Algeria - Foggaras oases and ksour of Grand Erg Occidental

In the spatial complex formed by the Grand Erg Occidental and the Saoura Valley, the stratification in time of the anthropic action has given rise to an original model of oasis implantation where the natural setting and the interventions due to the man contribute to the formation of the ecosystem. Wadi Saoura was defined as a "unique event throughout the African Sahara" and compared, in terms of geographical importance and impact on civilization, in the Nile of Egypt. The Saoura dug its valley in the course of the fourth quarter by encircling the lands of the tertiary continent of the southern atlastic piedmont. The narrow and well-designed valley is inserted between the chain of Ouargla and the continental tertiary. It was a great trans-Saharan caravan route that joined Gao on Malian territory after crossing Tanezrouft. It presents one of the most striking landscapes on either side of the Wadi Saoura, here juxtapose the reddish escarpments of the Hamada of Guir in the west and the dunes of the great western erg in the east. Between the two, palm grove and ksours punctuate the wadi. Everywhere balancing wells intended to raise the water; many ksour are still busy (Aguedel, El ouarta, Guerzim, Kerzaz ...).