[H-DS10] Literacy for Disaster Risk Reduction

[HDS10-07] Characteristic Issues in Damage Assessment Methodology to Tenement Houses Affected by Liquefaction - A Case Study of Himi City, Toyama, in the 2024 Noto Peninsula Earthquake -

*Munenari Inoguchi¹ (1.University of Toyama)

Keywords:Building Damage Assessment, Liquefaction, Tenement House

On January 1, 2024, the Noto Peninsula earthquake occurred with its epicenter off the coast of Noto. Centered in the Noto region of Ishikawa Prefecture, the earthquake caused extensive damage not only by shaking, but also by tsunami and fires. In western Toyama Prefecture, which is adjacent to Ishikawa Prefecture, the tremor also caused damage to residential buildings. In particular, liquefaction occurred in coastal areas due in part to the sandy soil, triggering damage to many buildings. The first step in assisting disaster victims to rebuild their lives is to conduct a "residential damage assessment. This survey is conducted based on the guidelines provided by the Cabinet Office. According to this guideline, in the case of earthquake disasters, the damage is assessed from the exterior as the primary survey. In Himi City, Toyama Prefecture, where much of the damage occurred, most of the houses were row-houses. Therefore, the extent of damage that could be determined from the exterior was very small. In addition, the damage caused by liquefaction was often difficult to see on the exterior. On the other hand, when the internal damage presented by the victims at the time of issuance of the disaster victim's certificate was confirmed, it was found that the damage was concentrated in the interior, in sharp contrast to the exterior. In other words, it was very difficult to determine the extent of damage only from the exterior survey based on the Cabinet Office guidelines. In addition, according to the guidelines, an interior survey is to be conducted as a secondary survey, but this is a time-consuming task. In order to rebuild the lives of disaster victims more quickly, it is essential to conduct an efficient survey to determine the extent of damage to their houses. To this end, a method to reliably and quickly determine the damage caused by liquefaction to tenement buildings was needed. The authors promoted damage assessment of dwellings based on photographs of the damage presented by the victims and interviews with them. In the process, the authors clarified the characteristics of damage that are often overlooked and organized points to keep in mind. In this study, we present these points systematically and compile them as a guideline for dealing with similar damage that may occur in preparation for the next disaster.