Measurement Simulation of Hourly Evapotranspiration in Paddy Field with Different Methods

Hourly evapotranspiration in paddy field was observed directly by lysimeter and eddy covariance method(EC),and was simulated with using Penman-Monteith(PM)equation and Shuttleworth-Wallace(SW)model,respectively.The reliabilities of the two models were verified through comparing the observed and simulated evapotranspiration.The results showed that1 the measured evapotranspiration by EC were obvious lower compared with the lysimeter in each rice growth stage,and the reliability of measured evapotranspiration by lysimerter was higher.2The simulated effect of Shuttleworth-Wallace model was better than Penman-Monteith equation,and the simulated evapotranspiration was closer to the measured evapotranspiration by lysimeter,especially during the periods with sparse canopy.3Soil evaporation had a lower proportion in total evapotranspiration as well as a smaller resistance because of the water in the paddy,and the sensitivity of soil resistance was smaller than that in arid regions.