Journal of Disaster Research
Online ISSN : 1883-8030
Print ISSN : 1881-2473
ISSN-L : 1881-2473
13 巻 , 1 号
選択された号の論文の21件中1~21を表示しています
Special Issue on Construction of Myanmar Disaster Response Enhancement System and Industry-Academia-Government Cooperation Platform
  • Kimiro Meguro, Gokon Hideomi
    原稿種別: Editorial
    2018 年 13 巻 1 号 p. 5
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    This special issue summarizes the main results of the first half of the five-year SATREPS project in Myanmar. SATREPS stands for “Science and Technology Research Partnership for Sustainable Development” and it is supported by the Japan International Cooperation Agency (JICA) and the Japan Science and Technology Agency (JST). The title of our project is “Construction of Myanmar Disaster Response Enhancement System and Industry-Academia-Government Cooperation Platform.” Ours is the first SATREPS project in Myanmar and Yangon Technological University (YTU) is our main counterpart institute and relevant organizations mainly national and local governments are collaborating as strategic partners.

    In Myanmar, rural and urban development has been progressing rapidly and on a large scale, and the expansion of urban population coupled with climate change has increased the risk of disaster to a critical level, especially in Yangon, Myanmar’s largest city. By monitoring changes in the urban environment, such as the topography, ground, buildings, and infrastructure, we seek to lower the level of risk. Our project will improve the disaster management system, plan and response capability, based on an evaluation of disaster vulnerabilities. Considering floods including tidal wave problems and earthquakes as the target hazards, we aim to contribute to the development of precise regional development plans and disaster management measures by identifying disaster risks in advance, and we will support the Myanmar government in strengthening its disaster response capabilities.

    We plan to set up a system by which industry, academia, and the government collaborate to promote the understanding of research content, to continue research activities, and to implement research results in Myanmar. We hope that our activities in the SATREPS project will become an ideal model for solving issues in urban development and disaster management, and that the project will also contribute the other Asian countries.

  • Thein Aye Zin, Kyaing, Ko Ko Lwin, Yoshihide Sekimoto
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 6-13
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    The ubiquitous massive mobile phone data generation presents new opportunities to determine the requirements of transportation, disaster management and public health care systems. Currently, data from mobile phone records can help in identifying the location of the users while they are making trips. Generally, this estimation is achieved using traditional data collection methods; however, these methods are difficult to apply in developing countries with rapidly growing cities owing to the high population and limitation in conducting a survey. Call detail records (CDRs) are used as base data because they are valuable data sources and can reduce the cost and time limitations. The aim of this study is to estimate origin-destination (OD) trips from each zone by using the CDRs. The OD trips are estimated by using the CDRs of one week taken from Myanmar Post and Telecommunication mobile operator for over 1.9 million users per day in Yangon, the economic center of Myanmar. The OD trips are estimated from CDRs based on the location of the base station in a limited time window and time frame. If the same mobile users is observed in two different the ones within the time limit, it is assumed that the mobile user is coming out from the first zone and the trips represents an originating trip. This trip would be the destination trip for zone where the mobile user enters. In this study, the originating (outgoing) and destination trips (incoming) from each township on a weekday and weekend are determined. These data are useful for infrastructure development and urban transportation planning.

  • Win Win Zin, Akiyuki Kawasaki, Wataru Takeuchi, Zin Mar Lar Tin San, K ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 14-21
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Flood hazard mapping is an effective non-structural measure for sustainable urban planning, protecting human properties, lives, and disaster risk reduction. In this study, flood hazard assessment for the Bago river basin was performed. The flood inundation map of the Bago river basin was developed by coupling a hydrological and hydraulic model with geographical information systems. Flood hazard maps with different return periods were developed. The flood hazard map can be utilized to enhance the effectiveness of disaster risk management activities.

