A Review of Methods to Reduce Evaporation from the Free Water Surface and the Introduction of Appropriate Methods of Practical and Economic

Due to the importance of water that is one of the first needs of human life and according to the problem that Iran has an average annual rainfall of 240 mm and its population of 80 million, It is a dry and semi-arid country, and it faces a lot of water stress, It is essential to prevent water loss as much as possible. One of these methods is the control of evaporation from water storage tanks, which is possible in different ways. Climate change on earth has also contributed to the cause, and the rate of evaporation has been increasing in recent decades. This can sometimes reduce more than 40% of the volume of water stored in the dam. This study introduces different methods and products of chemical and physical of evaporation control from the water surface and disadvantages and benefits of each. Finally, the methods were compared and prioritized using Analytical Hierarchy Process(AHP) in economic, executive, and environmental terms.