More than 520,000 people in Japan would be urged to evacuate for a week if an alert is issued for a possible megaquake in the Nankai Trough off the country’s Pacific coast, a government survey showed on Wednesday.
The figure exceeds the total number of evacuees after the March 2011 Great East Japan Earthquake and the subsequent Fukushima nuclear plant disaster, which came to about 470,000.
As tsunami is expected to reach some areas within minutes after a Nankai Trough megaquake, the government is asking municipalities to designate areas where advance evacuation is necessary.
These designated areas are divided into two types: those where all residents are required to evacuate in advance, and those affecting only residents who need more time to move, including the elderly.
The survey, conducted by the Cabinet Office from June to August, covered a total of 707 municipalities in 29 prefectures that were designated areas for promoting disaster countermeasures as of May.
Of them, 103 municipalities in 16 prefectures said they had designated advance evacuation areas, where more than 520,000 residents would be urged to evacuate in advance.
The total includes 245,600 residents in areas where all residents are subject to advance evacuation, and 274,800 in areas where only the elderly and some others are subject to it.
By prefecture, Kochi had the most residents for advance evacuation, at 92,100, followed by Miyazaki with 79,900 and Shizuoka with 70,200.
In 2019, the government introduced a system to issue two types of emergency information regarding the possible Nankai Trough megaquake: a megaquake alert, which requires advance evacuation, and a megaquake advisory, which does not.
Under the system, the first megaquake advisory was issued last August, causing some confusion, such as beach closures and hotel booking cancellations.
