Study on the Evaporation Suppression Efficiency and Optimal Diameter of Plain Reservoirs Covered by EPS Floating Balls in Arid Areas

Current research on the evaporation inhibition effect of polyethylene (PE) floats has been relatively comprehensive, and the cost is relatively high when it is arranged in remote mountainous areas. In order to find a more economical anti-evaporation material, five kinds of solid expanded polystyrene (EPS) floating balls with different diameters of 10 mm, 40 mm, 80 mm, 120 mm and 150 mm were selected to study the evaporation suppression efficiency (ESE) of EPS floating balls on the evaporation of reservoir water surfaces in arid areas. The outdoor evaporator test and the wind wave test in the reservoir area were carried out. Combined with various meteorological data, the evaporation inhibition rates of EPS floating balls with different diameters during a non-freezing period were calculated. The durability, seepage prevention, wind resistance, frost resistance, aging resistance and other properties of EPS were observed under different climatic conditions. In the evaporator test, the relationship between the diameter of the floating balls and the ESE was not a single function. The ESE of floating balls with a diameter of 40 mm was the highest, at 76.31%. In the wind wave test in the reservoir area, the ESE of the 10 mm floating balls was the lowest, at 34.79%, and the ESEs of the other four diameters of EPS floating balls were above 85% and positively related to the diameter of the floating balls. The test further improved the selection scheme for the diameter of the anti-evaporation floating balls, provided a reference for the practical application of EPS floating balls in future water-saving projects in the reservoir area, and enriched the content of water-saving projects for plain reservoirs in arid areas.