Evaluation of Radiation-Based Reference Evapotranspiration Equations versus FAO56-PM Equation at Sub-Humid Hazaribagh Region, India

In this study, the performance of 20 radiation-based equations for estimating reference evapotranspiration (ET ) was statistically analysed on weekly basis in comparison to widely accepted FAO Penman-Monteith (FAO-56 PM) equation for sub-humid Hazaribagh region of Jharkhand, taken as index method. The respective highest and lowest values of agreement index and root mean square error obtained with FAO24-Radiation method confirms its acceptability. The ratio of ET method/ET0 FAO-56 PM was found best (almost equal to 1.00) with Priestley-Taylor method.