Diffusion path and range of water flow and sediment in Yellow River Estuary during water-sediment regulation in 2012

The hydrological data were collected from 4 monitoring stations in the Yellow River Estuary during the period of water-sediment regulation in July 2012. Based on the observations,the hydrodynamic characteristics,the dispersal area of diluted water and the mechanism of suspended sediment diffusion are analyzed. The results show that during the period of water and sediment regulation,with the runoff emptying into the sea,the ebb tide dynamics were enhanced; the runoff was mixed up with the sea water as diluted water when it diffused into the open sea. The diffusion range of diluted water extended dramatically north to 38°10'N,east to 119°30'E and south to 37°45'N. The suspended sediment diffusion played a significant role in the sediment transport. In the nearshore zone,the suspended sediment deposited rapidly because of the cutting off by the tidal shear front. More rapid deposition occurred where the frontal cutting off was with the ebb tide inside and flood tide outside. On the other side,a sediment transport passage leading to the southern area of the Laizhou Bay was formed where the frontal cutting off was with the flood tide inside and ebb tide outside. The distribution diagram of suspended sediment concentration which was inversed from the MODIS remote sensing image indicated that waters with a surface sediment concentration larger than 0. 4g / L mainly distributed along the coastal zone and nearshore waters in the southern part of the Yellow Estuary,while the diluted water diffused to the northwest. As to waters with a surface sediment concentration of 0. 2 to 0. 4g / L,the diffusion range to the north was consistent with that of the main part of diluted water.