Revista de Gestão Costeira Integrada
Volume 15, Número 1, Março 2015, Páginas 65-80

DOI: 10.5894/rgci515
* Submission: 29 MAY 2014; Peer review: 6 JUL 2014; Revised: 19 SEP 2014; Accepted: 22 SEP 2014; Available on-line: 22 SEP 2014

Evolution of the hydrodynamics of the Tagus estuary (Portugal) in the 21st century *

Martha Guerreiro ^a, André Bustorff Fortunato ^{@, a}, Paula Freire ^a,
Ana Rilo ^a, Rui Taborda ^b, Maria Conceição Freitas ^c, César Andrade ^c, Tiago Silva ^c, Marta Rodrigues ^a, Xavier Bertin ^d, Alberto Azevedo ^a

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@ - Corresponding author: <afortunato@lnec.pt>
a - National Civil Engineering Laboratory, Av. do Brasil, 101, 1700-066 Lisbon, Portugal.
b - University of Lisbon, Faculty of Science, LATTEX, IDL., Bloc C-6, 2nd Floor, Campo Grande, 1749-016 Lisbon, Portugal.
c - University of Lisbon, Faculty of Science, Geology Department, Geology Center, Bloc C-6, Campo Grande, 1749-016 Lisbon, Portugal.
d - CNRS-Université de La Rochelle, UMR 7266 LIENSS, Institut du Littoral et de l’Environnement, 2 rue Olympe de Gouges, 17 000 La Rochelle, France.

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ABSTRACT
The ongoing rise in sea level affects tidal propagation and circulation in estuaries, and these changes can have far reaching consequences on the sediment dynamics, water quality and extreme water levels. This study aims at anticipating the evolution of the tidal dynamics in the Tagus (Portugal) in the 21st century, in particular due to sea level rise (SLR). The existence of a resonance mode of about 8 hours in this estuary, that selectively amplifies both semi-diurnal and quarter-diurnal tidal constituents, makes the response of the Tagus estuary to SLR unique. The study was conducted with a shallow water model, forced by present and future conditions, namely higher mean sea levels and an extrapolated bathymetry based on present sedimentation rates. Model results showed that SLR will significantly affect tidal asymmetry, in particular because the intertidal area can decrease by up to 40% by the end of the 21st century. As a result, the strong ebb-dominance of this estuary will decrease significantly. This evolution of tidal asymmetry will be counteracted by the effect of sedimentation of the saltmarsh areas. Also, SLR will enhance the resonance in the Tagus estuary. As a consequence, extreme water levels will be higher than the sum of present levels with the SLR.

Keywords: tidal asymmetry, resonance, climate change, SELFE, modeling.

Evolução da hidrodinâmica do estuário do Tejo (Portugal) no século XXI

RESUMO
A subida do nível médio do mar afeta a propagação da maré e a circulação em estuários, podendo estas alterações ter consequências significativas na dinâmica sedimentar, na qualidade da água e nos níveis de água extremos. O presente estudo visa antecipar a evolução da dinâmica de maré no estuário do Tejo (Portugal) no século XXI, em particular devido à subida do nível médio do mar (NMM). A existência de um modo de ressonância de cerca de 8 horas neste estuário, que amplifica seletivamente as constituintes semi-diurnas e quarto-diurnas, torna a resposta do estuário do Tejo à subida do NMM única. O estudo foi efetuado com um modelo hidrodinâmico, forçado por condições presentes e futuras, nomeadamente níveis médios do mar mais elevados e uma batimetria extrapolada com base em taxas de assoreamento atuais. Os resultados do modelo mostram que a subida do NMM irá afetar significativamente a assimetria da maré, em particular porque as áreas intertidais podem diminui até 40% até ao final do século. Em consequência, a forte dominância de vazante deste estuário irá diminuir significativamente. Esta evolução da assimetria da maré será parcialmente compensada pelo efeito da sedimentação nas áreas intertidais. A subida do NMM irá também amplificar o efeito de ressonância no estuário do Tejo, o que resultará em níveis extremos superiores à soma dos níveis extremos atuais com a subida do NMM.

