参考作物蒸散简易估算方法在黄土高原的适用性

参考作物蒸散(ET0)的简易估算方法在气象数据缺乏区域具有广泛的应用,但其适用性需要评估。基于1961~2009年48个气象站的数据,以FAO Penman-Monteith公式为标准评估了6种ET0简易估算方法(FAO-24Rad、FAO-24BC、Hargreaves、Priestley-Taylor、Makkink和Turc)在黄土高原应用的可能性。结果表明,对于ET0年值的估算,FAO-24BC和Hargreaves的结果令人满意,效果最差的是Makkink和Priestley-Taylor公式。ET0年值误差主要来源于11-3月,各方法对4-10月ET0的估算效果相对较好。各方法的适用性存在空间变异,FAO-24BC和Hargreaves公式的效果普遍较好,其他方法对该区各站ET0估算误差均较大,特别是Makkink和Priestley-Taylor公式;除Priestley-Taylor公式外,多数方法对西南区的估算误差较大。因此,黄土高原地区进行参考作物蒸散的简单计算时,推荐使用FAO-24BC和Hargreaves方法。

Applicability of simple estimating method for reference crop evapotranspiration in Loess Plateau

Some methods for estimating reference crop evapotranspiration (ET0) are widely used in regions with insufficient meteorological data, but their applicabilities should be evaluated. The performances of six simple methods for estimating ET0 (i.e. FAO-24 Rad, FAO-24 BC, Hargreaves, Priestley-Taylor, Makkink and Turc) are evaluated based on the meteorological data from 48 stations during 1961-2009 in the Loess Plateau. Results showed that FAO-24 BC and Hargreaves equations were satisfactory to estimate annual ET0 while Makkink and Priestley-Taylor methods are not. The estimation errors of annual ET0 mainly come from those in November to March, while in April to October were very small. Spatial variability exist in the applicability of the six methods. FAO-24 BC and Hargreaves performs better at most stations while the other methods, especially for Makkink and Priestley-Taylor, provide unsatisfactory results. Most methods are not suitable for estimating ET0 in the southwest region except for Priestley-Taylor. Overall, FAO-24 BC and Hargreaves are recommended as the priority simple methods for calculating ET0 in the Loess Plateau.