We are pleased to publish this special issue, dedicated to the NIED Frontier Research on Science and Technology for Disaster Risk Reduction and Resilience 2024. The fifth NIED mid-/long-term plan period began in 2023, and this issue includes the first results of six papers, two reviews, one survey report, one note, and one material. Recently, violent natural disasters have triggered the development of effective countermeasures. Akita, Yamaguchi et al., and Hirashima et al. dealt with climate hazards such as heavy rainfall, snow, and ice disasters. Yamazaki-Honda reported the progress and challenges of disaster reduction and climate change adaptation using DRR strategies. Yadab et al., Akita, and Naito et al. reported data analysis and suggestions to evaluate seismic and volcanic hazards. Nagata et al. proposed the ICT tool “YOU@RISK” to educate regarding volcanic disaster risks. Sato et al. emphasized the importance and effectiveness of information technology. Kimura et al. emphasized preparedness and elaborated on measures to improve preparedness for all natural hazards. These new outcomes will promote the development of a sustainable society against these hazards and will be flagships to proceed with NIED research projects.

There is little information which examines and compares climate zones or geology/topography in their relation to soil thickness along mountain slopes, where soil thickness is a possible contributing factor for the increase of sediment wash-off. In this study, the data obtained from handy penetration tests conducted throughout Japan are collected and attached to information on climate zones and geography/topography with the aim of clarifying the difference in soil thickness according to the climate zone and geological classification. The probability distribution of soil thickness was found to fit roughly with the probability density function of a log-normal distribution, regardless of the climate zone or geological age / lithology. A comparison of μ showed that the soil thickness at target sites in the Pacific climate zone, which have high rainfall, was large, at approximately 2.1 m. Meanwhile, the soil thickness was low, at approximately 1.5 m, at target sites in the Setouchi climate zone, which has low rainfall. A comparison of the geology showed that soil thicknesses of sites where the geology consisted of Tertiary and Quaternary sedimentary rocks were high, at approximately 2.1 m and 2.3 m, respectively. This suggests that, in high-precipitation regions, the weathering of rocks is promoted so that the soil layers tend to increase in thickness.

We report the information support activities conducted by the Information Support Team (ISUT) in the heavy rain since July 1, 2021, after it was dispatched to Shizuoka Prefecture. During the activities, ISUT-SITE and other information were provided and utilized by the disaster response organizations. This study reports on the characteristics and future issues in this disaster response activity.

More than half of Japan’s land area experiences significant snowfall during winter, and the damage caused by various snow and ice disasters remains a dire issue, which also leads to decreased living standards. Simultaneously, the nature of snow and ice disasters has been transformed due to climate change and the increasing occurrence of extreme weather conditions. The National Research Institute for Earth Science and Disaster Resilience (NIED) has been continuously conducting research to address these problems in relation to snow and ice disasters. This study presents the results of the project “Research on Combining Risk Monitoring and Forecasting Technologies for Mitigation of Increasingly Diverse Snow Disaster” conducted by the NIED over a seven-year period from April 2016 to March 2023. This project developed technology for conducting accurate observations of snowfall and snow cover conditions over wide areas as well as technology for areal prediction of snow and ice disasters through simulations. Based on collaboration with stakeholders, such as local governments, our study investigated how to optimize the use of our information products for snow and ice disaster mitigation. Through these insights, the NIED provides information for prompt and appropriate responses to snow and ice disasters, thus supporting safe and comfortable living in both snowy and non-snowy areas.

The “YukioroSignal” system, which provides snow load alerts, was developed to inform decision-making regarding snow removal from house roofs. It was launched in Niigata Prefecture in 2018 and expanded to cover all special heavy snowfall areas in Japan, including the Hokkaido, Tohoku, and Hokuriku regions in 2024. The system uses the SNOWPACK model to estimate high-accuracy snow weight from real-time snow depth data published online at observation points. At locations where snow depth gauges are not installed, such as in mountainous areas, snow weight is estimated using inverse distance-weighted interpolation, but accuracy is reduced. To overcome this problem, this study attempted to integrate this information with the snow water equivalent distribution calculated using the simple-layer snow distribution model. To validate this improvement, manual observations of snow weight were performed at 98 sites and compared with simulation results. The accuracy of snow weight estimation at distances far away from snow depth stations was improved. The six-year operation of YukioroSignal showed the additional required information that is vulnerable to damage even with less snowfall, such as vacant houses, and caution of changes in hazard levels by an increase in snowburst in a short period.

