REFERENCE EVAPOTRANSPIRATION ESTIMATION BY RADIATION BASED METHODS

Most of the studies have shown that the FAO-56 Penman-Monteith (PM) method gives very accurate estimation of reference evapotranspiration (ET 0 ) in different environments. However, under limited climatic data availability conditions, the simple empirical methods yielding results comparable with PM ET 0 may be selected at regional level for reasonable estimation of ET 0 . This study deals with the evaluation of monthly reference evapotranspiration(ET 0 ) estimation using radiation based methods of Priestley-Taylor(PT), FA O-24 Radiation(RA) and Makkink(MK) by comparing their performance with that of PM method, developing relationships between PM and other methods and recalibrating the methods with respect to PM method