Landform and local site effects on the colonies worst-hit by the 2004 mid-Niigata prefecture, Japan, earthquake

Landform and damage classification surveys have been conducted on six colonies worst-hit by the 2004 mid-Niigata prefecture earthquake. The landform was classified using aerial photographs taken by the US Air Force in 1947. Damage degree of each structure has been classified into four classes including foundation damage class, and location of each structure has been mapped with damage class. Around 1,000 houses and stores have been classified and mapped. In five of six colonies, buildings on the fans composed of colluvial deposits have been more likely suffered severe damage than those on terraces or dissected valleys. In the other colony located on a flood plain, no clear difference in degree of damage among landforms has been observed.