Department of Irrigation & Drainage Engineering, College of Technology, G. B. Pant University of Agriculture & Technology, Pantnagar- 263145, India
The present study was undertaken to calibrate, validate and evaluate the performance of some temperature-& radiation-based and Valiantzas’ ET0 equations in comparison to standard FAO56-PM model in humid climatic conditions prevailing at Dehradun district of Uttarakhand (India). Prior to analysis, quality control of 31 years (1989–2019) daily meteorological dataset was ensured by omitting days with missing data and neglecting outliers. For calibration, 65% dataset (20 years, 1989–2008) was considered while, remaining 35% dataset (11 years, 2009–2019) was utilized for validation. The analysis showed that almost all calibrated equations performed well with higher value of Agreement index (D), reduced errors (RMSE, MAXE, PE) and nearby optimum value of ratio (R) of ET to ET. The global performance indicator (GPI) analysis revealed that Valiantzas’ V3 equation performed best among all considered equations.
Calibration, Temperature-based, Radiation-based, Valiantzas’, Reference evapotranspiration
