Performance Comparison of Two Types of Natural and Artificial Covers in Reducing Evaporation from Water Reservoirs: A Case Study (Jiroft)

The high rate of evaporation from water surfaces, especially in hot and dry areas, is one of the most important challenges which the water resources managers are facing with. Jiroft is one of these areas where the evaporation rate reaches five to six times the global average. This region is one of the most important agricultural hubs in the country and has a large number of water storage pools for agricultural purposes, which a large volume of water are wasted annually due to the evaporation induced by high sunlight, high temperatures, long hours of sunshine and relatively strong winds. In the present study, the effect of two types of artificial (granular polystyrene) and natural (Cordia myxa leaves) cover on the intensity of evaporation from the water surfaces of this region (study location: Jiroft University’s research farm) in the hottest days of the year (May 15 Until June 15). The effect of each of these covers on the five densities of 10, 25, 50, 75 and 100% and three replications was investigated and the results were compared with the reference (without cover) test. The results of comparing the means and statistical analysis with the least significant difference (LSD) test showed that both types of covers in all densities had a significant effect on the reduction of evaporation. Comparison of the daily evaporation rate of covered treatments compared to reference test showed that artificial covers performed better than the natural covers in reducing the evaporation. The results of monthly evaporation showed that artificial and natural covers at 100% density, reduced evaporation by 29% and 24%, respectively, compared to the reference test.