Understanding the morphological changes in estuaries due to natural processes and human interventions is especially important with regard to sustainable water management and ecological impacts on the estuarine environment. In this contribution, we explore the morphological evolution in tide-dominated estuaries by means of a novel analytical approach using the observed water levels along the channel. The method could serve as a useful tool to understand the evolution of estuarine morphology.

Tide–river dynamics play an essential role in large-scale river deltas as they exert a tremendous impact on delta morphodynamics, salt intrusion and deltaic ecosystems. For the first time, we illustrate that there is a critical river discharge, beyond which tidal damping is reduced with increasing river discharge, and we explore the underlying mechanism using an analytical model. The results are useful for guiding sustainable water management and sediment transport in tidal rivers.

In this study, we assessed the impacts of the world’s largest dam, the Three Gorges Dam (TGD), on tide–river dynamics and concluded that the strongest impacts occurred during autumn and winter due to the TGD's operation. The results obtained will hopefully enhance our understanding of the impacts of large-scale human interventions on estuarine hydrodynamics and guide effective and sustainable water management in the Yangtze River estuary and other estuaries with substantial freshwater discharge.