Photo/IllutrationRescue officials in Oita in August conduct training based on a scenario of a Nankai Trough Earthquake. (Asahi Shimbun file photo)

The central government has provided guidelines to local governments and businesses on how to react when a heightened “alert” is issued for a major earthquake along the Nankai Trough off the Pacific coast.

The guidelines urge local governments and businesses to have plans in place for such an eventuality.

While the guidelines provide some reference data, they are too general to be of practical help, requiring each community to come up with specific plans based on their own local conditions.

Both the central government and local authorities need to continue working together to flesh out the guidelines and render them more useful.

A 70 percent to 80 percent chance is projected for a mega-quake of magnitude 8 to 9 occurring within the next 30 years along the Nankai Trough, which extends from off the central Tokai region to the southwestern island of Kyushu.

Based on a report released last December by the Central Disaster Management Council’s task force, the guidelines project various scenarios and indicate respective countermeasures.

One of the scenarios, termed “han-ware” (half-impact), is that the Nankai Trough Earthquake will impact either the east or west side of the Kii Peninsula. Under another scenario, termed “ichibu-ware” (partial impact), the impact of the quake will be felt in a smaller area than the above.

A total of 707 municipalities are projected to be affected, and evacuation sites for citizens are to be designated before the end of the current fiscal year.

The most crucial element concerns precautionary evacuation procedures after an alert is issued for a second mega-quake.

In the case of the “han-ware” scenario, the guidelines point out the possibility of the initially unimpacted side of the Kii Peninsula being struck later by a second mega-quake.

They said residents need to be pre-evacuated for about one week in communities prone to flooding from tsunami even on the unimpacted side.

Such communities will be along the coast, but it would not do to simply evacuate everyone across as broad an area as possible. Evacuation plans will have to take many details into consideration, such as how far each community is from higher ground and how easy or difficult it will be for residents to reach safety.

Other vital questions include which communities have large populations of senior citizens, and what sort of assistance is needed, and for how many people.

Having these details routinely checked out will certainly raise the level of disaster-preparedness.

The guidelines make no mention of preventive measures for areas prone to quake-triggered landslides, but such measures should definitely be worked out.

Starting this month, the Cabinet Office has been holding briefings for local governments. One of the most frequently asked questions concerns the cost of running evacuation facilities.

The government says it is considering applying the Disaster Relief Law to foot the bill, but an official decision needs to be made as soon as possible to enable local authorities to set up viable plans.

The first thing that must be borne in mind is that a mega-quake can strike without warning. Once such a quake strikes, high priority should also be placed on rescue and aid activities even if an alert is issued for unimpacted areas.

Necessary support will not reach the people who really need it if all economic activities are shut down, even in unimpacted areas.

The important thing is for society as a whole to maintain “normalcy” while remaining fully vigilant. There certainly are municipalities that will be expected to serve as post-disaster “hubs” of traffic of people and goods.

We need to remind ourselves that we will not be able to deal with an emergency unless we remain prepared at all times.

--The Asahi Shimbun, April 22