冬小麦农田日蒸散量的计算

本文从小气候观测资料着手，采用彭曼法、能量平衡法、波温比法和空气动力学等方法，对处于抽穗至乳熟期的冬小麦农田日蒸散量做了尝试性计算。着重考虑了彭曼公式的修正，并以水量平衡法为标准，对以上各方法的精度做了评价与误差分析。结果表明，订正后的彭曼公式可较为准确地计算各种能量、水分供应条件下有作物覆盖农田的日蒸散量，其它方法则存在较明显的不确定性误差。

The Calculation of Daily Evapotranspiration in the Field of Winter Wheat

Based on the microclimatological data the daily evapotranspiration in the field of winter wheat during the period of heading and milky maturity is preliminarily calculated with the help of the Penman formulas and the other methods, such as energy balance, Bowen ratio and aero-dynamics. The modification of Penman formula is principally considered. The accuracy and error analysis of the formulas and methods above are evaluated by the results of water balance method, which can be regarded as a standard. The conclusions show that after being modified by the crop coefficient water content and heat exchange in soil as well as the surface temperature of evaporation. Penman formula can be used to calculate accurately the daily evapotranspiration of cropcovered field on the conditions of different energy and water supply