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Ikki Niwa, Toshihiro Osaragi, Takuya Oki, & Noriaki Hirokawa. (2015). Development of Real Time Synchronous Web Application for Posting and Utilizing Disaster Information. In L. Palen, M. Buscher, T. Comes, & A. Hughes (Eds.), ISCRAM 2015 Conference Proceedings ? 12th International Conference on Information Systems for Crisis Response and Management. Kristiansand, Norway: University of Agder (UiA).
Abstract: In a large earthquake, rescue operations and fire-fighting are obstructed by fire-spreading and street-blockages. Therefore, it is important to quickly collect and utilize disaster information for disaster mitigation. In this paper, firstly, we develop a Web application for posting and viewing information collected by users in real time. Using this system, it is possible not only to easily share disaster information among users but also to apply to damage forecast such as fire-spreading. Next, we demonstrate the usefulness of the Web application by the following evaluation view points: (1) relationship between the access time of emergency vehicles from fire stations to the locations of fires and the ratio of collected information on street-blockage which is assumed to be collected with this system; (2) reciprocating time between a server and a client which is dependent on the number of users and band limitation after the occurrence of a disaster.
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Maki Tagashira, & Toshihiro Osaragi. (2021). Accessibility Assessment of Vulnerable Roadside Areas after a Major Earthquake. In Anouck Adrot, Rob Grace, Kathleen Moore, & Christopher W. Zobel (Eds.), ISCRAM 2021 Conference Proceedings – 18th International Conference on Information Systems for Crisis Response and Management (pp. 553–566). Blacksburg, VA (USA): Virginia Tech.
Abstract: In order to reduce human casualty after a large earthquake, it is vital to secure the traffic function of main roads. Local governments promote the seismic reinforcement of roadside buildings, however, the project is not going well as planned. There is a high demand for appropriate information of its effect. In this paper, we proposed a method to identify the roadside areas with vulnerable accessibility to disaster bases after a large earthquake. First, we defined the accessibility indices; Link Isolation ratio (LI ratio) and Network Isolation ratio (NI ratio). Then, using the simulation model, we evaluated the accessibility to disaster base hospitals using emergency transportation roads in the Tokyo Metropolitan Area. LI ratio tended to be low in areas with a sparse road network. Furthermore, some hospitals indicated a severely high NI ratio. In secondary medical areas with these hospitals, it is necessary to consider the measures to improve accessibility.
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Takuya Oki, & Toshihiro Osaragi. (2017). Evaluation of Conversion to Quake-Resistant Buildings in Terms of Wide-Area Evacuation and Fire-Brigade Accessibility. In eds Aurélie Montarnal Matthieu Lauras Chihab Hanachi F. B. Tina Comes (Ed.), Proceedings of the 14th International Conference on Information Systems for Crisis Response And Management (pp. 25–41). Albi, France: Iscram.
Abstract: It is important to evaluate the effects of improving the disaster vulnerability of towns by using various indices related to human damage. In this paper, we focus on conversion of low quake-resistant old buildings. Firstly, we construct a simulation model, which describes property damage (such as building-collapse and street-blockage), wide-area evacuation behavior, and fire-brigade's activities immediately after a large earthquake occurs. Next, using the simulation model, we estimate the travel time required for evacuation, the number of evacuees trapped on streets (or in blocks), and the access time of fire-brigades to fires in case that the ratio of quake-resistant buildings in the area increases to a certain value. Based on the results, we discuss the effects by converting old buildings into quake-resistant ones on reducing the difficulty in wide-area evacuation and improving the accessibility of fire-brigades in multiple study areas with different characteristics.
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Takuya Oki, & Toshihiro Osaragi. (2016). Wide-area Evacuation Difficulty in Densely-built Wooden Residential Areas. In A. Tapia, P. Antunes, V.A. Bañuls, K. Moore, & J. Porto (Eds.), ISCRAM 2016 Conference Proceedings ? 13th International Conference on Information Systems for Crisis Response and Management. Rio de Janeiro, Brasil: Federal University of Rio de Janeiro.
