Two-dimensional tidal simulations have been undertaken to investigate sediment transport induced by tidal currents around the palaeo-Changjiang estuary at 6 ka, when the estuary was more than 200 km landward from the present coastline.

Simulated phase distribution of tidal currents suggests that tidal currents at 6 ka in the southern Yellow Sea did not differ qualitatively from the present state except in Haizhou Bay and in the southwestern Yellow Sea. In the latter region, a radial current-ellipse pattern similar to that centered off present-day Qianggang is found off the mouth of the palaeo-Changjiang estuary.

Tidally-induced Lagrangian flow estimated from the trajectory of artificial tracers reveals that the radial current-ellipse pattern emerged both at present and 6 ka in the southwestern Yellow Sea has given rise to different patterns of Lagrangian transport: the trajectory forms a pair of clockwise and anticlockwise cells at present whereas only an anticlockwise cell appears in the 6-ka simulation. An additional tracer experiment for the 6-ka case indicates that the northern part of the palaeo-estuary should be dominated by particles from outside the estuary, whereas the influence of sediments discharged from the palaeo-Changjiang should be found mainly in the southern part of the estuary. This result is consistent with the grain-size distribution observed in the modern Changjiang delta.