At the World Conference on Disaster Reduction held in the Japanese city of Kobe, the United Nations University presented a report entitled “Underground Spaces: The Hidden Vulnerability of Megacities.” As Reuters reports, the report notes that significant underground volumes are created in large cities, which are often not equipped with the necessary safety systems in case of natural disasters.
Megacities lack systems for rapidly and reliably dividing underground space into isolated compartments, which is absolutely essential in fighting fires and floods. The report pays special attention to the condition of coastal cities. Megacities are exposed to many hazards – earthquakes, tropical hurricanes, floods; and there may not be enough time to prepare for these situations, according to experts.
Jan Egeland, UN Under-Secretary-General for Humanitarian Affairs, said that many of the world's megacities are extremely vulnerable to natural disasters, while the poorest cities and neighborhoods, due to a lack of investment and necessary planning, are the most vulnerable.
According to experts, it is necessary to introduce urban planning, develop infrastructure, and invest in poor areas, because it is the poor people who are most vulnerable.
Megacities are considered to be cities with a population of 10 million or more. The five largest megacities in the world, according to the UN, are Tokyo (population 35.3 million), Mexico City (19 million), New York (18.5 million), Bombay, and São Paulo (18.3 million each). The term “high relative vulnerability” means not so much increased seismic hazard on the territory of a particular country, but rather weak preparedness for earthquakes, whereby relatively weak tremors can lead to serious casualties and destruction.
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