干旱区生态环境知识资源中心

Most developed lands in arid and semi-arid areas of Algeria rest on a highly mineralized phreatic aquifer, the level of which is close (0-1.5 m) to the ground surface. Such a superficial water table, combined with the existence of highly severe climatic conditions, have enhanced the process of evaporation from the water table, which largely contributes to the salinization of soils and the degradation of the environment. The present study on the evaporation process of the phreatic aquifer in the Ouargla region shows that evaporation decreases the further the water table is from the ground surface. The study shows that evaporation of the water table reaches its maximum and is equal to the rate of evaporation of the aquifer at 0-0.6 m from the ground surface and its minimum rate when it is below 1.7 m. For better development of land and improved agricultural production, it is necessary to know the critical depth of the water table for which evaporation is low and therefore there is a low deposit of salts in sandy soils in the arid Ouargla region.