During the Anthropocene, regulating river discharge by high dams may have met the need for water demands in river basins, but resulted in carrying less freshwater and sediment to the sea, inducing land degradation and shoreline retreat in worldwide mega-river deltas. In land-ocean interaction, tide response to water discharge changes plays an important role and is crucial for the river-laden sediment transfer and dispersal, affecting both nearshore and estuarine deposits. The Yellow River Delta (YRD), which is under an increasing pressure of the new discharge regime of the Yellow River, has undergone drastic changes in terms of sediment dynamics and morphologic evolution. To gain a better understanding of the overall fluvial and marine hydrodynamics and morphodynamic processes in the YRD, in this study, a full-scale numerical model is built to investigate the interaction and impacts of changing environmental forcing and dynamics on flow and sediment transport in the estuary of YRD and its adjacent coasts. The results show that the river discharge strongly affects the tidal dynamics and morphology of the delta, particularly in the close vicinity of the outlet and the intertidal zone. Tidal constituents M2 and K1, which are the most significant ones in the YRD, are found to be noticeably affected with a decreasing trend when the river discharge increases. The model results also indicate that river discharge affects the location and intensity of the shear front that occurs in the nearshore areas of the YRD. Increasing the river discharge can induce a seaward movement of the shear front, reduce its width and concentrate its shear intensity. It is found that the reverse of the flow direction at each side of the shear front and strong longshore tidal current can act as a barrier for the sediment dispersal process by keeping suspended sediment in the inner zone, thus to form a particular sediment deposition zone and the depo-center.

在人类世期间，通过高坝调节河流流量可能已经满足了流域对水的需求，但导致向海洋输送的淡水和沉积物减少，导致了全球大河三角洲的土地退化和海岸线撤退。在陆地-海洋相互作用中，潮汐对排水量变化的响应起着重要的作用，对于含河沉积物的转移和扩散至关重要，对近岸和河口沉积物都有影响。黄河三角洲（YRD）在新的黄河排放制度的压力下不断增加，在沉积物动力学和形态演化方面发生了急剧变化。为了更好地了解长三角地区的整个河流和海洋流体动力学和形态动力学过程，在本研究中，建立了一个完整的数值模型，以研究环境强迫和动力学变化对长三角地区及其邻近海岸河口的水和泥沙输送的相互作用和影响。结果表明，河流流量强烈影响三角洲的潮汐动力学和形态，特别是在出口和潮间带附近。长江流域中最重要的潮汐成分M2和K1随着河流流量的增加而受到明显的影响，并呈下降趋势。模型结果还表明，河流流量影响了长三角近岸地区发生的切变锋的位置和强度。河流流量的增加会引起剪力锋向海运动，减小其宽度并集中其剪力强度。