  • Muhammad Mohsan, Ralph Allen Acierto, Akiyuki Kawasaki, Win Win Zin
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 22-30
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Intensive and long-term rainfall in Myanmar causes floods and landslides that affect thousands of people every year. However, the rainfall observation network is still limited in number and extent, so satellite rainfall products have been shown to supplement observations over the ungauged areas. One example is the estimates from Global Precipitation Measurement (GPM) called Integrated Multi-satellite Retrievals for GPM (IMERG), which has high spatial (0.1 × 0.1 degree) and temporal (30 min) resolution. This has potential to be used for modeling streamflow, early warnings, and forecasting systems. This study investigates the utility of these GPM satellite estimates for representing the daily rainfall for 25 rain gauges over Myanmar. Statistical metrics were used to understand the characteristic performance of the GPM satellite estimates. Daily rainfall estimates from GPM show a range of 29.3% to 81.1% probability of detection (POD). The satellite estimates show a capability of detecting no-rain days between 61.4 and 93.5%. For different rainfall intensities, the satellite estimates have a 12.9 to 39.1% POD for light rain (1–10 mm/day), 11.1 to 49% POD for moderate rain (10–50 mm/day), a maximum of 36% for heavy rain (50–150 mm/day), and a maximum of 12.5% for extreme rain (>150 mm/day). However, the correlation coefficient (CC) only ranges from 0.064 to 0.581, which is considered low, and is not uniform for all the stations. The highest CC scores and POD scores tend to be located in the northern part and deltaic region extending to the southern coasts in Myanmar, indicating a dependency of the statistical metrics on rainfall magnitude. The high POD scores indicate the utility of the estimates without correction for early warning purposes, but the estimates have low reliability for rainfall intensity. The satellite estimates can be used for forecasting and modeling purposes in the region, but the estimates require bias-correction before application.

  • Chaitanya Krishna Gadagamma, Aung Ko Min, Hideomi Gokon, Kimiro Meguro ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 31-39
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    The recent apprehensions about active seismicity in Myanmar is a reminder of the significant hazards caused by earthquakes. Since some cities are subjected to high seismic risk, its assessment can be invaluable for disaster mitigation. This study focused on the development of fragility/damage probability functions for reinforced concrete (RC) buildings in Yangon city because seismic vulnerability assessment is being an essential component of risk evaluation. Nonlinear static pushover analysis is carried out on a group of 54 RC buildings (39 low-rises and 15 high-rises) by varying the material strengths, as well as and analysis based on capacity curves over the demand spectrum with fixed performance points representing the damage probability as a function of both spectral displacement and ground accelerations.

  • Nuntikorn Kitratporn, Wataru Takeuchi, Koji Matsumoto, Kohei Nagai
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 40-49
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    In Myanmar, defects and possible deformation were reported in many long-span suspension bridges. The current state of bridge infrastructure must be inspected, so that deterioration can be stalled and failure can be prevented. A 3D laser scanner, specifically the terrestrial laser scanner (TLS), has demonstrated the ability to capture surface geometry with millimeter accuracy. Consequently, TLS technology has received significant interest in various applications including in the field of structural survey. However, research on its application in large bridge structure remains limited. This study examines the use of TLS point cloud for the measurement of three deformation behaviors at the Pathein Suspension Bridge in Myanmar. These behaviors include tower inclination, hanger inclination, and deflection of bridge truss. The measurement results clearly captured the deformation state of the bridge. A comparison of the measurement results with available conventional measurements yielded overall agreement. However, errors were observed in some areas, which could be due to noise and occlusion in the point cloud model. In this study, the advantages of TLS in providing non-discrete data, direct measurement in meaningful unit, and access to difficult-to-access sections, such as top of towers or main cables, were demonstrated. The limitations of TLS as observed in this study were mainly influenced by external factors during field survey. Hence, it was suggested that further study on appropriate TLS surveying practice for large bridge structure should be conducted.

  • Tanakorn Sritarapipat, Wataru Takeuchi
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 50-61
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Yangon is the largest city and major economic area in Myanmar. However, it is considered to have a high risk of floods and earthquakes. In order to mitigate future flood and earthquake damage in Yangon, land cover change simulations considering flood and earthquake vulnerabilities are needed to support urban planning and management. This paper proposes land cover change simulations in Yangon from 2020 to 2040 under various scenarios of flood and earthquake vulnerabilities with a master plan. In our methodology, we used a dynamic statistical model to predict urban expansion in Yangon from 2020 to 2040. We employed a master plan as the future dataset to enhance the prediction of urban expansion. We applied flood and earthquake vulnerabilities based on multi-criteria analysis as the areas vulnerable to disaster. We simulated land cover changes from 2020 to 2040 considering the vulnerable areas with a master plan for multiple scenarios. The experiments indicated that by using a master plan, some of the predicted urban areas are still located in areas highly vulnerable to floods and earthquakes. By integrating the prediction of urban expansion with flood and earthquake vulnerabilities, the predicted urban areas can effectively avoid areas highly vulnerable to floods and earthquakes.

