Abstract: Sediment transports in a bend channel affected by the tide are different from those dominated by the riverine flow. This paper used the flux decomposition mechanism method to examine the water and sediment transports in the Huangpu River Estuary, basing on the field observations in the 2002 flood season. The results showed that the water and sediment transports in the Huangpu River Estuary consisted of longitudinal and transversetransportsinduced by the secondary flow.The net water transport averaged over a tidal cycle points to the ebb direction, and the net sediment transport points to upstream dominated by the tidal pumping effect. The net transport of both water and sediment across the channel over a tidal cycle direct to the convex bank, in which an Euler transport predominated in water transport, and an advection transport controled sediment transport.Compared the longitudinal with the transverse water and sediment transport fluxes, we found that the crosschannel net water transports were bigger than alongchannel fluxes over a flood tidal cycle while crosschannel sediment transport fluxes were smaller than alongchannel fluxes, which implied that the tidal pumping played the major role in the net transports of sediment in the flood season.

Key words: Huangpu River Estuary, water and sediment transport, flux decomposition mechanism, secondary flow