Effects of monolayers made from different emulsions on surface water evaporation in a typical Algerian oasis

The extremely high rate of evaporation from surface water bodies in arid and semi-arid regions greatly reduces optimal utilization of water reservoirs. Therefore, techniques to reduce evaporation are greatly needed. During the last decades, a large number of dams (68 dams)were constructed and distributed over the entire country. Hence, preserving and protecting the stored waterby reducing evaporation is strategic future task of the Algerian state. Experiment was conducted in Touggourt during summer with four Colorado evaporation pans and weather station. Two fatty alcohols emulsion were selected and applied to reduce the evaporation in different pans. The first pan (OP) was filled with water without adding emulsion,while in the second pan (P2, Hexa)Hexadecanol emulsion was added at the concentration of 0.15g/m2. For the third pan (P3, Hexa/Octa)amixture of Hexadecanol/Octadecanol emulsion was added at the same concentration (0.075g Hexa:0.075g Octa)and for the fourth pan (P4, Octa) Octadecanol emulsion was added with a concentration of 0.15g/m2. The different formulations and concentrations were repeated on the respective water surface every three daysin order to form a monolayer.