Identification of Some Relevant Processes in Coastal Morphological Modelling

Abstract

This paper presents a coastal morphology modelling system based on an explicit forward time integration scheme for the morphological evolution involving the following stages: a) Initialisation, b) Sediment transport computation using a deterministic sediment transport model, c) Wave computation using an arbitrary wave model, d) Hydrodynamic computation assuming a mobile bed evolving at ∂z/∂t, with optional use of a module to determine the apparent roughness in combined wave-current motion and e) Bed level update scheme using an improved second order Lax Wendroff scheme. A series of numerical tests is performed with the aim of evaluating the effect of space-varying hydraulic roughness in combined waves and current, choice of wave modelling approach and of directionality of the waves on the morphological evolution. A detached breakwater is used as test case.