Influence of sea level rise on tidal waves of the Yangtze River estuary

In order to study the influence of sea level rise (SLR) on tidal wave in tidal reach, a hydrodynamic numerical model of the Yangtze River Estuary was established using MIKE 21. The verified model was used to simulate tidal wave changes from Wuhu to the estuary under SLR scenarios of 0.5 m, 1.0 m, and 2.0 m. The results show the following: (1) The impact of SLR on water level within the tidal reach can be divided into two segments: from the estuary to approximately 35 km upstream of Xuliujing and from there further upstream to the tidal limit.

(2) The average water level increase is less than the magnitude of SLR. The attenuation depends on both river discharge and location within the reach; higher river discharge and increasing proximity to inland areas reduce the influence of SLR. (3) Water level fluctuation amplitude increases with SLR, showing minimal sensitivity to river discharge within the estuarine section but significant sensitivity to discharge fluctuations in the upstream section. Finally, tidal current velocity generally increases in response to SLR, with the spatial extent of the increase controlled by river discharge.