Introducing affordable and accessible physical covers to reduce evaporation from agricultural water reservoirs and pools (field study, statistics, and intelligent methods)

Abstract

Nowadays, a major part of the stored surface water resources is wasted by evaporation. By implementing low-cost methods to prevent water evaporation, it is possible to return this part of water to the agricultural, industrial, and drinking cycles. The present study aimed to evaluate the effect of polystyrene (compressed foam), pieces of wood, and synthetic beeswax cover with different surface coverage of 60%, 70%, and 80% in the standard Colorado Sunken evaporation pan on the evaporation rate. The materials used in this research are accessible, natural, and affordable in terms of practical applications. Then, the parameters of minimum and maximum temperature, maximum and minimum relative humidity, sunny hours, pressure, and wind speed were obtained from Semnan Synoptic Station near the test site. Due to limited studies in simulation of evaporation reduction through intelligent methods, the evaporation values of polystyrene, pieces of wood, and synthetic beeswax covers were simulated and estimated by using artificial intelligence methods of M5 model tree, Artificial Neural Network, and Least-Square Support Vector Machine. Results indicated that compressed foam, pieces of wood, and synthetic beeswax covers, each with 60%, 70%, and 80% coverage could reduce the evaporation rate by 43%, 54%, and 65%, 10%, 19%, and 26%, and 8%, 18%, and 25%, respectively. From a statistical point of view, the meteorological data received from Semnan Synoptic Station had significant correlations with evaporation rate from station pan, Colorado pan, and pans containing polystyrene, pieces of wood, and synthetic beeswax covers. The temperature and relative humidity parameters are factors affecting the evaporation rate in Semnan station. After evaluating the simulation accuracy based on the parameters of the root mean square error (RMSE), mean absolute error (MAE), and determination coefficient ( R 2 ), the best estimation was obtained by the LSSVM method with R 2 = 99%. From an economic viewpoint, the compressed polystyrene sheet and synthetic beeswax imposed $1 and 8 cents per m 2 in Iran. Moreover, the discarded pieces of wood that are used in the present study are inexpensive. Regarding the cost and performance of the material in reducing evaporation, it is recommended to use polystyrene material, followed by pieces of wood and beeswax.

Laboratory Comparison of Evaporation Rate Between Colorado Sanken Evaporation Pan and Class A Evaporation Pan (Case Study: Semnan, Iran)

“…Figure 10 compares the changes of the parameters received from Semnan meteorological station including minimum temperature (Celsius), maximum temperature (Celsius), maximum humidity (percentage), minimum humidity (percentage), sunlight hours, pressure (hectopascal) and wind speed (meters per second) on test days; it also shows the rate of evaporation from the CASEP and CSSEP (mm) (Ghazvinian et al, 2021). From the obtained results, it can be deduced that wind speed and temperature are at their lowest correlation with the ER.…”

“…The results showed that the ER from the MDF-containing pan was 91% lower than that of the CSSEP. Ghazvinian et al (2021) went on to place various coatings such as polystyrene, wood, and synthetic honey wax on the CSSEP, where they measured the evaporation and compared the ER from the control pan with the pan containing the coatings. The results showed that the rate of evaporation in the pan containing polystyrene was less than the evaporation in other pans and the control pan.…”