Urban growth models

Urban ecologists examine how people adapt to their environments. They focus on the social context (environment) and the spatialization of modern behavior. For them, the form of the city is the result of “natural” growth—expansion, immigration, succession, etc. Below (Figure 1) are three models of urban growth developed by urban sociologists in the US. In general, a city grows from the center, then outwards. Different sectors/zones in city are the result of the convergence of these social forces. In Model A, Zone 1 is the central business district (CBD). Zone 2 is a transitional area containing rooming houses and deteriorating housing which breed poverty, disease, and vice. Zone 3 is the area thrifty workers have moved in order to escape the transitional Zone 2 yet maintain convenient access to their work. Zone 4 contains more expensive apartments, hotels, single-family home, etc. Commuters live in Zone 5 which consists of suburbs or satellite cities that have popped up around transportation routes.

In Model B, concentric zones can contain different sectors, one of working-class homes, another of expensive housing, and one of businesses, etc., all competing for the land. With immigrants settling in lower-rent areas, the population spills over to adjacent areas. In Model C, a city may have several centers of “nuclei”. Each nucleus contains a specialized activity—such as clusters of fast-food restaurants or retail districts. Areas with similar activities cluster together to draw consumers, or because land-use is similar in adjacent areas.

These sociologists acknowledged that no city perfectly fits these ideal models, with geography, development of transportation, innovated business models, cities are becoming increasingly diverse. For example, in the 1970s, the “growth machine” theorists emerged, arguing that instead of “natural processes”, urban growth is driven by a coalition of interest groups who all benefit from continuous growth and expansion. For them, the growth of cities is a social phenomenon.

Source: Henslin, J. M. (2015). Essentials of sociology: A down-to-earth approach. Pearson.