窎鱼嘴浅滩位于三峡水库变动回水区,水道具有弯、急、险的特点。为防止水道碍航,2018年汛期首次实施了维护性疏浚工程。通过对窎鱼嘴浅滩疏浚工作的设计方案、施工过程及时机、航道可持续性等方面进行分析和评价,综合评估年度疏浚维护效果并总结归纳维护性疏浚工作中存在的问题和不足。研究结果表明:2018年窎鱼嘴浅滩维护疏浚方案设计与河段河床演变及年度水沙输移规律相适应;疏浚时机选在汛后三峡蓄水河段水位抬高时,有效缓解了施工与通航的矛盾,并且利用汛后冲刷的规律达到了事半功倍的效果;但由于疏浚工程未改变引起河床演变的水沙条件及边界条件,维护疏浚工程难以保证航道的稳定性和可持续性。因此,建议继续加强河段水下地形观测,根据浅滩演变趋势 适时开展航道整治工程。该疏浚工程合理性、适应性的评估可为今后航道维护工作提供技术参考。

Diaoyuzui Shoal, located in a large curved passageway in the fluctuating backwater area of the Three Gorges Reservoir, was featured with curved and dangerous waterway and rapid current. A maintenance dredging project was first carried out in 2018. In this paper we analyzed the rationality, adaptability and sustainability of the dredging work based on summarizing the characteristics of shoals obstructing navigation, the dredging plan and the implementation process, etc., and then evaluated the effect of the dredging work and summarized its problems and shortcomings. Results demonstrated that the dredging design was well adaptive to riverbed evolution and annual water-sediment transport rules; the dredging was conducted when the water level of the Three Gorges storage reach rose, which not only alleviated the contradiction between construction and navigation, but also doubled the effect by taking the advantage of post-flood scouring. Nevertheless, the stability and sustainability of the channel are difficult to be maintained because the dredging project does not change the water and sediment conditions and boundary conditions that cause the riverbed evolution. Therefore, we suggested to strengthen the underwater terrain observation of the reach and carry out waterway regulation works in time according to the evolution trend of the shoal.