In 2023, which marked the midpoint of the post-2015 global agendas, the findings of midterm review process of the Sendai Framework (MTR SF) were presented. Various data demonstrate that hydro-meteorological disasters, presumably exacerbated by climate change, are increasing in frequency and intensity and causing widespread adverse impacts and associated losses, which calls for coherence among disaster risk reduction (DRR), climate change adaptation, and sustainable development. This article provides findings and recommendations through an analysis of publicly available data and reports, including monitoring for the Sendai Framework and Sustainable Development Goals as well as the MTR SF. The main findings in the MTR SF are that countries focus primarily on short- to mid-term adjustments rather than on long-term structural transformation and that policies and measures to reduce exposure are less well described. Recommendations include (i) the development of a national disaster loss database to collect data on both large- and small-scale and slow-onset disasters; (ii) the implementation of “custom indicators” to supplement the Sendai Framework Monitoring (SFM) by utilizing available loss data collection and exceptional governance measures in the case of high-impact disasters; (iii) the employment of common metrics with the SFM at the national level for climate change statistics and indicators to promote integrated data collection and coherence; (iv) the introduction of new indicators to measure and verify implementation; and (v) formulation and elaboration of a long-term comprehensive national strategy that goes beyond national DRR strategies to integrate DRR-related sectoral policies in support of relevant stakeholders, underpinned by secured resources and adaptive governance with monitoring and evaluation to enable a transformation toward more resilient and sustainable future.

S-net is a seafloor observation network for earthquakes and tsunamis around the Japan Trench, comprising 150 observatories with seismometers and pressure gauges. The region has been known to experience massive earthquakes, and several magnitude 6 and 7 class earthquakes have occurred after the network was established in 2016. This study constructed ground motion prediction equations (GMPEs) for horizontal peak ground accelerations (PGAs) and peak ground velocities (PGVs) using the S-net data and revealed that the GMPEs can be used to predict the PGAs and PGVs at the land stations where measured S-wave velocities are available. We used a relatively short time window of the S-net records from the viewpoint of earthquake early warning but included S waves. Data from earthquakes of magnitudes between Mw 5.5 and Mw 7.4 were used. The construction of the GMPEs was achieved in two steps. First, regression analysis was conducted for each event data, and mean site residual was obtained over the available records at each S-net site. Second, the data were adjusted by the mean site residuals, and stratified regression analysis, which decouples the source and path factors, was performed. Finally, we applied the GMPEs to predict PGAs and PGVs at the KiK-net sites on land. We determined that the residuals at the KiK-net sites were systematically biased with Vs30 (average S-wave velocity in the upper 30 m). We obtained correction factors for the bias and demonstrated that the PGAs and PGVs at the KiK-net sites could be predicted reasonably well.

The objective of this study was to clarify the actual physical and chemical properties of volcanic ejecta immediately after the explosive eruption of Shinmoe-dake, Mt. Kirishima, in Japan. The day after the explosive eruption occurred on March 25, 2018, permeability tests using a cylindrical frame were conducted, and samples collected in the test site were subjected to laboratory soil tests. The real infiltration capacity of the volcanic ejecta showed that the final values were lower (38–92 mm/h) in the talus inside the forest than in the plain outside the forest. This was attributed to the small particle size distribution above 1 mm, regardless of the particle size of the silt/clay particle size segment. The rainfall after the explosive eruption was at most 20–22 mm/h, indicating that the real infiltration capacity value at the end of the eruption was higher than the rainfall value. This was consistent with the fact that no debris-flow was observed at the foot of Shinmoe-dake after the recent eruption. On the other hand, examination of the chemical properties of the volcanic ejecta collected revealed high values of Ca and SO₄. These compounds form gypsums by reaction with water, could reduce the infiltration capacity of deposit, possibly contributing generation of mudslide.

