STORM SURGE AND STORM WAVES IN THE CENTRAL PHILIPPINES DUE TO TYPHOON HAIYAN IN NOVEMBER 2013

Abstract

In November 2013, Typhoon Haiyan caused devastating coastal disasters in the central Philippines triggered by large storm surges which occurred during its passage. It is the strongest typhoon that have ever attacked Philippines in its history. In this study, numerical simulations are performed for the storm surge and storm waves, together with dynamic meteorological fields such as wind and pressure induced by Typhoon Haiyan, using an integrated atmosphere-waves-ocean modelling system. The wave-induced dissipation stress from breaking waves, whitecapping and depth-induced wave breaking, is parameterized and implemented in the wave-current interaction process, in addition to its influence on the storm surge level in shallow water along the coast of central Philippines. The simulated track of the typhoon captures the best track well. The effects of wave-induced dissipation stress in the wave-current interaction resulted in increased surge heights in the relatively shallow areas such as Leyte Gulf and Visayan Sea in the central region, where the bottom slope of the bathymetry ranges from mild to moderate. The results also show that wave-breaking has to be considered for accurate storm surge prediction along the east coast of Samar Island over the narrow surf zone with much finer meshes of the order of several meters.ry. In this study, numerical simulations are performed for the storm surge and storm waves, together with dynamic meteorological fields such as wind and pressure induced by Typhoon Haiyan, using an integrated atmosphere-waves-ocean modelling system. The wave-induced dissipation stress from breaking waves, whitecapping and depth-induced wave breaking, is parameterized and implemented in the wave-current interaction process, in addition to its influence on the storm surge level in shallow water along the coast of central Philippines. The simulated track of the typhoon captures the best track well. The effects of wave-induced dissipation stress in the wave-current interaction resulted in increased surge heights in the relatively shallow areas such as Leyte Gulf and Visayan Sea in the central region, where the bottom slope of the bathymetry ranges from mild to moderate. The results also show that wave-breaking has to be considered for accurate storm surge prediction along the east coast of Samar Island over the narrow surf zone with much finer meshes of the order of several meters.