Study on Locally Varying Inundation Characteristics Induced by Super Typhoon Haiyan. Part 1: Dynamic Behavior of Storm Surge and Waves Around San Pedro Bay

Abstract

This paper investigates the characteristics of coastal damages caused by Super Typhoon Haiyan with special focuses on dynamic behavior of storm surge and waves around San Pedro Bay. Numerical experiments were carried out to investigate the sensitivity of storm surge characteristics to various conditions, such as typhoon tracks, forward speed, and bottom frictions. Computed characteristics of storm surge and waves were compared to the observed inundation characteristics. Primary findings of the study are: (i) bay seiche elevated the peak surge height at the inner part of the bay; (ii) forward speed of Haiyan was close to the worst condition that enhances the bay seiche; (iii) neither storm waves nor storm surge could explain the observed inundation characteristics around the bay mouth, where the witnessed time of initial inundation was about 1h before the one at the inner part of the bay and the water level rapidly descended just after the peak while it remained for an hour at the inner part of the bay; and (iv) strong anti-clockwise circulating current was developed around the peak surge time and this current might have significant impact on wave dissipation and blocking around the San Pedro Bay mouth.