EVALUATION OF EVAPOTRANSPIRATION MODELS IN HUMID REGION

Abstract

Forty fiit Evapotranspiration models have been evaluated and calibrated against FAO Penman-Monteith model, the models were grouped into: nine Temperature methods, twenty Radiation methods, nine Mass transfer methods and seven Pan Evaporation methods. It has been found that one version of Hargreaves Equation HAR was the best performing method among Temperature methods, FAO-MAK was the best among Radiation based methods, TRABERT and MAHRIN were the best models from mass transfer models. Pan methods were found to be with the lowest performance. Most of mass transfer has shown good performance. IV Seven ANN models with different inputs combination have been tested also and it has been found that ANN2 with temperature and wind speed as inputs is sufficient to estimate Evapotranspiration better than all conventional models.