Author(s): Justin Joseph Valdez; Tomoya Shibayama

Linked Author(s):

Keywords: Typhoon; Storm surge; Climate change; Numerical modelling; San Pedro Bay

Abstract: A weather-surge coupled model was utilized to simulate past and potential future climate storm surge events in San Pedro Bay, Leyte. The historical scenario of Typhoon Haiyan (2013) was first hindcasted with the Global Forecast System (GFS) meteorological data using the Weather Research and Forecasting (WRF) model. The Tropical Cyclone Bogussing scheme was utilized to significantly improve the simulation results. For the future climate change scenario, the Coupled Model Intercomparison Experiment (CMIP5) dataset under Representative Concentration Pathway (RCP) cases was used to update the change in Sea Surface Temperature (SST). Future case Haiyan simulations produced stronger typhoons but deviated away from the San Pedro Bay. A different typhoon event was then used, and the RCP 4.5 at year 2052 was able to simulate a future case Bopha with a track passing through the study area. The wind speed and pressure data from WRF results of the simulated 2013 Haiyan and 2052 Bopha typhoons were used in the Finite Volume Community Ocean Model (FVCOM). An unstructured triangular mesh was generated at San Pedro Bay for the propagation of the storm surge. Observations from Haiyan field surveys were used for validation, and the simulation showed good agreement at different locations. Overall, the WRF-FVCOM coupled model was able to simulate the weather conditions and storm surges for the 2013 Haiyan and the future 2052 Bopha case studies in San Pedro Bay. The observed trends of future climate typhoons were increased intensity and more northward movement, making the northern part of the Philippines potentially more susceptible to stronger typhoons and storm surge events.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1751-cd

Year: 2025