Evaluation of Eight Evaporation Estimation Methods in a Semi-arid Region (Dez reservoir, Iran)

Establishing satisfactory estimation methods of lake evaporation has been crucial vital for research and management of water resources and ecosystems. Determining the accurate method to estimate evaporation from reservoirs in the investigation and management of water resources is very important. Hence, in this study eight empirical methods such as; Makkink, DeBruin-Kejiman, Penman, Priestley-Taylor, Hamon, Jensen-Haise, Mayer and Rohver methods was used to estimate the evaporation from the Dez reservoir. These methods are divided into four categories: 1. Methods based on energy budget 2. Methods based on mass transfer 3. Methods based on radiation and temperature and 4. Combination of energy budget and mass transfer. The energy budget method is used to estimate evaporation rate as the reference method. Results showed that Priestly-Taylor and DeBruin-Kejiman estimation methods are better than other methods for this region.