Abstract: In aiming to decrease the number of casualties and people with difficulty in wide-area evacuations due to a large earthquake, it is highly important to visualize and quantify the potential danger in residential areas. In this paper, we construct a multi-agent simulation model, which describes property damage (such as building-collapse, the spread of fire and blocking of streets) and people?s evacuation behavior after an earthquake occurring. Using this simulation model, we quantify the wide-area evacuation difficulty in densely-built wooden residential areas, and evaluate the past project to improve buildings and streets based on this indicator. Furthermore, we demonstrate the effects of adding new evacuation routes between two intersections of streets with narrow width and long distance. Through these case studies, the effectiveness of our simulation model on urban disaster mitigation planning is shown.
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Takuya Tsuchiya, Toshihiro Osaragi, & Takuya Oki. (2015). Influence of Information-Hearsay on Wide-Area Evacuation at a Large Earthquake. In L. Palen, M. Buscher, T. Comes, & A. Hughes (Eds.), ISCRAM 2015 Conference Proceedings ? 12th International Conference on Information Systems for Crisis Response and Management. Kristiansand, Norway: University of Agder (UiA).
Abstract: In order to evacuate smoothly and safely at a large earthquake, it is important to obtain the information on property damages (such as street-blockage and fire) and on evacuation areas by hearsay, guidance and bulletin boards. In this paper, we construct a model, which describes wide-area evacuation, information-hearsay among evacuees and guidance behavior. Using this model, we evaluate the influence of information-hearsay on wide-area evacuation in terms of the evacuation time and the risk on evacuation routes. Simulation results demonstrate that the locational information of evacuation areas and damages is the most helpful for people who are unfamiliar with an area. In addition, we discuss the effective and efficient methods of evacuation guidance. The results show that the guides contribute to reducing the evacuation time and the risk on evacuation routes of evacuees, and sharing information among guides enables more efficient and safer evacuation / guidance.
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Toshihiro Osaragi. (2020). Accessibility Evaluation of Specific Emergency Transportation Roads and Benefits of Seismic Retrofits on Buildings Adjoining Roads. In Amanda Hughes, Fiona McNeill, & Christopher W. Zobel (Eds.), ISCRAM 2020 Conference Proceedings – 17th International Conference on Information Systems for Crisis Response and Management (pp. 143–156). Blacksburg, VA (USA): Virginia Tech.
Abstract: Securing the accessibility of emergency vehicles using specific emergency transportation road (SETR) is crucial for the rapid activities of emergency vehicles after a large earthquake. In this paper, we construct a simulation model that describes collapse of roadside buildings and following street blockages, and evaluate the accessibility of emergency vehicles. Performing the simulations, we demonstrate the effects of quake-resistant-conversion of roadside buildings as follows: (1) the accessibility of emergency vehicles using SETR is not good enough under the current situation, but (2) can be significantly improved by performing seismic retrofit of buildings according to seismic index of building structure.
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Toshihiro Osaragi. (2018). Crowding of Various Facilities Relevant to Supporting People Who Have Difficulty Returning Home after a Large Earthquake. In Kees Boersma, & Brian Tomaszeski (Eds.), ISCRAM 2018 Conference Proceedings – 15th International Conference on Information Systems for Crisis Response and Management (pp. 45–59). Rochester, NY (USA): Rochester Institute of Technology.
Abstract: When a large earthquake occurs, many people are presumed to have difficulty in returning home. However, no research has been achieved yet to discuss the congestion of supporting facilities for stranded people in terms of site, the number and spatial distribution. In this study, we construct a simulation model, which describes people's behavior such as returning home or going to other facilities after an earthquake occurs. Using the model, we estimate the congestion of facilities which varies according to day of the week or the time when the event occurs, and demonstrate the effective methods for reducing the congestion, which include offering information for people and cooperation of private institutions.
