2015 年 71 巻 2 号 p. I_1669-I_1674
School buildings are important facilities due to their capacity as evacuation shelters. In 2013, Typhoon Haiyan and its storm surge damaged most schools in the affected area because they were one story structures built using weak material. Therefore, school buildings used as evacuation shelters did not function effectively. Thus, more studies on vulnerability of school buildings to coastal disasters in terms of damage and use as evacuation shelters are needed. A field survey was conducted from 26 May to 2 June 2014 to observe damage to school buildings in Tacloban, Palo and Tanauan. One-third of the schools were damaged by a combination of both typhoon winds and storm surge, and the rest by typhoon winds only. Detailed damage data on 166 school buildings in 39 school districts was directly obtained from Tananuan. The data for each building contain economic damage, building area and percentage damage to building structure, namely roofing, roof frame, ceiling, wall, window and door. Economic damage ratio is calculated as the ratio of loss to building area. The data was then overlaid on the storm surge inundation map created by field surveys and the distance of each building from the sea measured. Numerical simulations were applied to obtain the maximum storm surge flow depth and flow velocity, with wind speed derived from JMA data and a parametric hurricane model. The percentage of damage, distance from the sea and other disaster-related parameters were plotted in order to compare damage between the buildings inside and outside the storm surge inundation zone. Results show the damage ratio to walls is 0.3-1.0 in the storm surge inundation zone and decreases to about 0.5 or less for buildings outside the inundation zone. The average loss ratio is about 5,500 Philippine Peso (PhP) per m2 due to the strong wind speed of 50-60 m/s.
