When it comes to destructive typhoons, the general agreement is that the worst in living memory occurred September 1959, when Typhoon No. 15 -- also referred to as Typhoon Vera and the Ise-wan Taifu -- struck the Chubu region. Packing ultra-low pressure of 895 hectopascals and maximum sustained winds of 305 km/h (190 mph), it left 4,697 dead, 401 missing and 38,921 injured. An estimated 1.6 million people were rendered homeless, and its economic impact was profound and long-lasting.
By contrast, Typhoon No. 10 that passed by Okinawa and Kyushu earlier this month, while large and powerful, left only two fatalities, 102 reported injured and four missing (as of Sept 8). Damage from its torrential rains was considerably less than the downpours that caused severe flooding in Kyushu during the July rainy season.
The lower number of casualties and damage can be credited at least in part to a much better forecasting system and the government's announcement of a "special alert" that put in force proactive measures, including evacuation of residents from potentially hazardous areas.
"The typhoon weakened in strength, but it's a mistake to think that damage was completely avoided," meteorologist Masamitsu Morita tells Shukan Shincho (Sept 17). "Certainly the scale turned out to be slightly smaller than the forecast; but over 500 millimeters of rain was recorded, and peak winds gusted to just under 60 meters per second -- equivalent to 216 kilometers per hour. Even half that speed is enough to send an adult flying; 40 meters per second is enough to knock a light truck on its side."
Credit should go to the government and media, which tracked No. 10's path for a week before its arrival and kept the population updated on its progress.
What Shukan Shincho is leading up to is, what would happen if the Tokyo metropolitan area were to be struck by one of these monsters?
Associate Professor Tetsuya Takemi of Kyoto University points out that along coastal areas of the Pacific, water temperature has been measured at over 30 degrees, 2 degrees higher than normal. "There is sufficient possibility that powerful typhoons of the magnitude that struck Chiba's Boso Peninsula last year (Nos 15 and 19) will occur."
"Tokyo is a city that's quite vulnerable to flood damage," Nobuyuki Tsuchiya, a civil engineer who authored a book titled "The Capital Sinks," tells the magazine. "In preparation, a plan issued in March 2018 mapped out a hypothetical storm surge for a typhoon with atmospheric pressure of 910 hectopascals.
"If directly struck by a typhoon of the largest category, 17 of Tokyo's 23 wards are believed vulnerable to flooding," Tsuchiya says. "The storm surge might even reach as far inland as Kawaguchi, Warabi, Toda, Koshigawa and Soka in Saitama. There are also sections of five Tokyo wards whose elevation is at sea level, and it's believed that it would take a week or longer for floods to recede."
In a worst-case scenario, a sizable portion of the 2.5 million residents of five wards in eastern Tokyo might be forced to evacuate.
Since July 2017, realtors in the greater metropolitan now required to include a hazard map in the details of the properties they sell. On one map, the high-rise apartments near Musashikosugi station in Kawasaki City can be seen colored in bright red.
"Since the basement flooding damage the buildings suffered last year, agents haven't been able to move any properties," says housing journalist Junji Sasaki.
If a surge from a major storm were to hit the Ginza-Shimbashi area, one disaster simulation projects 115 trillion yen in damages and as many as 8,000 dead.
The huge Ansei Edo Typhoon of September 1856 is estimated to have taken over 100,000 lives. One year prior to that, an earthquake killed between 4,000 and 10,000. The cumulative damage wrought by these two events so weakened the Tokugawa government's hold on power they played no small part in bringing about its downfall twelve years later.
Aside from keeping emergency foods and bottled water, what are some precautions can we take? Journalist Minoru Watanabe recommends acquiring an electric vehicle. In addition to providing transportation, its onboard lithium batteries can supply power to one's home air conditioner and refrigerator in the event of a blackout.
Since we're still in the midst of the coronavirus pandemic, mass evacuations will almost certainly pose difficult challenges. Needless to say, it's difficult to maintain social distance when you're camping out on the floor of a school gymnasium with several hundred other people.© Japan Today