ABSTRACT
For a deeper understanding of flow and sediment dynamics of gravel-bed rivers with steady vegetated alternate bars, two-dimensional numerical simulations of flow and bed evolution are performed. The solution of the depth-averaged shallow water equations and sediment mass conservation equations involves the introduction of closure models for friction, turbulence and sediment transport processes, which might present uncertain parameters. These parameters must be calibrated and validated before further investigating the response of the study reach to different flow and sediment supply scenarios. To this goal, in situ measurements are essential to impose for example, the initial and boundary conditions, as well to confront the model results to field observations. With a focus on the hydrodynamics processes commonly found in river reaches, this work aims at emphasizing the needs and the potential of advanced measuring techniques (e.g. LSPIV, aDcp, SCAF, hydrophones and cryogenic coring, etc.) as well of automatic calibration and data assimilation techniques for getting an optimal parameterization of the input variables for hydrodynamics, sediment transport and morphodynamics study cases.
