Earthquake loss estimation of residential buildings in Bantul regency, Indonesia
Bantul regency in 2006 had experienced considerable earthquakes and suffered many casualties. The factors such as high population density and lack of seismic design of residential buildings in Bantul besides its location in a high seismic region have increased its vulnerability to earthquake disasters that can lead to widespread economic losses and casualties. This research aims to capture earthquake risk in Bantul towards economic losses and casualties by using risk curve. Risk curve is a combination of several sources from literature containing hazard curve and vulnerability curve together with exposure.
The result showed that the expected economic loss in 50 years for residential buildings is $647.22 million; however, the highest value of economic losses shows a value up to $7600 million, which occurs in an earthquake of 7.15 MW scale. The same worst-case scenario caused casualties of up to 49 000 people at nighttime and 15 000 people at daytime. The result established that the confined masonry building type conduces the highest value of economic losses and timber frame buildings show the highest vulnerability to the earthquake disaster than other building types. Furthermore, in order to reduce the risk, the authors applied a hypothetical policy to build a simple earthquake-resistant house called Simple Instant Healthy House. The result indicates that this mitigation policy can effectively reduce both economic losses and casualties.