Understanding the Extreme Tsunami Inundation in Onagawa Town by the 2011 Tohoku Earthquake, Its Effects in Urban Structures and Coastal Facilities

The 2011 Tohoku Tsunami is considered to be one of the most tragic events in Japan's disaster history, and represents an important milestone for the research community regarding the investigation of the characteristics of tsunami inundation. A thorough analysis of tsunami inundation was conducted using numerical modeling, and measurements from a video recorded from the rooftop of a building in Onagawa in Miyagi Prefecture. In this study, we analyze the destruction of buildings using numerical simulations and tsunami fragility functions. Numerical results for the locations at which the tsunami eyewitness video was recorded are compared with measurements. In addition, we considered the effect of the breakwater in Onagawa bay to evaluate its contribution to reducing overland tsunami inundation depths. The results of our simulations show that the maximum inundation depth due to the first incoming wave was over 16 m, and over 500 buildings were washed away with this first wave. This result is consistent with the video data. Further, we found that the breakwater, which was not originally designed against tsunami waves, reduced the maximum tsunami inundation depth at least by 2.0 m in Onagawa town.

[1]  S. Koshimura,et al.  The 2011 Tohoku Tsunami Flow Velocity Estimation by the Aerial Video Analysis and Numerical Modeling , 2013 .

[2]  F. Imamura,et al.  Building damage characteristics based on surveyed data and fragility curves of the 2011 Great East Japan tsunami , 2012, Natural Hazards.

[3]  Stephen V. Stehman,et al.  Selecting and interpreting measures of thematic classification accuracy , 1997 .

[4]  Costas E. Synolakis,et al.  Runup Measurements of the December 2004 Indian Ocean Tsunami , 2006 .

[5]  Utku Kânoğlu,et al.  The Fukushima accident was preventable , 2015, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[6]  Ian Parsons,et al.  Surface deformation due to shear and tensile faults in a half-space , 1986 .

[7]  C. Synolakis,et al.  Lagrangian flow measurements and observations of the 2015 Chilean tsunami in Ventura, CA , 2016 .

[8]  Mohsen Azadbakht,et al.  Tsunami Modeling, Fluid Load Simulation, and Validation Using Geospatial Field Data , 2014 .

[9]  Tsunami Assessment Method for Nuclear Power Plants in Japan 2016 , 2006 .

[10]  Alison Raby,et al.  Tsunami damage to coastal defences and buildings in the March 11th 2011 Mw9.0 Great East Japan earthquake and tsunami , 2013, Bulletin of Earthquake Engineering.

[11]  Tomoya Shibayama,et al.  Field Survey of the 2011 Tohoku Earthquake and Tsunami in Miyagi and Fukushima Prefectures , 2012 .

[12]  Shunichi Koshimura,et al.  Mapping of Building Damage of the 2011 Tohoku Earthquake Tsunami in Miyagi Prefecture , 2012 .

[13]  Narumi Takahashi,et al.  Tsunami Inundation Modeling of the 2011 Tohoku Earthquake Using Three-Dimensional Building Data for Sendai, Miyagi Prefecture, Japan , 2014 .

[14]  S. Koshimura,et al.  Improving Tsunami Numerical Simulation with the Time-Dependent Building Destruction Model , 2014 .

[15]  Dmitry J. Nicolsky,et al.  Validation and Verification of a Numerical Model for Tsunami Propagation and Runup , 2011 .

[16]  Gaku Shoji,et al.  Analysis of Tsunami Flow Velocities during the March 2011 Tohoku, Japan, Tsunami , 2013 .

[17]  Fumihiko Imamura,et al.  Examination of three practical run-up models for assessing tsunami impact on highly populated areas , 2011 .

[18]  Kenji Satake,et al.  Tsunami generation by horizontal displacement of ocean bottom , 1996 .

[19]  S. Koshimura,et al.  Tsunami Inundation Mapping in Lima, for Two Tsunami Source Scenarios , 2013 .

[20]  Nobuhito Mori,et al.  Survey of 2011 Tohoku earthquake tsunami inundation and run‐up , 2011 .

[21]  F. Imamura,et al.  Lessons Learned from the 2011 Great East Japan Tsunami: Performance of Tsunami Countermeasures, Coastal Buildings, and Tsunami Evacuation in Japan , 2013, Pure and Applied Geophysics.

[22]  Isamu Aida,et al.  RELIABILITY OF A TSUNAMI SOURCE MODEL DERIVED FROM FAULT PARAMETERS , 1978 .

[23]  C. E. Synolakis,et al.  Validation and Verification of Tsunami Numerical Models , 2008 .

[24]  U Kânoğlu,et al.  Tsunamis: bridging science, engineering and society , 2015, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[25]  Shunichi Koshimura,et al.  Lessons from the 2011 Tohoku Earthquake Tsunami Disaster , 2013 .

[26]  Fumihiko Imamura,et al.  Developing Fragility Functions for Tsunami Damage Estimation Using Numerical Model and Post-Tsunami Data from Banda Aceh, Indonesia , 2009 .

[27]  Yoshimitsu Tajima,et al.  The 11 March 2011 East Japan Earthquake and Tsunami: Tsunami Effects on Coastal Infrastructure and Buildings , 2013, Pure and Applied Geophysics.

[28]  Hermann M. Fritz,et al.  The 2011 Japan tsunami current velocity measurements from survivor videos at Kesennuma Bay using LiDAR , 2012 .

[29]  Nobuhito Mori,et al.  Nationwide Post Event Survey and Analysis of the 2011 Tohoku Earthquake Tsunami , 2012 .

[30]  Shunichi Koshimura,et al.  Response to the 2011 Great East Japan Earthquake and Tsunami disaster , 2015, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[31]  F. Imamura,et al.  Empirical fragility analysis of building damage caused by the 2011 Great East Japan tsunami in Ishinomaki city using ordinal regression, and influence of key geographical features , 2014, Stochastic Environmental Research and Risk Assessment.

[32]  Hermann M. Fritz,et al.  2004 Indian Ocean tsunami flow velocity measurements from survivor videos , 2006 .

[33]  Fumihiko Imamura,et al.  Advanced Tsunami Computation for Urban Regions , 2013 .

[34]  Costas E Synolakis,et al.  Tsunami: wave of change. , 2006, Scientific American.