Palavras-chave: assimetria de maré, ressonância, alterações climáticas, SELFE, modelação.

 

Aldridge, J.N. (1997) - Hydrodynamic Model Predictions of Tidal Asymmetry and Observed Sediment Transport Paths in Morecambe Bay. Estuarine, Coastal and Shelf Science, 44(1):39-56. DOI: 10.1006/ecss.1996.0113

Andrade, C.; Pires, H.O.; Silva, P.; Taborda, R.; Freitas, M.C. (2006) – Zonas Costeiras. In: F.D. Santos e P. Miranda (eds.), Alterações climáticas em Portugal. Cenários, impactes e medidas de adaptação. Projecto SIAMII, pp.169- 208, Gradiva, Lisboa. Available on-line at http://siam.fc.ul.pt/siamII_pdf/ SIAMII.pdf

Antunes, C.; Taborda, R. (2009) - Sea level at Cascais tide gauge: data, analysis and results. Journal of Coastal Research, SI 56: 218–222, Lisbon, Portugal, Available on-line at http://www. cerf-jcr.org/images/
stories/218.222_C.Antunes_ICS2009.pdf

Aubrey, D.G.; Speer, P.E. (1985) - A study of non-linear tidal propagation in shallow inlet/estuarine systems. Part I: observations. Estuarine, Coastal and Shelf Sc. 21: 185–205. DOI:
10.1016/0272-7714(85)90096-4

Azevedo, A.; Oliveira, A.; Fortunato, A.B.; Zhang, J.; Baptista; A.M. (2014) - A cross-scale numerical modeling system for management support of oil spill accidents. Marine Pollution Bulletin, 80(1-2): 132 - 147. DOI: missing

Bertin, X.; Fortunato, A.B.; Oliveira, A. (2009) - A modeling-based analysis of processes driving wave-dominated inlets. Continental Shelf Research, 29(5-6): 819-834. DOI: missing

Bertin, X.; Li, K.; Roland, A.; Zhang, Y.J.; Breilh, J.-F.; Chaumillon, E. (2014) - A modeling-based analysis of the flooding associated with Xynthia, central bay of Biscay. Coastal Engineering, in press.

Bilskie, M.; Hagen, S.; Medeiros, S.C.; Passeri, D. (2014) - Dynamics of sea level rise and coastal flooding on a changing landscape. Geophysical Research Letters, 41(3):927-934.

Brown, J.M.; Davies, A.G. (2010) - Flood/ebb tidal asymmetry in a shallow sandy estuary and the impact on net sand transport. Geomorphology, 114(3), 431-439.

Bruneau, N.; Dodet, G.; Bertin, X.; Fortunato, A.B. (2011) - Development of a three-dimensional coupled wave-current model for coastal environments, Journal of Coastal Research, SI64:986 - 990.

Church, J.; White, N. (2006) - A 20th century acceleration in global sea-level rise. Geophysical Research Letters, 33: L01602. DOI: 10.1029/2005GL024826

Dastheib, A. (2012) - Long-term process-based morphological modeling of large tidal basins, Ph.D. Dissertation, Balkema, ISBN 978-1-138.00022-3. Unpublished.

Dias, J.M.; Valentim, J.M. (2011) - Numerical modeling of Tagus estuary tidal dynamics. Journal of Coastal Research, SI64:1495-1499.

Dodet, G. (2013) - Morphodynamic modelling of a wave-dominated tidal inlet: the Albufeira lagoon. Ph.D. Dissertation, Université de La Rochelle, 181p., La Rochelle, France. Unpublished.

