HHT在年最大洪峰流量规律分析中的应用

Application of Hilbert-Huang Transform on analysis of law of annual maximum peak flood

Hilbert-Huang变换能够定量描述非线性、非平稳、弱相依、高度复杂时间序列的时频特性,较传统的时间序列分析方法更具优势。通过对时间序列进行EMD分解,得出其演化过程的内在模函数和趋势项,并对内在模函数做Hilbert-Huang变换,获得序列的变化周期。以汉江上游的两个代表水文站——石泉和安康水文站的年最大洪峰流量为例分析,石泉站年最大洪峰流量变化存在3.06年、7.11年和24.98年的周期,安康站年最大洪峰流量变化存在3.01年、6.07年、15.97年和29.65年的周期,且两站的年最大洪峰流量序列呈降低的趋势。

Compared with traditional analytical method of time series,Hilbert-Huang Transform has advantages to quantitatively describe time-frequency characteristics for nonlinear,unsteady,weak-dependency and highly complex time series.Empirical Mode Decomposition （EMD） method is adopted to analyze time series and Intrinsic Mode Function （IMF） and trend term are obtained. Then,Hilbert transform is made for each IMF.Taking two of the typical hydrological stations：Shiquan and Ankang stations in the upper Hanjiang River as examples,periods analysis of IMF show that annual maximum peak flood of Shiquan station has periods of 3.06,7.11 and 24.98 years.Annual maximum peak flood of Ankang station has periods of 3.01,6.07,15.97 and 29.65 years.