Why are cities getting bigger rather than smaller? One of the main reasons is the continuous growth of population. In 1804, the world population was only 1 billion, increased to 2 billion in 1927, and reached 3 billion in 1960... By 1999 at the end of the 20th century, the world population had reached 6 billion and was still growing. Taking Shanghai as an example, there were about 1 million people in 1900, but by 2011, it had reached more than 23 million, and the population has increased nearly 22 times in 111 years.
Another important reason is the urbanization process after the industrial revolution. In 1900, only 10% of the world's population lived in cities. By 2007, this proportion had reached 50%. It is predicted that by 2050, 75% of the world's population will become urban people. The changes in China and other developing countries are particularly obvious. For example, China's urban population accounted for only about 12% of the total population in 1950. By 2011, this proportion exceeded 50%.
Due to the concentration of work, education, culture, entertainment and other resources in cities, more and more people leave rural areas to live in cities, and the population of small and medium-sized cities is also flowing to big cities. Mega cities such as London, New York, Tokyo and Shanghai often attract talents from all over the world because of their important position in the social, economic and cultural system. In this way, the city is getting bigger and bigger.
However, while most cities are getting bigger and bigger, some cities are gradually "smaller" for various reasons.
The adjustment of global industrial structure has led to the decline of manufacturing industry in Detroit. Over the past 40 years, the local population has shrunk from more than 1.8 million to more than 710000. In the first 10 years of the 21st century, the population has shrunk by 1 / 4, followed by the reduction of taxes, the extension of service hours such as house vacancy and garbage collection, the lack of police force and the rise of crime rate.
Some European cities are also facing the problems of urban population reduction and population aging.
It can be seen that excessive and rapid expansion of cities will bring many environmental and life problems. However, shrinking cities are also facing the threat of survival, and social problems such as cultural conflict and population aging are also very serious. To solve these problems, city managers must make great efforts.