The Tokyo Metropolitan Government is the first in the country to compile a plan to raise the sea level in anticipation of 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 Tokyo Metropolitan Government is
constructing a
seawall with a total length of about 60 kilometers and a
height of 8 meters at the highest point in Tokyo Bay.
I have put together a proposal for a plan to raise the existing seawall.
Based on simulations with experts, etc.,
▼ The distance that the
seawall
will be raised is about
30km
, which is half of the total.
▽It is 1.4 meters, which is the highest in the eastern area
.
From the 7th, the metropolitan government will present a draft of this plan and implement a public comment to seek 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.
Seawall raising plan
This time, the proposal for raising the height of the seawall was presented in the Tokyo Metropolitan Government's Basic Plan for Conservation of the Coastal Coast of Tokyo Bay.
This was established in 2004 based on the national law to indicate the development and utilization of facilities such as seawalls to prevent storm surges.
This time, mainly the part of the seawall development policy was revised, and with the rise in sea level and the intensification of typhoons due to global warming in mind, specific sections of the seawall and how much to raise were indicated. rice field.
Formulation of coastal disaster prevention plans
The trigger was the movement of the country.
Based on the report of the United Nations Intergovernmental Panel on Climate Change (IPCC), which predicts that the sea level will rise by 2100 due to the progress of global warming, the national government is concerned that storm surge damage will become more serious nationwide in the future. Two years ago, we asked prefectures to formulate disaster prevention plans for coastal areas based on predictions of the impact of global warming.
Furthermore, last year, the Cabinet decided to formulate a plan by fiscal 2025 to expedite the response for prefectures.
A 2°C increase in temperature may not prevent damage in the future
Under these circumstances, the Tokyo Metropolitan Government first conducted storm surge simulations based on discussions with experts, assuming that the temperature will rise by 2°C by 2100.
Specifically,
▽The sea level is assumed to rise by about 60 cm, which is considered the most serious, and
▽The typhoon is assumed to be stronger than the Isewan Typhoon, which caused great damage in 1959. did.
In addition,
▽ Three routes to landing were assumed, and the worst damage was simulated.
As a result, it was found that there is a possibility that the ▽ total length of about 60 km
▽ up to 8 m seawall
currently installed in Tokyo Bay will
not be able to prevent damage in the future.
The specific plan is
Therefore, the metropolitan government has
compiled a plan this time , assuming ▽
sea level rise in 2100,
▽ storm surges and waves due to stronger typhoons, and ▽
a margin of 30 centimeters .
According to it,
▼The area to be raised is
about
30
km, which is half of the
seawall
.
1.4 meters high
and so on.
Furthermore, as climate change
increases the amount of rainfall and increases
the risk of inland water flooding,
it is also indicated that the capacity of the drainage pump station to discharge accumulated water inside the water gate to Tokyo Bay will be increased.
Specific start date and budget
The draft plan this time only states that the construction will be completed by 2100, and does not include a specific start date or budget.
After presenting this proposal on the 7th, the Tokyo metropolitan government will implement public comments soliciting opinions from a wide range of citizens, aiming to formulate it by the end of this fiscal year. It is our policy to proceed with the construction from where we judge it to be expensive.
Ryota Masuyama, head of flood prevention measures at the Port and Harbor Bureau of the Tokyo Metropolitan Government, said, "We believe that climate change is a new threat to coastal disaster prevention. We would like to carry out construction in stages, looking ahead to the future." rice field.