Dodet, G.; Bertin, X.; Taborda, R. (2010) - Wave climate variability in the North-East Atlantic Ocean over the last six decades. Ocean Modeling, 31(3-4):120-131. DOI: 10.1016/j.ocemod. 2009.10.010

Fortunato, A.B.; Baptista, A.M.; Luettich, R.A. (1997) - A threedimensional model of tidal currents in the mouth of the Tagus Estuary. Continental Shelf Researh, 17(14):1689-1714. DOI: 10.1016/S0278-4343(97)00047-2

Fortunato, A.B.; Oliveira, A.; Baptista, A.M. (1999) - On the effect of tidal flats on the hydrodynamics of the Tagus estuary. Oceanologica Acta, 22(1):31-44. DOI: 10.1016/S0399-1784(99) 80030-9

Fortunato, A.B.; Oliveira, A. (2000) - On the representation of bathymetry by unstructured grids. In: L.R. Bentley, J.F. Sykes, C.A. Brebbia, and W.G. Gray (eds), Computational Methods in Water Resources XIII, Vol. 2, pp.889-896, Balkema, Rotterdam, Netherlands ISBN: 9058091252.

Fortunato, A. B.; Oliveira, A. (2005) - Influence of intertidal flats on tidal asymmetry. Journal of Coastal Research, 21(5):1062– 1067. DOI: 10.2112/03-0089.1

Fortunato, A.B.; Rodrigues, M.; Dias, J.M.; Lopes, C.; Oliveira, A. (2013) - Generating inundation maps for a coastal lagoon: a case study in the Ria de Aveiro (Portugal). Ocean Engineering, 64:60-71. DOI: 10.1016/j.oceaneng.2013.02.020

Freire, P.; Andrade, C. (1999) - Wind-induced sand transport in Tagus estuarine beaches. First results. Aquatic Ecology, 33(3): 225–233. DOI: 10.1023/A:1009911012260

Freire, P. (2003) - Evolução morfo-sedimentar das margens estuarinas. Estuário do Tejo, Portugal. 380p., LNEC, Lisboa, Portugal. ISBN: 9724919595

Freire, P.; Taborda, R.; Silva, A. M. (2007) - Sedimentary Characterization of Tagus Estuarine Beaches (Portugal). A contribution to the sediment budget assessment. Journal of Soils and Sediments, 7 (5), 296-302. DOI: 10.1065/jss2007.08.243

Friedrichs, C.T.; Aubrey, D.G. (1988) - Non-linear tidal distortion in shallow well-mixed estuaries: a synthesis. Estuarine, Coastal and Shelf Science, 27, 521-545.

Guerreiro, M.; Fortunato, A.B.; Freire, P.; Rilo, A.; Taborda, R.; Freitas, M.C.; Andrade, C.; Silva, T.; Rodrigues, M. (2013) - Impacte da subida do nível médio do mar na inundação marginal do estuário do Tejo. 11º Simpósio de Hidráulica e Recursos Hídricos dos Países de Expressão Portuguesa e VII Congresso sobre Planeamento e Gestão das Zonas Costeiras dos Países de Expressão Portuguesa, 19p., APRH, Portugal. Available on-line at http://www.lnec.pt/organizacao/dha/nec/
estudos_id/morfeed /Guerreiro_et_al_2013.pdf

Hagedoorn, J.M.; Wolf, D.; Martinec, Z. (2007) - An estimate of global mean sea-level rise inferred from tide-gauge measurements using glacial-isostatic models consistent with the relative sea-level record. Pure and Applied Geophysics, 164:791–818. DOI: missing

Hong, B.; Shen, J. (2012) - Response of estuarine salinity and transport processes to potential future sea-level rise in Chesapeake Bay. Estuarine, Coastal and Shelf Science, 104- 105(1): 33-45. DOI: 10.1016/j.ecss.2012.03.014

Horsburgh, K. J.; Wilson, C. (2007) - Tide-surge interaction and its role in the distribution of surge residuals in the North Sea. Journal of Geophysical Research, 112(C08):003. DOI: 10.1029/ 2006JC004033

Idier, D.; Dumas, F.; Muller, H., (2012) - Tide-surge interaction in the English Channel. Natural Hazards and Earth System Science, 12:3709–3718. DOI: 10.5194/nhess-12-3709-2012

INE (2012) - Census 2011 – Definitive results – Region of Lisbon. 320p., Instituto Nacional de Estatística, Lisboa, Portugal.

