Suspended Sediment Transport Tendency and the Study of Sedimentary Divisions in the Northern Liaodong Bay

Key words: 
• northern Liaodong bay /
• bottom confiquration /
• suspended sediment transport /
• division of sedimentary environment

Abstract: The sea area around the Liaohe estuary refers to a region between the Liaohe estuary to the east and the Xiaolinghe estuary to the west, of which the water depth is defined less than 20 m. Drainages which enter into the sea are the Liaohe, Shuangtaihe, Dalinghe and Xiaolinghe rivers, characterized by 9.14×10 ⁹ m ³/a of total water discharge and 4.9×10 ⁷ t/a sediment input. Broad tidal flat and submerged deltas were attributed to the large capicity of sedimentary input. Based on the spot investigating data(1988), the authors calculated the distribution of the suspended deposit in the northern Liaodong Bay, and analysed sediment divisions of the Liaohe delta. The results indicated that the suspended matter moved in longitudinal direction. Water and sand from the Shuangtai river and the west area of the river are the main facter for the shoal development in the eastern part of this area. During spring tide, the suspended sediment of the rivers and marine sources can remain in river mouths and aroun shallow water. Main dispersion directions of sediments are southeastwards to the western and the central areas and northeastwards to the eastern part during flood tide. During neap tide, however, sediments from rivers and resuspended sediment from the estuary migrate in the same directions mentioned-above. The investigating area is divided into six modern sediment areas, they are tide flat deposit area, subaqueous delta fine sedimentary area, estuarine sand bank deposit area, estuarine alluvial deposit area, tidal stream and wave cut deposit area, and tide and waterway deposit area. It is noted that bottom configurations of the east in this area are very complicated and the bottoms are subjected to intensive disturbing and scouring, which induce active slide and flows in underconsolidated sediments on the Liaohe delta.