近60年黄河下游年水沙量变化的多时间尺度特征

Multiple Time-scale Characteristic of Annual Runoff and Sediment in Lower Reaches of Yellow River in Recent 60 Years

以黄河下游花园口站为例,基于1952～2009年年水量和年沙量资料,采用经验模态分解及Hilbert-Huang变换方法分析了年水沙量变化的多时间尺度特征,探讨了各波动分量的变化原因及影响因素,获得了不同波动周期的振荡分量及趋势分量,揭示了年水沙量变化的多时间尺度结构,其中准3年左右的周期波动是引起水沙波动的重要原因。

Taking Huayuankou Station in lower reaches of the Yellow River for an example, based on the data of annual runoff and sediment from 1952 to 2009, the methods of empirical mode decomposition （EMD） and Hilbert-Huang transform （HHT） are applied to analyze the multiple time-scale characteristic of annual runoff and sediment series. And the reasons and influence factors for the variation of each fluctuation component are discussed. Then oscillation and trend components with different fluctuation periods are obtained. Finally, multiple time-scale structure of the variation of annual runoff and sediment is revealed, and the variation of annual runoff and sediment is caused by the periodic oscillations of 3-years.