IPCC (2007) - Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor & H. L. Miller (eds.)], 996p., Cambridge University Press, Cambridge, U.K. and New York, NY, USA, Available on-line at http://www.ipcc.ch/publications_and_data/ publications_ipcc_fourth_assessment_report_wg1_report_the_p hysical_science_basis.htm ISBN: missing

IPCC (2013) - Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex & P.M. Midgley (eds.)], 1535p., Cambridge University Press, Cambridge, U.K. and New York, NY, USA. Available on-line at http://www.ipcc.ch/
report/ ar5/wg1/ ISBN: missing

Lanzoni, S.; Seminara, G. (2002) - Long-term evolution and morphodynamic equilibrium of tidal channels. Journal of Geophysical Research, 107(C1):1-13. DOI: missing

Martyr, R.C.; Dietrich, J.C.; Westerink, J.J.; Kerr, P.C.; Dawson, C.; Smith, J.; Pourtaheri, H.; Powell, N.; Van Ledden, M.; Tanaka, S.; Roberts, H.; Westerink, H.; Westerink, L. (2013) - Simulating Hurricane Storm Surge in the Lower Mississippi River under Varying Flow Conditions. Journal of Hydraulic Engineering, 139(5):492-501. DOI: 10.1061/(ASCE)HY.1943- 7900.0000699.

Muir-Wood, R. (2011) - The 1941 February 15th Windstorm in the Iberian Peninsula. Trébol (ISSN 1137-246X), 56:4-13, Fundación MAPFRE, Madrid, Spain. Available on-line at http://www.mapfre.com/
mapfrere/docs/html/revistas/trebol/n56/ docs/Articulo1en.pdf

Neves, F.S. (2010) - Dynamics and hydrology of the Tagus estuary: results from in situ observations. 210p,, PhD thesis, Universidade de Lisboa, Portugal. Unpublished. Available online at http://repositorio.ul.pt/handle/10451/2003

Pethick, J. ( 2001) - Coastal management and sea-level rise. Catena, 42(2-4): 307–322. DOI: 10.1016/S0341-8162(00)00143-0 Pinto, L.; Fortunato, A.B.; Zhang,, Y.; Oliveira, A.; Sancho, F.E.P. (2012) - Development and validation of a three-dimensional morpho-dynamic modelling system for non-cohesive sediments. Ocean Modelling, 57-58: 1-14.

Portela, L.I.; Neves, R., (1994) - Numerical modelling of suspended sediment transport in tidal estuaries: a comparison between the Tagus (Portugal) and the Scheldt (Belgium-The Netherlands). Netherlands Journal of Aquatic Ecology, 28(3-4):329-335. DOI: 10.1007/BF02334201

Porto de Lisboa (2013) – Publicação Estatística 2013. 17p., Porto de Lisboa web site, Lisboa, Portugal. Available on-line at http://www.portodelisboa.pt/portal/page/portal/PORTAL_PORT O_LISBOA/ESTATISTICAS/ACTIVIDADE_PORTUARIA/T AB_
PUBLICACOES/publica%E7%E3o2013- sem%20comparativo.pdf

Pryor, S.C.; Barthelmie R.J. (2010) - Climate change impacts on wind energy: A review, Renewable and Sustainable Energy Reviews, 14(1):430-437. DOI: 10.1016/j.rser.2009.07.028

Pugh, D.; Vassie, J. (1980) - Applications of the joint probability method for extreme sea-level computations. ICE Proceedings, 69(4):959–975. DOI: 10.1680/iicep.1980.2179

Rahmstorf, S. (2010) - A new view on sea level rise. Nature reports Climate Change, 4:44-45. DOI: 10.1038/climate.2010.29 Rego, J.L.; Li, C. (2010) - Nonlinear terms in storm surge predictions: Effect of tide and shelf geometry with case study from Hurricane Rita. Journal of Geophysical Research, 115(C06):020, DOI:10.1029/2009JC005285.

