Tidal hydrodynamics under future sea level rise and coastal morphology in the Northern Gulf of Mexico

This study examines the integrated influence of sea level rise (SLR) and future morphology on tidal hydrodynamics along the Northern Gulf of Mexico (NGOM) coast including seven embayments and three ecologically and economically significant estuaries. A large-domain hydrodynamic model was used to simulate astronomic tides for present and future conditions (circa 2050 and 2100). Future conditions were simulated by imposing four SLR scenarios to alter hydrodynamic boundary conditions and updating shoreline position and dune heights using a probabilistic model that is coupled to SLR. Under the highest SLR scenario, tidal amplitudes within the bays increased as much as 67% (10.0 cm) because of increases in the inlet cross-sectional area. Changes in harmonic constituent phases indicated that tidal propagation was faster in the future scenarios within most of the bays. Maximum tidal velocities increased in all of the bays, especially in Grand Bay where velocities doubled under the highest SLR scenario. In addition, the ratio of the maximum flood to maximum ebb velocity decreased in the future scenarios (i.e., currents became more ebb dominant) by as much as 26% and 39% in Weeks Bay and Apalachicola, respectively. In Grand Bay, the flood-ebb ratio increased (i.e., currents became more flood dominant) by 25% under the lower SLR scenarios, but decreased by 16% under the higher SLR as a result of the offshore barrier islands being overtopped, which altered the tidal prism. Results from this study can inform future storm surge and ecological assessments of SLR, and improve monitoring and management decisions within the NGOM.

[1]  A. Cearreta,et al.  Sea-level rise and local tidal range changes in coastal embayments: An added complexity in developing reliable sea-level index points , 2011 .

[2]  S. Hagen,et al.  Impacts of historic morphology and sea level rise on tidal hydrodynamics in a microtidal estuary (Grand Bay, Mississippi) , 2015 .

[3]  E. Robert Thieler,et al.  National assessment of coastal vulnerability to sea-level rise; U.S. Atlantic Coast , 1999 .

[4]  S. Hagen,et al.  Dynamics of sea level rise and coastal flooding on a changing landscape , 2014 .

[5]  A. Bennett,et al.  TOPEX/POSEIDON tides estimated using a global inverse model , 1994 .

[6]  Giovanni Coco,et al.  Modeling the morphodynamic response of tidal embayments to sea-level rise , 2013, Ocean Dynamics.

[7]  Mark R. Byrnes,et al.  Geomorphic response-type model for barrier coastlines: a regional perspective , 1995 .

[8]  A. Cox,et al.  Dynamic simulation and numerical analysis of hurricane storm surge under sea level rise with geomorphologic changes along the northern Gulf of Mexico , 2016 .

[9]  N. Plant,et al.  Using a Bayesian Network to predict shore-line change vulnerability to sea-level rise for the coasts of the United States , 2014 .

[10]  M. Capobianco,et al.  The coastal tract (Part 1): A conceptual approach to aggregated modelling of low-order coastal change , 2003 .

[11]  Nathaniel G. Plant,et al.  Predicting coastal cliff erosion using a Bayesian probabilistic model , 2010 .

[12]  Jürgen Jensen,et al.  The impact of sea level rise on storm surge water levels in the northern part of the German Bight , 2015 .

[13]  Katsuto Uehara,et al.  The impact of rapid coastline changes and sea level rise on the tides in the Bohai Sea, China , 2013 .

[14]  M. Fenster,et al.  Coastal Impacts Due to Sea-Level Rise , 2008 .

[15]  I. Caçador,et al.  Sea level rise impact in residual circulation in Tagus estuary and Ria de Aveiro lagoon , 2016 .

[16]  S. Hagen,et al.  Terrain-driven unstructured mesh development through semi-automatic vertical feature extraction , 2015 .

[17]  John A. Hall,et al.  Global sea level rise scenarios for the United States National Climate Assessment , 2012 .

