The study looked at how sediment moves in the South Channel of the Yangtze River Estuary. By analyzing data from different seasons, researchers found that sediment is mainly carried by the flow of water, but tides also play a role in moving sediment. The flow of water changes with depth, affecting how much sediment can be carried. Sediment flows out in the main channel and comes in at shallow areas, causing sediment to build up slowly in certain areas.