than the south, supports most of the few persons who
live in the region and contains most of the desert's oases. Sand
dunes are the most prominent features of this area's topography,
but between the desert areas of the Grand Erg Oriental and the
Grand Erg Occidental (Great Western Erg) and extending north to
the Atlas Saharien are plateaus, including a complex limestone
structure called the Mzab where the Mzabite Berbers have settled.
The southern zone of the Sahara is almost totally arid and is
inhabited only by the Tuareg nomads and, recently, by oil camp
workers. Barren rock predominates, but in some parts of Ahaggar
and Tassili-n-Ajjer alluvial deposits permit garden farming.
Data as of December 1993
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