基于HHT变换的雅鲁藏布江径流多时间尺度分析

Multi-temporal Scales Analysis of Runoff Series in Yarlung Zangbo River Based on Hilbert-Huang Transform

采用HHT变换对雅鲁藏布江流域拉孜等4个典型水文站1956-2000年年径流量进行了多时间尺度分析。结果表明,雅鲁藏布江全流域范围内存在3、6-8、14-16 a的近似周期,与采用小波分析法所得结果吻合,验证了HHT变换有效、可行。该法为水文序列多时间尺度分析提供了一种新途径,值得推广。

The article details the Hilbert-Huang Transform （HHT） and applies this method to analyze multiple time scales of annual runoff series in Yarlung Zangbo River. With the measured annual runoff data from 1956 to 2000 in Yarlung Zangbo River,the Intrinsic Mode Function （IMF） and Hilbert spectrum are used to extract hydrological series period. The results have shown that the runoff series in Yarlung Zangbo River can be decomposed into four timescales quasiperiodic oscillations,including a 3 year signal,a 6-8 year signal and a 14-16 year signal,as well as a trend. The annual mean runoff in 1956-2000 is characterized by a great fluctuation and a positive trend around the late 1960s and the early 1980s,after that the runoff tended to increase and was increasing intensively in the 1990s. The study shows that the Hilbert-Huang Transform can be used widely in the research of hydrology and water resources.