Nicolas Zimmermann, Koen Trouw, Li Wang, Mieke Mathys, Rosalia Delgado, Toon Verwaest


The harbour of Blankenberge in Belgium experiences strong sedimentation in its entrance channel requiring frequent dredging. In order to investigate under which conditions this sedimentation is the most pronounced, the instationary coastal model XBeach is used. This paper presents results of long-term morphology modelling of channel sedimentation after applying a specific methodology for input reduction. A reduced time series representative of the annual wind-wave climate is run in combination with a representative tide and a constant morphological acceleration factor (morfac) to cover one year of erosion-sedimentation. While this approach does come with side effects, it has the important advantage to be easy to implement and to preserve part of the climate history compared to other approaches such as MorMerge and a time-varying morfac approach (described in the paper). With this approach and default settings, XBeach is shown to reproduce both qualitatively and quantitatively well the measured sedimentation. Results show that tide, wind and waves all contribute significantly to the total sediment transport, and that both continuous transport and individual storm events cause strong sedimentation. Some aspects of morphological modelling methodologies are discussed, relative to the calibration, input reduction and long-term modelling methods.


morphological modelling; XBeach; input reduction; channel sedimentation; acceleration

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Booij, N., Ris, R. and Holthuijsen, L. (1999). A third-generation wave model for coastal regions, Part I, Model description and validation. Journal of Geophysical Research, vol. 104 (C4), pp. 7649-7666.http://dx.doi.org/10.1029/98JC02622

DHI (2001). LITPACK 2001, Longshore current and littoral drift, Litdrift User Guide. Danish Hydraulic Institute, Denmark.

Doorme, S.; Verwaest, T.; Trouw, K.; Verelst, K. (2009). Determination of the wave climate for the Belgian coastal waters. In: 1st international SWAN workshop, TUD, Delft (NL), 8-10 June 2009.

Dujardin, A.; Van den Eynde, D.; Vanlede, J.; Ozer, J.; Delgado, R.; Mostaert, F. (2010a). BOREAS - Belgian Ocean Energy Assessment: A comparison of numerical tidal models of the Belgian part of the North Sea. Version 2_0. WL Rapporten, 814_03. Flanders Hydraulics Research, Soresma & MUMM: Antwerp, Belgium. BELSPO contract SD/NS/13A

Hoitink, A.J.F., Hoekstra, P., and Van Maren, D.S. (2003). Flow asymmetry associated with astronomical tides: Implications for the residual transport of sediment. Journal of Geophysical Research, vol. 108 (C10), p. 3315.http://dx.doi.org/10.1029/2002JC001539

Holthuijsen, L., Van Vledder, G., Zijlema, M., Salmon, J. (2012). SWAN variations of waves in a North Sea super storm. Proceedings of the International Conference on Coastal Engineering 2012, Santander, Spain.

Houthuys, R. (2012). Update of the sediment budget for the nearshore of Blankenberge Zeebrugge. Version 1.0. WL Rapporten, 744_30. Flanders Hydraulics Research & IMDC: Antwerp, Belgium.

Konings, P. (1989). Shallowing of the Blankenberge harbour entrance: morphodynamical evolution and sediment transport processes. Natuurwetenschappelijke tijdschrift (Gent, Belgium), 71, pp. 121-143.

Latteux, B. (1995). Techniques for long-term morphological simulation under tidal action. Marine Geology, vol. 126, pp. 129-141.http://dx.doi.org/10.1016/0025-3227(95)00069-B

Lesser, G. R., Roelvink, J. A., van Kester, J. A. T. M. and Stelling, G. S. (2004). Development and validation of a three-dimensional morphological model. Coastal Engineering, vol. 51, pp. 883-915.http://dx.doi.org/10.1016/j.coastaleng.2004.07.014

Lesser, G.R. (2009). An approach to medium-term coastal morphological modelling. PhD dissertation, Unesco-IHE Institute for Water Education and Delft University of Technology, The Netherlands.