  • Rena Kikuchi, Muneyoshi Numada, May Myat Mon, Tun Naing, Khin Than Yu, ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 62-69
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Recently, national level disaster management legislation systems have been established in Myanmar, and preparation of disaster management plans at the township level has also been encouraged. This study aims to explain these disaster management plans in Myanmar through content analysis and comparison with the Japanese Municipality Disaster Management Plan. The classification of activities by 45 categories revealed the prioritized activities in the disaster management plan for each township. Furthermore, the comparison identified differences between the disaster management plans of the two countries, of which some are explained by the difference in situations in Myanmar and Japan, but the others indicate activities missed in the township disaster management plans in Myanmar.

  • Naruhiko Shirai, Seemanta Sharma Bhagabati, Akira Kodaka, Naohiko Koht ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 70-79
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Cross-sectional communication for data sharing among multiple stakeholders involved in disaster responses is one of the fundamental non-structural measures that directly influence the performance of disaster risk reduction. Taking the event of the 2008 Cyclone Nargis as the watershed experience, Myanmar has been developing a nationwide disaster risk reduction scheme. Transition from the past structure of a vertically divided administration to cross-sectional interaction is underway, making use of lessons learned from past disaster events, yet many challenges remain in communications among stakeholders. To address the issue, this research proposes a communication scheme for data sharing among multiple stakeholders to complement the current scheme for better decision making of the stakeholders during both normal times and emergencies. The proposed scheme is evaluated by the stakeholders, and it is shown that the benefits would include not only the strengthening of the current scheme for decision making but also a contribution to the design of long-term plans in areas such as agriculture, irrigation, and disaster preparedness. This research anticipates further development of the scheme by employing more concrete needs of the stakeholders by reiterating contextual inquiries as well as by physically modeling a database taking case scenarios into account for its design.

  • Liyanto Eddy, Takeshi Miyashita, Koji Matsumoto, Kohei Nagai, Win Bo
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 80-87
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Myanmar officials have observed damage and unwanted movement of some bridge structures situated within the Yangon, Myanmar region. Low bearing capacity soils (termed “soft soil” herein) may be responsible for the observed damage and unwanted movement. The observations may indicate that the current bridges have not been adequately designed and constructed to fully accommodate the soft soils. Several damaged bridges were repaired; however, it was not clear if these repairs halted the unwanted movement of the structures. We conducted comprehensive observations of the existing conditions to fully understand the contributing factors of the damage and unwanted movements. We utilized our detailed observations to develop a simple and straightforward independent monitoring system to assess whether the bridge repairs were successful in arresting further unwanted movement. The Thakhut Bridge and Twantay Bridge were selected as the subjects of our study. A monitoring system consisting of two displacement transducers and a portable data logger were installed on the Thakhut Bridge to monitor movement of the central pier. The monitoring results indicated that the central pier of the Thakhut Bridge moved 3.5 mm over an eight month period along the direction aligned with the bridge axis. Because the movement of the central pier in Thakhut Bridge behaves linearly with time, the future relative displacement can be predicted to be on the order of 5–6 mm per year. A monitoring system consisting of an inclinometer and a portable data logger were installed on the Twantay Bridge to monitor the inclination of the south main tower. Our observations indicated that the inclination of the south main tower of the Twantay Bridge ranged from 0.00° to 0.04° (in the direction of the bridge axis). The very small angles of inclination that were observed led us to conclude that the south main tower was in a stable condition. The implementation of a simple and straightforward independent monitoring system will permit Myanmar officials to effectively plan and implement the requisite maintenance and corrective measures for damaged bridges.

  • Michael Henry, Chika Yamasaki, Kohei Nagai, Koji Matsumoto, Hiroshi Yo ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 88-98
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    While the creation of new infrastructure has played an important role in Myanmar’s rapid economic growth, maintenance of the existing infrastructure is also necessary to ensure its continued safe development. The objective of this paper is to clarify the current practices and technologies for the maintenance and life cycle management of road bridges in Myanmar by reporting and analyzing the results of a series of surveys carried out with Myanmar’s Ministry of Construction. It was found that the maintenance cycle in Myanmar is not fully functional, as there are no standardized methods for inspection and repair, and the results of the inspections are not recorded in a database. However, efforts are under way to prepare a comprehensive manual for road bridges, and a database is being developed as part of a Japanese capacity development project. Analysis of technology transfer activities for maintenance found that the mismatch in conditions between Japan and Myanmar made it difficult to adapt the knowledge acquired in training programs to the local conditions. Furthermore, low awareness of maintenance and an inadequate maintenance budget also hinder opportunities to practice maintenance activities. To achieve sustainable transfer of maintenance technology, future activities should consider financial support for opportunities to acquire practical on-site maintenance experience in Myanmar.

