Abstract La Rochelle marina, in the south-west of France, is one of the largest recreational port in Europe. As many ports around the world, La Rochelle marina is not spared by siltation and has to face serious dredging operations over a period of 8 months per year. Consequently, there is a big interest in determining sediment fluxes in the area and implementing measures to minimise siltation and/or to optimise dredging operations. In the present study, a three-dimensional hydro-sedimentary model (TELEMAC-3D) was calibrated with field measurements from 2014 to 2019. Analysis of the in situ measurements (turbidity, bathymetric surveys, seabed elevation) showed that the macro-tidal influence and local wind-wave regime significantly contributed to the siltation in the marina. In order to minimise the cost and time associated with maintenance dredging, multiple scenarios have been tested numerically and subsequently analysed. Numerous sediment trap configurations were defined to focus the deposition of sediment in dredged traps and constructional measures were also assessed in terms of siltation reduction (e.g. entrance closure, narrowing entrances, Current-Deflecting-Wall). Numerical simulations showed that the best solution is to create a sediment trap at the downstream corner of the marina, along the main navigation channel, to intercept sediment particles arriving from the ocean. The constructional measures as well as the use of sediment traps inside the marina are not efficient in reducing siltation. These results highlight the importance of using operational numerical model to define a more sustainable strategy to fight against siltation in a more efficient and less costly way.

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大潮汐码头淤积的动力学和管理：以法国拉罗谢尔码头为例

摘要 拉罗谢尔码头位于法国西南部，是欧洲最大的休闲港口之一。与世界各地的许多港口一样，拉罗谢尔码头也不能幸免于淤泥，每年必须面临长达 8 个月的严重疏浚作业。因此，确定该地区的沉积物通量和实施措施以最大限度地减少淤积和/或优化疏浚作业引起了极大的兴趣。在本研究中，三维水沉积模型 (TELEMAC-3D) 通过 2014 年至 2019 年的现场测量进行了校准。 现场测量分析（浊度、测深测量、海底高程）表明大潮汐影响和当地的风浪状况对码头的淤积产生了显着影响。为了最大限度地减少与维护疏浚相关的成本和时间，已对多种情景进行了数值测试并随后进行了分析。定义了许多沉积物捕集器配置以集中沉积在疏浚捕集器中的沉积物，并且还在减少淤积方面评估了建筑措施（例如入口关闭、变窄入口、电流偏转墙）。数值模拟表明，最好的解决方案是在码头的下游拐角处，沿着主航道设置一个沉积物捕集器，拦截来自海洋的沉积物颗粒。码头内的建造措施以及使用沉积物收集器在减少淤积方面效率不高。这些结果强调了使用操作数值模型来定义更可持续的策略以更有效和更低成本的方式对抗淤积的重要性。