The lower Yellow River's sediment sink affects the size of sediment flowing into the sea. Sediment deposition and erosion in the river change the composition of sediment in motion. Sediment deposition in the lower Yellow River influences the fractions of sediment reaching the sea. More sediment deposition leads to a higher percentage of fine fractions in the sediment flux to the sea. However, sedimentation decreases the percentages of medium and coarse fractions in the sediment flux. The average diameter of sediment reaching the sea decreases when the river's thalweg shifts less annually. With decreased water discharges and channel shrinkage, the sediment exchange between the main channel and floodplain weakens, resulting in coarser sediment reaching the sea.