  • May Myat Mon, Tun Naing, Muneyoshi Numada, Khin Than Yu, Kimiro Meguro ...
    原稿種別: Survey Report
    2018 年 13 巻 1 号 p. 99-115
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Myanmar has experienced many types of geologic hazards such as earthquakes and landslides and to a lesser extent, subsidence. In recent years, landslides have been a major form natural disaster in Myanmar, especially in the country’s mountainous regions, such as Chin State. In geomorphological terms, Myanmar has two mountainous regions: namely the Western Ranges and the Eastern Highlands. Steep slopes, unstable geologic conditions, and heavy monsoon rains make these regions the most landslide-prone areas in Myanmar.

    The study area, Hakha City and its environs, is situated in Chin State, which occupies a part of the Western Ranges. Chin State suffers many landslide incidents each year. Human settlement has recently increased as a result of rapid population growth. Consequently, natural and man-made disasters are on the rise and affecting people more than before. The most devastating landslide on record in Myanmar occurred in July 2015 due to the impact of Cyclone Koman. After this landslide, some places of Hakha City resettled in new location. However, a detailed slope stability analysis and assessment of the new location have not yet been carried out. In addition, management procedures and systems for the relocation and resettlement process still need to be evaluated for the urban safety space. Existing research and papers focus mainly on the areas affected by the landslide rather than on the city’s new location based on geographic information system (GIS) tools. It is essential to study the potential risk of landslides in the new location properly, and identify an appropriate management system.

    Geological conditions including highly weathered and crushed rocks, heavy rainfall intensity, and poor drainage systems combine slope stability. Systematic management programs and technical control methods can mitigate the number and magnitude of future disasters.

  • Ralph Allen Acierto, Akiyuki Kawasaki, Win Win Zin, Aung Than Oo, Khon ...
    原稿種別: Note
    2018 年 13 巻 1 号 p. 116-124
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Hydrological monitoring is one of the key aspects in early warning systems that are vital to flood disaster management in flood-prone areas such as Bago River Basin in Myanmar. Thousands of people are affected due to the perennial flooding. Owing to the increasing pressure of rapid urbanization in the region and future climate change impacts, an early warning system in the basin is urgently required for disaster risk mitigation. This paper introduces the co-establishment of the telemetry system by a group of stakeholders. The co-establishment of the system through intensive consultations, proactive roles in responsibility sharing, and capacity building efforts, is essential in developing a base platform for flood forecasting and an early warning system in the basin. Herein, we identify the key challenges that have been central to the participatory approach in co-establishing the system. We also highlight opportunities as a result of the ongoing process and future impact on the disaster management system in the basin. We also highlight the potential for scientific contributions in understanding the local weather and hydrological characteristics through the establishment of the high-temporal resolution observation network. Using the observation at Zaung Tu Weir, Global Satellite Mapping of Precipitation (GSMaP) and Global Precipitation Measurement (GPM) satellite estimates were assessed. Near real-time and standard versions of both satellite estimates show potential utility over the basin. Hourly aggregation shows slightly higher than 40% probability of detection (POD), on average, for both satellite estimates regardless of the production type. Thus, the hourly aggregation requires correction before usage. The results show useful skills at 60% POD for standard GSMaP (GSMAP-ST), 55% POD for near real-time GSMaP (GSMAP-NR), and 46% POD for GPM, at 3-hourly aggregations. Six-hourly aggregations show maximum benefit for providing useful skill and good correspondence to gauge the observation with GSMAP-ST showing the best true skill score (TSS) at 0.54 and an equitable threat score (ETS) at 0.37. While, both final run GPM and GSMAP-NR show lower POD, TSS, and ETS scores. Considering the latency of near real-time satellite estimates, the GSMAP-NR shows the best potential with a 4-hour latency period for monitoring and forecasting purposes in the basin. The result of the GSMAP-NR does not vary significantly from the GSMAP-ST and all GPM estimates. However, it requires some correction before its usage in any applications, for modeling and forecasting purposes.

