参考作物蒸发蒸腾量计算方法的应用比较

应用国家"863"节水农业重大专项子课题示范现场的气象资料,对4种分属于不同类型的参考作物蒸发蒸腾量ET0计算公式进行了日ET0值的验证计算。结果显示,在时间序列上,随气象因素变化各方法计算的日ET0值呈相同的变化趋势,但计算值有较大的差异;选取FAO56Penman-Monteith公式计算结果为标准,Priestley-Taylor(1972)方法结果与之最为接近,其余依次是Irmark-Allen拟合法和Hargreaves-Samani(1985)法;不同天气类型条件下,Priestley-Taylor(1972)结果与FAO56Penman-Monteith有较高的一致性,而其他2种方法随n/N的减小,误差急剧增加,尤其是Hargreaves-Samani(1985)方法。

Comparison of Reference Crop Evapotranspiration Computing Methods

Based on the meteorological data derived from the national "863" special project, daily evapotranspiration were calculated by four different methods. Results show, in time series, daily evapotranspiration vary with the same trend to the climate factors, but the different is not negligible. Take the Penman-Monteith value as criteria, comparison and analysis were made under different climate condition, Priestley-Taylor value shows remarkable consistency with Penman-Monteith value, others have much bigger errors. With the decrease of relative sunshine hours n/N, the error of Hargreaves-Samani and Allen empirical increase dramatically, especially the Hargreaves-Samani method.