Leyssen,G.; Vanlede, J.; Decrop, B; Van Holland, G; Mostaert, F. (2012). Modellentrein CSM-ZUNO. Deelrapport 2: Validatie (in Dutch). WL Rapporten, 753_12. Waterbouwkundig Laboratorium & IMDC: Antwerpen, Belgium.

Liang, L. (2010). A fundamental study of the morphological acceleration factor. MSc thesis, Delft University of Technology, The Netherlands.

Mol, A.C.S. (2007). R&D Kustwaterbouw Reductie Golfrandvoorwaarden. OPTI Manual. Rapport H4959.10, WL|Delft Hydraulics, Nederland.

Ranasinghe, R., Swinkels C., Luijendijk A., Roelvink J.A., Bosboom J., Stive M.J.F. and Walstra D.J.R (2011). Morphodynamic upscaling with the morfac approach: dependencies and sensitivities. Coastal Engineering, 58 (8), pp. 806-811.http://dx.doi.org/10.1016/j.coastaleng.2011.03.010

Ris, R., Booij, N. and Holthuijsen, L. (1999). A third-generation wave model for coastal regions, Part II: Verification. Journal of Geophysical Research, vol. 104 (C4), pp. 7649-7666.http://dx.doi.org/10.1029/1998JC900123

Roelvink J.A. (2006). Coastal morphodynamic evolution techniques. Coastal Engineering, vol. 53, pp 277-287.http://dx.doi.org/10.1016/j.coastaleng.2005.10.015

Roelvink, D., Reniers, A., van Dongeren, A., van Thiel de Vries, J., Lescinsky, J. and McCall, R. (2009). Modelling storm impacts on beaches, dunes and barrier islands. Coastal Engineering, vol. 56, pp. 1133-1152.http://dx.doi.org/10.1016/j.coastaleng.2009.08.006

Roelvink, D., Reniers, A., van Dongeren, A., van Thiel de Vries, J., Lescinski, J., and McCall, R. (2010). XBeach model description and manual. Unesco-IHE Institute for Water Education, Deltares and Delft University of Technology, Report 1002266, version 6.

Soulsby, R. (1997). Dynamics of marine sands. Thomas Telford Publications, London, UK.


Teurlincx, R.; Van der Biest, K.; Reyns, J.; Verwaest, T.; Mostaert, F. (2009). Haven Van Blankenberge - Verminderen van de aanzanding van de havengeul en het voorplein: Eindrapport (Dutch). Versie 1_1. WL Rapporten, 643_12. Waterbouwkundig Laboratorium: Antwerpen, België.

Van de Kreeke, J., and Robaczewska, K. (1993). Tide-induced transport of coarse sediment : Application to the Ems estuary. Netherlands Journal of Sea Research, vol. 31 (3), pp. 209-220.http://dx.doi.org/10.1016/0077-7579(93)90022-K

Van der Wegen, M., and Roelvink, J.A. (2008). Long-term morphodynamic evolution of a tidal embayment using a two-dimensional, process-based model. J. Geophysical Research, 113, C03016.

Van der Westhuysen, A., Zijlema, M. and Battjes, J. (2007). Nonlinear saturation-based whitecapping dissipation in SWAN for deep and shallow water. Coastal Engineering, vol. 54, pp. 151–170.http://dx.doi.org/10.1016/j.coastaleng.2006.08.006

Van Rijn, L.C. (1993). Principles of Sediment Transport in Rivers, Estuaries and Coastal Seas. Aqua Publications, The Netherlands.


Walstra, D.J. (2011a). Process-based Long Term Morphological Modelling: the present state-of-the-art and the way ahead. Deltares webinar, November 10th 2011. Avail. at

Walstra, D.J. (2011b). How to perform realistic morphodynamic simulations with acceptable run-times. Deltares webinar, December 14th 2011. Avail. at

DOI: https://doi.org/10.9753/icce.v33.sediment.111