Shoreline Retraction and the Opening of a New Inlet Implications on Estuarine Processes

• Published in: Estuaries and coasts Vol. 42; no. 8; pp. 2004 - 2019
• Main Authors: Siegle, Eduardo, Couceiro, Mariana Afonso Abade, de Mello e Sousa, Silvia Helena, Figueira, Rubens Cesar Lopes, Schettini, Carlos Augusto França
• Format: Journal Article
• Language: English
• Published: New York Springer Science + Business Media 01.12.2019; Springer US; Springer Nature B.V
• Subjects: Beaches; Brackishwater environment; Climate change; Coastal Sciences; Drainage channels; Earth and Environmental Science; Ecology; Environment; Environmental Management; Estuaries; Estuarine dynamics; Freshwater & Marine Ecology; Inlets; Inlets (waterways); Mathematical models; Moisture content; Morphology; Numerical models; ORIGINAL PAPERS; Shoreline changes; Shorelines; Tides; Water and Health; Water content; Water flow; Caravelas estuary; Morphological change; Estuarine processes; Inlets
• ISSN: 1559-2723; 1559-2731
• DOI: 10.1007/s12237-019-00635-w

The dynamics of estuarine systems is sensitive to changes in its forcing conditions, including the morphology of its inlets. Coastline retraction, which may be induced by climate change, can result in modifications of estuarine inlet morphology. Through the use of a validated numerical model, we evaluate the effects of the opening of a new inlet on a tide-dominated estuary (Caravelas estuary, Brazil). During the last decades, shoreline retraction and the breach of an internal drainage channel led to the formation of a new inlet that became the main estuarine channel. The morphological changes of the estuary resulted in changes to its estuarine processes, including the general increase in the influence of the tide on the system and changes to its asymmetry. Internal channels that interconnect adjacent estuaries present great changes caused by the morphological alterations, not only in the magnitude of the processes but also in the resulting net transport direction. The increase in the water flow caused by the opening of the channel leads to an increase in the amount of water and materials carried toward the estuary. The changes presented here for the Caravelas estuarine system and the possible implications for the functioning of such systems demonstrate the importance of evaluating morphological aspects in relation to their use and management.