Simulating the development of tidal basins and estuaries over many decades has proven to generate quasi-equilibrium geometries that are remarkably realistic and appear to be governed mainly by the (deterministic) tidal forcing and the constraints such as dikes and hard layers. A persistent issue in these
simulations however is a tendency of channels to become too much incised, after which their freedom to move horizontally reduces. Crude methods such as an exaggerated slope correction effect or an avalanching mechanism have been applied as somewhat unsatisfactory, though empirically adequate fixes. There are different possible causes of the problem:

1. Inadequate formulation and/or software implementation of the relevant physical processes, e.g., sediment mixture effects, the bed-slope effect on sediment transport
2. Numerical problems due to an inadequate numerical scheme and/or its software implementation.

In this work package we will investigate which numerical and physical processes are responsible for creating the problem and to come up with sound solutions to them.