Abstract
When waves are incident to a sandy beach from two opposite directions, a cuspate foreland or a landtied island may develop. A typical land-tied island can be seen offshore of Shodo Island in the Seto Inland Sea. Another example is Chiringashima Island located in the south part of Satsuma Peninsula, Kyushu. In both cases, the island and land are connected by an extremely slender sand bar that has been stably maintained for a long time, suggesting that it is stable against wave action from both sides of the sand bar. We developed a numerical model for predicting the elongation of a sand bar of a land-tied island using the BG model.
