黄河下游径流输沙多时间尺度特征及其耦合分析

基于黄河下游花园口、高村、艾山、利津四站1950~2005年实测年径流量、年输沙量,运用小波变换方法分析了径流量、输沙量多时间尺度特征及其耦合关系。研究表明:(1)黄河下游径流量存在10年、15年、21年的主要变化周期,其中21年为首要主周期,周期变化特性最为显著,周期长度为10年左右;(2)黄河下游输沙量存在7年、15年、20年的主要变化周期,其中20年为首要主周期;(3)水量、沙量的主要周期基本保持一致。根据主周期对应尺度下小波系数曲线变化情况可以得出黄河下游径流量、输沙量在2005年以后十几年呈下降趋势。

Multi-timescale characteristics of runoff and sediment discharge along Lower Yellow River and their coupling analysis

Based on the measured annual runoffs and annual sediment discharges of 1950~2005 from the hydrological stations of Huayuankou， Gaocun， Aishan and Lijin along the Lower Yellow River， the multi-timescale characteristics of the runoff and the sediment and their coupling relationship are analyzed herein with the method of wavelet transform. The study shows that：（1）the main oscillation periods of 10 a，15 a，21a are there for the runoff series along the Lower Yellower River， in which the period of 21a is the primary one with a periodic length of about 10 years and its periodic oscillation characteristics is most significant；（2）the main oscillation periods of 7a，15a，20a are there for the sediment discharges， in which the period of 20a is the primary one；（3）the main periods of both the runoff series and the sediment discharge series are basically consistent. In accordance with the change of the main period that is corresponding to the wavelet coefficient curve， it can be concluded that the runoff and sediment discharge of the Lower Yellow River show the declined trends in a period of more than ten years after 2005.