Modelling of coastal evolution on yearly to decadal time scales

There is still no universal model for analysing and predicting coastal evolution and its governing processes on yearly to decadal time scales. Instead, depending on the nature of the problem and project objectives, there is a wide of models available, each focusing on the problem complex from a specific standpoint. The present paper gives overview of available numerical model types. A differentiation is made between equilibrium and non-equilibrium model types as well as between longshore uniform and non-longshore uniform model types. These models are discussed in terms of their general assumptions, approaches, and applicability. Most of the model descriptions are supplemented by an illustrative example. In addition, generic issues, such as level of knowledge on different scales, selection model type on the basis of the nature of the application, the concept of equilibrium, model validation and utilisation are discussed.