Quantitative efficiency of composite plates in reducing evaporation from water surface

Document Type : Complete scientific research article

Authors

1 Corresponding Author, Associate Prof., Dept. of Water Science and Engineering, Agricultural Sciences and Natural Resources University of Khuzestan, Khuzestan, Iran

2 Assistant Prof., Dept. of Water Science and Engineering, Agricultural Sciences and Natural Resources University of Khuzestan, Khuzestan, Iran

Abstract

Background and objectives: The average annual evaporation rate in Iran is 2100 millimeters, which is three times the global average. This figure indicates that if the evaporation rate of reservoirs decreases with appropriate methods, we can make better use of these resources. Neglecting the high evaporation rate in the country has caused billions of cubic meters of water to evaporate from the reservoirs of more than 600 dams in the country every year. In this research, the effectiveness of composite plates in reducing evaporation from the free surface of water under real conditions was studied.
Materials and methods: The present study was conducted in the meteorological station of Ahvaz airport, with a geographical latitude of 31° 32', a geographical longitude of 48° 66', and an altitude of 16 meters above sea level. Class A evaporation pans with a diameter of 120.7 millimeters and a depth of 25 centimeters made of galvanized iron were used. All experiments were conducted between July and December 2022. In this study, composite plates with aluminum coating were used to reduce evaporation from the water surface with a thickness of 4 millimeters and consisted of two layers of aluminum sheet in the outer shell and a layer of polyethylene in the middle were used. In order to investigate the effectiveness of composite plates, floating balls, which are a relatively common method of reducing evaporation, used. In addition, the effect of various meteorological variables such as temperature, relative humidity percentage, average vapor pressure, wind speed and solar radiation on the efficiency of composite panels was investigated. Two-way analysis of variance was used to investigate the effect of various weather variables on the performance of composite plates.
Results: Experiments showed that square composite plates had an efficiency of 69%, triangular composite plates had an efficiency of 67%, and floating balls had an efficiency of 73% in reducing evaporation from the water surface. Therefore, floating balls had a slightly greater effect on reducing evaporation from the free surface. The empty space between square composites, due to their larger dimensions compared to triangular composites, is less, which can be considered as one of the reasons for the reduction of evaporation in square composites compared to triangular composites. According to the results of the analysis of variance, two parameters, relative humidity and wind speed, have a significant effect on the efficiency of composite plates in reducing evaporation from the water surface. Based on the results of the analysis of variance considering the interaction effects, none of the interaction effects have a significant effect on the efficiency of composite plates. However, considering the interaction effects in addition to the main effects increased the R-squared value of the created model to 0.669, which indicates that the interaction effects had a contribution of about 0.2 to this value.
Conclusion: Based on the results of the analysis of variance considering the main effects, two parameters, relative humidity and wind speed, have a significant effect on the efficiency of composite panels in reducing evaporation from the water surface. Relative humidity has an effect of 0.182, and wind speed has an effect of 0.197 on the efficiency of composite panels. Relative humidity and wind speed are among the parameters that have a significant impact on the rate of evaporation from the water surface, causing a decrease and an increase in evaporation from the water surface, respectively. The presence of composite panels has greatly reduced the effect of these two parameters on the evaporation rate from the water surface.

