Search

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. [ABSTRACT FROM AUTHOR]

To understand the workload of house cleanup and related workforce shortage after a disaster, the actual work situation in disaster-stricken areas is accounted for by disaster volunteer work management data created by the Disaster Volunteer Center of Joso City in Ibaraki Prefecture at the time of the Kanto–Tohoku Heavy Rain Disaster in September 2015. Using the classification of inundation depth, judged from ground elevation, the weekly workload of house cleanup according to the work content is recorded to clarify the characteristics of each area. Comparing this with the inundated areas without destructions by water flow, near the bank break with house destructions, in the urban area, and around the farmland along the old road, a model to estimate the workload is constructed. It was observed that indoor work to recommence living in urban areas continued for a long time, while the work was completed in a relatively short time in the area along the old road. The area near the bank break, with a small number of houses, witnessed very few house destructions. Hence, it is not necessary to separately calculate the workload caused by house destructions. The appropriateness of the estimated results was verified by using a method to estimate the workload based on the amount of disaster waste. As a result, the total workload estimated by disaster volunteers and victims for the busy period of two months was a million people. In the case of the Joso City flood, very few houses were completely destroyed, therefore, regular living could be resumed swiftly and people settled there after the disaster due to its proximity to the metropolitan area. Hence, the population decreased by the flood was recovered in two years. [ABSTRACT FROM AUTHOR]

In recent years, a wide-area disaster causing enormous damage has occurred almost every year in Japan. The authors have been involved in the management of disaster volunteer centers in various places and have realized the difficulty in coordinating the actual number of activities in disaster-stricken areas and the required number of disaster volunteers. The number of disaster volunteers required varies greatly on a daily basis. The number of volunteer activities often depends on the quantity of disaster waste created from damaged houses. Accordingly, if the quantity of waste was grasped immediately on the spot, the number of disaster volunteers required in the short term could be estimated. In this study, the actual conditions in Hitoyoshi City, Kumamoto Prefecture, at the time of the Heavy Rainfall in July 2020 are considered as an example, and the method is considered to immediately grasp the quantity of waste to be disposed of and the number of people required for this task. We compared the amount of waste disposal work estimated from the in-vehicle camera image with the number of active residents and volunteers. As a result, it was estimated that 40–50% of the work was carried out by volunteers at the peak of volunteer activities. [ABSTRACT FROM AUTHOR]