Algerian Desert

The Sahara covers over 90% of Algerian territory. It is crossed by ergs (sand dunes), regs (stony terrain), as well as volcanic massifs in the far south.[4] The Algerian Desert is characterized by low rainfall, recording less than 100 mm per year. However, it rarely snows and floods, sometimes reviving the wadis (river valleys) that have been dry since prehistoric times. The subsoil is full of water in the Albian Aquifer which extends under a large part of the Algerian Desert, a remnant of the steppe climate that the region experienced 10,000 years ago.[4]

In the north, the grass of the steppe slowly becomes rarer while the species change until it makes way for the reg. The erg, the sandy desert, covers only a fifth of the Sahara. The Grand Erg Oriental (Great Eastern Sand Sea) borders the Wadi Righ, a succession of oases that stretches along the underground wadi. The Saoura valley limits the Grand Erg Occidental to the west. Between these two large ergs is the M'zab valley cut into a plateau. The northern Algerian Desert contains several oases, as opposed to the southern Algerian Desert, that is dominated by the Hoggar massif at an altitude of more than 3,000 meters. Vast monotonous hamadas (hard rocky desert plateaus) like the Tademaït plateau between El Goléa and In Salah connect the large geographical areas of the Sahara.[5]