Estimation of Direct Damage Caused by the Nankai Trough Earthquake Considering Hazard and Social Characteristics

The Nankai Trough Earthquake, which is estimated to have a 70%–80% probability of occurring within the next 30 years, necessitates considering various scenarios due to the extensive seismic source region and call for advancing disaster preparedness measures. Assessing direct damage caused by earthquakes is considered particularly challenging compared to assessing human and physical damage due to its intricate composition. However, the existing research in model analysis aimed at real-time estimation has yielded results, namely, the ability to promptly calculate direct damage from earthquakes using seismic motion and stock quantities as inputs. This study aimed to leverage the research outcomes of real-time estimation to approximate the direct damage costs that would be caused by the Nankai Trough Earthquake. Three hazard assessment cases were selected, based on damage estimations to be attempted. The results indicated that a damage estimation approach based on a common foundation dataset and model analysis considering different occurrence scenarios is more suitable for evaluating results and assessing the importance of mitigation measures than conventional scenario-based damage estimations.