Laboratory experiments were conducted to investigate the effect of edge wave on wave overtopping in a nearshore zone with abruptly changing bathymetry. Experiments demonstrated that the presence of standing edge wave would produce local increase in wave run-up. Detailed measurements of water surface elevations and velocities were conducted in a large wave basin in which nearshore bathymetry in front of Ashizaki district, one of districts damaged by the giant wave in 2008, was reproduced with a scale of 1/100. It was found in the experiments that standing edge wave with periods in a range 10s to 13s was developed in the narrow channel between the seawall and a group of detached breakwaters. The development of the standing edge wave was found to increase the wave overtopping rate by about 30%.
