A modelling study of SPM transport in the Bohai Sea

A 3-D SPM transport model is applied to the Bohai Sea in China. The model includes: (1) the movement of the SPM in the water body, (2) the movement of the sediment fine fraction in the sea bottom and (3) the deposition and erosion processes at the seabed. The model is of Lagrangian type, i.e., the tracer method is used. The influence of the SPM on the hydrodynamic condition is studied here because the Yellow River releases huge amount of SPM into the Bohai Sea. Thus, the usual model configuration is modified by taking into account the density change due to the SPM. The results show that the effect of the SPM can not be neglected near the river mouth area where the SPM concentration gradient is very high. With the SPM considered the SPM is disposed over a wider area. Based on the modified model a one-year simulation is performed for the year 1982. The results are compared with the CZCS satellite data at the same time. The results of the monthly averaged SPM concentrations in the Bohai Sea are compared between the seasons. They agree reasonably with observations. The exchange of SPM and water through the Bohai Strait is also studied. The results show that most of SPM from the Yellow River stays in the Bohai Sea.