Observation of Flood-driven Sediment Transport and Deposition Off a River Mouth

Abstract

A series of field observation of turbidity and current velocity etc. were carried out at the sea bottom off a river mouth during flood periods. The measurement location was 1.2km off the mouth of Tenryu River, Japan, where water depth was about 18m. Four flood events of which the maximum mean hourly discharge ranged from 1,570m3/s to 4,620 m3/s were selected and the time series of river discharge, turbidity, water temperature, salinity and current velocity were compared with each other and the relationships between them were discussed. Furthermore, vertical profiles of turbidity and salinity observed after a flood were used in the discussion. Bathymetric changes surveyed off the river mouth were also taken into account.