Hazard and risk researchers are using their research results to target several vastly different stakeholders: the scientific community, governmental institutions, engineers and the larger technical community, companies, and finally the local residents. Each of these groups has a different focus on the results and is drawing different conclusions from them. In this special issue for the Journal of Disaster Research (JDR), we address the problems surrounding hazard and risk communication by asking important questions. How can we communicate hazard and/or risk to the public? How can we involve communities in risk assessment? How can we raise the acceptance of risk models in communities? How can communities be involved in mitigation measures? Finally, how can we explain the inherit uncertainties of hazard and risk assessments? To answer these questions, it is essential to integrate knowledge from the social sciences, natural sciences, and engineering.

As the first step in this effort, we selected seven papers in the present special issue: six are related to the 2016 Kumamoto earthquakes in Japan and one to a research in Taiwan. They include studies on hazard and risk estimates before the disaster, risk communication during the earthquake sequence by the Japan Metrological Agency, the psychological and behavioral characteristics of disaster victims, resident evacuation patterns, the recovery process, and risk communication in disaster. The paper of the research in Taiwan addresses the importance of resident involvement to earthquake science for disaster preparedness.

It has been about 20 years since the Headquarters for Earthquake Research Promotion (HERP) was established following the Great Hanshin-Awaji Earthquake Disaster. Now the time has come to examine its contributions to disaster resilience. On April 14 and 17, 2016, a series of large earthquakes, including M6.5 and M7.3 events, occurred in Kumamoto Prefecture in Kyushu, Japan. More than 200 fatalities and 8,600 totally collapsed houses were reported. The earthquakes occurred on known active faults, which were assessed by the Earthquake Research Committee (ERC) before the events. The regional disaster management plan by Kumamoto Prefecture had predicted the events reported by the ERC and estimated damages at about the same level as what was actually seen. However, even though the estimate was accurate, the countermeasures were insufficient: the local people still did not seriously expect a large earthquake to strike in their local area, and their efforts to enhance the disaster resilience of the Kumamoto area were insufficient. This suggests that the efforts by the HERP were not sufficient to make the local community resilient enough to withstand a large earthquake.

The Kumamoto Prefecture suffered an earthquake of M_JMA6.5 on April 14, 2016 at 21:26 (Japan Standard Time). A seismic intensity of 7, on the Japan Meteorological Agency (JMA) seismic intensity scale, was observed, which, by definition, is the maximum possible value. After 18 hours of the earthquake, the JMA issued a prospect for aftershock activity, where the probability of aftershocks with a seismic intensity of 6 Lower (6-) or greater, was 20% within three days following 16:00 JST on April 15, 2016. Ten hours post the issuance of the prospect, at 01:25 on April 16, a larger earthquake of M_JMA7.3, with a maximum JMA seismic intensity of 7, occurred in the same region as the M_JMA6.5 event, triggering many distant earthquakes. As this seismic occurrence did not follow a mainshock-aftershock sequence, the JMA discontinued the issuance of prospective aftershock activity. With lessons learned from this occurrence sequence, the Earthquake Research Committee of Japan (ERC), including JMA, seismologists and social scientists, have formulated new guidelines for the assessment of successive seismic activity, in order to enhance the understanding of strong ground motions after large earthquakes. The five main points of the guidelines are as follows: (1) alert to a similar strong ground motion, (2) highlighting previous examples of successive large events, (3) consideration of all active source faults, (4) quantitative forecasting of aftershocks a week after the event, and (5) not using the term “aftershock” in information issued by the JMA for disaster prevention. The JMA has commenced the implementation of these new guidelines, effective August 2016.

In order to reveal the current status and issues of the victims of the 2016 Kumamoto Earthquake eight months after its occurrence, we conducted large-scale random sample questionnaire surveys with victims aged 18 and over in the most affected municipalities from November to December 2016. We decided to sample a total of 7,000 victims (1,600 from Kumamoto City and 5,400 from the other thirteen municipalities) with an expected collection rate of 25% and a sampling error of 5%; 3,272 victims effectively responded to the questionnaires (effective collection rate: 46.7%). The Kumamoto Earthquake was a series of earthquakes including foreshocks and main shocks of magnitude 7 on the Japanese seismic intensity scale, and aftershocks that appear to have significantly influenced the victims’ response behaviors as well as the recovery and reconstruction of the affected areas.

The questionnaire survey on whether the victims’ pre-earthquake knowledge and awareness had any influence on their post-earthquake behaviors reveals that not more than 30% were aware of the active faults present in their areas before the earthquake occurred and that half of them hoped that no earthquakes would occur. On the other hand, the victims who were aware of the active faults present in their areas and who were afraid that an earthquake could occur within 10 years had planned accordingly and had stocked the necessary goods and provisions.

The questionnaire survey on how the victims behaved in the event of the foreshocks and main shocks reveals that about half of them evacuated and found shelter after the foreshocks. Those who feared any aftershocks, and the damage to their buildings due to the aftershocks, evacuated and took shelter. Those whose buildings were not damaged and whose lifelines were available did not evacuate or take shelter. After the main shock, about 70% of the victims evacuated and took shelter because, in addition to their fears of the aftershocks, their buildings were actually damaged and their lifelines had been rendered unavailable.

