Proceedings of the Seventh International Conference on Hydroscience and Engineering, Philadelphia, PA, September 2006. http://hdl.handle.net/1860/732In this study, a series of numerical simulations with simple shape of model river mouse is conducted to understand the fundamental mechanism of forces affecting the formation of the sandbars. A coupling scheme of waves, wave induced currents, deformation of bathymetry and river discharge flow is proposed. Incident wave condition is the multi-directional irregular wave, which is closed to real field wave condition. Development of sand bar with bathymetry change is calculated, applying the local sediment transport model proposed by Bailard. Temporal developments of wave, currents, bathymetry change are interacting in the same time step of the numerical program. Configuration of the sandbar is quite sensitive to the direction of wave and currents. Asymmetric development of the sand bar in river mouth is caused by principal wave direction of multi-directional wave
