The present paper aims at studies of the suspended sediment transport in inner Ishikari Bay in snowmelt season using numerical approach and field observation data. The sediment transport and bottom boundary layer models are coupled into the Princeton Ocean Model to compute suspended sediment concentration in the system. The following findings have been deduced: (1) the suspended sediment transport in the study area in snowmelt season is dominated by the sediment discharge from the Ishikari River. The effect of sediment resuspension due to wave current interaction is limited in a very shallow area along the coast. The average erosion depth in this area is 0.16mm. Net deposition locates in a wider area northern of the inner bay. The average deposition depth in this area is 0.04mm.

The winter current pattern in 2003 in the Ishikari Bay was investigated by using the Princeton Ocean Model (POM) and field observation data. The model was forced by six hour, spatially distributed wind and open boundary forcing. The later was obtained from larger scale model namely Japan Coastal Ocean Predictability Experiment (JCOPE). Through three numerical experiments with different driving forces the following conclusions have been deduced: (1) the open boundary forcing is the major driving force for current in deep water, the effect of wind in this region is limited in few surface layers (2) the flow along the shelf and current in shallow region are mainly driven by wind forcing (3) circulations occur in the shallow area during strong wind conditions. A comparison between observed and computed current velocities showed that the model is capable to reproduce current pattern in the bay.

No abstract