Aiming to support disaster recovery, we have developed a new method to extract damaged buildings by using machine learning that combines 10 explanatory variables obtained from analysis of aerial photographs and observation data. We used site amplification factors, seismic intensities of foreshock and mainshock, distance from faults, estimated building structures and ages, coverage by blue tarps, texture analysis, and digital surface model differences before and after the earthquake as explanatory variables, in addition to convolutional neural network prediction results based on post-earthquake aerial photographs. The random forest method resulted in an overall accuracy of about 81% and an average F-measure of three classes was about 70%, indicating that it can classify possible damage to buildings more accurately than our previous studies.

This study developed a volcanic disaster risk reduction education program that aims to help junior high school students visually understand the risks of volcanic eruptions using map information and acquire independent assessments and actions to protect their own lives from eruption disasters. First, this program analyzed the present state, problems, and educational needs of volcanic disaster risk reduction education in Japan, and thereafter designed the learning content to fuse information and communication technology (ICT) education based on the Global and Innovation Gateway for All (GIGA) School Initiative promoted by Japan with disaster risk reduction education from a geographical viewpoint. We adopted the ADDIE model from instructional design theory to develop the program. An important feature of this program is the realization of geography learning using the “YOU@RISK Volcanic Disaster Edition,” a web-based GIS application developed by the National Research Institute for Earth Science and Disaster Resilience (NIED), as an ICT tool. Learners use YOU@RISK on their tablets and perform operations such as visualizing the risk range in the event of a volcanic eruption and searching for appropriate evacuation sites and routes, while acquiring the knowledge and skills necessary for geographical literacy and emergency response actions. The program is able to realize interactive learning, which is a step ahead of education that relies on conventional paper-based hazard maps. Among active volcanoes nationwide, Mt. Nasu was selected as target volcano for this study. In addition, a junior high school located in the area surrounding Mt. Nasu, Nasu Junior High School in Nasu Town, Tochigi Prefecture, was selected as the target school. The program was implemented by teachers using tablets provided for each student at the school. We evaluated the effectiveness of the program by measuring and analyzing the effects of learning through the practice. Consequently, the effectiveness of the volcanic disaster risk reduction education program using ICT was confirmed.

In this study, we analyzed data collected from an internet survey targeting Japanese citizens on the Scale of Attitude toward Culture of Living with Disaster Risk (SAC-LDR), which was proposed in our previous study. The scale quantifies respondents’ attitude toword living with nature and its risks, to examine how the SAC-LDR scores are affected by the respondents’ attributes, such as age or lifestyle, and frequency distributions and correlations between variables. We found that: (1) the SAC-LDR scores had a mean value of 41.1 out of 60 and displayed not a completely normal distribution, but a distribution with slightly long left tail; (2) the SAC-LDR scores had a high correlation with the Power to Live with Disasters, which represents individual traits favorable to surviving through disasters; and (3) the SAC-LDR scores displayed regional differences within Japan.

This study elaborates on the measures to improve preparedness for natural disasters by elucidating the present situation of preparedness for natural disasters at home in Japan as well as the effective factors to promote such preparedness. An Internet monitoring survey was conducted throughout Japan, and valid responses (n=1,599) were obtained. To measure preparedness for natural disasters at home, we used 31 items, including the ones in the “public opinion poll on disaster management” conducted by the Cabinet Office, Government of Japan. The Internet monitoring survey revealed that approximately 30% of the respondents arranged for articles they may require in the event of a disaster and had contemplated their evacuation actions immediately after a disaster. The Internet monitoring survey results were compared with the results of the Cabinet Office, Government of Japan’s public opinion poll. It revealed that the internet monitoring survey results better represent the tendency of the Japanese people as a whole. A multiple regression analysis was conducted to determine six independent variables—age, marital status, prior disaster experience, awareness of hazard maps, disaster imminence, and communal exchanges—statistically significant as effective factors to improve preparedness for natural disasters at home. Particularly, considering a large standardizing coefficient (β) for awareness of hazard maps, it is proposed that the most effective measure to improve preparedness for natural disasters at home to comprehend the risks posed to one’s community and own house is by using the opportunities of disaster prevention education and drill rather than simply viewing the hazard maps aimlessly.

