Based on the measured data of hydrological sediment and water depth over multiple years in Oujiang River estuary and Wenzhou shoal,this paper studies the evolution characteristics of scouring and silting.The results show that the runoff in Oujiang River basin is characterized by the difference of annual and flood fluxes,which plays a crucial role in the erosion and deposition of the Oujiang riverbed.Muddy sand suspends again at the Oujiang River estuary and the Wenzhou shoal area due to the wind and wave actions,resulting in an increased sediment concentration.Oujiang estuary topography behaves a “flood season erosion and dry season sedimentation” features.Although the vertical and horizontal erosion and deposition of the riverbed changes frequently,the year-to-year changes of the bed erosion and sediment amplitude and river volume is little,and the riverbed is relatively stable.But Wenzhou shoal is in a state of continuous siltation.In particular,the construction of the recent reclamation project has further accelerated its deposition rate.Silting generally occurs at the shoals,and the sedimentation is most frequent near the southern end of the shoal and the northern section of the shoal near the Liten River dike.At the same time,since Wenzhou shoal near the south exit waterway blocked the tidal volume from the northern side due to the construction and completion of the Lingdi north dike,the tidal volume entering the shoal between the large and small islands increased,so it was in the state of erosion from1999 to 2010.