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Metro Tokyo discussing night buses as flood evacuation method

TOKYO -- The Tokyo Metropolitan Government has begun discussions with transportation firms about emergency late night train and bus services in the event that the capital and surrounding area is set to be hit with a flood disaster on the scale of the torrential rains that hit western Japan in July.

The plan aims to evacuate the residents of the wider metropolitan area smoothly and reduce the number of possible victims, and is set to be put together during the next fiscal year.

According to the metro government and other bodies, if a large typhoon with a central atmospheric pressure measuring around 910 hectopascals makes landfall and the tide rises, flooding is expected to hit one-third of central Tokyo's 23 wards, mainly those in eastern part of the capital -- an area of roughly 212 square kilometers. If levees break or other incidents occur, the flood waters could remain in extensive areas for over a week. In addition, if the Arakawa River and Edogawa River simultaneously overflow, the areas where 90 percent of the residents of the eastern Tokyo wards of Sumida, Koto, Adachi, Katsushika and Edogawa live could be inundated.

Meanwhile, Tokyo area railway operators have decided that if a storm like the powerful Typhoon Kathleen, which hit the Kanto region in 1947 and killed some 1,100 people, is forecasted to approach the metropolis, subway services will be halted 12 hours in advance, when the risk of levee failures is highest. All rail services will be halted six hours before the storm strikes. Because of this, if the period where the levee overflow risk is the lowest happens to fall in the middle of the night, the metro government is discussing with operators if they could instead offer an emergency night train and bus service.

The key point is just how early evacuations could begin using the public transportation system. According to a central government simulation, if the Arakawa and Edogawa rivers overflowed at the same time, 1.78 million of the 2.55 million people living in the five eastern Tokyo wards would have to be evacuated. It is estimated that it would take approximately 17 hours for over 90 percent of those people to complete the evacuation.

The Tokyo Metropolitan Government is currently in talks with transportation system operators, carefully identifying possible snags in an evacuation situation, but if it becomes necessary to get people out of the metropolis during the day, then increasing the number of buses and trains in service is also being considered.

"We are working toward raising the effectiveness of possible evacuations in the future by reaching an agreement with transportation operators and incorporating such an accord in regional disaster plans," a Tokyo government representative said.

(Japanese original by Kazuki Mogami, City News Department)

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