In this research, the initial formation and long-term evolution of channel-shoal patterns in schematised basins is simulated using a model based on the software package Delft3D. The resulting channel-shoal patterns are validated with field observations, among which the Western Scheldt estuary. This has proven that a complex model is able to simulate the emergence and evolution of nature-like patterns, on time scales from decades to centuries. Additionally, a comparison with other model types has given insight into the influence of different model assumptions and formulations and into the processes underlying the morphodynamic behaviour of channels and shoals in estuaries. Applying this new knowledge we are able to set up predictive models, which help us to manage our estuaries in a durable way, combining different model types and data, such that optimal use can be made of each research method.