A Two-Dimensional Horizontal Wave Propagation and Mud Mass Transport Model on Muddy Coastal Regions

Abstract

It is well known that surface water waves interact with fluid mud on the sea bed. Wave mud interaction results in high wave energy dissipation and mud mass transport. This kind of wave energy dissipation, which generally is much more significant than wave dissipation due to bottom friction, should be considered in the simulation of wave evolution and transformation in muddy coastal environments. In this research, a two-dimensional horizontal wave propagation and morphodynamic model for muddy coasts was developed. The model can be applied on a general three dimensional bathymetry of a soft muddy coast to calculate wave damping, fluid mud transport and resulting bathymetry change under wave action. In addition to the effect of wave-mud interaction on wave propagation, the dissipation due to wave-mud interaction was also implemented in SWAN (a third generation numerical model for Simulating WAves Nearshore) using a multilayered wave mud interaction model. These two models combined can be used for generation and propagation of waves in muddy coastal areas. The nonlinear constitutive equations of the visco-elastic-plastic model are adopted for the rheological behavior of fluid mud in this research. The results of the numerical model are compared against a series of wave-basin experiments, wave flume experiments and field observations. Comparisons between the simulated results with the both field and laboratory data reveal the capability of the proposed model to predict the wave transformation and mud mass transport.