Abstract
The 2011 earthquake in Tohoku, Japan caused extensive liquefaction in the coastal area of the Tokyo Bay and the lower banks of the Tone River in the North Kanto region. Because small-diameter underground pipelines were subjected to ground deformation, the amount of pipeline damage can be considered an indicator of the severity of the liquefaction. An analysis of the pipeline damage in the Kashima region along the lower banks of the Tone River showed that the damage was concentrated in an area of 1 km2 . In this study, the reason for the concentration of damage in that small area was analyzed with respect to landform and land use changes that had occurred. The area in which the pipeline damage was concentrated was identified using old topographic maps compiled in the 1880s, as it was difficult to identify the area of concentrated pipeline damage using the current topographic map alone.
