The Yomiuri Shimbun
Up to 7,600 people would die along Tokyo Bay if tidal waves caused by a strong typhoon strike the bay after sea levels have risen as a result of global warming, the government’s Central Disaster Management Council predicted Friday.
The council’s forecast was part of a report made by its expert panel about the damage likely to be caused by large-scale flooding when an extremely strong typhoon hits Tokyo and its vicinity. It was the council’s first prediction of human casualties from tidal waves as a result of higher sea levels caused by global warming.
The panel calculated the likely number of casualties based on a forecast by the U.N. Intergovernmental Panel on Climate Change, which predicted sea levels will have risen by as much as 59 centimeters at the end of the 21st century.
The report said that if a typhoon equivalent to the 1934 Muroto Typhoon passes through the Kanto region, a total of 280 square kilometers along coasts in Tokyo and Chiba and Kanagawa prefectures will be flooded. About 3,000 people died or went missing in western Japan as a result of the Muroto Typhoon.
In the worst-case scenario of such flooding, 7,600 people would die by being swept away by water or drown while trapped on the low floors of buildings, the report said.
In areas located at sea level, including Tokyo’s Koto Ward, flood waters would be five meters deep, it said. Flood water would also remain for at least two weeks in an area covering about 51 square kilometers.
If torrential rain breaks through dikes on a large river, 6,300 people could die in areas along the Tonegawa river and 3,500 along the Arakawa river, the report warned. These figures were in addition to the victims of tidal waves.
The panel said discussion in this country about measures to combat flooding lags behind those concerning earthquakes and volcanic eruptions.
“As the possibility of massive flooding has been increasing due to the effects of global warming and other factors, the nation should implement well-organized efforts for far into the future,” the report says.
Based on the report, the government plans to compile an outline of measures to deal with large floods, as guidelines for central and local government efforts by the end of this fiscal year.
(Apr. 3, 2010 The Yomiuri Shimbun)