A numerical simulation study of the hydrodynamic effects caused by morphological changes in the Guadalquivir River Estuary

This study presents an analysis of the impacts of the changes in bottom depth along the Guadalquivir Estuary on tidal dynamics. A realistic non-linear 1D numerical model, incorporating changes in both breadth and bottom depth, was employed to investigate the involved effects. The findings reveal a significant amplification of the M2 tidal wave towards the upper region of the Estuary, resulting from the gradual deepening caused by multiple dredging operations. The Estuary exhibits a pronounced tendency towards resonance, which is further enhanced by its deepening, resulting in reduced bottom friction and a smaller decrease in tidal wave amplitude as it propagates through the Estuary. The alterations in depth, particularly in breadth, along the Estuary play a crucial role in determining the magnitude of the resonant response of the M2 tidal wave. [Display omitted] •The non-linear 1D numerical model is able to reproduce the hydrodynamic behavior of the Guadalquivir Estuary successfully.•The use of different bottom depths along the Estuary leads to changes in tidal dynamics.•Gradual deepening of the channel provokes a notable amplification of the M2 tidal wave.•Resonance tendencies and reduction of bottom friction contribute to the amplification phenomena.