三峡水库蓄水初期库区航道条件分析

Analysis on navigation condition of the Three Gorges Reservoir at initial stage of water storage

三峡水库试验性蓄水后,长江干支流水利枢纽陆续投入运行,入库沙量大幅减少,导致库区航道条件变化与论证阶段成果有一定差异。基于2008年以来库区航道原型观测资料,分析常年回水区与变动回水区航道条件变化及其主要原因。结果表明,常年回水区局部河段的细沙淤积对主航道尺度侵蚀程度需要密切关注;变动回水区消落期部分河段卵石输移及暂时性淤积将引起航道航深不足,期间天然河道转化过程中形成的复杂流态将对通航条件产生不利影响。

The inlet sediment discharge rapidly decrease as a series of hydro-hub projects working in the mainstream and tributary stream of the Yangtze River after the operation of the Three Gorges Reservoir,leading to some differences on the changes of the channel condition compare to research achievements in the argumentation stage.Based on the measured channel data from 2008,we analyze the navigation condition changes of permanent backwater zone and fluctuating backwater zone and the main reasons in the Three Gorges Reservoir.The results show that the sedimentation in some reach sections should be focused on its impact on the main channel width in the permanent backwater zone.The gravels motion and temporary deposition in the main channel will lead to a shortage of the navigation depth in the falling stage,and the navigation problem in the fluctuating backwater zone also will involve the complex flow patterns occur in the falling stage.