The term megalopolis is a relatively recent term that is used to designate large urban areas with very large population numbers. Contrary to what one might think, the concept of a megalopolis normally encompasses several nearby cities that, when added together, represent an important contribution to the population and economic movement for the region in which they are located. The best-known megacities are, for example, those in the eastern United States (where New York is located), Tokyo and São Paulo.
For a region or a group of cities to be considered a megalopolis, one of the main elements that must characterize it is the presence of more than 10 million people, which already speaks of a number of inhabitants much higher than the average city . In this sense, some few cities can reach that number on their own, while others reach it by adding to their territory the suburbs that can sometimes mean a better quality of life and in other cases worse. For example, New York City in the United States has a population of 8 million people, but if metropolitan areas are added to this, the number is higher. On the contrary, the city of São Paulo in Brazil already has eleven million inhabitants by itself, a figure that rises to 19 million if the metropolitan area is included.
The megacities are a deeply current phenomenon due to the very important population increase that humanity experienced during the 20th century and the beginning of the 19th century. This has to do with technological improvements and advances in medicine that make a large part of the population live longer, at the same time that the transition from rural to urban areas appears as a typical characteristic of our time due to the better opportunities labor, cultural diversity and better living conditions. Thus, while in some countries, while a large part of the territory is sparsely populated, the cities concentrate a large part of the total population of the space.
