Photo/IllutrationMount Miharayama on Izu-Oshima island south of Tokyo erupts in 1986 for the first time in 209 years. At that time, the Tokyo metropolitan government ordered all the residents there to evacuate from the island. (Asahi Shimbun file photo)

Only about 30 percent of 155 municipalities located around 49 volcanoes have worked out evacuation plans required by the government to deal with eruptions, according to a Cabinet Office survey.

Of the five municipalities around the Kusatsu-Shiranesan mountains in Gunma Prefecture, which erupted on Jan. 23 killing one person and injuring 11, four have not done so.

In response to the deadly eruption of Mount Ontakesan in 2014, the government revised the special measures law to deal with active volcanoes. As a result, 155 municipalities were designated as areas that need to take precautionary measures.

They are situated around 49 volcanoes that are observed by the Japan Meteorological Agency 24 hours a day. The 49 are among 111 active volcanoes.

The 155 municipalities were required to work out evacuation plans consisting of six items and incorporate them to prepare for natural disasters. The items included establishing evacuation locations and routes for mountain climbers and residents and implementation of evacuation drills.

According to the Cabinet Office, however, only 51 of the 155 municipalities, or 33 percent, had worked out the six-item plans as of June 2017.

Of the five municipalities around Kusatsu-Shiranesan, only Tsumagoi has formulated a plan. The other four, including Kusatsu in Gunma Prefecture and Takayama in the neighboring prefecture of Nagano, have yet to do so.

Kusatsu has taken measures such as implementing evacuation drills and constructing shelters near the summits. However, it has yet to complete the six-item evacuation plan due to a delay in coordinating with neighboring municipalities.

In Takayama, areas around the volcanoes are surrounded by state-owned forests. Roads for mountain climbing are not open to the public.

Though some people enter the mountains to gather edible wild plants, an official of the Takayama village government said, “It is not realistic to construct shelters for those people whose whereabouts are not known.”

In Otaki, Nagano Prefecture, located near Mount Ontakesan, the village government devised a plan to prepare for a disaster after the 2014 eruption that included evacuation routes and locations.

However, the 2015 revisions to the law made it necessary for the village government to work out a more concrete plan.

“We have to coordinate with related organizations. We must also consider how to convey information to mountain climbers and skiers and evacuate them. There are many challenges to examine,” said an official of the Nagano prefectural government’s crisis management and disaster preparedness section.

In some of the 155 municipal governments, there is only one official in charge of disaster preparedness. Many of the 155 municipalities also have not experienced disasters involving volcanoes. Therefore, generally speaking, they tend to be slow in working out evacuation plans.

“Much has to be described in the evacuation plan. As municipal governments alone cannot offer sufficient staff members for the job, the central government is also dispatching its employees to them,” an official of the Cabinet Office said, adding, “We want to proceed with the job in cooperation with them.”