Investigation of Flow Velocity and Salinity Behaviour in Ota River Estuary Using Acoustic Tomography Method and Numerical Modeling

Abstract

This paper investigates the behaviour of current velocity and salinity in tidal channel network, particularly in tidal junction. Acoustic tomography method and numerical model were applied to analyse flow field pattern in tidal junction between Tenma river and Kyu Ota river. The velocity patterns by numerical model and FATS were in a satisfactory result with reference data by ADCPs. Interplay between tidal action and geometrical shape of the channel network can cause change of current velocity pattern in the tidal junction. It is found that the ratio of current velocities in the tidal junction between Kyu Ota river and Tenma river is ± 62%. Behaviour of salinity pattern in Kyu Ota and Tenma river during neap and spring tide indicates that salinity during neap tide is greater than that during spring tide. However, there is no significant difference of salinity pattern between Kyu Ota and Tenma river in tidal junction.