EROSION MECHANISUMS OF COASTAL DUNES USING HYDRAULIC MODEL TEST AND NUMERICAL SIMULATION

Abstract

 This study investigated erosion mechanisms of coastal dunes through hydraulic model tests and numerical simulations. In the case of hydraulic model tests, the eroded portion of the dune depends on the regime of tsunami overflow. Seaward and landward slope was eroded by supercritical flow. In contrast, landward side was remarkably eroded by subcritical flow. In reproduction simulation of the hydraulic model test, eroded area was roughly matched by adjusting the parameters. Numerical simulation of topographic change of Nakatajima dune, which has a large crown width shows resistance to the erosion by tsunami overflow.