Abstract
The salt wedge in the Ishikari River has become very long due to dredging activity. Studies of the salt wedge have suggested a new coefficient in addition to the interfacial friction coefficient, which has been widely used in research. On the basis of detailed observations of time-dependent changes in the interface of long salt wedges, the method we are proposing can be used not only to explain how the shape of the salt wedge changes due to tide, but also will allow useful predictions of time-dependent changes in the shape of the interface in response to flowrate and sea level.
