The Progress and Grand Challenge of Urbanization in China

Over the past few decades, China’s economy has maintained rapid growth, with an average annual gross domestic product (GDP) growth rate of more than 10% (Fig. 1 [1]). In recent years, the Chinese economy has entered a “new normal,” in which the GDP growth rate has slowed but remained stable at around 7%. Rapid development and urbanization in China supplement and promote each other, enabling 400 million people to live in cities and enjoy the modern urban life. For most of its long history, China has been a traditional agricultural country, with 90% of people living and farming in rural areas and only 10% living in cities. Until the 1970s, this proportion remained almost unchanged, and at present, the majority of middle-aged people, their parents, and their grandparents still live in rural areas. After 1978, however, due to the demand for labor for economic development, the labor force began to flow from rural to urban areas. Rough estimates put the growth rate of the urban population at almost 1% per year, which means that 10 million people move from the countryside to cities every year (Fig. 2 [2]). By the end of 2012, China’s urbanization rate had reached 52.57%, or a population of 0.71 billion.


China's urbanization amid high economic growth
Over the past few decades, China's economy has maintained rapid growth, with an average annual gross domestic product (GDP) growth rate of more than 10% ( Fig. 1 [1]). In recent years, the Chinese economy has entered a "new normal," in which the GDP growth rate has slowed but remained stable at around 7%. Rapid development and urbanization in China supplement and promote each other, enabling 400 million people to live in cities and enjoy the modern urban life.
For most of its long history, China has been a traditional agricultural country, with 90% of people living and farming in rural areas and only 10% living in cities. Until the 1970s, this proportion remained almost unchanged, and at present, the majority of middle-aged people, their parents, and their grandparents still live in rural areas.
After 1978, however, due to the demand for labor for economic development, the labor force began to flow from rural to urban areas. Rough estimates put the growth rate of the urban popula-tion at almost 1% per year, which means that 10 million people move from the countryside to cities every year ( Fig. 2 [2]). By the end of 2012, China's urbanization rate had reached 52.57%, or a population of 0.71 billion.

Logistics and passenger flow drive large-scale infrastructure construction
In the process of rapid urbanization, logistics and traffic surge have led to massive urban infrastructure construction. For example, prior to 1979, China's highway networks were not developed; however, after over 30 years of development, China's total expressway mileage reached 104 000 km by the end of 2013, exceeding the US mileage of 92 000 km and ranking first in the world. China's railway construction has also witnessed rapid growth. By the end of 2014, China's operated railroad reached 112 000 km, ranking second in the world. China's high-speed railway, operating at more than 300 km·h -1 , will cover 16 000 km and rank first in the world (Fig. 3).
With my own family living in Shanghai, I am especially impressed with the convenience brought about by the high-speed railway. In the past, it took two hours to travel from Beijing to Shanghai by plane. However, due to weather conditions, regulatory control, and other reasons, flights were frequently delayed. It now takes only four hours to travel from Beijing to Shanghai by high-speed railway; and the trip is very convenient and efficient, with no delays. Of course, the rapid development of the automotive industry has also introduced significant problems. Every year, during National Day and the Spring Festival, there are seven days of holidays. Many people choose to travel by car during this vacation, and traffic becomes extremely heavy, leaving people waiting for long periods of time at the entrances of highways (Fig. 4 shows the situation in Shanghai). Even the overpasses are usually blocked by excessive numbers of cars. Thus, the question of how to ease the pressure on urban traffic is a major challenge for city leaders and managers.

China's urbanization faces environmental restrictions
China possesses 20% of the world's population but only 7% of the global arable land; and China's water resources per capita are only 28% of the global average (Fig. 5). According to the 2009 United Nations statistics, more than 400 cities in China have insufficient municipal water supplies, and 110 cities suffer water shortages. Resources such as timber, minerals, oil, and natural gas are also scarce. It is impossible for China to use rich resources to support its many people as well as supporting societal development, so urbanization must be accomplished in an environmentally sustainable manner.

Severe air pollution in urban areas of East China
Industrial and social developments have resulted in a certain degree of air pollution. In recent years, large-scale air pollution incidents have occurred at times in East China, especially in regions near Beijing and regions with relatively rapid economic development. In 2014, large-scale smog incidents occurred repeatedly in such regions. In January of 2015, the number of severe smog days (Class VI pollution) in Beijing reached 14 consecutive days (Fig. 6).

New urbanization must strengthen infrastructure and overcome "city diseases"
In the past 20 years, China's urbanization has been oriented   by the construction of iconic facilities such as central business districts (CBDs) and industrial parks in order to attract investment. However, the construction of urban infrastructure has often lagged behind. Although the investment in infrastructure in China's major cities is enormous, the construction of underground drainage systems has often been neglected, with serious consequences. For example, Beijing witnessed a rainstorm event on July 21, 2012 that flooded many areas of the city, causing 79 deaths and economic losses of 11.64 billion CNY (Fig. 7). Culture is the spirit and soul of a nation. Protecting and developing the national culture and promoting cultural revival should become an important responsibility of urban construction. Therefore, we should retain some of the characteristics of the national culture in city designs, and large cities should include buildings with Chinese characteristics and a cultural heritage.

New urbanization must inherit historical and cultural elements and achieve diversity
Many small Chinese towns and villages have maintained a pleasant natural landscape and cultural characteristics of their ethnic regions, remaining beautiful and quiet (Fig. 8). At the same time, however, many of the metropolitan regions resemble each other. For example, large cities such as Beijing, Shanghai, and Hong Kong look very similar and lack major differences.