Misconceptions of Reference and Potential Evapotranspiration: A PRISMA-Guided Comprehensive Review

One of the most important parts hydrological cycle is evapotranspiration (ET). Accurate estimates ET in irrigated regions are critical to planning, control, and regulation agricultural natural resources. estimation necessary for irrigation scheduling. a nonlinear complex process that cannot be calculated directly. Reference (RET) potential (PET) two primary forms ET. The ideas, equations, application areas PET RET different. These terms have been confused used interchangeably by researchers. Therefore, terminology clarification ensure their proper use. research indicates concepts long distinguished history. Thornthwaite devised original idea, it has ever since, although with several improvements. development RET, initially PET, was formally defined as standard method. In this study, Preferred Reporting Item Systematic reviews Meta-Analysis (PRISMA) used. Equations were retrieved from 44 articles, equations collected 26 studies. Both divided into three distinct categories: temperature-based, radiation-based, combination-based. results show that, among temperature-based Thornthwaite’s (1948) equation mentioned 12,117 publications, whereas Hargreaves Samani’s (1985) quoted 3859 Similarly, Priestley (1972) had highly cited radiation-based (about 6379), Ritchie (around 2382) equations. Additionally, combination-based Penman Monteith’s 9307 studies, but Allen et al. (1998) subject significant number citations 23,000 publications. Based on application, often applied fields hydrology, meteorology, climatology, more frequently utilized agronomy, agriculture, irrigation, ecology. derive drought indices, employed single crop dual coefficient approaches. This work examines describes ideas methodologies, widely applications, advanced approaches associated discusses future enhancements increase accuracy calculation attain accurate use tools such remote sensing satellite technologies, addition machine learning algorithms, will help improve estimates. Researchers able distinguish between study’s results.