抄録
In this study, some observations were conducted in order to estimate the separating ratio of freshwater in the Ota Branch Rivers. A method for estimating a salinity profile was proposed based on observed salinity data. Moreover, the estimated salinity profile was compared with the observed salinity profile in order to confirm the validity of the proposed method.It was confirmed that the estimated salinity profile was almost similar to the observed salinity profile. It is considered that the separating ratio of freshwater is decided by the cross-sectional area of a river and freshwater ratio calculated using the estimated salinity profile. The observation results suggested that the retention of freshwater in a river channel of the Tenma River (one of the Ota Branch Rivers) occurred during neap tide.
