Hydric functioning of Saharan endoreic systems

The natural Saharan regions are characterized by a Pluviometry ≤ 80 mm/year. The water supply of the Ouargla basin is ensured by the drillings exploiting the deep aquifers (CT and CI) of mineralization between 2 and 8 g/l. The water table is fed by drainage and sanitation. It reveals a static level of 0-11 m very high conductivity (416 mS/cm) the direction of flow South-North as well as an annual fluctuation ≥ 0.5 m around the discharge area . The study of water flows at the Cuvette scale (99000 ha) shows Inflows >87 million m3 & Capacity Outflows>85 Mm3/year of which. 80% evaporative flows take place March-October. The main outflows are evapotranspiration from palm groves (70 Mm3/year) evaporation from water bodies (13 Mm3/year) and groundwater (2 Mm3/year). The study highlights a technical solution for the transfer of 130 Mm3/year of surplus water. It proposes the reuse of water in irrigation after treatment with carbon based on date pits. The first treatment results are very encouraging. The conductivity of the water of this table reduced by 15 -22%.