At 9:26 pm on April 14, 2016, a magnitude 6.5 earthquake struck directly beneath Kumamoto prefecture, Japan, producing a seismic intensity level (JMA) of 7 in Mashiki Town. Although the earthquake damage forecasting system in operation at the time predicted that this earthquake would cause no damage, it resulted in extensive human casualties and property damage centered in Mashiki Town. Past midnight on April 16, 28 hours after the first shock, the second and main shock hit, which recorded magnitude 7.3 and was the strongest recorded urban earthquake in Japan since 1995. The hypocenter extended from Kumamoto prefecture to Oita prefecture, cutting across the island of Kyushu. Mount Aso also saw increased volcanic activities which led to several landslides. This resulted in the collapse of the Great Aso Bridge, an important transportation point, causing the loss of human lives as well as obstruction of traffic for an extended period. Much confusion arose in the process of implementing measures in response to the earthquakes, which produced damage in urban areas as well as hilly and mountainous regions, raising many issues and prompting several new approaches.
Researchers in many fields have conducted various activities at the disaster sites in the one-year period following the earthquakes, and produced significant findings in many areas. In order to make these results available to the wider global community, JDR is releasing a special issue on the 2016 Kumamoto Earthquakes with excellent papers and reports to mark their one-year anniversary. While the submitted papers to this special issue went through our regular peer review process, no publication charge was imposed so as to encourage as many submissions as possible.
It is our hope that this special issue will contribute to throwing light on the 2016 Kumamoto Earthquakes in its entirety.
Synthetic Aperture Radar (SAR) remote sensing is a useful tool for mapping earthquake-induced building damage. A series of operational methodologies based on SAR data using either multi-temporal or only post-event SAR images have been developed and used to serve disaster activities. This presents a critical problem: which method is more likely to obtain reliable results and should be adopted for disaster response when both pre- and post-event SAR data are available? To explore this question, this study takes the 2016 Kumamoto earthquake as a case study. ALOS-2/PALSAR-2 SAR images were employed with a machine learning framework to quantitatively compare the performance of building damage mapping using only post-event SAR images and mapping using multi-temporal SAR images. The results show that an overall accuracy of 64.5% was achieved when only post-event SAR images were used, which is 2.3% higher than the overall accuracy when multi-temporal SAR images were used. The estimated building damage ratio for the former and the latter are 29.7% and 31.1%, respectively, which are both close to the building damage ratio obtained from an optical image.
It takes a significantly long time to estimate a direct damage amount based on a damage investigation. However, in the response immediately after a disaster, the investigation and estimation of damage are often conducted later because of a lack of human resources. Especially in the case of a huge earthquake that affects a wide area, the disaster cannot be fully responded to by the municipalities and prefectures alone. Support from the entire country, and in some cases from other countries, is essential to the disaster response. Precise information regarding the direct damage amount must be transmitted promptly. Accordingly, in this study a simple method to promptly estimate the direct damage amount caused by an earthquake disaster is proposed and applied to the case of the 2016 Kumamoto Earthquake.
In April 2016, the Kumamoto earthquakes in Japan killed 50 people and injured more than 3,000. Because Japan is a primary tourist destination for Thai citizens, due in part to the current visa relaxation policy, many Thai people were visiting Japan when these earthquakes occurred. However, while a variety of public information related to the imminent danger and disaster response was broadcast and published, foreigners sometimes had little access to or understanding of local notices or instructions because of language barriers.
This study researches the evacuation process for Thai citizens – including tourists, students, and residents from Thailand – in the disaster-affected areas during the 2016 Kumamoto earthquakes. Through prompt collaboration among the relevant organizations, particularly the Royal Thai Embassy in Tokyo, the evacuation of Thai citizens was successfully completed within a few days. Moreover, some other foreigners were also assisted by the Thai embassy. This paper presents an overview of the evacuation process, including the critical role of information and communication technology (ICT) in disseminating information, transmitting rescue requests, and providing emergency communications. The lessons learned from these efforts can be applied in future natural disasters, especially for foreign organizations working in similar capacities overseas. In addition, this study suggests disaster preparedness and response guidelines for tourists when traveling overseas.
