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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