Vulnerability Assessment and Damage Estimation: An Input for the Mitigation and Preparedness Plan for “The Big One” Earthquake in Barangay Cangatba, Porac, Pampanga

Abstract

The Barangay Cangatba, Porac, Pampanga is situated in an area prone to earthquakes, and several earthquake sources nearby might produce an earthquake of any magnitude at any moment. This study aimed to assess the vulnerability and estimate the possible damages by the Big One earthquake as an input for the mitigation and preparedness plan in Brgy. Cangatba. This study also aimed to generate several scenarios of the Big One; to determine the damage ratio of the buildings; and to estimate the human loss, human injury, and economic loss in Brgy. Cangatba; as well as to create a GIS evacuation map. The damage ratio in different types of buildings was calculated using fragility curves of buildings of the Philippines. Computed population data of each building in different occupancy times, damage ratios, mortality ratios, injury ratios, and building prices were used to compute the number of human losses, human injury, and economic loss due to the Big One. The results reveal that the worst event of an earthquake is from 7.2-7.7 Mw along the West Valley Fault. The buildings in Brgy. Cangatba are subject to intensity VII, which is destructive based on MMI (Modified Mercalli Intensity), which can cause 11.42-47.31% damage to buildings equivalent to an anticipated 58 fatalities and 29 injuries in a 2 PM event, 92 fatalities, and 34 injuries in a 5 PM event, and nine fatalities and five injuries at 2 AM. The community might suffer a projected ₱ 362,195,715.31. The feedback from the residents shows that an evacuation map would help the community once the worst earthquake event occurs.