Sediment trapping of turbidity maxima in the Changjiang Estuary

► An undercurrent and sediment cloud appear in the flood and dry seasons respectively. ► Spiraling currents control sediment transport over a tidal cycle. ► Both flocculation and deflocculation can play a dual role in sediment trapping. ► The advance of saline wedge would influence sediment transport. ► TM diversity caused by interaction between stratified flows and cohesive sediments.