The study looked at how sediment moves in Hangzhou Bay. They found that sediments are mainly transported from the north to the south side of the bay. This movement is influenced by tides and the shape of the bay. Sediments are carried by the water flow and tidal forces, with tides being stronger in the north and weaker in the south. The bay is changing over time, with more sediment building up on the south side and eroding on the north side.