中文摘要：

根据长江大通站近50年（1957～1999年）的水沙数据，利用复Morlet小波变换，分析水沙时间序列多尺度小波特征，建立了不同时间尺度上的水沙关系式。分析结果显示：（1）呔通站水沙序列年内洪、枯季周期波动最为显著，流量的长周期特征明显，含沙量与输沙量的短周期特征显著。（2）大通站水沙序列多尺度特征明显，流量的振荡周期主要为3～6a和8～16a；含沙量多尺度振荡周期较为平稳，4～6a的周期振荡中心尺度呈明显下降的趋势；输沙量以4～6a和10～14a的周期显著振荡，输沙量变化平稳，较含沙量变化有一定的滞后期。（3）根据流量小波特征分析，近50年的水沙变化过程大致可分为3个时期，分时段拟合水沙关系曲线，发现总体水沙曲线的指数与正常期和丰水期的接近，而与少水期的存在较大的差距。少水期系数较小、指数较大，表明在少水期泥沙的供给量较少，但水流的搬运能力增强。

英文摘要：

The fluxes and variation of materials from rivers into the ocean reflect the integrated responses to the regional climate change, human activities and other factors. Researchers have paid continued attention to the study of material fluxes from the Changjiang River to the East China Sea in recent years. However, most of the knowledge has been obtained from simple statistics of measurements from the hydrological stations. Uncertainty of the material fluxes usually estimation always results in low comparability for various periods or different sites. Many factors including natural factors and human activities, may limit the solution of this intractable problem, and the characteristics of the long-term hydrological time series are understood rather insufficiently. These two aspects are discussed and more reasonable rating curves in terms of wavelet technology are built up in the paper. Nearly 50 years （1957 - 1999） of monthly-averaged river discharge, suspended sediment concentration （SSC） and sediment fluxes were collected at the Datong Gauging Station approximately 640 km upstream of the Changjiang river mouth, and a complex Morlet continuous wavelet transform was used to investigate the multiple time scales of the long-term hydrological processes and further to develop the rating curves over distinct time scales. Main results are as follows： （1） Seasonal oscillation of the river discharge and sediment fluxes predominates over other time scales, which is controlled by the regional climate characteristics （especially seasonal precipitation）. The peaks of the river discharge and sediment fluxes occur out of phase, indicating different behaviors of water and sediment transport. Long-term oscillation of the river discharge is relatively apparent, while short-term fluctuations of the SSC and sediment fluxes are relatively obvious. （2） Multi-scale property of the hydrological time series at Datong was found. The river discharge has noticeable scales with 3-6 a and 8-16 a, and the 2-3 a scale