disaster

Environmental Cognition and Tsunami Evacuation Planning
＜Presented at the 44th Annual Conference of Environmental Design Research Association, May. 2013＞　＜Special Issue of MERA Journal, pp. 20-23, Mar. 2014＞
Teruyuki Isagawa, Ryuzo Ohno
The Great East Japan Earthquake caused massive tsunami and brought serious damage along the coast of eastern Japan. Since the delay of evacuation had caused many victims, importance of the behavior studies in field of disaster prevention measurement has been recognized. This study focuses on the effects of environmental factors such as topography or road network upon residents’ behavior. This knowledge will aid in the reconsideration of effective announcement and navigating evacuees in case of emergency. In this study, we distributed questionnaire forms to all 2,272 households in the coastal area of Onjuku, Chiba prefecture, where the large-scale tsunami warning was issued. The questionnaire asked about their behavior in the form of flowchart and mapping with which we can identify where they were at the time of the earthquake and trace how they behaved after that as well as the reason of their choice such as knowledge and information used. With these, we aim to clarify the effects of environmental factors on their decision-making and path choice behavior. From the data, 447 valid responses (collection rate: 19.7%), large numbers of residents did not evacuate although they had received the disaster information. The results revealed that their decision-making was related to environmental factors (such as an estimation of hazard areas, altitude), while their belief was not always accurate. Our result also indicates importance of considering various travel activities (e.g. stopping at home, going to the coast, or picking up their children) when we discuss evacuation route.	Full paper　→　PDF

Residents' Behavior in a Potential Area for Tsunami Disaster after the Great East Japan Earthquake
<Presented at the International Association for People-Environment Studies (IAPS22 Conference), Jun. 2012>
Teruyuki Isagawa, Ryuzo Ohno
On March 11, 2011, Japan was hit by the Great East Japan Earthquake that caused massive tsunami along the shore of Tohoku to Kanto region and brought serious damage. More than 15,000 people were killed. Since the delay of evacuation had caused many victims, importance of the behavior studies in field of disaster prevention measurement has been recognized. To understand how coastal residents made decision and how they behaved at urgent situation become important because this knowledge will aid in the reconsideration of effective announcement in case of emergency and disaster education. Right after the earthquake, meteorological agency gave a large-scale tsunami warning including the coast area of Onjuku town, Chiba prefecture where the local government also issued an evacuation counsel to coastal residents. In this study, we distributed to all households in the coastal area of Onjuku town, totally 2,272 questionnaire forms. We asked to respond only who were in the town at the time of the earthquake. The questionnaire asked about their behavior in the form of flowchart and mapping with which we can identify where they were at the time of the earthquake and trace how they behaved after that as well as the reason of their choice such as knowledge and information used. With these, we aim to clarify the influential factors on their decision-making and path choice. From the data, 451 responses (collection rate: 19.8%), we analyzed residents' behavioral patterns. As a result, respondents acquired information from various source, while the degree of influence on decision-making varied with what type of information and how they received. Behavioral patterns are different according to the location and situation at the time of earthquake. At the same time, we found some risky behaviors made by the residents; some people came back to the home near the sea and others went to the seaside to watch tsunami.

Full paper -> PDF (CUEE 2012, pp. 1923-1930)

Influence of Fire Information and Architectural Space on Evacuation Decision-making
＜Proceedings of the 42nd Annual Conference of Environmental Design Research Association, pp. 327-328, May. 2011＞
Ryuzo Ohno, Atsushi Hikita
In a fire, the “normalcy bias” makes people tend to ignore emergency announcements and waste critical time before they start to evacuate. Most previous research on fire evacuation has dealt with architectural solutions for smoothing movement after people decide to take action. The present study focuses instead on the process leading up to the decision to evacuate, examining how it is influenced by the kinds of fire information people receive and the characteristics of the architectural space they are in. For the study, a virtual office room was created inside an audio-visual simulation laboratory using images projected on three front screens (each 2 meters square) covering a 180-degree visual field. The 26 subjects were asked to imagine they had come to this room to perform routine computer tasks. Nine scenarios (settings) combined five patterns of fire information with three types of architectural space, and the subjects acted as they would under each situation; they could, for example, “move” out of the room to see what was happening outside by flipping a switch to change the images projected onscreen. All actions were recorded with a video camera until the subject declared that he/she had decided to evacuate, at which point the experiment was terminated. Findings revealed that 1) hearing a fire alarm and a fire-alarm warning prior to the actual fire announcement encourages earlier decision-making, 2) persistent repeating of fire alarms and announcements is effective in prompting people to investigate their surroundings and therefore decide to evacuate, and 3) decision-making tends to be delayed in a room with no windows along the corridor and higher sound insulation, whereas it is speeded in a room with a corridor-side window or a nearby void space that allows people to more easily see what is going on.	Full paper　→　PDF

Effect of Wording of Fire Warning Announcements on Evacuation Behavior in Subway Stations

Ryuzo Ohno, Hidekazu Tamaki, and Masashi Soda

Generally speaking, fire protection has not been considered as great a priority in subway stations as in other urban public facilities because they are assumed to have fewer fire hazards. However, several major subway disasters have occurred in recent years, such as the fire caused by a suicidal man at a subway station in Taegu, Korea, that took 192 lives in 2003 and the terrorist bombings on the London Underground in 2005. Since people tend to follow the flow of the crowd in emergencies, it is important for them to be led in the appropriate direction in the early stages of evacuation. Although in the case of subways, station staffs are expected to provide this guidance, the number of personnel available in any one place is limited, and those who are on hand may not always be fully informed of the overall situation. One possible solution is to make better use of loudspeaker systems, recent technological advancements in which afford precise control of the area and direction covered by individual units, making it possible to tailor warning announcements to the layout and signs of specific locations in the station. The present study experimentally examines how the wording of broadcast warning announcements combines with the effects of nearby spatial features and signs to influence evacuation behavior at subway stations.
A series of experiments was conducted in an existing Tokyo subway station at five settings, each with a different stair and sign layout. For each session, the subjects (13 male and 8 female university students) were asked to listen twice through headphones to a recorded announcement played over a portable voice recorder, then to start heading in whichever direction they believed safest. Experimenters followed them to record their behavior until they started to go up/down a stair, at which point the subjects were asked why they chose that route.
The following results were obtained by the study: (1) After hearing announcements that do not give any directional instructions, subjects tend to choose their way according to prominent spatial features (most notably upward stairs) and exit signs or, in the absence of such physical cues, to rely on their own behavioral history. (2) Subjects tend to feel uneasy about and sometimes distrust announcements that direct them downstairs, unless the instructions indicate that going downstairs first is necessary to eventually reach the exit. (3) Similarly, when subjects hear an announcement that leads them in the same direction as the location of the fire, they tend to feel uneasy and reluctant unless they are given more details about the situation. These results point to possible problems with recently built or remodeled stations in Tokyo that are designed to have one concentrated ticket area shared by several subway lines of different depths, so that some platforms have only downward stairs leading to the exit. Such unintuitive layouts may result in dangerous confusion for evacuees in an emergency situation.

Proceedings　→　PDF file(extended abstract)