摘要
Priestley-Taylor equation(PT)and the Penman-Monteith equation(PM)are commonly used methods for regional evapotranspiration monitoring,using the PT coefficient(α_(a))and PM crop/vegetation coefficient(K_(c)).This paper investigates the seasonal changes inα_(a)and K_(c)at five sites in Australia and China,to understand the relation-ship between environmental conditions and evapotranspiration when applying different evaporation estimation methods.The research shows that higher actual evapotranspiration does not lead to higherα_(a)and K_(c)values.α_(a)and K_(c)perform similarly in cropland and forest environments in both China and Australia.Bothα_(a)and K_(c)continuously increase to a peak during the growing season and then decrease to their lowest values during the winter season.Considering K_(c)’s similar performance toα_(a)and its greater data processing requirements,K_(c)has few advantages for estimating regional evapotranspiration.Applying the Priestley-Taylor equation with a regional𝛼indicator will enhance the accuracy and reduce the workload when estimating regional evapotranspiration for similar landcover types based on remote sensing.
基金
This work was supported by the open Fund of State Key Laboratory of Remote Sensing Science(Grant No.PFSLRSS202023)
the Qinghai Science and Technology Plan(Grant No.2019-SF-155)
the National Natural Scientific Foundations of China(Grant No.41701403).