| 摘要: |
| 根据参考作物蒸散量时间序列的随机变化特征，本文探讨了建立蒸散量变化的自回归滑动平均（ARMA（p，q）模型的方法。应用矩估计法对模型作初步估计，用最小二乘法对ARMA（p，q）模型参数作精估计，模型最佳阶数判别采用AIC准则。结果表明，蒸散量的随机变化特征可用ARMA（1，1）模型描述。最后，根据建立的模型对蒸散量进行了预测。 |
| 关键词: 参考作物蒸散量,随机模型 |
| DOI： |
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| 基金项目:国家自然科学基金 |
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| A Stochastic Model for Evapotranspiration Variability |
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| Abstract: |
| Based on stochastic variations of reference crop evaportranspiration (ETp) time series, a methodology has been developed with a generalized autoregressive moving average (ARMA(p, q) ) model for the daily ETp in this paper. A moment estimation mothod is applied for the model primary selection.The ARMA(p,q) model parameters are estimated accurately with the method of the least squares. The optimal model order is selected by AIC (Akaika Information Criterion) value. The results showed that the variation of the daily ETP is represented with a ARMA (1, 1 ) model. Using the developed model, the daily ETp is predicted for the study site. |
| Key words: reference crop evapotranspiration,stochastic model |
