Ian Bentley, Harshinie Karunarathna


The need for reliable modelling techniques for the prediction of morphological change in coastal settings has become increasingly important to coastal planners and policy makers in recent years due to the effects of accelerated sea level rise and a shift in approach from coastal defence to coastal management. In this research a new cellular automata based model is developed in order to bridge the gap between current bottom-up, process based models and top-down behaviour oriented models of estuarine morphodynamic evolution, and make predictions of morphological change over medium time-scales (one year to several decades). The key processes of tidal flows, waves, sediment transport and salt marsh ecology are represented in simplified form in order to capture the complex interactions and feedbacks that occur between them and which ultimately determine how the morphology will develop in response to environmental change. The initial bathymetry of the estuary is represented by a cluster of rectangular cells in a CA domain. Tidal flows are estimated using a new routing model, which shows good agreement with a conventional 2D hydrodynamic model but is much more computationally efficient.


estuaries; morphological modelling; cellular automata

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Chow, V.T. 1959. Open-channel hydraulics. New York, McGraw- Hill Book Co., 680 p.


Coulthard, T. J. 1999. Modelling Upland Catchment Response to Holocene Environmental Change. Unpublished Phd Thesis, School of Geography, University of Leeds, U.K. 181pp.

D'Alpaos, A., S. Lanzoni, S. M. Mudd, and S. Fagherazzi (2006), Modeling the influence of hydroperiod and vegetation on the cross-sectional formation of tidal channels, Estuarine Coastal

PMid:16707583 PMCid:1482495

Shelf Sci., 69, 311–324, doi:10.1016/j.ecss.2006.05.002http://dx.doi.org/10.1016/j.ecss.2006.05.002

EMPHASYS Consortium. 2000. A Guide to prediction of morphological change within estuarine systems, Estuary Research Programme, Phase 1, HR Wallingford, Wallingford, Report No: TR 114, -51.

HR Wallingford. 1997. Estuaries: The case for research into morphology and processes. HR Wallingford Report SR 478. Huthnance, J.M., G. Karunarathna, A. Lane, A. J. Manning, P. Norton, D. Reeve, J. Spearman, R. L.

Soulsby, I. H. Townend, J. Wolf, and A. Wright. 2007. Development of estuary morphological models, R&D Technical Report FD2107/TR, Joint Defra/EA Flood and Coastal Erosion Risk Management R&D Programme.

Mariotti G., S. Fagherazzi. 2010. A numerical model for the coupled long-term evolution of salt marshes and tidal flats. J Geophys Res 115:F01004http://dx.doi.org/10.1029/2009JF001326

Mudd, S.M., S. Fagherazzi, J. T. Morris, and D. J. Furbish. 2004. Flow, sedimentation, and biomass production on a vegetated salt marsh in South Carolina: Toward a predictive model of marsh morphologic and ecologic evolution, in The Ecogeomorphology of Tidal Marshes, Coastal Estuarine Stud., vol. 59, edited by S. Fagherazzi, M. Marani, and L. K. Blum, pp. 165–187, AGU, Washington, D. C.http://dx.doi.org/10.1029/CE059p0165

Murray, A.B., and C. Paola. 1994. A cellular model of braided rivers, Nature, 371, 54–57.http://dx.doi.org/10.1038/371054a0

Soulsby, R. 1997. Dynamics of Marine Sands, Thomas Telford, London.


Syme,W.J. 1991. Dynamically linked two-dimensional/one-dimensional hydrodynamic modeling program for rivers, estuaries & coastal waters. M. EngSc research thesis, Dept. of Civil Engineering, The Univ. of Queensland, Australia.

U.S. Army Corps of Engineers. 2002. Coastal Engineering Manual. Engineer Manual 1110-2-1100,

U.S. Army Corps of Engineers, Washington, D.C. (in 6 volumes).

Van Rijn, L.C. 2007a. Unified view of sediment transport by currents and waves: I. Initiation of motion, bed roughness and bed load transport. J. Hydraul. Eng., 133(6), 649–667.http://dx.doi.org/10.1061/(ASCE)0733-9429(2007)133:6(649)

Van Rijn, L.C. 2007b. Unified view of sediment transport by currents and waves. II: Suspended transport. J. Hydraul. Eng., 133(6), 668–689.http://dx.doi.org/10.1061/(ASCE)0733-9429(2007)133:6(668)

Van Rijn, L.C. 2007c. Unified view of sediment transport by currents and waves, III: Graded beds. J.

DOI: https://doi.org/10.9753/icce.v33.sediment.27