参考作物腾发量时间序列的长程相关性和多重分形分布

Long-term correlation and multi-fractality of reference crop evapotranspiration time series

本文应用修正的Penman-Monteith模型计算了分布在全国各地的16个站点的参考作物腾发量时间序列,并采用新近发展的多重分形非趋势波动分析法(MF-DFA)计算了序列的长程相关指数H和奇异谱f(α)。结果表明,潜在蒸散序列围绕一定趋势的波动不是完全随机的现象,而是由内在自相似机制决定的长程相关过程;其不同层次的波动是一个有序的多重分形分布,奇异谱可用二项倍增串级模型描述。

The Penman-Monteith model was applied to calculate the time series of reference crop evapotranspiration in 16 stations distributed in the mainland of China, and their long-term fluctuation exponents H and muhi-fractal spectra f（ a ） were obtained by using the recently developed multi-fractal detrended fluctuation analysis（MF-DFA） method. The analysis results show that the fluctuation of ETo around the general trend exhibits self-similar scaling behavior and long-term correlation rather than a complete random process at time scales, which is governed by the intrinsic self-similar properties. The fluctuations at different level are well-regulated generalized multi-fractal, whose spectra can be described with a expression of the muhiplicative cascade model.