Assessment of Valiantzas’ reference evapotranspiration equations for Chabahar region

Evapotranspiration (ET) is the most important parameter in climatic and hydrological studies and also in the management and planning of irrigation. Estimation of reference evapotranspiration (ET) in a simple way, is of great interest, especially in developing countries, where meteorological data required for standard method of FAO Penman-Monteith (PMF-۵۶) is incomplete or not available.The aims of this study were: Evaluation of the two models of the newest methods to estimate ETo by Valiantzas with six methods including: FAO Penman-Monteith, Hargreaves-Samani, Priestley Taylor, Makkink,Turc. For this study meteorological data from Chabahar stations located in the South coastline was used.The statistical results showed that among ETo estimation methods in terms of lack of data PriestleyTaylor method has the best performance compared to standard method. Among the methods developed by Valiantzas, method of Valiantzas ۲ has the highest correspondence compared to standard method.

Keywords:

evapotranspiration , Iran , coastlines , Valiantzas methods.