Evaluation of different methods for reference evapotranspiration assessment: A case study for Ukraine

Abstract

Reference evapotranspiration (ETo) is the most widely implemented agrometeorological index for establishment of irrigation rates and irrigation scheduling (Hargreaves, 1994). The best accurate ETo assessment is provided by lysimetric measurements. However, lysimeters are expensive, require trained staff for maintenance, and are more of scientific rather than practical use. Therefore, in practice, reference evapotranspiration is mainly estimated through indirect calculation methods. There are different approaches to ETo estimation using different meteorological and climatic parameters, but the most widespread in practice are methods developed by Penman-Monteith and Hargreaves