Seasonal Variation Trend and Probability Distribution Pattern of Potential Evapotranspiration
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摘要: 利用北京昌平气象站多年系列观测资料和世界粮农组织(FAO)建议的公式计算了历年各月逐旬潜在腾发量的平均值(ETp).通过分析表明,潜在腾发量呈明显的季节性变化趋势。潜在腾发量的多年均值和标准差(STD)都能用Fourier级数的二阶分量来作很好的近似。潜在腾发量是一个随机变量,其随机变化规律服从正态分布,该分布的均值和标准差都随着季节而变化。Abstract: Based on the serial meteorological data from Changpin Meteo rological Stations located in the suburb of Beijing the every ten-day period average potential evapot ranspiration(ETp)were calculated and analyzed.The analysis shows that the ETp changes in a strong seasonal trend of which the mean and STD fit to the two-harmonics of Fourier series approximately.Moreover,ETp is a random variable which follows the normal distribution with mean and deviation changing with season.Finally,the probability density function of ETp is given.
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[1] 1 Aboitiz M,Labadie J,Heermann D.Stochastic soil moisture estimation and forecasting for irrigated fields.Water Resour.Res 1986,22(2):180～190
2 Or,D,Hanks R J Spatial and temporal soil water estimation considering soil variability and evapotranspiration uncertainty.Water Resour.Res.1992,28(3):803～814
3 Or D,Groeneveld D P.Stochastic estimation of plant-available soil water under fluctuating water table depths.Journal of Hydrology.1994,(163):43～64
4 谢贤群,左大康,唐登银主编.农田蒸发—测定与计算.北京:气象出版社,1991.134～142
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