High-resolution Monitoring of Sedimentary Processes in an Estuarine Channel

The erosion and deposition dynamics in a highly turbid estuarine channel were successfully surveyed using an echo sounder in combination with a high-resolution acoustic Doppler profiler. While the surface level of the channel bed was stable during neap tide, it underwent fluctuations as the current velocity increased. The bed sediment was eroded by the flood tide and was found as suspended sediment. During slack high tide, the suspended sediment was deposited on the channel bed and fluid mud was formed rapidly. The fluid mud was gradually eroded by the ebb tide, and the fluid mud thickness was approximately 0.05 m per semi-diurnal cycle during spring tide. Lastly, the height of the channel bed increased by 0.8 m during a semi-lunar tide.