An accident occurred at Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station (FDNPS) in March 2011, following an earthquake and tsunami. Local government staff members who worked in the area had a variety of experiences due to the accident, including trauma. This cross-sectional study was conducted to clarify the relationship between years of service and radiation-related traumatic experiences among 490 staff members in municipalities around the FDNPS exactly a decade after the accident. They were classified as <5 years, 5–10 years, and >10 years, relative to their lengths of employment. The experienced staff (>10 years of service) had a rich array of traumatic experiences, compared to those with less experience (<5 years of service). By contrast, the experienced staff had a lower SOC-13 score than those with less experience, and a higher percentage of them reported that their workload was greater than that imposed on other local government employees. The study results suggested that the experienced staff members who worked in the affected towns prior to the FDNPS accident have been burdened with a prolonged heavier workload, including radiation-related duties.

The present study discusses flood hazard characteristics in the lower reaches of the West Rapti River based on the results obtained from field surveys and numerical computations using depth averaged 2-D numerical models for flood flow and associated sediment transportation. To evaluate the inundation process with sediment erosion and deposition in the floodplain, a new erosion term was introduced into the mass conservation equations for suspended sediment and bed sediment. The results obtained from numerical computations indicated that field data on the spatial distributions of depths for inundation, and sediment erosion and deposition can be evaluated by the numerical model. Thus, numerical predictions were performed for the inundated areas, and the accumulated volumes of sediment erosion/deposition for floods with return periods of 50, 100, and 200 years, as a step towards damage assessment and risk assessment due to floods with active sediment transportation in the floodplains.

This study presents a proposal for procedures and recommendations for the evacuation of people from cable cars. The proposals and procedures were carried out in a specific facility located in the east of Slovakia. Cable cars represent a certain risk of endangering the lives and health of people. This threat can be caused by technical failures, meteorological conditions, or human factors. Despite the existing safety measures, which are at a high level today, extraordinary events occur on cable cars that require the intervention of the integrated rescue system. The rescue services themselves have their own specific rescue procedures and equipment for rescuing people from heights, and in this paper the most frequently used rescue procedures and methods performed by members of the Fire and Rescue Service will be presented. This paper summarizes individual rescue actions, activities, and technical equipment used in rescuing people from cable cars, as well as an analysis of individual rescue and evacuation techniques from the Skipark Erika cable car. The result of the contribution is a proposal for coordination and an evaluation of the best and most suitable method of rescue in terms of time and safety.

Combined with the structure from motion (SfM) technique, unmanned aerial vehicles (UAVs) are powerful tools for generating high-resolution digital elevation models (DEMs) for application in hazard assessments. During our field observations in October 2015 at Langtang Village, which was destroyed by the Gorkha earthquake in April 2015, three different UAVs with mounted cameras were operated to evaluate the volume of the avalanche deposit covering the village. This study evaluated the performance of DEMs created from the different cameras on board those UAVs. Multiple DEMs for the different cameras, including Sony-α7R (PA7), Ricoh-GR (XGR), and Canon-IXUS (EIX), were created using SfM software. All DEMs were compared with a base DEM created from differential global positioning system survey data, which was obtained simultaneously with the UAV campaigns. The results show that the elevation difference of PA7-, XGR-, and EIX-DEMs are within ±0.14 m; the standard deviations of elevation difference range from 0.33 to 0.40 m. Although there were slightly larger differences in elevation on the southwest-to-west sides of the XGR- and EIX-DEMs, which can be attributed mainly to the flight paths and ground control point network, our DEMs are still of high enough quality to be used in hazard assessments.

Due to an authors' error, the original version of this article contained error in the in-text citations for tables in Section 4.1. The referenced table number should be corrected as follows:

Now reads

The self-assessment by the officials in charge of disaster management in the local governments was based on the Sustainability Scoring Index that was formulated by the authors for this study (Table 3).

Should read

The self-assessment by the officials in charge of disaster management in the local governments was based on the Sustainability Scoring Index that was formulated by the authors for this study (Table 2).

The authors regret this error, and this error has now been corrected in the PDF version of the article.