海洋地质前沿2024，Vol.40Issue(7)：56-67,12.DOI:10.16028/j.1009-2722.2024.072
长江口北支上口江心沙近期演变及其对北支上段的影响
The recent morphological evolution in the upper mouth sandbar of the North Branch and the impacts on its upper reach in the Changjiang Estuary
摘要
Abstract
Due to the new-born sandbank found in the upper river mouth of the North Branch in Changjiang Estu-ary,the bathymetry data during 2010-2020 was used to investigate its evolution and trends in the last decade.Additionally,a hydrodynamic numerical model combined with an empirical formula was used to further explore the effects on the hydrodynamics and bathymetry after the sandbank was further silted up or dredged.Results in-dicate that,in the past 10 years,the area of the sandbank has increased by nearly 5 times,and its elevation has gradually developed from less than 1 m to more than 3 m.In the recent years,the sandbank has stopped growing larger,but still gradually grown taller,and exhibited a trend of transformation from the lower tidal flat to the high-er one.If the sandbank further silts up,the water diversion ratio of the North Branch will be further reduced.At the same time,the velocity of the main channel from Haimen Port to Rixin River will decrease,which may lead to siltation and the restrict of inflow in the North Branch.The nearshore water speed around Yuejin Port will in-crease,and may enhance the erosion there,which may threaten the safety of sea dikes.If the sandbank is dredged off,the water diversion ratio of the North Branch will increase,which takes advantageous to alleviate the S-shaped river regime in the upper North Branch.At the same time,the velocity from Haimen Port to Rixin River will in-crease,the main channel will be deepened,which will promote the water diversion ratio in the North Branch,de-crease the nearshore water speed around Yuejin Port,induce the local siltation,and finally benefit the safety of sea dikes.关键词
北支上口/江心沙/演变特征/数学模型Key words
upper river mouth of the North Branch/sandbank/evolution characteristics/numerical model分类
海洋科学引用本文复制引用
李路,季永兴,滕飞,徐双全..长江口北支上口江心沙近期演变及其对北支上段的影响[J].海洋地质前沿,2024,40(7):56-67,12.基金项目
上海市科学技术委员会科研项目(22DZ1202700,18DZ1206400,19DZ1201500) （22DZ1202700,18DZ1206400,19DZ1201500）
上海市水务局科研项目(沪水科 2020-03,沪水科 2022-11) （沪水科 2020-03,沪水科 2022-11）
