The mapping of storm surge-prone areas and characterizing surge-producing cyclones in Leyte Gulf, Philippines

• Main Authors: Rodrigo, Socorro Margarita T, Villanoy, Cesar L, Briones, Jeric C, Bilgera, Princess Hope T, Cabrera, Olivia C, Narisma, Gemma T
• Format: text
• Published: Archīum Ateneo 2018
• Subjects: Storm surge; Leyte Gulf; J48 Decision tree; Return period; Monte Carlo simulation; Earth Sciences; Environmental Sciences; Other Physics; Physics
• Online Access: https://archium.ateneo.edu/physics-faculty-pubs/19; https://link.springer.com/article/10.1007/s11069-018-3252-9
• Institution: Ateneo De Manila University

Historically, Leyte Gulf in central eastern Philippines has received catastrophic damage due to storm surges, the most recent of which was during Typhoon Haiyan in 2013. A city-level risk assessment was performed on Leyte Gulf through synthetic storm generation, high-resolution ocean modeling, and decision tree analyses. Cyclones were generated through a combination of a Poisson point process and Monte Carlo simulations. Wind and pressure fields generated from the cyclones were used in a storm surge model of Leyte Gulf developed on Delft3D. The output of these simulations was a synthetic record of extreme sea level events, which were used to estimate maximum surge heights for different return periods and to characterize surge-producing storm characteristics using decision tree analyses. The results showed that the area most prone to surges is the Tacloban–Basey area with a 2.8 ± 0.3 m surge occurring at a frequency of every 50 years. Nearby Palo area will likely receive a surge of 1.9 ± 0.4 m every 50 years while Giporlos–Salcedo area a surge of 1.0 ± 0.1 m. The decision tree analysis performed for each of these areas showed that for surges of 3–4 m, high-velocity winds (> 30 m/s) are consistently the main determining factor. For the areas, Tacloban, Basey, and Giporlos–Salcedo, wind speed was also the main determining factor for surge > 4 m.