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

Abstract

Port developments in estuaries can significantly affect the estuarine dynamics, causing hydrodynamic changes that can in turn affect the sediment transport patterns. Understanding these impacts is crucial given 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-port development 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, pre-and post-development cases are compared to determine the effects of the port expansion on estuarine dynamics. We find that the expansion has led to a deepening and straightening of the primary channel of the estuary, with a marked increase in sedimentation either side. This has negative implications for the operation of the Port of Figueras, and in particular for its shipyard, on the other side of the estuary (opposite the Port of Ribadeo)-which proves the potential of port expansions for non-localised impacts on estuarine activities.

Impact of Jetty Configuration Changes on the Hydrodynamics of the Subtropical Patos Lagoon Estuary, Brazil

“…In [10], the authors explained that changes in the circulation pattern could also negatively impact the navigation of large vessels and the pollution and sedimentation processes (by the reduction of the ebb currents and natural dredging in the access channel). Other effects, such as the migration of the tidal delta as a result of changes in the morphodynamics of the central channel and the infilling or formation of banks on the jetty sides, which could influence the maintenance of adequate water depth, were mentioned by [2] after the Ribadeo port expansion in Spain. Ecologically, the reduction of saltwater intrusion and sporadic saltwater peak events could greatly impact the entrance of oceanic organisms, which contribute to the increase of recruitment of estuarine dependent species and are essential for maintaining the fish stocks in the Rio Grande do Sul coastal region.…”

“…Approximately 60% of the world's population inhabits coastal regions [1], and most of it is located around estuarine areas. Important ports and large cities are located inside estuaries, making them vulnerable to changes by natural processes and anthropogenic alterations associated with economic development [2,3]. Changes in the geomorphology, river discharge, and circulation patterns influence pollution and the distribution of nutrients and suspended sediments [2].…”

“…Important ports and large cities are located inside estuaries, making them vulnerable to changes by natural processes and anthropogenic alterations associated with economic development [2,3]. Changes in the geomorphology, river discharge, and circulation patterns influence pollution and the distribution of nutrients and suspended sediments [2]. The ecological consequence of these alterations is enhanced because estuaries serve as habitats and nurseries for the initial stages ecological consequence of these alterations is enhanced because estuaries serve as habitats and nurseries for the initial stages of the development of many species [4,5], are rich in nutrients, influence primary production [6], and provide abundant food and protection against predators [7,8].…”

“…Studies on human-induced impacts on the hydrodynamics, saltwater intrusion, sediment transport, pollutant dispersion, and ecology of coastal systems have been gaining ground during the last century. Port expansions can increase sedimentation and the migration of tidal delta and infill of channels [2]. Jetty construction can change the direction of the tidally induced currents, influence the evolution of the bed level, and induce sedimentation and erosion [9].…”

“…Patos Lagoon is the largest choked coastal lagoon in the world [16] and extends 250 km with a 40 km width and a total area of 10,360 km 2 (Figure 1). The lagoon connects to the Atlantic Ocean through a 700 m wide channel.…”