Tsunami inundation in the event of a huge earthquake A series of reviews of disaster prevention plans by local governments

Tsunami inundation in the event of a huge earthquake October 15, 5:05 a.m., following a series of reviews of disaster prevention plans by local governments

It has been shown that 38 municipal government buildings nationwide may be flooded in the event of a tsunami in the event of a huge earthquake in the “Chishima Trench” and “Japan Trench” announced by the National Review Committee, but NHK’s interview showed that nearly half of the government buildings have established alternative facilities or reviewed evacuation plans in the event of a disaster.
In response to the Great East Japan Earthquake, the National Review Committee examined the assumption of the largest class of earthquakes along the “Chishima Trench” and the “Japan Trench” from the southern coast of Hokkaido to the offing of Iwate Prefecture, and announced last month in April that the area except Iwate Prefecture was located.

As a result, it was shown that 38 municipal government buildings from Hokkaido to Ibaraki Prefecture were flooded by the tsunami, and that the center of the city could be damaged.

NHK interviewed 38 municipalities and found that nine municipalities, including Aomori Prefecture and Kamaishi City, Iwate Prefecture, were considering new proposals and changes to alternative government buildings in the event of a disaster.

In addition, in Noboritsu City, Hokkaido and Kazamaura Village, Aomori Prefecture, it is known that the planned site for the construction of a new government building may be flooded, and the plan is being reviewed.

Evacuation plans for residents have also been affected due to the risk of damage to the city center.

13 municipalities, including The town of Heighta in Hokkaido and Miyako City in Iwate Prefecture, are considering revising their plans, including changing some evacuation sites.

On the other hand, some local governments are struggling to cope with new assumptions.

At the government building in Samanya-cho, Hokkaido, which is expected to have the highest flood of 10.6 meters, it is not possible to relocate government buildings or set up alternative government buildings due to financial resources issues, so we would like to seek financial support from the government.

The tsunami which exceeds the great earthquake is assumed, and Kamaishi in the disaster area also reviews measures.

Local governments in Iwate Prefecture, which was affected by the Great East Japan Earthquake, have been forced to review disaster prevention measures that have been promoted since the Great East Japan Earthquake, as some areas have exceeded the estimated tsunami of the largest class along the Japan Trench.

According to the government, it is assumed that the government buildings of five municipalities will be flooded in Iwate Prefecture, and four municipalities, such as Kamaishi City and Kuji City, will consider changing alternative government buildings and specifying new ones.

In addition, since flooding of the city center is expected, all five municipalities are considering reviewing some of the evacuation sites.

In Kamaishi City, where 1064 people were killed in the Great East Japan Earthquake, more than 180 billion yen was invested in the development of seawalls and the relocation of luxury homes to higher ground, and the prefecture and the city have been promoting reconstruction projects.

In addition, since the city hall was flooded by the tsunami, we have been promoting measures such as establishing a disaster response headquarters as an alternative government building in the fire department building built inland if a large tsunami warning is issued at night or on holidays.

However, this time, the assumption of a tsunami exceeding the earthquake was shown, and there was a possibility that the tsunami would be flooded to the fire department building and even inland residential areas.

In response, the city decided to change the location of the alternate government building and designate the community center, which is about five kilometers from the sea, as an alternative government building.

Kamaishi City is also holding briefing sessions for each district in an area to provide detailed information to residents of the newly flooded area.

In the future, the city will hold briefings in all districts and will change and add evacuation sites by the end of this fiscal year.

Mr. Satoshi Sasaki, Director of Crisis Management in Kamaishi City, said, “We would like to make full use of the lessons learned from the Great East Japan Earthquake to call on residents to regain their awareness of evacuating, and work hard to prevent victims from the tsunami.”

Aomori Kazamaura Village Revised Plans to Relocate Public Offices

In the case of a huge earthquake caused by the “Chishima Trench” and “Japan Trench” off the coast of Iwate Prefecture from the offing of Hokkaido, it is found that the relocation destination of the government office may be flooded by the tsunami in Kazamaura Village in Aomori Prefecture, and the relocation plan is being reviewed.

Kazamaura Village in Aomori Prefecture, facing the Tsugaru Strait, was built in 1984, 84 years ago, and is aging, and it was said that it would be flooded about 1 to 2 meters under the assumption of a tsunami indicated by the prefecture eight years ago, so we are moving forward with the relocation plan from the day before yesterday.

The relocation site was the site of an elementary school about 6 meters above sea level, and it was planned to move as early as four years later, but it was found that the area around the site of the elementary school could be flooded by about 2 to 5 meters due to the tsunami caused by the huge earthquakes of the Chishima Trench and the Japan Trench, which was announced by the National Review Committee in April.

For this reason, the village is returning the plan to a blank sheet and looking for a new relocation destination, but the high ground in the village does not have public land with the size to which the government building can be built, and there is no hope of relocation.

In addition, the relocation cost of approximately 2 billion yen was planned to be covered by utilizing the “Emergency Disaster Prevention and Mitigation Business Bond”, which the government effectively bears 70% of the cost when the government relocates the government office for disaster prevention reasons, but the financial burden of the village is expected to increase even if the relocation destination is found, as the system is expected to end in March next year, 10 years after the Great East Japan Earthquake.

Hiroshi Tsujioka, director of Kazamaura Village, said, “The announcement of the assumption of a new tsunami overlaps with the time of the spread of the new coronavirus infection, and it is a double pain, but we want to secure a safe place even if it takes a long time and proceed with the relocation.”

Experts: “Development and training of alternative government buildings based on new assumptions”

Hiroaki Yoshii, professor emeritus of Tokyo University of Economics, who is familiar with local government planning for disaster prevention, said of the local government’s response to the new flood assumption: “In the Kumamoto Earthquake, government buildings will be unusable in five municipalities, and if government buildings are damaged, it will be very difficult to respond to subsequent disasters. It is necessary to prepare for the construction and training of alternative government buildings based on new assumptions.”

On the other hand, since responding to new assumptions is a major burden for small municipalities, it is necessary for the government and prefectures to support and develop effective plans.

Professor Emeritus Yoshii also said, “We must not repeat the tragedy of the disaster in which government buildings were damaged and many staff members died, as they were during the Great East Japan Earthquake. It is important to make a plan for the evacuation of employees through this review of the assumptions,” he said, pointing out that it is necessary not only to respond to residents, but also to take measures to protect the lives of employees.