  • Osamu Murao, Takuma Usuda, Hideomi Gokon, Kimiro Meguro, Wataru Takeuc ...
    原稿種別: Note
    2018 年 13 巻 1 号 p. 125-137
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    It is indispensable for a government to assess urban vulnerability to natural disasters such as earthquakes or flood in order to take appropriate disaster measures. However, it is sometimes difficult to obtain necessary dataset for cities or regions, especially for developing countries. The authors have been involved in a SATREPS project named “Development of a Comprehensive Disaster Resilience System and Collaboration Platform in Myanmar,” which aims to make urban vulnerability maps for Yangon City based on several datasets including building inventory of each ward. However, Yangon City has not catalogued enough data for the assessment so far. In this context, in order to understand and to arrange regional building characteristics of the city, this paper explores the possibility of using digital building model (DBM) data obtained from remote sensing imageries for the urban vulnerability assessment.

    Firstly, a field survey was conducted in Sanchaung Township, and building characteristics such as structural types and the number of stories were analyzed. Therefore, DBM data was prepared for the following comparative analysis. Thirdly, additional field surveys were conducted in Latha and Pabedan Townships, located in the central business districts in the city. Finally, DBM data and the actual building data obtained by the surveys were compared to examine the applicability of DBM for building collapse risk assessment. As a result, it was found that DBM data of 3 m- 7 m represent low-rise buildings, and DBM data of more than 18 m reflect high-rise buildings.

  • Yasmin Bhattacharya, Takaaki Kato, Tomoko Matsushita, Ei Ei Tun, Tin T ...
    原稿種別: Note
    2018 年 13 巻 1 号 p. 138-151
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    The process of urbanization often results in the accumulation of risks within the urban fabric. These later develop into major vulnerabilities that can cause immense devastation in the event of a disaster. Therefore, as a city develops, it is essential to monitor its growth in order to 1) guide its development to avoid accumulating further risks and 2) enable the urban system to cope with the risks that already exist. This paper focuses on dealing with existing risks and the potential to address disaster-risk response within the existing firefighting framework. It identifies GIS-based spatial-analysis methods that can assist in determining the urban system’s capacity to accommodate the necessary service functions during both regular emergencies and disaster situations. As an example, response-capacity analysis for firefighting services in Yangon City is carried out to identify the inadequacies of the current system. These are then matched with the potential-fire-risk map to consider the demand increase for fire stations in disaster situations due to the likelihood of multiple ignitions. Areas where infrastructural and logistical improvements should be prioritized are discussed, and urban planning measures to help develop a safe and resilient city are considered within the developing-country context.

Regular Papers
  • Ahmed Alhourani, Junji Kiyono, Aiko Furukawa, Hussam Eldein Zaineh
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 153-167
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    An important criterion for conducting an accurate seismic hazard analysis and assessment is the compiling of a representative and completehistorical seismic catalog for the region of interest. This paper describes the procedure to assemble a full earthquake events catalog for Syria from the years 37 AD to 2011 AD. The procedure starts with improving the quality of the compiled full catalog by eliminating manmade events by choosing a cutoff magnitude of 2.5; and by eliminating the potential aftershocks and afforeshcks using an appropriate declustering method. To examine the quality of the resultant seismic catalog (after eliminating artificial, aftershock and afforeshok earthquake) the magnitude of completeness (MC) was calculated and the distribution of MC with time showed an overall good quality of the adopted complete catalog. The adopted complete seismic catalog is then used to generate peak ground acceleration hazard maps for 475, 1000 and 2475 years return periods. The study also concludes that to accommodate for the quiescence of the DSFS and potential undetected buildup and release of seismic energy it is important to introduce 1000 and 2475 years return periods seismic hazard maps especially in the design of important structures.

  • Titaya Sararit
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 168-176
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    This study focuses on some houses in Phang Nga Province in Thailand that were permanently relocated after the Indian Ocean tsunami in 2004. It aims to analyze extensions and improvements by residents who have lived in the houses for a long time. Most previous research has painted spatial extensions in a bad light because of the negative feedback from residents regarding post-disaster housing; this could mean that residents were less than satisfied with such houses in comparison to their previous ones with respect to construction, function, or size. Observing and interviewing residents allowed me to infer that spatial extensions can also represent the positive development of long-term recovery projects, as they increase the satisfaction of residents who, more than 10 years after the tsunami, have changed their lifestyles, family sizes, and jobs. It also demonstrates why residents are more satisfied with house types that allow them to carry out the required space adaptions or extensions when they have an increase in their income. In this study, it was observed that extensional space could also be a positive factor revealing the developments in residents’ lives as they showed their intent to live permanently in this type of housing even after the disaster.

