新水沙条件下长江下游东北水道航道演变趋势分析

Analysis of evolution trend of Dongbei waterway in middle reach of the Yangtze River under new water and sediment conditions

针对三峡水库蓄水后新水沙条件对东北水道航道条件的影响问题,进行了东北水道航道演变趋势研究。采用动床模型试验研究的方法,得到了三峡水库蓄水后典型年和系列年试验水沙条件下东北水道水位、流速、流态、地形冲淤及航道条件变化趋势。分析结果表明:在无工程情况下,三峡水库蓄水运用后,由于来沙量的减小,东北水道航道条件出现不利变化趋势;方案实施后,可以遏制水道的不利变化趋势,维持当前较好的滩槽格局和航道条件,对工程河段沿程水位、流速分布以及近岸流速等因素的影响较小,能够为航道尺度的进一步提升奠定基础。

Aiming at the problem of effects of water and sediment conditions after impoundment in the Three Gorges Reservoir on the channel conditions of Dongbei waterway,the evolution trend of the channel of Dongbei waterway is studied.Based on the physical moving bed model experiment,the trend of water level,velocity,flow state,terrain and channel conditions of Dongbei waterway under the water and sediment conditions of typical year and series year is discussed.The analyzing result reveals that,in the absence of engineering,the development of the channel conditions of Dongbei waterway is unfavorable due to the decrease in the amount of incoming sediment after the Three Gorges Reservoir is impounded;after the project is implemented,it can curb the unfavorable trend and maintain the current better shoal pattern and navigation conditions,thus there is less influence on water level,velocity distribution and nearshore velocity along the engineering section,and it can lay the foundation for further improvement of the channel scale.