不同时间尺度径流的多重分形特征解析

Multifractal Analysis of Runoff Time Series at Different Temporal Scales

径流时间序列的变化过程呈现出复杂的非线性特征,分形是非线性时间序列的典型特点。以锦江流域为例,研究了1967年~2018年的年、月尺度平均流量时间序列的多重分形结构特征。分析结果表明,锦江流域过去52年的年、月尺度的平均流量均表现出明显的多重分形特征。其中,年平均流量的波动幅度最小,月平均流量中9月平均流量序列的波动幅度较大,即9月平均流量表现出强烈的多重分形特征;锦江流域10月平均流量波动行为的混乱程度和奇异性最低,而11月平均流量波动行为的混乱程度和奇异性最高。研究说明锦江流域年、月平均流量时间序列具有较为复杂的混乱特性,可为锦江流域年、月平均流量的复杂性规律的解析提供依据。

The change process of runoff time series presents complex nonlinear characteristics,and the fractal is a typical feature of nonlinear time series.Taking Jinjiang River Basin as an example,the multifractal structures of annual and monthly mean flow time series from 1967 to 2018 are studied.The results show that,(a)the average flows at annual time scale and monthly time scale of the Jinjiang River Basin in the past 52 years show obvious multifractal characteristics;(b)the fluctuation range of the annual average flow is the smallest,and the fluctuation range of the monthly average flow in September is the largest,that is,the average flow in September shows strong multifractal characteristics;and(c)the chaos and singularity of the fluctuation behavior of average flow in Jinjiang River Basin in October are the lowest,and is the highest in November.This study shows that the time series of annual and monthly average flow in Jinjiang River Basin have more complex chaotic characteristics,which can provide a basis for the analysis of the complexity characteristics of the annual and monthly average flow in Jinjiang River Basin.