Prepare for major disasters in Tokyo: Stockpiling and choosing home evacuation

An ounce of prevention is worth a pound of cure: Secure as many disaster prevention stockpiles as possible

An “earthquake centered directly under the capital” literally refers to an earthquake occurring with its epicenter in the Greater Tokyo Area, including Tokyo. A severe earthquake with an intensity of upper 6.0 on Japanese seismic scale, which is equivalent in intensity to the Great East Japan Earthquake of 2011 and the Kumamoto Earthquake of 2016, is anticipated to occur and hit the region in the future. Such an earthquake is said to occur with a probability of 70% within the next 30 years. According to the damage estimates by the JapaneseTokyo Metropolitan gGovernment, it is estimated that fires and the collapse of buildings would cause death to , at the maximum, approx. 23,09,700 people at the maximum.

Such a large-scale earthquake is obviously expected to cause lifelines, including water supply, sewage system, electricity and gas, as well as such infrastructures as communication and traffic networks to be out of service. Generally, lifelines would be shut down for about a week. During the time, people would have to wait for and depend on relief suppliers. Therefore, maintaining a stockpile with a week’s worth of supplies—including foods, water, portable toilets, portable gas stoves and cartridges, and batteries—is recommended. The importance of sufficient disaster preparation cannot be overemphasized. It should be kept in mind that actual damages could be twice as severe as predicted. Stockpiling should be prepared in anticipation of at least a two-week shutdown of lifelines. An ounce of prevention is worth a pound of cure. Disasters cannot be over prepared for.

The same approach should be applied to the emergency preparation for heavy rain and typhoons causing windstorm and flood damage disasters, including typhoons. There is, however, one difference from earthquake preparation: Rain and wind are foreseeable to some extent based on weather forecasts and, therefore, evacuation before the occurrence of damage is possible. Preparation for storm and flood disasters should include identifying and remembering places to evacuate to, given that evacuating to the highest place possible is imperative in the event of a storm and flood disaster. Referring to a hazard map, which might be also called a disaster map, is very useful. It is highly recommended that where to evacuate be identified and confirmed on a regular basis and establish a chronological evacuation action plan (My Timeline) in advance. Especially areas close to the sea could be attacked by tsunami in the event of an earthquake, as in the case of the Great East Japan Earthquake. So, people living near the sea should identify in advance high places to evacuate to.

Choosing home evacuation to prevent overcrowding at evacuation centers

Considering the possible occurrence of an earthquake centered directly under the capital, Tokyo’s large population of approx. 14 million is definitely an issue to be addressed. In Tokyo, there are approx. 3,000 designated evacuation centers with a total accommodation capacity of approx. 3.17 million people. It is unrealistic to get all the residents of Tokyo to evacuate to the evacuation centers.

In some cases, home evacuation could be less stressful. However, there are certain conditions that have to be met in staying home, either at an apartment or a detached house. Choosing home evacuation could be an option if the following three conditions are fulfilled: sufficient stockpiles maintained; high quake-proof performance of the building; and low inundation risk. The more people choose home evacuation, the more people who might be concerned about home evacuation due to, for example, their age and physical disabilities, can go to evacuation centers with a sense of security. Such dispersed evacuation would prevent overcrowding at evacuation centers, thereby mitigating the risk of infections, one of the secondary disasters.

Quake proof performance of buildings can be assessed by seismic diagnosticians, specialists who have completed a specific training program. The Tokyo Metropolitan Government categorizes the buildings into three grades in terms of quake proof performance. The highest grade “III” indicates that the building’s risk is low in terms of possible collapse and/or ruination due to the tremor and shock from an earthquake. The next grade “II” means that there is a risk that the building could collapse and/or be ruined due to the tremor and shock from an earthquake. The grade “I” indicates that the building’s risk is high in terms of possible collapse and/or ruination due to the tremor and shock from an earthquake. Seismic diagnosticians, who have completed a specific training program, are qualified to evaluate buildings’ quake-proof performance. Receiving seismic diagnosis as part of disaster preparation would help determine the appropriateness of home evacuation. Especially note that those buildings built based on the former quake proof performance standard before its revision in 1981 might need urgent anti-seismic reinforcement.

Cooperate with experts and maintain a local “stockpile of people”

We, experts, strongly emphasize the importance of stockpiles because today’s society is highly dependent on lifelines and infrastructures. If water supply, sewage systems, electricity, gas, communication networks and/or traffic networks get shut down due to an earthquake centered directly under the capital, that would severely affect our day-to-day lives that are otherwise normal to us. Maintaining a stockpile of sufficient emergency supplies would mitigate problems and prevent people from feeling confused in the event of a disaster. It would be also wise to have a tent as part of the emergency kit to shelter from rain and wind in light of the possibility of outdoor evacuation.

On top of a stockpile of supplies, a “stockpile of people” is also a necessity in preparation for a major disaster. In the case of emergency, no one would be more reliable than such individuals as nurses, public health nurses, seismic diagnosticians who evaluate the condition of buildings damaged by the primary disaster, and members of voluntary disaster prevention associations who help prevent fires that could occur following an earthquake. It is important for the residents of local communities and of apartment buildings to maintain a “stockpile of people” by consistently keeping close contact with experts and thereby to prepare for emergencies. Isolation should be avoided especially when people are affected by a disaster. Tokyo, a city with a large population, must have many experts who are capable of functioning in the case of emergency.

The probability of occurrence of an earthquake centered directly under the capital within the next 30 years is said to be 70%. Minimizing the damage from an earthquake with a seismic intensity of upper 6.0 necessitates sufficient stockpiles of supplies and people and appropriate evacuation methods suitable for the situation. It is imperative to consistently maintain a high awareness of disaster prevention.