Impacts of port development on estuarine morphodynamics: Ribadeo (Spain)

Port developments in estuaries can significantly affect estuarine dynamics, causing hydrodynamic changes that can in turn affect sediment transport patterns. Understanding these impacts is crucial in view of the socioeconomic relevance of estuaries and their high sensitivity - as the complex natural systems that they are. The objective of this work is to investigate the impact of port expansion on estuarine dynamics through a case study. Process-based models are implemented to investigate the morphodynamic response of the estuary to the expansion of the Port of Ribadeo. The models simulate the hydrodynamics and sediment transport of the estuary with and without the port development. In total, 12 scenarios are considered: pre- and post-expansion cases; morphological times of 1, 2 and 4 years; and two tidal energy situations (equinoctial and solstitial tides, i.e. high and low energy, respectively). The models are forced with the tide (prescribed through the nine major constituents) and river inflow, and the significant variation in sediment size over the estuary is accounted for. Excellent agreement (R > 0.95) is achieved between computed and observed water levels and flow velocities. Having validated the model, the cases pre- and post-expansion are simulated and compared to determine the effects of the port expansion project on estuarine dynamics. The project is found to result in a marked increase in sedimentation on the eastern bank, leading to the infilling of a channel that is vital to the operation of the Port of Figueras and, in particular, its shipyard. More generally, these results prove the capacity of port expansion projects to exert relevant nonlocal impacts on estuarine activities.