Mechanism Study of Transport and Distributions of Trace Metals in the Bohai Bay, China

This study shows that there are two regions with high trace metal concentrations in the Bohai Bay, China. The numerical hydrodynamic model coupled with geochemical analysis was applied to understand the mass transport and sedimentation in the bay. The modeling results show that the two regions are located within the residual current vortexes. Results from the particle-tracking model indicate that the trace metals released from the land sources enter the regions and take a relatively long residence time in the vortexes. The sediment radionuclide data indicates that the two regions experienced continuous and high sedimentation, and trace metals are prone to deposit in the regions. The correlations among trace metals, residual currents and radionuclides data suggest that the tides are the governing factor controlling the distributions of the trace metals in the bay. The consistence among these results also supports the reliabilities of the numerical simulation results of water and trace metal transport in this study.