Evaluation of Modified Climatological Approaches for the Estimation of Evapotranspiration

Four modified empirical methods viz. Blaney Criddle method, Radiation method, Modified Penman method and Pan evaporation methods of determining potential evapotranspiration were compared for Ludhiana conditions. The potential evapotranspiration values calculated by these methods were multiplied by crop coefficient to find the actual evapotranspiration and these actual ET values were compared with lysimeter data. The study suggested that Modified Penman method is best for cumulative evapotranspiration (CET) and radiation method is best for calculating the daily/fortnightly evapotranspiration.