1:45 PM - 2:00 PM
[MIS14-07] Damage investigation activities utilizing Geopark organization for the 2016 Itoigawa Station North Great Fire in Itoigawa City, Niigata Prefecture
Keywords:Itoigawa city, Massive fire, Foehn phenomena, Damage investigation, Natural disaster, Itoigawa UNESCO Global Geopark
The fire was safely contained at 8:50 p.m. and after continued firefighting efforts it was finally extinguished the following day at 4:30 p.m. 17 people suffered minor to moderate injuries, but in part due to police and the residents’ efforts, there were no casualties. 147 buildings were damaged in the fire (120 completely destroyed, 5 half destroyed and 22 partially damaged), including Kaga-no-I, Niigata Prefecture’s oldest sake brewery established in 1650; 200 year old restaurant Tsurukiya; and the similarly old inn Heiando Ryokan. Roughly 40,000 square meters were consumed in the fire, making it the worst fire in Japan in the past 20 years (Fig. 1).
In 2009, Itoigawa City became one of Japan’s first three Global Geoparks. Even before that time, the city worked to promote the “geostories” which connect the regions’ unique climate, topography and geology. For this reason, the city was able to quickly explain that this fire’s devastating spread was a result of this Renge-oroshi wind phenomenon, a product of regional geological features such as the Umidani Mountains, Northern Alps and valleys created by the Itoigawa-Shizuoka Tectonic Line. This fire is the first in Japan to be classified as a natural disaster as defined by the Act on Support for Reconstructing Livelihoods of Disaster Victims due to the effect of strong wind. The government’s decision to classify this fire as a natural disaster is in no small part due to the efforts of the Geopark in making a clear case to the administration that this fire spread as a result of this Renge-oroshi phenomenon and how this phenomenon is related to Itoigawa unique topography, geology and climate.
The investigation of the fire damage was undertaken by the existing Geopark Organization. The defining feature of this fire is how it spread through leaping flames carried by gale force winds recorded at speeds up 27.2 m/s. As the flames leapt from building to building, the sources of the fire increased and by noon over 3 distinct fires were confirmed. Because of this, it is important that the damage investigation includes a detailed investigation of when and where the fire spread, especially with regard to leaping flames. In interviews with responders from the Itoigawa City Fire Department, most of the fires caused by leaping flames broke out far from the original fire where no firefighters were responding so the details are unclear. For this reason, it is important to collect information through interviews with the residents, business owners and banks in and around the affected area.
This damage investigation will be conducted with the help of volunteers from the Itoigawa Geopark Tourist Guide Association and the Friends of the Fossa Magna Museum Society, both member organizations in the Itoigawa Geopark Council. The reason for choosing these volunteers was the need for people who could interview the many people affected in and around the disaster site from a scientific perspective. The investigation was conducted from the beginning of February 2017 with volunteers conducting face-to-face interviews with those affected by the fire and collecting anonymous surveys regarding the spread of the fire and the conditions at the disaster site. This data was then compiled and analyzed at the Fossa Magna Museum (Fig. 2).
Through this data, a clear image emerged of how the fire spread through leaping flames on the day of the fire. Hours after the fire broke out, the flames leapt to a building a few hundred meters from the original fire and the strong winds made extinguishing the flames difficult. We also learned that windows broken by the fire causing the fire to leap into the buildings where the flammable interiors quickly burst into flame. Also, burning wood falling in between cracks in roof tiles caused the roofs to catch fire.
Through further consideration of the results of this investigation, we hope to better understand the conditions surrounding the spread of this fire. The information gathered from the investigation will be shared throughout the Geopark Network in the hope that it will be useful for disaster prevention.