我孫子市の液状化被害とそれを教訓としたハザードマップの改訂

抄録

 The 2011 off the Pacific coast of Tohoku Earthquake brought severe damage caused by wide-ranging soil liquefaction across the Tohoku and Kanto districts. In Abiko City, Chiba Prefecture, heavy liquefaction damage occurred in a small area, which was not accurately predicted by the existing liquefaction hazard map. The authors consider the reason to be land history, such as landform development and artificial landfill, which was not taken into account in the assessment of liquefaction risk. Accordingly, Abiko City has revised the hazard map to take account of micro-landform classifications using land condition maps, old edition maps, and aerial photographs with the assistance of the Geospatial Information Authority's support team.