A quantitative and qualitative investigation of ball and foam covers coated with cement slurry and their composition on reducing evaporation and choosing the best coating by the AHP method

The present study sought to use a 20 mm thick foam coated with cement slurry and a blue ball with a diameter of 6 cm, as physical methods, in 50 and 80% surface covers, and their composite in 80% surface coverage in the Colorado pan. The water depth in the pans was measured for 1 month in the autumn season. Then, the pans' daily evaporation was calculated and compared with the amount of control evaporation. The results indicated that the combined method (plastic ball and foam) with 80% reduced the evaporation by about 68%, plastic ball with 80% (B80%) cover about 58%, foam with 80% coating about 53%, plastic ball with 50% coating about 34%, and finally 50% foam (F50%) by about 28%. Concerning the statistical analysis of this research, a significant correlation was observed between the control pan and average temperature, although there was no fixed and uniform relationship between the control pan and the maximum wind speed, air pressure, average relative humidity, and the number of sunshine hours. In this research, foam 50%, composite 80%, foam 80%, ball 80%, and ball 50% had better performance in terms of the best water quality based on the water electrical conductivity, respectively.