The questionnaire survey on whether the victims’ pre-earthquake knowledge and awareness had any influence on their post-earthquake behaviors reveals that in the event of an earthquake, like in the case of the foreshocks of the Kumamoto Earthquake in which human beings and buildings were not so scathed and people could not decide whether to evacuate or take shelter, those with more pre-earthquake knowledge and with awareness of earthquake damage better anticipated the aftershock occurrences. On the other hand, in the event of the main shocks of the Kumamoto Earthquake, in which there was great damage to humans and buildings, people with or without pre-earthquake knowledge and awareness on earthquake damage were urged to evacuate and take shelter.

The 2016 Kumamoto earthquake consisted of a magnitude 6.2 foreshock that occurred on the 14th of April, and a magnitude 7.3 main shock that occurred on the 16th of April. The main shock occurring over the magnitude 6.2 foreshock was not anticipated because the foreshock was originally considered to be the main shock. After the earthquakes occurred, the Japan Meteorological Agency (JMA) discontinued its policy of announcing the probability of aftershock occurrences. The experience of the Kumamoto earthquake and the policy change concerning risk communication may affect the public risk perception of earthquakes, as well as the public trust toward authorities. In this study, we examined the reasons residents made the decision to evacuation both the foreshock and the main shock. Moreover, we investigated how residents perceived subsequent earthquake risk and they evaluate similarity and trust toward the authorities (the JMA, government, mass media, prefecture, and municipality). This study analyzed data from a mail survey implemented by the MEXT of Japan in the areas of the Kumamoto prefecture that were damaged by the earthquake. As a result, there were differences in the reasons for evacuation decisions between the foreshock and the main shock. Although residents decided to evacuate based on a fear of disaster in the foreshock, they decided to evacuate the main shock based on neighborhood communication. Moreover, the residents’ evacuation patterns influenced the earthquake risk perception. As well, the evacuation pattern influenced similarity toward the authorities and then reduced trusts toward the authorities. This study indicates that residents amplified the evaluations of the authorities after the earthquake. The influences of similarities toward the authorities became salient as a determinant of trust. This study reveals features of residents’ risk reactions to the earthquake, and discusses the importance of the similarity of the authorities for disaster risk communication.

This paper discusses the reduction effect of a foreshock on casualties during the mainshock of people who evacuated to shelters and their private cars during the 2016 Kumamoto earthquake. In the first part of this paper, we discuss the number of human casualties caused by the collapse of wooden buildings. The characteristics of casualties in the Kumamoto earthquake are classified as household attributes and building damage caused by the foreshock and mainshock. In the second part, we apply equations (Nakashima and Okada 2008 and Okada and Nakashima 2015) to the Masiki area to determine the total number of casualties with a focus on deaths. The number of deaths due to total building damage from the foreshock and the mainshock in the case of 0 evacuees was estimated as 147. We then estimated the reduction effect on the number of casualties caused by the foreshock by using the survey data of the mainshock and foreshock. We found that evacuation during the mainshock decreased the death toll by 128 people. Moreover, the number of injured people decreased by 657. Generally, most people who evacuate tend to return home over time. As a result, many people die at the time of a subsequent mainshock. It is important to provide death risk information to each household to support their decision-making regarding appropriate evacuation.

Japan has experienced many disasters. However, the question of when and how much work is generated in support of rebuilding disaster victims’ lives remains unsolved. Considering this situation, this study solves the question through a time-series analysis of daily workload in support of rebuilding the lives of victims of the 2016 Kumamoto Earthquake. In addition, a correlation analysis is conducted through comparison with the case of the 2007 Chuetsu-oki Earthquake that a prior study focused on, and another correlation analysis is conducted between municipalities affected by the Kumamoto Earthquake. These analyses do not indicate the presence of a high correlation in tasks for which the requirements for payment vary depending on the disaster but do indicate the presence of a high correlation between disasters in tasks for which the requirements for payment are uniform, thereby indicating the presence of a possible generalization. In addition, the correlation analysis results of comparisons between municipalities affected by the Kumamoto Earthquake indicate a high correlation between local public entities that have suffered great human and property damage. These results indicate that when a certain condition is met, it is highly likely that daily workload can be estimated.

