Comparison of the Inverse Analysis Method with the Bowen's Ratio Method and the Eddy Covariance Method for Estimation of Evapotranspiration

― Case study on the abnormal criteria applied ―

Abstract

This paper described the feature of lE (Latent heat flux) and H (Sensible heat flux) derived from the IABM (Inverse analysis of Bowen Ratio method), B_O (Bowen ratio) method and Eddy covariance method and compared the feature among them. Above three methods are applied by the abnormal criteria that α×ABS(Rn-G)>ABS(H) and ABS(lE) as proposed by the previous research. ① The hourly changes of lE and H of the three methods are very well consistent with each other during crop growing season (α=1.0 in the IABM). ② Comparison of three set of daily data of the lE between the two methods among the IABM, B_O and Eddy covariance methods shows they are very well consistent with each other. ③ Comparison of monthly change for the lE among the three methods describe very well their consistency with each other in case of α＝1.0. ④ The ratio of the abnormal data is remarkably many in the B_O method than the Eddy covariance method and IABM. ⑤Monthly evapotranspiration required for water resources and irrigation planning can be estimated by the three methods sufficiently.