Experimental Study of Evaporation Reduction Using Polystyrene Coating, Wood and Wax and its Estimation by Intelligent Algorithms

Evaporation from the surface of water reservoirs leads to loss of water used in agriculture, industry and drinking. One of the methods of controlling evaporation is the use of physical coatings. In this research, polystyrene sheets, pieces of wood, and honey-bee wax sheets were used as physical coatings on the surface of the water to reduce evaporation from standard buried Colorado evaporation pans. The effect of each coating with three replicates (in three separate pans) was investigated and also three pans were considered as control. Evaporation was measured daily from all pans for 4 months. Results of the experiment showed that polystyrene, wood and wax coatings reduced evaporation by 54, 19 and 18%, respectively. Next, to estimate the percentage of evaporation reduction, decision tree M5, least squared support vector machine (LSSVM) and artificial neural network (ANN) were used. Meteorological data of Semnan synoptic station was used as input data for all the three models. All three methods were highly accurate in the training period. During the test period, the LSSVM method, decision tree M5 and ANN were more accurate, respectively. The values ​​of R2, RMSE and MAE of the LSSVM method at the test step were 0.9834, 2.3718, and 1.7212, respectively. The general results of this study showed that using polystyrene coating can have proper function in controlling evaporation from reservoirs and water storage pools.