黄河宁-蒙河段流量变化及周期研究

采用小波分析法，对黄河宁夏-内蒙古河段青铜峡站和头道拐站46 a(1961-2006年)的流量资料进行多时间尺度分析。结果表明：不同频域尺度下2站流量随时间的变化具有同步性。通过进一步分析小波方差图，确定了黄河宁-蒙河段年均流量具有18 a和31 a的主周期变化规律。对其结果进行小波系数过程线的检验，得到2站流量丰枯变化趋势，并预测今后一段时间内宁-蒙河段流量将处于偏枯期。流量变化的主要因素除了降水量减小和用水量增加外，水库的运行也起到关键作用。此成果可为黄河上游的水资源保护和预测及宁-蒙河段水沙防治工作提供参考依据。

Research on Change and Periodicity of Annual Runoff Volume along the Ningxia - Inner Mongolia Section of the Yellow River

In this paper,the change and periodicity of average annual runoff volume and its main affecting factors along the Ningxia-Inner Mongolia section of the Yellow River were lucubrated based on 46-year(from 1961 to 2006) average annual runoff volume data measured at Qingtongxia and Toudaoguai hydrological stations,and the multi-temporal scales were analyzed.The results show that the change of average annual runoff volume at these two stations at different temporal scales was synchronicities.After analyzing the wavelet variance plots,it was found that there were 18-year and 31-year periodic fluctuations of annual runoff volume.The results were tested and verified with the process line of the real part of wavelet to obtain the change trend of annual runoff volume at these two stations,and it was predicted that a low flow will continue along the Ningxia-Inner Mongolia river section in next few years.Reduction of annual runoff volume of the river section was mainly caused by the decrease of precipitation,increase of water consumption and operation of reservoirs.The study results can provide the references for conserving water resources,controlling sediment and predicting annual runoff volume along the Ningxia-Inner Mongolia section of the Yellow River.