Research on the relocation of castle towns to higher ground in Koromo

Abstract

This study clarified the history of flood damage and flood control measures in the former Kyomo (now Toyota City, Aichi Prefecture), a flood-prone area, and the circumstances and factors leading to the relocation of the castle. The decision to relocate the castle to higher ground was triggered by the flood of 1871, which was caused by the Yahagigawa River becoming an overhead river. The biggest cause of the flood was the conversion of the Yahagigawa River into an overhead river. The main cause was the sedimentation caused by the riverbed replacement work in the early Edo period, but the damage was compounded by the upstream tsunami and the delay of the Yasunaga River construction due to farmers' protests.