Beach Morphology Change Caused by Overwash on Yokosuka Coast

Abstract

At the beginning of October 2006, an extreme Typhoon 18th hit Yokosuka coast of Japan. There is a big amount of sediment transported and deposited inland after the typhoon. This study is to evaluate of this overwashed sediment volume and the prediction of overwash occurrence. These estimation are significant for coastal authorities and local managers to give evacuation warnings to people who live near the coast, it is useful for planners and engineers to mobilise equipment for cleaning up sediment after a storm. Profile change estimations are useful for planners creating “buffer zones” indicating where it is safe to build houses. And this calculation is also important for evaluating sediment budgets of sand beach or barrier islands, especially where these sand beach or islands are migrating due to overwash.