Abstract
Beach and dune scarps can be seen often after a typhoon, hurricane and northeaster. In general, beach scarp and resulted shoreline recession are computed using a cross-shore sediment transport model in EU countries and US. On the other hand, beach scarp due to longshore sediment transport mechanics has been often estimated using N-line model in Japan. There is still unknown factor to distinguish which process is dominant to cause beach and dune scarp in natural condition. Here, field studies were conducted after typhoons to clarify that at least longshore process could cause beach scarp in sandy beach. Then, a quasi 3-D model to simulate a beach scarp generation is developed based on longshore sediment transport calculation and resulted shoreline position. The new concept is applied to an idealized bathymetry condition.
