The Tokyo Metropolitan Government is the first in the country to compile a plan to raise the sea level, assuming rising sea levels and intensifying typhoons due to global warming.
According to the latest report of the United Nations IPCC = "Intergovernmental Panel on Climate Change", if the global average temperature rises by 2 degrees above pre-industrial levels by 2100, the average sea level will decrease in 20 years by 2014 It is predicted to rise by up to about 60 centimeters compared to the average, and there are concerns that storm surge damage will become more serious.
Currently, the metropolitan government is constructing a seawall with a total length of about 60km and a maximum height of 8m in Tokyo Bay. I learned from interviews with people involved that a plan to raise the height was put together.
Based on simulations with experts and others, the total distance that the embankment will be raised will be about 30 kilometers, which is half of the total. It is to be raised by meters.
The Tokyo metropolitan government will present a draft of this plan from the 7th, and will implement public comments to solicit opinions from the citizens of Tokyo, and will proceed with construction from where it is judged to be of high priority in the future.
According to the Ministry of Land, Infrastructure, Transport and Tourism, it is the first time in Japan that a seawall is planned to be raised in light of global warming.
Expert "We should consider response from now"
Professor Shinji Sato of Kochi University of Technology, who is familiar with coastal disaster prevention, points out that we should start discussing upgrading facilities to deal with storm surges, given that the accuracy of climate change predictions is increasing.
Professor Sato said, ``We should make predictions for each region, such as how the course of waves and typhoons will change due to rising sea levels, and we need to take measures accordingly. Considering what we have to do, we have no choice but to plan for several decades, so we should consider responding now."
Storm surge measures in Tokyo
In Tokyo, the so-called zone of zero meters above sea level spreads out in the eastern part of the wards, and was severely damaged by the typhoon of 1917 and the storm surge caused by Typhoon Kitty in 1949.
In 1959, the Isewan Typhoon, which caused the worst damage in history, prompted the Tokyo Metropolitan Government to take concrete countermeasures against storm surges.
Two years later, in 1961, the metropolitan government decided to develop seawalls and water gates in Tokyo Bay that could withstand typhoons of the "Isewan Typhoon" class, and after nearly 20 years, they were completed in 1979.
After that, after undergoing earthquake resistance measures based on the Great East Japan Earthquake, we are currently building a seawall with a total length of about 60 kilometers and a maximum height of 8 meters.