鹅头分汊河段航道整治工程适应性分析

Adaptability analysis of waterway regulation engineering of goose-head braided reach

对鹅头分汊河段进行了分析.鹅头分汊河段多汊并存,洲滩易变,航道条件较差.三峡工程蓄水前后,长江中下游鹅头分汊河道一般都实施了航道整治工程,整治原则以稳定洲滩、保持分汊为主.但由于鹅头分汊河段均处于周期性调整过程中,对于不同演变阶段,河段碍航特性存在差异,工程治理重点和效果也不同.演变初期的汊道,周期性调整动力较强,洲滩演变剧烈,整治思路以稳定分流格局为主,但整治工程往往不能立刻发挥效果,需要反复强化;处于演变中期和末期的汊道,整治工程更着重局部航道条件的改善,一般治理效果较好,但仍需重视河段周期性调整动力及三峡工程蓄水后河段河床冲淤特性,加强观测,及时采取措施,巩固工程效果.

The navigation condition of the goose-head braided channel is poor because of its multi-branch- state swing, beach volatile and periodic evolution. In order to prevent the deterioration of the channel con- dition, most goose-head braided channels have implemented regulation engineering. However, the naviga- tion obstacle characters of the channel are different for the continuous and periodic evolution, that lead to different regulation thoughts and effects. In the early evolution stage, the channels are under intense un- folding, so the regulation thoughts are stabling branching pattern; but the engineering effects are certainly lag and unsuited. In the middle and late stages, the regulation engineering can improve the navigation con- dition of local channel. However, the hydrodynamics of the periodic evolution and the river bed adjusts af- ter the Three Gorges Project operation should be given attention. In order to consolidate the engineering effect, more observation and timely implementing measures are required.