Sediments and Subgrid: A Great Combination

Long term morphodynamic simulations are used for predicting the impact of climate change and human interventions in our estuarine and coastal regions. The accuracy of this type of simulations suffers generally from low resolution grids. Eventhough high resolution bathymetry data is increasingly more available thanks to new measurement techniques...

Accurate vertical profiles of turbulent flow in z-layer models

Three-dimensional hydrodynamic z-layer models, which are used for simulating the flow in rivers, estuaries, and oceans, suffer from an inaccurate and often discontinuous bottom shear stress representation, due to the staircase bottom. We analyze the governing equations and clearly show the cause of the inaccuracies. Based on the analysis, we...

A numerical study of mixing and stratification dynamics in the Ria de Arousa estuary (nw Spain) during summer

In this paper we explore the role of the river run-off, the tidal regime and the local winds in the dynamics of the Ria de Arousa estuary during the summer period, using for that purpose the numerical model Delft3D. First of all, a simulation under real hydrological and meteorological conditions is conducted in order to validate the ability of...

An accurate momentum advection scheme for a z-level coordinate models

In this paper, we focus on a conservative momentum advection discretisation in the presence of zlayers. While in the 2Dcase conservation ofmomentum is achieved automatically for an Eulerian advection scheme, special attention is required in the multi-layer case. We show here that an artificial vertical structure of the flow can be introduced...

A streamline tracking algorithm for semi-Lagrangian advection schemes based on the analytic integration of the velocity field

A new scheme for the construction on an unstructured grid of the streamlines of the three-dimensional shallow water equations is presented. The qualitative advantages of the scheme, notably closed streamlines and realistic treatment of closed boundaries, are derived and the spatial accuracy is demonstrated. Semi-Lagrangian advection schemes...