The BG model (a three-dimensional model for predicting beach changes based on Bagnold's concept) was applied to predict the three-dimensional topographic changes of a sandy island due to waves, which were observed in a movable-bed experiment by Uda and Yamamoto (1991). Taketomi island in the Sea of Okhotsk was formed as an island composed of sand by a volcanic eruption, the the island was markedly deformed by wave action, resulting in the formation of a double tombolo behind the island (Zenkovich, 1967). The BG model was also applied to predict these topographic changes of the island. The predicted and measured topographic changes in the two examples were in good agreement
