Millions of people have been left without water, sewage systems or power following Japan’s devastating earthquake and tsunami.
10m high waves
More than 1.4M households were left without water supply, 1.25M homes have no electricity, and 28 sewage treatment plants failed in the aftermath of the disaster. Tsunami waves of up to 10m were reported.
Ibaraki prefecture’s water infrastructure was the worst hit as 11 of its wastewater plants failed due to liquefaction, land uplift, subsidence and flooding. An estimated 470,000 homes in the area were also without water.
The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) reported that Miyagi prefecture to the north and Chiba just to the south were also badly hit, with water supply cut off to 310,000 and 300,000 households respectively.
Eight wastewater plants were flooded or destroyed in Miyagi, and two in Chiba. Fukushima prefecture lost the use of one wastewater plant due to liquefaction, and had 190,000 households without water.
MLIT has dispatched 15 staff to Ibaraki, Miyagi, Chiba and Fukushima to investigate the damage. The government has also begun delivering water supplies by road − but a UN Office for the Coordination of Humanitarian Affairs (OCHA) spokesman said it appears that these supplies could be “far from sufficient”. There are also concerns that the tsunami could have contaminated some water supplies.
Around 1.25M households are also without power. Eleven of the 54 nuclear generators in the tsunami-affected areas have had to reduce or cut off their output.
An irrigation dam in Fukushima is also reported to have collapsed, washing away hundreds of homes. A spokesman for the Japan Water Agency said information on the incident is “very limited” because the area has been rendered inaccessible.
“The tsunami might have a wave length of several kilometres, whereas the barrier might be just metres”
Tiziana Rossetto, University College London
In the Tohoku region of Japan − comprising Aomori, Iwate, Miyagi, Akita, Yamagata and Fukishima −2,852 buildings were destroyed and over 40,000 were damaged by either earthquakes, the tsunami or fire. Five thousand houses remain flooded in Iwate alone. These figures do not include the areas and buildings which remain isolated by damage to transport infrastructure, and the numbers are likely to rise once access is re-established.
Japan is known for being well protected against tsunamis, but many of its defences were simply overwhelmed by the size and speed of this incident.
Tsunamis are unpredictable in size and location, making it difficult to plan and build defences, said University of Dundee physical geography lecturer Sue Dawson. Defence planning can only be based on past events − buttwo tsunamis are never the same, she said.
“In some cases the sea walls have done their job, but there will always be a wave that can overtop it”
Sue Dawson, University of Dundee
Breakwaters and sea walls are very effective against small tsunamis, but are vulnerable to being overtopped by large events. “If you have 9m waves it’s very difficult to mitigate against that,” said Dawson. “In some cases the sea walls have done their job, but there will always be a wave that can overtop it.”
University College London Earthquake and People Interaction Centre director Tiziana Rossetto said when a tsunami is this large it is difficult for defences to even slow it down.
“They won’t actually reduce the energy the tsunami carries that much, if you think of the comparative size. The tsunami might have a wave length of several kilometres, whereas the barrier might be just metres.
“It’s difficult to reduce the energy of such waves because they move the entire water column, down to the sea bed.”
Up to 40% of Japan’s coastline is protected by breakwaters, flood gates and sea walls. Elevated evacuation platforms are also increasingly in use.
First steps to relief
The immediate disaster relief effort will be led by the Japanese government, NCE has learned.
The Japanese government has set up an Emergency Response Team to lead the relief effort. Search and rescue and re-establishing essential services are the immediate priorities.
The government will deploy 100,000 defence personnel, 3,660 police personnel, 96 helicopters, seven fixed wing aircraft and 58 naval vessels.
“Japan is a very advanced economic country and the government has very sophisticated systems in place,” said ICE President Peter Hansford.
“Tsunamis are not unexpected in that part of the world. International humanitarian support will not necessarily be called upon immediately.
“First line of response will come from Japan,” he said.
A seven-person UN Disaster Assessment and Coordination (UNDAC) team has arrived in Japan to support the relief effort coordination, but it said its role will be minimal.
It said the government “has a very strong disaster preparedness and response mechanism in place”.
The UK Department for International Development (DfID) has dispatched its own team to Japan, comprising 59 fire service personnel and a medical support team.
The team took 11t of specialist equipment including heavy lifting and cutting equipment to free survivors from debris.
The relief effort is being hampered by road damage and flooding that has left some areas inaccessible.
Engineering disaster relief charity RedR member Brian Davison, speaking in the UK, said the first step to overcoming such access challenges is usually an aerial assessment to determine the best way to reach the isolated communities.
Helicopters can only be used if there is a landing space suitably clear of trees, mud and debris. If this is the case, Davison said, a small party is usually sent in ahead to prepare a landing zone. Access by boat may also be an option for isolated coastal towns.
Aid agencies have warned that the rebuilding of access to the worse affected areas could take a year.