The Priestley–Taylor parameter and the decoupling factor for estimating reference evapotranspiration
The Priestley–Taylor parameter and the decoupling factor for estimating reference evapotranspiration
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DOI：
10.1016/j.agrformet.2004.04.002
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发表时间：
2004-10
影响因子：
6.2
通讯作者：
Antonio R. Pereira
中科院分区：
文献类型：
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作者：
Antonio R. Pereira
利用从湿润热带（巴西SP皮拉西卡巴）到半干旱（美国CA Davis）气候条件下参考蒸散量（E0, mmday−1）的两个广泛的日蒸散测量数据集，本文提出了一个证据，证明Priestley-Taylor α参数可以设置为McNaughton-Jarvis解耦因子Ω的逆，即α=Ω−1。这种方法不需要局部校准，它允许变量α。拟合优度的几个统计度量表明，这种简化是理论上更稳健的Penman-Monteith与FAO-56参数化方案的一个很好的替代方案。粮农组织-56估算值与观测值几乎完全匹配的选定日（e0在0.60至7.0mmday−1之间变化）的Ω值在0.69至0.93之间。Ω随风量线性下降。α的Perrier-Katerji-Goose-Itier模型不适用于目前的数据集。这里的主要问题是用蒸汽压差的日平均值确定临界阻力。
Using two extensive data sets of daily lysimetric measurements of reference evapotranspiration (E0, mmday−1) under climatic conditions ranging from humid tropical (Piracicaba, SP, Brazil) to semi-arid (Davis, CA, USA) it is here presented an evidence that the Priestley–Taylor α parameter can be set equal to the inverse of the McNaughton–Jarvis decoupling factor Ω, that is, α=Ω−1. This approach does not require local calibrations and it allows for a variable α. Several statistical measures of the goodness of fit indicate that this simplification represents a good alternative to the theoretically more robust Penman–Monteith with the parameterization scheme of the FAO-56. Selected days with almost perfect match between FAO-56 estimates and observations, with E0varying from 0.60 to 7.0mmday−1, showed Ω values from 0.69 to 0.93. Ω decreased linearly as a function of the wind run. The Perrier–Katerji–Goose–Itier model for α did not work well for the present data sets. The main problem here is the determination of a critical resistance with daily averages of vapor pressure deficit.