[18]  Robert A. Morton,et al.  National Assessment of Shoreline Change: Part 1, Historical Shoreline Changes and Associated Coastal Land Loss Along the U.S. Gulf of Mexico , 2004 .

[19]  Huib J. de Vriend,et al.  The Coastal-Tract (Part 2): Applications of Aggregated Modeling of Lower-order Coastal Change , 2003 .

[20]  B. Kjerfve,et al.  Tides of Mississippi Sound and the adjacent continental shelf , 1987 .

[21]  K. Horsburgh,et al.  The impact of future sea-level rise on the European Shelf tides , 2012 .

[22]  Scott C. Hagen,et al.  Adjusting Lidar-Derived Digital Terrain Models in Coastal Marshes Based on Estimated Aboveground Biomass Density , 2015, Remote. Sens..

[23]  Stephen C. Medeiros,et al.  On the significance of incorporating shoreline changes for evaluating coastal hydrodynamics under sea level rise scenarios , 2013, Natural Hazards.

[24]  P. V. Sundareshwar,et al.  RESPONSES OF COASTAL WETLANDS TO RISING SEA LEVEL , 2002 .

[25]  Norman W. Scheffner,et al.  ADCIRC: An Advanced Three-Dimensional Circulation Model for Shelves, Coasts, and Estuaries. Report 1. Theory and Methodology of ADCIRC-2DDI and ADCIRC-3DL. , 1992 .

[26]  A. Cox,et al.  Data and numerical analysis of astronomic tides, wind-waves, and hurricane storm surge along the northern Gulf of Mexico , 2016 .

[27]  N. Plant,et al.  Coupling centennial‐scale shoreline change to sea‐level rise and coastal morphology in the Gulf of Mexico using a Bayesian network , 2016 .

[28]  G. Cozannet,et al.  Brief communication "Evaluating European Coastal Evolution using Bayesian Networks" , 2012 .

[29]  R. Morton.  Historical Changes in the Mississippi-Alabama Barrier-Island Chain and the Roles of Extreme Storms, Sea Level, and Human Activities , 2008 .

[30]  J. Donoghue.  Sea level history of the northern Gulf of Mexico coast and sea level rise scenarios for the near future , 2011 .

[31]  P. L. Silva,et al.  Morphological evolution of the Guadiana estuary and intertidal zone in response to projected sea‐level rise and sediment supply scenarios , 2011 .

[32]  G. Stone,et al.  Geomorphologic Evolution of Barrier Islands along the Northern U.S. Gulf of Mexico and Implications for Engineering Design in Barrier Restoration , 2009 .

[33]  Nathaniel G. Plant,et al.  A Bayesian network to predict coastal vulnerability to sea level rise , 2011 .

[34]  Jon French,et al.  Hydrodynamic Modelling of Estuarine Flood Defence Realignment as an Adaptive Management Response to Sea-Level Rise , 2008 .

[35]  W. F. Boer.  Biomass dynamics of seagrasses and the role of mangrove and seagrass vegetation as different nutrient sources for an intertidal ecosystem , 2000 .

[36]  Sarah F. Griffee,et al.  Sediment Budget: Mississippi Sound Barrier Islands , 2011 .

[37]  K. Alizad,et al.  The dynamic effects of sea level rise on low‐gradient coastal landscapes: A review , 2015 .

[38]  O. Edenhofer,et al.  Mitigation from a cross-sectoral perspective , 2007 .

[39]  G. F. Hall,et al.  A high‐resolution study of tides in the Delaware Bay: Past conditions and future scenarios , 2013 .

[40]  L. Walters,et al.  Interactions between native barnacles, non-native barnacles, and the eastern oyster Crassostrea virginica. , 2009 .

[41]  G. Egbert,et al.  Efficient Inverse Modeling of Barotropic Ocean Tides , 2002 .

[42]  Bruce K. Wylie,et al.  Upscaling carbon fluxes over the Great Plains grasslands: Sinks and sources , 2011 .

[43]  Vincent R. Gray.  Climate Change 2007: The Physical Science Basis Summary for Policymakers , 2007 .