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1.Han, K. W., Shi, K. B., Yan, X. J., & Cheng, Y. Y. (2019). Water savings efficiency of counterweighted spheres covering a plain reservoir in an arid area. Water Resources Management. 33, 1867-1880.
2.Rezazadeh, A., Akbarzadeh, P., & Aminzadeh, M. (2020). The effect of floating balls density on evaporation suppression of water reservoirs in the presence of surface flows. Journal of Hydrology. 591, 125323.
3.Oosthoek, J., & Gills, B. K. (2005). Humanity at the crossroads: The globalization of environmental crisis. Globalizations. 2 (3), 283-291.
4.Wang, W., Zou, S., Shao, Q., Xing, W., Chen, X., Jiao, X., Luo, Y., Yong, B., & Yu, Z. (2016). The analytical derivation of multiple elasticities of runoff to climate change and catchment characteristics alteration. Journal of Hydrology.
541, 1042-1056.
5.Ghazvinian, H., Farzin, S., Karami, H., & Mousavi, S. F. (2020). Investigating the effect of using polystyrene sheets on evaporation reduction from water-storage reservoirs in arid and semiarid regions (Case study: Semnan city). Journal of Water and Sustainable Development. 7 (2), 45-52. [Translated in Persian]
6.Alizadeh, A. (2013). The principles of applied hydrology. Ferdowsi University of Mashhad. [Translated in Persian]
7.Arabi Yazdi, A., Niknia, N., Majidi, N., & Emami, H. (2015). Water security assessment in arid climates based on water footprint concept (case study; south Khorasan province). Iran J. Irrig. Drain. 4 (8), 735-746. [Translated in Persian]
8.Mokarram, M., Zarei, A. R., & Etedali, H. R. (2021). Optimal location of yield with the cheapest water footprint of the crop using multiple regression and artificial neural network models in GIS. Theoretical and Applied Climatology. 143, 701-712.
9.Mozafari, A., Mansouri, B., & Chini, S. F. (2019). Effect of wind flow and solar radiation on functionality of water evaporation suppression monolayers. Water Resources Management. 33, 3513-3522.
10.Sepaskhah, A. R. (2018). Evaporation reduction from water reservoir of dams. Strategic Research Journal of Agricultural Sciences and Natural Resources. 3 (1), 13-26. [Translated in Persian]
11.Madadi, M. R., Kouhestani, S., Jadavi, M., & Zakariayi, M. (2020). Performance comparison of two types of natural and artificial covers in reducing evaporation from water reservoirs: A case study (Jiroft). Iranian Journal of Irrigation and Drainage. 14 (4), 1448-1459. [Translated in Persian]
12.Rezazadeh, A., Akbarzadeh, P., & Aminzadeh, M. (2020). Modelling and Experimental Investigation of the Evaporation Suppression Using Floating Covers in the Presence of Surface Flows. Amirkabir J. Mech. Eng.53 (1), 1-3. [Translated in Persian]
13.Benzaghta, M. A., Mohammed, T. A., Ghazali, A. H., & Soom, M. A. M. (2013). Testing of evaporation reduction methods in humid climates. In Proceedings of the Institution of Civil Engineers-Water Management (Vol. 166, No. 4, 207-216). Thomas Telford Ltd.
14.Taboada, M. E., Cáceres, L., Graber, T. A., Galleguillos, H. R., Cabeza, L. F. & Rojas, R. (2017). Solar water heating system and photovoltaic floating cover to reduce evaporation: Experimental results and modeling. Renewable Energy. 105, 601-615.
15.Han, K. W., Shi, K. B., & Yan, X. J. (2020). Evaporation loss and energy balance of agricultural reservoirs covered with counterweighted spheres in arid region. Agricultural Water Management. 238, 106227.
16.Shalaby, M. M., Nassar, I. N., & Abdallah, A. M. (2021). Evaporation suppression from open water surface using various floating covers with consideration of water ecology. Journal of Hydrology. 598, 126482.
17.Karimzadeh, M., Zahiri, J., & Nobakht, V. (2023). Efficiency of monolayers in evaporation suppression from water surface considering meteorological parameters. Environmental Science and Pollution Research. 30 (17), 50783-50794.
18.Razzaghi, F., Rajabpor, R., Layani, G., & Mirzaei, F. (2022). Estimation of the Economic Value of Water for Urban and Agricultural Use: A Case Study for Kowsar Dam. Journal of Agricultural Economics Research. 14 (1), 76-91. [Translated in Persian]
19.Grabovac, I., & Whittaker, D. (2009). Application of bonded composites in the repair of ships structures–A 15-year service experience. Composites Part A: Applied Science and Manufacturing. 40 (9), 1381-1398.
20.El Baradei, S. A., & Al Sadeq, M. (2019). Optimum coverage of irrigation canals to minimize evaporation and maximize dissolved oxygen concentration: case study of Toshka, Egypt. International Journal of Environmental Science and Technology. 16, 4223-4230.