  • Shinya Miura, Hiroaki Sano, Nobuyuki Handa, Tai-Young Yi, Hitoshi Tagu ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 177-192
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Many researchers have highlighted the necessity of disaster prevention countermeasures based on regional characteristics. However, in situations wherein disaster prevention measures are executed, often, no index (data) objectively indicates the risk of disaster considering regional characteristics. Therefore, disaster prevention measures are sometimes implemented without considering regional characteristics. As such, a way to extract and present disaster prevention countermeasures and examples that consider regional characteristics, including the risk of disaster are now needed. In the present study, we search for indices of the regional characteristics necessary to implement disaster prevention countermeasures and study a method to extract these countermeasures and examples based on the indices. In addition, the appropriateness of the method to extract the disaster prevention countermeasures and examples considering regional characteristics is verified through a questionnaire survey and interview.

  • Shun Araki, Tatsuya Noguchi, Masao Komazawa, Shoya Arimura, Mitsuhiro ...
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 193-198
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    Gravity survey has been carried out around central part of Mashiki, Kumamoto, Japan, where was severely damaged by 2016 Kumamoto earthquake. Dense observations were performed at more than 450 sites around the central part of Mashiki. The observation sites satisfy enough density to discuss density structure shallower than 500-meter depth around the target area. After applying some corrections to the observed data, Bouguer anomaly is obtained and three dimensional model of gravity basement is estimated. As a result, a graben runs parallel to the Akitsukawa River and some isolated small basins are found inside of the graben. The central part of Mashiki is located immediately above of the one of such the small basins. We also analyze focusing and defocusing effects of ray of seismic wave under very simple assumptions and it is found that the central part of Mashiki locates close to a focusing area.

  • Miki Ozeki, Kan Shimazaki
    原稿種別: Material
    2018 年 13 巻 1 号 p. 199-204
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    The aim of the current study was to test whether direct experience of a large-scale natural disaster enhanced disaster-prevention consciousness, using the disaster-prevention consciousness scale created by Shimazaki and Ozeki (2017). An online survey was conducted in February 2017 targeting those who lived in Kumamoto Prefecture, which was seriously damaged by the Kumamoto Earthquake. Participants were divided into two groups: a group of people who lived in 14 local towns where public employees of other local governments came to provide backup assistance after the Kumamoto Earthquake (heavily damaged group), and a group of people who did not live in these areas when the Kumamoto Earthquake occurred (damaged group). Results showed that interest in disasters, sense of danger in current disaster prevention, others orientation, and anxiety increased after large-scale natural disasters, irrespective of the extent of damage. Directly experiencing damage from the disaster enhanced imagination for damage situation.

  • Nario Yasuda, Norihisa Matsumoto, Zengyan Cao
    原稿種別: Paper
    2018 年 13 巻 1 号 p. 205-215
    発行日: 2018/02/20
    公開日: 2018/10/01
    ジャーナル 認証あり

    During the Iwate-Miyagi Nairiku Earthquake (M7.2) of June 14, 2008, seismic motions with a maximum acceleration of 1,024 cm/s2 in the stream direction were recorded at the foundation bedrock of Aratozawa Dam, a rockfill dam located approximately 16 km from the epicenter. However, the maximum response acceleration in the same direction near the center of the dam crest was 525 cm/s2, and the acceleration amplification ratio of the dam body was far lower than that normally considered for a rockfill dam. Furthermore, it was measured that the crest settled down 19.8 cm after the earthquake. In this study, the dynamic properties of the embankment materials were identified using reproduction analysis of past earthquakes, and the recorded behaviors of the dam body during the mentioned strong earthquake were simulated. The generating mechanism of the peculiar earthquake behavior was investigated based on the results of the earthquake response analysis. Furthermore, in order to understand the deformation mechanism, sliding stability analysis and cumulative damage analysis were performed. According to the results, the residual deformation of the dam body after the strong earthquake is inferred to be caused by the shaking settlement of the embankment materials.

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