RECALIBRATION OF REFERENCE EVAPOTRANSPIRATION ESTIMATION METHODS

Reference evapotranspiration (ET 0 ) estimates are often required in irrigation system design, crop yield simulation and water resources planning and management. Many reference evapotranspiration (ET 0 ) estimation methods have been developed for different types of climatic data, and the accuracy of these methods varies with climatic conditions. In this study, the weekly ET 0 values estimated from nine different ET 0 equations are evaluated with ET 0 estimated by FAO-56 Penman-Monteith(PM) equation in order to select an appropriate ET 0 equation for the semi- aridNellore region of Andhra Pradesh, India.