Identification of Critical Vulnerable Areas During a Typhoon Haiyan Event in the Metro Manila Area Using Storm Surge Hazard Maps

Abstract:

Sudden rises in sea water over and above astronomical tides due to an approaching storm are known as storm surges. The development of an early warning system for storm surges is imperative, due to the high threat level of these events; Typhoon Haiyan in 08 November 2013 generated storm surges that caused casualties of over 6,000. Under the Department of Science and Technology, the Nationwide Operational Assessment of Hazards (DOST - Project NOAH) was tasked to generate storm surge hazard maps for all the coastal areas in the Philippines. The objective of this paper is to create guidelines on how to utilize the storm surge hazard map as a tool for planning and disaster mitigation. This study uses the case of the hypothetical situation in which a tropical storm with an intensity similar to Typhoon Haiyan hits Metro Manila. This site was chosen for various reasons, among them the economic, political, and cultural importance of Metro Manila as the location of the capital of the Philippines and the coastal bay length of the area. The concentration of residential areas and other establishments were also taken into account. Using the Japan Meteorology Association (JMA) Storm Surge Model, FLO-2D flood modelling software and the application of other GIS technology, the impact of Haiyan-strength typhoon passing through Manila was analysed. We were able to identify the population affected, number of affected critical facilities under each storm surge hazard level, and possible evacuation sites. The results of the study can be used as the basis of policies involving disaster response and mitigation by city authorities. The methods used by the study can be used as a replicable framework for the analysis of other sites in the Philippines.