SHIZUOKA, Mar 21, 2025 (News On Japan) - The Japanese government on March 21st released a report outlining countermeasures for volcanic ash in the event of a Mount Fuji eruption, including a four-stage evacuation plan based on ashfall volume.
Shizuoka Prefecture plans to incorporate the findings into its basic evacuation framework.
"The damage from volcanic ash rarely leads directly to loss of life. Residents are expected to continue living at home as much as possible. Therefore, it is essential to maintain adequate daily supplies as a basic principle," said Toshitsugu Fujii, chair of the government’s ashfall task force for the Tokyo metropolitan area.
According to government estimates, a major eruption of Mount Fuji could result in approximately 490 million cubic meters of volcanic ash — equivalent to about 400 Tokyo Domes — falling on residential areas, roads, and other infrastructure. This could severely disrupt daily life and economic activity.
The report, compiled by a panel of experts, outlines four evacuation stages depending on the ashfall volume. In Stages 1 through 3, where ash accumulation is less than 30 centimeters, residents are generally expected to remain at home. In Stage 4, where ash exceeds 30 centimeters, evacuation is advised. The report also recommends households stockpile at least one week’s worth of supplies, with two weeks’ worth preferred where possible, to prepare for prolonged disruption.
Shizuoka Prefecture, together with Yamanashi and Kanagawa prefectures, has been developing hazard maps and basic evacuation plans through the Mount Fuji Volcanic Disaster Prevention Council.
"The effects and evacuation methods for each ashfall level require responses similar to those being considered in the Tokyo metropolitan area. Based on the national report, we will proceed with analysis and discussions next fiscal year and work on integrating them into the prefecture’s evacuation plan," said Hiroyuki Sakai, head of the Crisis Management Division of Shizuoka Prefecture.
Ash removal and disposal also remain major challenges. The report notes the need for future studies into temporary storage sites and final disposal methods.
"It’s important to fear disasters correctly — knowing what could happen allows us to respond appropriately when the time comes. We hope people will pay more attention to Mount Fuji and understand the potential risks involved," said Sakai.
Source: SBSnews6
