Abstract
Influences on the tidal current off the coast of Shimabara due to the construction of the sea dike in the Isahaya wan land reclamation project was evaluated by a hydraulic model test. The results of hydraulic model test were as follows. On the line connecting Ariake and Nagasu, strong currents occurred near the Shimabara Peninsula. Tidal current changed complexity at a point near the Shimabara Peninsula at the ebb tide, especially in the spring tide. Tidal current decreased approximately 5% due to the construction of the sea dike in average on the Ariake-Nagasu line, which corresponds to the amount of decrease of tidal discharge by the closing of the Isahaya bay.
