不同参照作物腾发量计算模型在鄂西地区的适用性研究

鄂西地区地理环境复杂多样，气候季节差异性显著，准确估算各类作物的参照作物腾发量（ET₀）是进行灌溉管理的基础。为在气象资料缺测条件下鄂西地区选取ET₀的计算方法提供依据，通过宜昌气象站1951—2013年气象资料，以Penman-Monteith公式法计算ET₀结果为标准值，对Hargreaves、Priestley-Taylor、FAO-24 Radiation及Mc-Cloud 4种公式计算的ET₀结果进行对比分析。结果表明：FAO-24 Radiation公式的适用性较好，典型年平均相关系数为0.994，平均相对误差均为85.9%，可直接用于当地参照作物腾发量的计算； Hargreaves公式和Priestley-Taylor公式误差分析结果分别为189.8%、164.4%；Mc-Cloud的相关性最低，丰水年相关系数不足0.900，3种公式在鄂西地区参照作物腾发量计算时适用性较差。FAO-24 Radiation经过修正后，平均相对误差均处于6%左右，可直接用于鄂西地区参照作物腾发量的计算，特旱年（p=90%）、枯水年（p=75%）、平水年（p=50%）、丰水年（p=25%）的修正公式分别为ET′_{0 d}=0.616×ET_{0 d（F-R）}-1.936、ET′_{0 l}=0.583×ET_{0 l（F-R）}-2.532、ET′_{0 m}=0.580×ET_{0 m（F-R）}-1.928、ET′_{0 h}=0.589×ET_{0 h（F-R）}-1.209。

Applicability of Different Reference Crop Evapotranspiration Calculation Models at Western Region of Hubei Province

The western region of Hubei province is complex and diverse geography， and distinct climatic seasons， therefore， a sound estimation of reference crop evapotranspiration for various crops is the basis for irrigation management. In order to provide basis for the use of ET₀ method for the western region of Hubei province， the meteorological data of Yichang Meteorological Station in Western Hubei from 1951 to 2013 was collected to make comparison of the values of ET₀ by Hargreaves， Priestley-Taylor， FAO-24 Radiation and Mc-Cloud formula to the ET₀ calculated by Penman-Monteith formula method. The results showed that： FAO-24 Radiation formula， with a typical annual average correlation coefficient of 0.994 and an average relative error of 85.9%， was highly applicable and might be used directly for the calculation of local reference crop evapotranspiration. The Hargreaves formula and Priestley-Taylor formula had an analysis error as high as 189.8% and 164.4%， respectively. And Mc-Cloud had the lowest correlation coefficient which was less than 0.900 in high flow year， therefore， the 3 formulas had poor applicability to calculating reference crop evapotranspiration in the western region of Hubei province. The FAO-24 radiation had an average error of about 6% after correction， and could be directly used for the of special dry year （p=90%）， low flow year （p=75%）， median water year （p=50%）， high flow year （p=25%） calculation of reference crop evapotranspiration in the western region of Hubei province， and their correction formulas were ET′_{0 d}=0.616×ET_{0 d（F-R）}-1.936， ET′_{0 l}=0.583×ET_{0 l（F-R）}-2.532， ET′_{0 m}=0.580×ET_{0 m（F-R）}-1.928， ET′_{0 h}=0.589×ET_{0 h（F-R）}-1.209，respectively．