Morphodynamic modelling over alluvial and non-alluvial layers : literature review, update to Tuijnder concept

Rijkswaterstaat is responsible for managing the river system in the Netherlands. As such, it is of crucial importance to predict morphodynamic changes. In the first part of this report, an overview and historical perspective of the possible approaches for predicting morphodynamic changes is given. This aims to help river managers in discerning which method to use depending on their specific needs. One particular morphodynamic process related to fixed layers is currently of special relevance for Rijkswaterstaat. Modelling of this process using DELFT3D is currently done in a simplified manner which is not able to capture some particularly important features. A model that aims at improving the modelling of this process was developed, but it presented several shortcomings. In the second part of this project, this model is carefully analyzed and the shortcomings clearly identified. Based on this, an alternative model is proposed and tested against laboratory data and a field case. The model satisfactorily predicts morphodynamic development in the presence of fixed layers. Points for improvement of the model are identified and further testing against other laboratory data is recommended. In a subsequent project, the model developed here will be applied to a field case relevant for Rijkswaterstaat .