A Comparative Experimetn on Evapotranspiration for Validating the Estimates Made Using the Bucket with a Bottom Hole (BBH) Model

Abstract

An experiment was conducted in a vegetation-covered experimental field in Karatsu, Saga, Japan for one year to compare the estimates of evapotranspiration (ET) made using the bucket with a bottom hole (BBH) model of soil hydrology with the measurements made by the Bowen ratio method. The BBH model estimates the daily ET as the product of the daily potential evaporation and a soil moisture availability that is a function of soil moisture in the surface layer a few tens of centimeters thick. As a result, it was shown that this model estimates the daily evaporation fairly well if the seasonal change of a model parameter σ, which specifies the resistance to evaporation, is taken into account