Tralck analysis, simulation, and field survey of the 2013 Typhoon Haiyan storm surge

The authors have examined the characteristics of Typhoon Haiyan (Yolanda), which made landfall on the coast of the Philippines on November 2013, generating a substantial storm surge. In order to better understand the storm surge phenomenon, its nature and severity were analysed by means of a numerical simulation and a field survey. Unlike most other tropical cyclones that weaken before they hit land, Haiyan struck Leyte Island at near peak strength, with maximum sustained wind speeds of 160 knots, the strongest in the recorded history of the Western North Pacific. Haiyan approached very quickly with a forward speed of 41 km/ h towards Leyte, which was also the fastest among typhoons with similar intensities. As a result of these extreme gusts and the exceptionally low central pressure of the typhoon (895 hPa), Haiyan caused the largest storm surge in the recorded history of the Philippines. Numerical simulations show that the maximum storm surges occurred in Leyte Island and Samar Island. A stormsurge field survey conducted by the authors corroborated this, with maximum inundation height of 7 m recorded in Tacloban, located at the northern end of Leyte Gulf. The simulation results also corroborate the fact that water levels at some locations first lowered and then rapidly began to increase after an hour.