Abstract
On coral reef, complex flow fields are frequently developed by wind-driven flow and nearshore currents induced by breaking waves at the reef edge. Characteristics of sediment movement and beach transformation are different from silicate beaches owing to the differences in hydrodynamics and sediment properties. We conducted a field survey in an eroding artificial beach in Miyakojima Island to understand the mechanism of sediment transport and topography change in coral reef. It was concluded that strong currents observed in summer at the gap of the breakwater enhanced offshore-ward transport of sediments through the gap. The presence of continuous sand belt around the headland suggested the offshore sand loss due to northern wind in winter.
