Abstract
An artificial mound was produced from dredged materials containing sand and gravel in the Nakatsu tidal flat facing the Suo-nada Sea, and this artificial mound served as a supply source of sediment for the development of a barrier island. A sand spit extended from this mound in an extremely shallow sea and attached to the opposite shore, resulting in the formation of a barrier island. The planar changes in the sand spit were investigated using aerial photographs. Observations were compared with the results of a numerical simulation regarding the formation of a barrier island on a sloping bed with a 1/40 slope using the BG model (a model for predicting three-dimensional beach changes based on Bagnold's concept). The observed change in the barrier island and the calculated results were in good agreement.References
Bird, E. 2001. Coastal Geomorphology, Wiley, 322 p.
Miyahara, S., T. Uda, M. Serizawa, and T. San-nami. 2015. Elongation of sand spit and profile changes
on sloping shallow seabed, 8th Int. Conf. on Asian and Pacific Coasts (APAC 2015), Procedia
Engineering, 116, 245-253.
Nummedal, D. 1983. Barrier Islands, in Handbook of Coastal Processes and Erosion, P. D. Komar
(ed.), 77†' 121, Boca Raton, FL: CRC Press.
San-nami, T., T. Uda, M. Serizawa, and S. Miyahara, S. 2014. Numerical simulation of elongation of
sand spit on seabed with different water depths and slopes, Proceedings of 34th International
Conference on Coastal Engineering, ASCE, 1-13.
Schwarz, M. L. 1971. The multiple causation of barrier islands, J. Geology, 79, 91-93.
Seino, S., T. Uda, Y. Ashikaga, Y. Kanda, and H. Jono, 2007. Mechanism of deformation of a sand bar in Sanbyakken area in Nakatsu tidal flat, Proc. Japan. Coastal Eng. Conf., 54, 566†'570. (in Japanese)
Uda, T., S. Seino, Y. Ashikaga, and H. Jono. 2008. Rapid deformation of sand spit triggered by storm surge in Sanbyakken area in Nakatsu tidal flat, Proc. Japan. Coastal Eng. Conf., JSCE, 55, 481- 485. (in Japanese)
Uda, T., and M. Serizawa. 2011. Model for predicting formation of bay barrier in flat shallow sea, Coastal Sediments '11, 1176-1189.
Uda, T., S. Onaka, and M. Serizawa. 2015. Beach erosion downcoast of Pengambengan fishing port in western part of Bali Island Japan, 8th Int. Conf. on Asian and Pacific Coasts (APAC 2015), Procedia Engineering, 116, 494-501.