Abstract
It has been already reported by Nguyen et al.(2008) that at the river entrances facing the Sea of Japan, frequent occurrence of water level rise caused by wave set-up can be observed in storm waves during winter. It is hence expected that saline water intrusion is generated into the tidal estuary due to wave set-up, resulting in more frequent and more severe impact to the estuarine environment. In the present study, the additional amount of the sea water discharge caused by wave set-up is estimated from measured water level variation at the Iwakigawa and Yoneshiro river mouths in the northern part of Japan. Furthermore, theoretical expression is proposed to estimate the additional amount of sea water discharge expressed in terms of the deep water wave height and an empirical coefficient proposed Nguyen et al.(2008).
