Summary
Process-based modelling is believed to give a detailed insight on the long-term morphological changes of inlets and the respective roles of tides and waves in driving these changes. The use of these tools is a valuable resource to support adequate management decisions at systems undergoing pronounced morphological changes such as the Ria de Aveiro tidal inlet and entrance channel. The main goal of this project is thus to study the morphodynamics of this area, using two distinct but interconnected methodologies: field work and several numerical modelling approaches.

The sedimentological characterization of the study area will be performed through detailed sampling of bottom and suspended sediments under different conditions. Simultaneous measurements of velocity vertical profiles will allow the estimation of sediment fluxes. Foraminifera analysis of sediment samples will be used to identify the main source of sediments to this area. These results will be used to extend the characterization of the study area, as inputs to the morphodynamic models and to strengthen the validation of the several models.

A two-dimensional horizontal morphodynamic modelling system (MORSYS2D), combining modules for hydrodynamics, waves, sediment transport and bathymetry updates, will be improved and explored. Specific changes in each of the modules and in the controlling script code will be performed, to obtain a more robust and flexible modelling system.

A new morphodynamic equilibrium response model (‘box model’) will also be developed and applied in this project. These models, which are based on simple concepts, have proved to be efficient to study the large-scale morphological evolution of tidal inlets.

The use of process-based models requires a schematization of the input conditions, through field data (to be collected in the frame of the project or historical data) and numerical models. An unstructured grid hydrodynamic model of the Ria de Aveiro and adjacent coast will be applied using one of models currently available in MORSYS2D, providing the elevation and velocity fields for the morphodynamic analysis, as well as additional insight into th circulation in the system. A new methodology will be developed to simplify a given offshore wave regime into a subset with fewer representative waves, that cause the same morphological evolution as the complete set of measured waves. The simplified wave regime will be used for forcing in the morphodynamic system.

The above tools will be used to analyse specific items such as the sediment budget and trends of erosion/deposition in this area, relative importance of waves and currents importance on the long-term evolution of the inlet and its seasonal evolution, and the transposition of sediment across the inlet.

This proposal outlines a project that will provide valuable (and presently inexistent) knowledge of the morphodynamics of Ria de Aveiro inlet that can be relevant for adequate management of this area.

Goals
The main goal of EMERA is to study the morphodynamics of Ria de Aveiro tidal inlet and entrance channel, using two distinct but interconnected methodologies: field work and several numerical modelling approaches.



Publications
Peer-reviewed articles

• Silva, P.A., X. Bertin, A.B. Fortunato, A. Oliveira (2009) - Intercomparison of sediment transport formulas in current and combined wave-current conditions, Journal of Coastal Research, SI56, 559-563.
• Bertin, X.; A. Oliveira; A.B. Fortunato (2009). - Simulating morphodynamics with unstructured grids: description and validation of a modeling system for coastal applications, Ocean Modelling, 28/1-3: 75-87.
• Fortunato, A.B. and A. Oliveira (2007). Improving the stability of a morphodynamic modeling system, Journal of Coastal Research, SI50: 486-490. (Resumo)

Book chapter

• Oliveira, A.; M. Rodrigues; A.B. Fortunato; Bertin. X. (2008) Numerical analysis of the impact of morphodynamics on the water quality of a coastal lagoon, Estuarine and Coastal Modeling X, Spaulding [Ed.], ASCE, 651-670.

Conference proceedings

• Fortunato, A.B.; L. Pinto; P. Freire; Bertin, X.; A. Oliveira. (2008) Sand transport in surface waters: an uncertainty analysis, 8th. World Congress on Computational Mechanics (WCCM8),CD-ROM, 2 pp.
• Vaz, N, Plecha, S., Bertin, X., Silva, P., Oliveira, A., Fortunato, A.B. E Dias, J.M. (2008). Aplicação de um modelo morfodinâmico à embocadura de uma laguna: análise de sensibilidade, Actas da 6ª Assembleia Luso Espanhola de Geodesia e Geofísica, 521-522.
• Plecha, S., Vaz, N., Bertin, X., Silva, P., Oliveira, A., Fortunato, A.B., e Dias, J.M (2008). Sensitivity analysis of a morphodynamic modeling system applied to a coastal lagoon inlet, PECS2008. 4pp.
• Bertin, X., Fortunato, A.B. e Oliveira, A. (2007). Sensitivity analysis of a morphodynamic modeling system applied to a Portuguese tidal inlet. Proceedings of the 5th IAHR Symposium on River, Coastal and Estuarine Morphodynamics: RCEM2007, Editors: C.M. Dohmen-Janssen, S.J.M.H. Hulscher, Taylor & Francis, ISBN: 978-0-415-44167-4, Vol.1, 11-17.
• Fortunato, A.B. e A. Oliveira (2006). Uma comparação de métodos para melhorar a estabilidade de um sistema de modelos morfodinâmico, Actas da I Conferência Nacional de Métodos Numéricos em Mecânica dos Fluidos e Termodinâmica, em CD-ROM.
• Oliveira, A., Fortunato, A.B. e Dias, J.M. (2007). Numerical modeling of the Aveiro inlet dynamics, Coastal Engineering 2006, Editor: Jane McKee Smith, World Scientific Publishing Co., ISBN 978-981-270-636-2, Vol. 4, 3282-3294.
• Plecha, S., Rodrigues, S., Silva, P., Dias, J.M., Oliveira, A. e Fortunato, A.B. (2007). Trends of Bathymetric Variations at a Tidal Inlet. Proceedings of the 5th IAHR Symposium on River, Coastal and Estuarine Morphodynamics: RCEM2007, Editors: C.M. Dohmen-Janssen, S.J.M.H. Hulscher, Taylor & Francis, ISBN: 978-0-415-44167-4, Vol.1, 19-23.
• Silva, P.A., Oliveira, A., Fortunato, A.B. Ramos, M. (2006). "Estudo numérico da evolução temporal de uma escavação de extracção de inertes", Proceedings do 8º Congresso de Água, 15pp.

Related projects
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•    Tidal inlet morphodynamics
•    Long-term morphologic evolution of estuaries and lagoons