长江日径流序列的多重分形性质研究

Study on Multifractal Behavior of Yangtze River Runoff Time Series

讨论了长江宜昌站1950年至1999年日径流时间序列的多重分形性质,计算了50年日径流时间序列和每一年日径流时间序列的质量指数τ(q)、广义分形维数Dq、奇异性指数α和多重分形谱f(α).结果表明,不论是长期(50年)还是短期(1年),长江日径流序列均具有明显的多重分形性质.这对研究长江日径流的非线性性质提供了重要的理论基础.

In this paper , the multifractal behavior on the daily runoff series of the Yangtze River from 1950 to 1999 is discussed .The partition function χq（ε） , exponent function τq , generalized fractal dimen-sions Dq,singularity αand multifractal spectrum f（α） are calculated.It is found that this series of differ-ent timescales, namely, one year and 50 years, obey multifractal scaling.The results provide theoretical basis for the research of runoff series ’ nonlinear characteristics .