DIFFUSION OF SEDIMENT IN RADIAL SAND RIDGES IN SOUTHERN YELLOW SEA
LIU Tao;SHI Xue-Fa;LIU Yan-Guang;LIU Sheng-Fa;WANG Kun-Shan;Guangxi Mangrove Research Center,Guangxi Key Lab of Mangrove Observation and Utilization;Key Lab of Marine Resources and Environmental Geolog State Oceanic Administration;
Using large amount of in-situ data of the grain size and concentration of suspended particles in the radial sand ridges of Southern Yellow Sea, the sediment resuspension and diffusion were studied. In total, 411 sites were deployed and sample collected in May to June, 2008 during which local maritime weather was normal. An LISST-100X in-situ laser particle size analyzer(SEQUOIA, USA) was used to profile suspended particle-size distribution in water column; the instrument could cover size ranges 2.73—462μm in 32 grades. Results show that between the radial sand ridges and the abandoned Yellow River delta, suspended sediments were restricted within shallow water and could be transported only along coast by rectilinear tidal current. In addition, rectilinear tidal current in the northern radial sand ridges played a role in sorting sediment, which trended to transport coarse particles onto the sand ridges and fine particles northward(seaward). Moreover, in the area outside local turbid plume, surface sediment on sand ridges was too coarse to be resuspended by normal tidal current. Therefore, the suspend matters in water column above these sand ridges were mainly come from adjacent channels by horizontal movement.