Morphological model of the river Rhine : first (v0.5) model of the IJssel branch

The riverbed of the Rhine branches is dynamic, influenced by morphological processes and human intervention. The current DVR model used to predict morphodynamics is outdated due to: Calibration based on periods before key interventions (Room for the River, Water Framework Directive). Transition to new software (6th generation models in the D-HYDRO Suite). New data and insights on morphological developments. A new model and tools are being developed, starting in 2023, with progress reported for 2023-2024, resulting in model version v0.5. The final model will be fully described in a future report. In 2023-2024, the first version of the IJssel morphological model (v0) was set up using existing hydrodynamic models, requiring modifications for morphological simulations. The IJssel model's lower grid resolution compared to the Waal model affects bed level schematization, which can be adjusted by choosing appropriate summer bed roughness. Calibration runs have been conducted, leading to model version v0.5. Results for bed level changes and sediment transport are promising, but local deviations need further calibration. The model is sensitive to parameter changes, suggesting the need for additional diffusion in the software. All development steps and analysis methods are defined in Matlab scripts for reproducibility and future use.