A STUDY OF THE EDGE WAVE EFFECTS INDUCED BY THE TSUNAMI OF 26 DECEMBER 2004 AT PHI-PHI ISLAND IN THAILAND

The present study compares experimental laboratory results of the edge wave effect along Phi-Phi Island in Thailand with field-trip observations taken after the 26 December 2004 tsunami. A physical model of the island was constructed, with vertical scale of 1:500 and horizontal scale of 1:2500 in a 6!6 m steel tank. Waves were generated by the sudden opening of a gate releasing water from an elongated rectangular reservoir (6m!0.5m!0.6m). The initial tank water level was adjusted to simulate tsunami waves of various heights. The experimental observations focused on input wave heights, speed of propagation and the effect of edge waves on tsunami run up heights. The results explain how edge wave propagation was strongly affected by the size and shape of Phi-Phi Island and how it contributed to greater destruction. Additionally, the experimental observations provide valuable benchmark results that can help calibrate and validate numerical tsunami models.