Lessons from the 2011 Tohoku earthquake tsunami disaster

Based on a comprehensive study of the lessons from the 2011 Great East Japan earthquake and tsunami that devastatedmuch of the northeast Japan (Tohoku), we discuss insights into reconstruction and tsunamiresilient communities. Through field measurement, remote sensing, and numerical modeling approaches with spatial information sciences, we clarified the hydrodynamic characteristics of the tsunami inundation flow, the tsunami fragility curves. As observed in devastated areas and the analysis of the tsunami fragility curves, buildings were especially vulnerable when the local flow depth exceeded 2 m, while a 6 m flow depth would cause everything to be washed away. The findings and results lead to implications for land use management and relocation planning for reconstructing tsunami-resilient coastal communities. As a case study, we conducted the numerical tsunami modeling in Sendai city to evaluate the performance of the reconstruction plan based on the land use and coastal protection scenarios.