Sensitivity of different evapotranspiration calculation methods in different crop-weather models

The calculation of evapotranspiration and its components transpiration and evapotranspiration is of crucial importance in dynamic crop-weather models, irrigation models and SVAT models. Although many approaches were developed and adapted for various applications and based on available input data, there is still a remarkable range of uncertainty related for a representative calculation. However, many of the problems are based on weak quality of model input data, but others are related to the method itself and its sensitivity to various environmental conditions. In our study, several methods of evapotranspiration estimation in different crop weather models are compared and tested against data from lysimeters at a location in Austria. An analysis shows differences in the results, related sensitivities in the used methods and crucial parameters for their parameterisation.