Rilo, A.; Freire, P.; Mendes, R.N.; Ceia, R.; Catalão, J.; Taborda, R.; Melo, R.; Andrade, C.; Caçador, M.I.; Freitas, M.C.; Fortunato, A.B. (2014) - Metodologia para o traçado da Linha de Máxima Preia-Mar de Águas Vivas Equinociais em ambientes de transição: aplicação ao estuário do Tejo, Revista Gestão Costeira Integrada, 14(1):95-107. DOI: 10.5894/rgci450.

Rodrigues, M.; Oliveira, A.; Queiroga, H.; Fortunato, A.B.; Zhang, Y.J. (2009) - Three-dimensional modeling of the lower trophic levels in the Ria de Aveiro (Portugal). Ecological Modelling, 220(9-10):1274-1290 DOI: missing

Rodrigues, M.; Oliveira, A.; Guerreiro, M.; Fortunato, A.B.; Menaia, J.; David, L.M.; Cravo, A. (2011) - Modeling fecal contamination in the Aljezur coastal stream (Portugal). Ocean Dynamics, 61(6):841-856. DOI: missing

Rodrigues, M.; Oliveira, A.; Queiroga, H.; Brotas, V. (2012) - Seasonal and diurnal water quality and ecological dynamics along a salinity gradient (Mira channel, Aveiro lagoon, Portugal). Procedia Environmental Sciences, 13:899-918. DOI: missing

Roland, A.; Zhang, Y.J.; Wang, H.V.; Meng, Y.; Teng, Y.-C.; Maderich, V.; Brovchenko, I.; Dutour-Sikiric, M.; Zanke, U. (2012) - A fully coupled 3D wave-current interaction model on unstructured grids, Journal of Geophysical Research, 117(C11). DOI: 10.1029/2012JC007952.

Silva, T.A.; Freitas, M.C.; Andrade, C.; Taborda, R.; Freire, P.; Schmidt, S. (2013) - Geormophological response of saltmarshes in the Tagus estuary to sea level rise. Journal of Coastal Research (ISSN 0749-0208), SI65:582-587, Lisbon, Portugal. Available on-line at http://www.lnec.pt/organization /organizacao/dha/nec/
estudos_id/morfeed/Silva_etal_2013.pdf

Speer, P.E.; Aubrey, D.G. (1985) - A study of non-linear tidal propagation in shallow inlet/estuarine systems. Part II: Theory. Estuarine, Coastal and Shelf Science, 21(2):207-224.

Tawn, J. (1992) - Estimating probabilities of extreme sea-levels. Applied Statistics, 41(1):77–93. Article Stable URL: http://www.jstor.org/stable/
2347619

Vale, C.; Sundby, B. (1987) – Suspended sediment fluctuations in the Tagus estuary on semi-diurnal and fortnightly time scales. Estuarine, Coastal and Shelf Science, 25(5):495-508.

Vargas, C.I.C.; Oliveira, F.S.B.F.; Oliveira, A.; Charneca, N. (2008) - Análise da vulnerabilidade de uma praia estuarina à inundação: aplicação à restinga do Alfeite (estuário do Tejo). Revista de Gestão Costeira Integrada 8 (1): 25-43. DOI: 10.5894/rgci26

Zhang, Y.; Baptista, A.M. (2008) - SELFE: A semi-implicit Eulerian-Lagrangian finite-element model for cross-scale ocean circulation. Ocean Modeling, 21(3-4):71-96. DOI: 10.1016/ j.ocemod.2007.11.005

 

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