Sediment Grain Size Characteristics and Transport Patterns in the Northwestern Shenzhen Bay, China

Key words: 
• grain size parameters /
• geostatistics /
• grain size trend analysis /
• sedimentation rates /
• Shenzhen Bay

Abstract: Surface sediment samples were collected in the northwestern Shenzhen Bay, China, and then analyzed using by Mastersize 2000 and sieving to obtain grain size data. The results indicate that the silt sediment covers the North Bay with little poorly sorting and poorly sorted coarse sand and gravel in some areas. In order to use the grain size trends analysis model, the geostatistic method is used for the determination of characteristic distance. The geostatistic results are associated with the some “normal” or “abnormal” grainsize parameters in the study area. A variation range is remarkably determined after eliminating some “abnormal” values, which could be considered as the characteristic distance. The grain size trends analysis shows that sediment transport northeastwards in the west bay, and westwards in the Shenzhen River estuary area. Thus, the near shore area adjoining the north coast becomes a net sediment transport converge area. This pattern is highly consistent with the local hydrodynamics. Furthermore, 210Pb dating result suggests that the sedimentation rate in this area is much higher than other area in the bay, which is consistent with the results of grain size trends analysis. 