TY - JOUR
T1 - Revealing complex tsunami evacuation process patterns induced by social interactions
T2 - A case study in Ishinomaki
AU - Makinoshima, Fumiyasu
AU - Oishi, Yusuke
AU - Nakagawa, Masaharu
AU - Sato, Shosuke
AU - Imamura, Fumihiko
N1 - Funding Information:
We would like to express our sincere thanks to the interviewees who agreed with the motivations behind this study and cooperated with the survey. Our thanks also go to the interviewers from 3.11 Future Support Association, Mr. Toyokazu Abe and Ms. Seiko Ito and to Mr. Takashi Fukuda who participated in the data preparation and confirmation for the analysis in this study. This research was supported by a joint research grant from the International Research Institute of Disaster Science, Tohoku University and by the Core Research Cluster of Disaster Science in Tohoku University (Designated National University).
Publisher Copyright:
© 2021 The Author(s)
PY - 2021/5
Y1 - 2021/5
N2 - Compared to evacuation behaviours, behaviours preceding evacuation including milling during tsunamis remain unclear. This study developed an analysis approach that evaluates the similarities in behaviour sequences throughout the evacuation process and investigated both the preceding behaviours and evacuation behaviours in Ishinomaki during the 2011 tsunami. The developed method was first applied to 101 detailed evacuation interview data and identified 16 major evacuation trip patterns in the study area during the 2011 tsunami. Then, we characterised the major patterns based on narratives and found key behavioural characteristics during tsunamis that both expanded and mitigated human loss. The analysis only considered the different destinations visited by people during evacuation processes; however, the proposed method successfully distilled evacuation processes with not only similar behavioural patterns but also similar thoughts or intentions. The collected behaviours revealed the complex evacuation processes during the tsunami, i.e., nearly half of the interviewees had two or more destinations in their evacuation trips. Evacuating alone was rarely observed, and many local residents first attempted to perform safety or damage confirmations, which caused evacuation delays. On the other hand, the results also indicated that this tendency of unification along with immediate school evacuation promoted evacuations in the study area by triggering household movements towards a hill, which unintentionally worked as a tsunami evacuation trip. We inferred that such secondary household movements potentially triggered other evacuation movements as tertiary effects by being sighted by other people. The findings of this study provide evidence suggesting that evacuation processes are largely affected by social structures or ties and highlight the importance of evacuation preparedness considering the revealed behaviour characteristics.
AB - Compared to evacuation behaviours, behaviours preceding evacuation including milling during tsunamis remain unclear. This study developed an analysis approach that evaluates the similarities in behaviour sequences throughout the evacuation process and investigated both the preceding behaviours and evacuation behaviours in Ishinomaki during the 2011 tsunami. The developed method was first applied to 101 detailed evacuation interview data and identified 16 major evacuation trip patterns in the study area during the 2011 tsunami. Then, we characterised the major patterns based on narratives and found key behavioural characteristics during tsunamis that both expanded and mitigated human loss. The analysis only considered the different destinations visited by people during evacuation processes; however, the proposed method successfully distilled evacuation processes with not only similar behavioural patterns but also similar thoughts or intentions. The collected behaviours revealed the complex evacuation processes during the tsunami, i.e., nearly half of the interviewees had two or more destinations in their evacuation trips. Evacuating alone was rarely observed, and many local residents first attempted to perform safety or damage confirmations, which caused evacuation delays. On the other hand, the results also indicated that this tendency of unification along with immediate school evacuation promoted evacuations in the study area by triggering household movements towards a hill, which unintentionally worked as a tsunami evacuation trip. We inferred that such secondary household movements potentially triggered other evacuation movements as tertiary effects by being sighted by other people. The findings of this study provide evidence suggesting that evacuation processes are largely affected by social structures or ties and highlight the importance of evacuation preparedness considering the revealed behaviour characteristics.
KW - 2011 Tohoku tsunami
KW - Evacuation
KW - Trip patterning
KW - Tsunami
KW - Tsunami evacuation
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U2 - 10.1016/j.ijdrr.2021.102182
DO - 10.1016/j.ijdrr.2021.102182
M3 - Article
AN - SCOPUS:85103096412
VL - 58
JO - International Journal of Disaster Risk Reduction
JF - International Journal of Disaster Risk Reduction
SN - 2212-4209
M1 - 102182
ER -