Introduction

Coastal (geo)morphology is the study of the changing shape of coastal landforms and is of critical importance to the development of human infrastructure on or near the coast. Poor understanding of coastal processes and potential coastal morphological change leads to poor decisions regarding coastal management and development. Present understanding of the coastal processes responsible for morphological change is considerable, based on decades of painstaking scientific research, but is still far from complete (e.g. Stive and Wang, 2003 ). The concept of separation of scales is also critical (de Vriend et al., 1993 ; Stive and Wang, 2003 ) as the prospect of describing the movement of every grain of sand on several kilometres of beach or in an entire estuary due to every wave and tidal cycle for a decade is daunting, to say the least. Because of this, coastal morphological modelling approaches need to rely on some level of process aggregation. High levels of process aggregation are employed in the “behaviour-oriented” modelling approaches described by Stive and de Vriend, 1995 and Stive and Wang, 2003 wherein the general behaviour of large-scale morphological elements is modelled without attempting to describe the low-level physical processes responsible for the changes. The “process-based” modelling approach described in this thesis employs a much lower level of process aggregation. Individual sediment grains and/or waves are not directly modelled, however an attempt is made to explicitly represent all the important physical processes acting on sediment in the coastal environment.