下荆江熊家洲至城陵矶河段演变分析与治理思路探讨

Channel Evolution of the Reach from Xiongjiazhou to Chenglingji in Lower Jingjiang River and Regulation Considerations

利用三峡水库蓄水运用前后的水沙和地形资料,系统分析了下荆江熊家洲至城陵矶河段演变特点和趋势。结果表明:由于三峡工程蓄水运用以来水沙条件的变化,该河段河势较之前发生了一定程度的调整,八姓洲、七姓洲上游侧及观音洲弯道左岸未护段岸线均发生崩退,七弓岭弯道段的主流线已发生明显变化,并发生了切滩撇弯现象,若遇不利水文年时存在自然裁弯的可能性。在此研究基础上提出了分阶段进行河道综合治理的思路,以期为该河段的治理提供科学依据。

The characteristics and tendency of channel evolution in the reach from Xiongjiazhou to Chenglingji in lower Jingjiang River is systematically analyzed on the basis of water-sediment and terrain data before and after the operation of the Three Gorges Reservoir（TGR）.The results reveal the river regime adjustments as follows： collapse has occurred at the upstream side of Baxing sandbar and Qixing sandbar as well as the river bankline at the unprotected section of the left bank of Guanyin sandbar;evident changes including chute cutoff has been found in the mainstream line of Qigongling bend,and natural cut-off of river channel is likely to happen during big floods.In view of the above analysis,considerations of comprehensively harnessing the channel by stages is proposed to provide scientific basis for the river reach regulation.