SILTATION RATE IN A TRENCH DREDGED ON FLOODPLAIN IN ESTUARY

I. INTRODUCTIONA discharge of 100--200 m3 / s is needed to be diverted from a tidal reach and utilized as cooling water for a Droposed power plant in the Yangtze Estuary. The diversionchannel is divided into two parts by a levee along the river bank, an open channel stretchinside the levee is connected with a trench dredged on the floodplain, as shown in Pig. 1.Since the flow and sediment regimes in these two stretches are different, analysis is madeseparately for each of them.11. ESTI…

SILTATION RATE IN A TRENCH DREDGED ON FLOODPLAIN IN ESTUARY

Based on the analysis of flow and sediment regimes of stratified and non-stratified now over a trench dredged on the floodplain in estuary for diverting water to a pro posed power plant, a schematic model on lateral diffusion of sediment transport towards the floodplain from the main channel is developed to predict siltation rate in the dredged trench. The computation results are calibrated with prototype data. The siltation rate in.the diversion canal connected with the outer dredged trench is also estimated after determining the mean settling velocity of sediment particle with the aid of prototype data measured in a nearby diversion channel.