10:00 AM - 10:30 AM
[MIS24-04] Land history of the liquefied sites in the Fushiki district of Takaoka city during the 2024 Noto Peninsula earthquake based on old pictorial maps and historical documents
★Invited Papers
Keywords:Liquefaction, Land history, 2024 Noto Peninsula earthquake, Old pictorial maps, historical documents
Severe liquefaction damages were occurred caused by the 2024 Noto Peninsula earthquake in the Fushiki district of Takaoka City, Toyama Prefecture. In the liquefaction-affected area of the Fushiki district, severe damages such as tilting and subsidence of detached houses, ground deformation such as subsidence of residential land, road surface damage, and subsidence and tilt of electric poles were occurred due to the liquefaction. As a result of examining the topographical conditions of the liquefied sites of this district using the GSI of Japan topographical classification map, liquefaction occurred in flood plains, embankments and reclaimed land in the coastal area, and the inland edge of sandbars. In addition, liquefaction also occurred in the reclaimed land in the coastal area of the Fushiki district.
We compared the liquefaction areas in the Fushiki district caused by this earthquake with the Liquefaction Susceptibility Map which shows the liquefaction susceptibility trends of this district. The liquefaction areas of the reclaimed land in the coastal area were classified as "high probability of liquefaction (risk level 4)" on this map. However, although some areas in the floodplain in the center of Fushiki were classified as "possible liquefaction (risk level 3)," liquefaction and severe damage occurred even in areas that were assumed to have a relatively low liquefaction risk, with "low probability of liquefaction (risk level 2)." Therefore, it can be considered that the liquefaction in the Fushiki district caused by this earthquake occurred in a different trend from the "Liquefaction Susceptibility Map."
The land history of the liquefaction-affected area in the center of Fushiki, where severe liquefaction damage occurred, was examined using historical documents, old pictorial maps, and old topographical maps from the Edo period onwards. According to these old pictorial maps and documents, the liquefaction-affected area in the center of Fushiki was a "newly developed area" that was developed and cultivated in water areas and marshes around 1700, and was reclaimed land and embankment that had been developed for 300 to 400 years. It is assumed that the newly developed land was farmland until the early 1800s, but it was developed into residential and urban areas from the end of the Edo period to the Meiji period. Paddy fields remained in some areas until the end of the Meiji period, but by the early Showa period, the paddy fields had disappeared and urbanization (housing) was complete.
We compared the liquefaction areas in the Fushiki district caused by this earthquake with the Liquefaction Susceptibility Map which shows the liquefaction susceptibility trends of this district. The liquefaction areas of the reclaimed land in the coastal area were classified as "high probability of liquefaction (risk level 4)" on this map. However, although some areas in the floodplain in the center of Fushiki were classified as "possible liquefaction (risk level 3)," liquefaction and severe damage occurred even in areas that were assumed to have a relatively low liquefaction risk, with "low probability of liquefaction (risk level 2)." Therefore, it can be considered that the liquefaction in the Fushiki district caused by this earthquake occurred in a different trend from the "Liquefaction Susceptibility Map."
The land history of the liquefaction-affected area in the center of Fushiki, where severe liquefaction damage occurred, was examined using historical documents, old pictorial maps, and old topographical maps from the Edo period onwards. According to these old pictorial maps and documents, the liquefaction-affected area in the center of Fushiki was a "newly developed area" that was developed and cultivated in water areas and marshes around 1700, and was reclaimed land and embankment that had been developed for 300 to 400 years. It is assumed that the newly developed land was farmland until the early 1800s, but it was developed into residential and urban areas from the end of the Edo period to the Meiji period. Paddy fields remained in some areas until the end of the Meiji period, but by the early Showa period, the paddy fields had disappeared and urbanization (housing) was complete.