摘要
河道水沙变化过程具有非线性特征,基于长江寸滩站、朱沱站和嘉陵江北碚站(简称"三站")1955-2011年的水文资料,应用多重分形消除趋势波动分析法(MF-DFA方法),研究长江重庆河段水沙变化过程的多重分形特征。结果表明:三站日流量和日输沙率序列具有多重分形特征,该多重分形特征是由序列的长程相关性引起的;日流量序列的奇异谱呈右钩状曲线,小涨落的影响在序列中占优势,日输沙率序列的奇异谱对称,大小涨落的标度行为在序列中基本一致;水沙时序变化的复杂程度可用多重分形谱宽Δα表征,且日输沙率序列的Δα相对较大,变化更为复杂;不同时段水沙序列的谱曲线形状存在较大差异,丰水丰沙时序的谱曲线较宽,顶部较圆滑,Δα较大,枯水枯沙时序的谱曲线较窄,顶部较尖锐,Δα较小。
Evolution processes of flow and sediment is nonlinear,based on observed hydrological data of 1955-2011 years at three hydrological stations as Cuntan,Zhutuo and Beibei（ referred as ＂the three stations＂）,adopting the method of multifractal detrended fluctuation analysis（ MF-DFA）,the multifractality characteristics of the evolution processes of flow and suspended sediment transport rate（ SSTR） records in Chongqing reach of the Yangtze River were studied. The result shows that：（ i） The daily flow and SSTR series of the three stations are multifractal,and the mulfiractality is caused by the long-term persistence.（ ii） The singular spectrum of daily flow series shows a right hook shape curve,which indicates that small fluctuation to occupy the dominant position. Meanwhile,the singular spectrum of daily SSTR series are symmetry,and the scaling behavior of fluctuation for different sizes is basically the same in the series.（ iii） Complex variations of daily flow and SSTR can be described by the width of the multifractal spectrum Δα,and the Δα of daily SSTR is relatively larger,which reflects the variation of daily SSTR is more complex.（ iv） There is a big difference in the shape of spectral curves for different periods,in flood season the spectral curve is wide and the top is smooth,accordingly Δα is larger; on the contrary,in non-flood season the spectral curve is narrow and the top is sharp,and Δα is smaller.
出处
《泥沙研究》
CSCD
北大核心
2016年第5期66-73,共8页
Journal of Sediment Research
基金
国家自然科学基金资助项目(51509026)
重庆市基础与前沿研究计划项目(CSTC2015JCYJA90013)
关键词
长江重庆河段
流量
悬移质输沙率
消除趋势波动分析
多重分形
Chongqing reach of the Yangtze River
flow
suspended sediment discharge
detrended fluctuation analysis
multifractality
