The Rance estuary is a relatively small low-discharge steep-sided ria, located along the Brittany coast in northern France, with a maximum spring tidal range of 13.5 m. Taking advantage of this hyper-tidal regime, the first and currently the second largest operational tidal power station in the world was built at the estuary's mouth and has been in operation since the 1960s. Despite the well-known effect of damping of estuarine water levels, little attention has been given to quantifying the influence of the plant on the propagation and asymmetry of the tidal wave inside the estuary. In this study, hydrodynamics and tidal wave patterns were analyzed in this anthropogenically influenced estuarine system. A two-dimensional depth-averaged numerical model of the Rance estuary was developed. Two scenarios without the tidal power plant involving the dam's pre- and post-construction bathymetry (1957 and 2018 respectively) and present-day conditions scenarios were designed, to highlight the impact of bed evolution and the tidal power station on hydrodynamics and tidal asymmetry. Numerical results showed that, without the structure, bathymetric evolution did not substantially influence estuarine hydrodynamics. Nevertheless, on the estuary-side of the dam, the presence of the tidal power plant induced (i) a decrease in both tidal range and tidal prism, (ii) an increase of low water levels, and (iii) a decrease in both flood and ebb currents. Contrastingly, the region close to the structure reacted differently to plant operating modes, with an increase in flood currents (ebb currents) upstream of the sluice gates (downstream of the turbines). For both the natural condition and the artificially-induced hydrodynamic forcing due to the presence of the plant, numerical results showed that the Rance estuary mainly exhibits flood-dominant behavior, with a longer duration of falling than rising water and stronger peak flood currents than ebb currents. Spanning a period of approximately 60 years, this study presents a quantitative analysis of the influence of the tidal power station on the hydrodynamics in the Rance estuary, and its possible consequences for sediment dynamics. This approach is novel for this particular enclosed water body, characterized by the presence of a dam at its mouth and a lock at its uppermost limit.

兰斯河口是一个相对较小的低放电陡峭的RIA位于法国北部布列塔尼海岸，最大春季潮汐范围为13.5 m。利用这种超潮机制，世界上第一座，目前第二座最大的潮汐发电站建在河口口，自1960年代以来一直在运行。尽管有众所周知的河口水位衰减效应，但很少有人注意量化植物对河口内潮汐波的传播和不对称性的影响。在这项研究中，在这个人为影响的河口系统中分析了流体动力学和潮汐模式。建立了兰斯河口的二维深度平均数值模型。没有潮汐电站涉及大坝的两种情况 设计了施工前和施工后的测深法（分别为1957年和2018年）和当今的状况方案，以强调河床演化和潮汐发电站对水动力和潮汐不对称的影响。数值结果表明，在没有结构的情况下，测深的演变基本上不会影响河口的水动力。然而，在大坝的河口侧，潮汐发电厂的存在导致（i）潮差和潮汐棱镜均减小，（ii）低水位增大，并且（iii）两者均减小。洪水和退潮。相反，靠近该结构的区域对电厂运行模式的反应不同，闸门上游（涡轮机下游）的洪水电流（退潮）增加。数值结果表明，对于自然条件和由于植物的存在而导致的人工水动力强迫，数值结果表明，兰斯河口主要表现为洪水主导行为，下降持续时间长于上升水流，峰值洪峰流量大于退潮。潮流。这项研究历时约60年，对潮汐电站对Rance河口水动力的影响及其对泥沙动力的可能后果进行了定量分析。对于这种特殊的封闭水体，这种方法是新颖的，其特征在于在其水口处有水坝，在最高处有水闸。下降持续时间比上升水流更长，峰值洪流比潮汐流更强。这项研究历时约60年，对潮汐电站对Rance河口水动力的影响及其对泥沙动力的可能后果进行了定量分析。对于这种特殊的封闭水体，这种方法是新颖的，其特征在于在其水口处有水坝，在最高处有水闸。下降持续时间比上升水流更长，峰值洪流比潮汐流更强。这项研究历时约60年，对潮汐电站对Rance河口水动力的影响及其对泥沙动力的可能后果进行了定量分析。对于这种特殊的封闭水体，这种方法是新颖的，其特征在于在其水口处有水坝，在最高处有水闸。