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Toshihiro Osaragi. (2016). Estimation of Transient Occupants on Weekdays and Weekends for Risk Exposure Analysis. In A. Tapia, P. Antunes, V.A. Bañuls, K. Moore, & J. Porto (Eds.), ISCRAM 2016 Conference Proceedings ? 13th International Conference on Information Systems for Crisis Response and Management. Rio de Janeiro, Brasil: Federal University of Rio de Janeiro.
Abstract: Understanding the characteristics of the spatiotemporal distribution of a population, which varies according to the time of the day and the day of the week (weekday or weekend), is one of the most important issues in the field of urban disaster mitigation planning. However, the existing Person Trip Survey data based on weekdays is not appropriate for estimating the spatiotemporal distribution of population on weekends. In the present study, we proposed a method for converting existing Person Trip Survey data from a weekday base to a weekend base and examined the differences in the spatiotemporal distribution of the population. Using these databases, we attempted to compare the number of deaths due to building collapse estimated for weekdays and weekends for various districts in the Tokyo Metropolitan area.
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Toshihiro Osaragi. (2015). Spatiotemporal Distribution of Automobile Users: Estimation Method and Applications to Disaster Mitigation Planning. In L. Palen, M. Buscher, T. Comes, & A. Hughes (Eds.), ISCRAM 2015 Conference Proceedings ? 12th International Conference on Information Systems for Crisis Response and Management. Kristiansand, Norway: University of Agder (UiA).
Abstract: When discussing human casualties from a severe earthquake with regard to urban disaster mitigation planning, it is important to clarify the characteristics of the spatiotemporal distribution of people. In this paper, we construct a model that estimates the spatiotemporal distribution of automobile users using data from the Person Trip Survey and the Road Traffic Census. We use this model to estimate the spatiotemporal distribution of automobile users in Tokyo and demonstrate several ways to apply this data to urban disaster mitigation planning.
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Toshihiro Osaragi, Koji Ogino, Noriaki Hirokawa, & Takuya Oki. (2022). Severity of Crowding at Evacuation Shelters after a Major Earthquake. In Rob Grace, & Hossein Baharmand (Eds.), ISCRAM 2022 Conference Proceedings – 19th International Conference on Information Systems for Crisis Response and Management (pp. 22–43). Tarbes, France.
Abstract: A number of residents are presumed to evacuate to shelters after a large earthquake. However, the congestion of evacuation shelters has not been enough discussed. In this paper, we propose an evacuation behavior model, which includes sub-models on building damage, water-supply failure, power failure, fire damage, and elevator stall. Using the model estimated using the survey data of the past earthquakes, we discuss the congestion of evacuation shelters under the assumption of Tokyo Bay northern earthquake. Finally, we discuss improvement of water pipes for earthquake resistance to reduce the congestion degree of evacuation shelters, which varies according to regional vulnerability.
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Toshihiro Osaragi, & Noriaki Hirokawa. (2019). Simulation Analysis of Fire Hydrant Usability Levels after Large Earthquake. In Z. Franco, J. J. González, & J. H. Canós (Eds.), Proceedings of the 16th International Conference on Information Systems for Crisis Response And Management. Valencia, Spain: Iscram.
Abstract: Since large earthquakes can disrupt water supply networks, it is essential to gain an understanding of the expected
usability of fire hydrants in post-quake firefighting activities. In this study, data about water supply networks was
collected and a water outage simulation model was constructed in order to predict the likelihood that individual
fire hydrants would become unusable in the wake of a large earthquake. The water outage simulation model was
integrated with a previously developed urban zone damage simulation and a fire department activity simulation
in order to carry out a simulation-based analysis of the 23 wards of Tokyo, after which a quantitative analysis of
the relation-ship between use of fire hydrants and the number of buildings lost to fire was performed. This analysis
revealed the benefits of hardening water lines against earthquakes, fire hydrant usage variations depending on
locality, and the benefits of using water pressure sensors to identify usable fire hydrants.
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