Taiwan is located at the convergent plate boundary between the Eurasian and the Philippine Sea plates. As a result, intense earthquake activity and associated surface deformation are manifesting in this region. To implement and promote citizen earthquake science in Taiwan, we have developed several web-based platforms with multi-purpose themes, such as earthquake science information, popular science education, and crowdsourcing systems. First, with the rapid earthquake report issued from the Taiwan Central Weather Bureau (CWB), the available near real-time scientific results obtained from the Taiwanese seismology community are collected and published to a platform, the Taiwan Earthquake Science Information System (TESIS). The scientific information archived at TESIS includes CWB earthquake reports, focal mechanisms, shake maps, and finite source models (for strong earthquakes). All real-time results are integrated into a GIS system with background geospatial information, such as geological maps, traces of active faults, background seismicity, and inter-seismic GPS velocity fields. Second, by collaborating with Stanford University to maintain a regional Quake-Catcher Network (QCN) server in Taiwan, we have promoted citizen seismology in Asia by bringing earthquake information and scientific knowledge to the public. More than 200 school teachers have already installed the QCN sensors in Internet-enabled computers. Through two web-based educational platforms, users are able to access the guidelines and further interact with the recorded waveforms. Third, we also developed an earthquake damage reporting system – the Taiwan Scientific Earthquake Reporting (TSER) system – to encourage the citizen to collect field observation for significant earthquake-induced ground damages such as surface fault rupture, landslide, rock fall, liquefaction, and landslide-triggered dam or lake. The TSER system is constructed under the Ushahidi mapping platform, which has been widely used in crowdsourcing for the geospatial archiving of events. Trained high school teachers and public volunteers can send their ground damage observations, including photographs, through the TSER system. Most of these products and online systems are now being operated by the Taiwan Earthquake Research Center (TEC). With these newly developed platforms and materials, we aim to not only raise earthquake awareness and preparedness, but also encourage public participation in earthquake science in Taiwan.

How to identify the fault causes quickly and improve the efficiency of maintenance, which can reduce the fault disaster, has always been one of the key problems in equipments fault diagnosis. In this paper, a new qualitative fault diagnostic approach based on control change cause analysis (3CA) is proposed to identify the fault causes and fault risk index, which can be utilized to control the risk of equipment fault. We employed an existing method that was events and conditional factors analysis (ECFA+) to identify the analysis objects of 3CA, and put forward integrated methods including first principle-best practices approach, barrier failure analysis and prioritization rating code (PRC) matrix to accomplish control analysis, change analysis and significance rating of 3CA respectively, and those technical methods could be used to build the procedure diagram of identifying the content in each column of 3CA worksheet. According to the procedure of 3CA, we built a worksheet of 3CA for a vehicle engine fault, then fault causes and significance rating on behalf of the rating of fault risk index were determined. Meanwhile fault risk index had also been used to rank the fault causes, accomplishing fault diagnosis and verifying the availability or this method for fault diagnosis. The proposed approach can be able to identify fault causes of different fault modes that they have different risk index, and provide the fault causes rating that is the foundations of troubleshooting, which can mitigate and control fault disaster.

South Africa is a country that is prone to droughts, earthquakes and other disasters. In this environment, non-governmental stakeholders often provide a substantial part of the relief in affected areas. Non-governmental stakeholders have the experience needed to address the various disaster management challenges currently facing South Africa. This is especially true in the context of local disasters. Therefore an attempt is made in this report to investigate the relevant legal framework, which allows for the formalization of the involvement of non-governmental stakeholders in official disaster management activities in South Africa. Parts of the basic disaster management legislation, i.e. the Disaster Management Act no. 57/2002, contain definitions and requirements for the establishment of the relevant multi-stakeholder crisis management platforms, i.e. the “disaster management advisory forums.” This legislation is analysed in relation to the Hyogo Framework for Action and the Sendai Framework for Disaster Risk Reduction. Disaster management systems from two cities in the Western Cape Province of South Africa, i.e. Knysna and Cape Town, were identified as models for the potential practical execution of these multi-stakeholder platforms at the local government level. Importance of additional aspects of the legal framework, e.g. the role of traditional leaders, are also outlined.

To offer aid to the victims of the 2016 Kumamoto earthquake, the Japan Platform, an intermediary support group, used the network it had built to carry out support activities coordinating between support groups and mediating support from companies to the affected areas. In addition, through subsidies to NGOs that carry out support activities on the scene, they facilitated support activities and support projects that focused on helping disaster victims in the reconstruction phase. However, there were several challenges in providing different types of support on the scene. Therefore, it is necessary to examine how best the efforts can be improved to cope with the problems that could not be addressed in the 2016 Kumamoto earthquake. Disaster victims have now begun to move into temporary housing. In a future reconstruction period, community-led reconstruction by local residents is crucial. To achieve this, Japan Platform continues to develop local NPOs and other support groups and human resources and support intermediary support groups that lead local reconstruction.

The duration of strong motion exceeding the bridge design spectra in the bridge design specification in Japan is evaluated for the 2016 Kumamoto Earthquake. The structural response duration is defined as the total threshold interval of the velocity response envelope calculated for a viscously damped (5%) single-degree-of-freedom oscillator with various natural period. The prescribed design spectra are employed as frequency-dependent thresholds. The ground acceleration records observed at the K-NET and KiK-net stations during the Kumamoto earthquake are used for the analysis. Spectrum representations of the duration and number of cycles are obtained for four representative ground motion observation stations. The distribution maps of the duration are also presented for the strong motion observation stations in the Kumamoto prefecture.