Due to language issues, foreign people in Japan encounter more troubles in disasters than do Japanese natives. However, apart from language problems, there are other problems that stem from cultural differences. We also found that foreign residents showed different emergency evacuation and shelter-seeking behaviors from those of the local Japanese residents in the past earthquake. It is necessary to comprehend the emergency evacuation and shelter-seeking behaviors of foreign nationals and indicate their evacuation sites in order to explore useful ways to improve prevention and support work for foreign residents in times of disaster. On 14 April 2016 at 9:26 pm, a 6.5-magnitude earthquake struck in the Kumamoto, Japan area, followed by a second 7.3-magnitude earthquake on 16 April 2016 at 1:25 am. The two earthquakes impacted Kumamoto Prefecture, the area hardest hit by these earthquakes. In this study, we interviewed the foreign residents who experienced the Kumamoto Earthquake in order to examine their emergency evacuation and shelter-seeking behaviors and evacuation sites. We found the emergency evacuation and shelter-seeking behaviors of foreigners to differ depending on why they were in Japan. We found that foreigners living in Kumamoto Prefecture, including permanent residents, spouses of Japanese, and others, are likely to evacuate to locations within Kumamoto Prefecture, and their emergency evacuation and shelter-seeking behaviors are very similar to those of local Japanese natives. Many of the foreigners who come to Japan for work or study tend to evacuate out to locations outside of Kumamoto Prefecture or to even return to their home countries. However, immediately after the earthquake, they evacuate to parks near their residences, to parking lots, to universities, or to other facilities that are used on a daily basis. We also showed the possibility of foreigners taking various emergency evacuation and sheltering actions, and we presented the unique problems of foreigners, including loneliness in evacuation centers and language issues. In addition, we examined evacuation sites (universities, churches, international exchange halls, etc.) where foreigners gathered apart from the designated evacuation shelters in local areas. We also studied the users of these facilities/organizations as well as the actual conditions of support activities. We presented the characteristics of facilities and places that can serve as bases for supporting foreigners. Although these results can not represent all foreigners, we hope the results of this research will become the basic data from which to extract candidates for support sites. Understanding such places and facilities before disaster strikes is considered useful in making support plans for foreigners.
Serious damages to enterprises as well as residences and infrastructure resulted from the 2016 Kumamoto Earthquake. Important factories of the automobile, information technology, chemical, and other industries were located in the affected area. The nature of the damage was that there was significant damages to the building of enterprises located near the fault that caused the strong Earthquake. The geographical scope of damage to the enterprises was not very wide.
The authors performed continuous research on the public announcements posted on the websites of the affected enterprises for several months, following up with news reports on damaged enterprises and on-site interviews. We found that a considerable number of enterprises supplied their products to their important customers from substitute sites to achieve their business continuity. On the other hand, many enterprises attained early on-the-spot recovery, which might be explained partly by the fact that recovery of essential utilities, particularly electricity and telecommunications, was relatively quick.
The authors found many examples of effective utilization of the lessons learned from the Great East Japan Earthquake (GEJE). For example, some enterprises adopted the substitution strategy of business continuity management (BCM) that fulfills the responsibility to maintain supplies to the customers. Other enterprises that had experienced the GEJE avoided serious direct damage by having installed adequate earthquake countermeasures to their buildings and facilities.
The 2016 Kumamoto Earthquake occurred in April 2016, causing extensive damage over a wide area. In this research, ICT (Information Communication Technology), geospatial information, and satellite information have been utilized to demonstrate a new mechanism for collecting, analyzing, and sharing damage information using WebGIS as a practical system during the emergency and recovery period of the 2016 Kumamoto Earthquake. In the collection process, damage information over a wide area has been collected in a short period of time using two collection methods: participatory information collection and multiple organization collection. Then, by analyzing the collected damage information, the damage distribution can be obtained. Furthermore, by sharing the damage information using WebGIS, it is possible to share the data quickly and utilize it easily. It is expected that collecting and analyzing damage information from multiple organizations and broadly sharing such information is significant during the emergency and recovery period of a large-scale disaster.