Yasumoto, Y.; Kuroiwa, M.; Shibutani, Y.; Osakada, Y., and Matsubara, Y., 2016. 3D morphodynamic model for sand recycling system. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 502–506. Coconut Creek (Florida), ISSN 0749-0208.

Sand nourishment such as sand bypassing or sand recycling is an effective measure against beach erosion as an alternative technique. The method for setting the optimum injecting amount, site and running cost has not been developed. A numerical model considering the sand nourishment is needed to evaluate the performance of the sand recycling and bypassing projects. This paper is concerned with the development of 3D beach evolution model for taking account the sand dredging and injection processes. In this paper, a model test for sand recycling in an area with artificial reefs was carried out. The model was applied to a sand recycling project conducted at a field site with five artificial reefs (an erosion area). The applicability against the morphodynamics around the five artificial reefs was investigated. Although the volume of erosion/deposition behind the artificial reefs was overestimated, the developed numerical model qualitatively agreed with the measured bathymetry.