月蒸散发能力解集模型研究

针对目前研究蒸散发能力解集方面的不足,对联合期望-方差模型进行改进并进一步扩展,建立了将月蒸散发能力解集到日蒸散发能力的解集模型.将模型应用于梅山气象站,1980~1985年蒸发资料用于确定模型参数,1986~1987年资料被合并为月蒸发量用于模型解集计算.结果表明:解集产生的日蒸发量序列随季节的变化趋势与观测值一致,并且变化幅度也与观测值基本一致,日蒸发量观测值与解集值的均值和标准差很接近,部分月份二者几乎相等;所建立的解集模型能够很好地将月蒸发量序列解集到日蒸发量序列,并充分反映日蒸发量的时间变异特性.

Downscaling model of monthly potential evapotranspiration

For further study on potential evapotranspiration downscaling,a model,which downscales the potential evaporation time step from monthly to daily,was established on the basis of modifying and improving the expectation-variance model.In a case study at Meishan station,the model parameters were calibrated using evaporation data from 1980 to 1985,and data from 1986 to 1987,after combined into monthly evapotranspiration,were used to downscale the calculation.The results show that the seasonal change of the downscaled daily evaporation sequences has the same tendency and extent as the observed data.The mean values and standard deviations of the downscaled daily evaporation are close to,and in some months even equal to,the observed data.Therefore,the downscaling model can successfully downscale monthly evaporation to daily sequences that reproduce the temporal variation characteristics of daily data.