The concept of megacity was developed by the United Nations (UN) to refer to any urban agglomeration with a population of over ten million inhabitants. Therefore, the group of megacities encompasses the largest inhabited urban areas on the planet. Most of them are made up of municipalities in emerging and underdeveloped countries, although the largest is Tokyo, capital of Japan.
The Japanese capital, however, has an excess population due to a series of specific factors, mainly the question of the restricted habitable area that the country has for its more than 125 million population. Tokyo, by the way, is already part of a new concept, that of metacities, because it has more than 30 million people in its urban area, which involves a series of metropolitan cities.
Tokyo already has more than 30 million people today
The formation of megacities and their proliferation around the world happen based on some main factors: the intense urbanization of societies, especially during the 20th century, and the accelerated
metropolization, that is, the concentration of urban populations in the large metropolises of their countries. This process occurs because of the greater employment and housing opportunities that these cities offer, in addition to the process of rural exodus that has been occurring with greater intensity in underdeveloped and emerging.To get an idea of this reality, 2010 was the first year in which most of the world's population lived in cities, that is, in which the urban population finally surpassed the rural population in the entire geographic space of the Earth. Of this amount, a considerable part lives in megacities, which currently total 21 urban areas. Of these, 17 belong to peripheral or developing countries.
Some of these megacities in underdeveloped countries have been showing high rates of population growth, both by the migratory aspect and by the high birth rates, as is the case of Lagos, in Nigeria, and Karachi, in the Pakistan. The main challenge of these and other large cities is the provision of social infrastructure that allow a minimum quality of life for its inhabitants in the face of accelerated growth and cluttered.
Therefore, most megacities suffer from problems related to the lack of basic sanitation, expansion of slums and irregular occupations, high rates of violence, socio-spatial segregation, lack of mobility both on traffic routes and when traveling by public transport, among many others factors. Therefore, in addition to containing this disorderly expansion, more efficient public policies aimed at correction of these problems with direct investments in sanitation, security, education, housing, mobility, among others.
Another negative aspect that exists in megacities includes environmental problems. They happen due to high levels of pollution, removal of vegetation, degradation of watercourses and others, generating general and specific environmental problems, such as heat islands and inversion thermal. For this reason, it is necessary to decentralize existing services and promote greater democratization in social structures to guarantee all citizens the right to the city.
Below, we can check the list of megacities and their respective populations:
Tokyo, Japan – 36,669,000 inhabitants
Delhi, India – 22,157,000 inhabitants
São Paulo Brazil – 20,262,000 inhabitants
Mumbai, India – 20,041,000 inhabitants
Mexico City, Mexico – 19,460,000 inhabitants
New York, United States – 19,425,000 inhabitants
Shanghai, China – 16,575,000 inhabitants
Calcutta, India – 15,552,000 inhabitants
Dhaka, Bangladesh – 14,648,000 inhabitants
Los Angeles, United States – 13,156,000 inhabitants
Karachi, Pakistan – 13,125,000 inhabitants
Buenos Aires, Argentina – 13,074,000 inhabitants
Beijing, China – 12,385,000 inhabitants
Rio de janeiro Brazil – 11,950,000 inhabitants
Manila, Philippines – 11,628,000 inhabitants
Osaka-Kobe, Japan – 11,635,000 inhabitants
Cairo, Egypt – 11,005,000 inhabitants
Lagos, Nigeria – 10,578,000 inhabitants
Moscow, Russia – 10,550,000 inhabitants
Istanbul, Turkey – 10,525,000 inhabitants
Paris, France – 10,485,000 inhabitants
By Me. Rodolfo Alves Pena