Concentric zone model

The Concentric zone model, or Burgess model is a model to explain how a settlement, such as a city, will grow. It was developed by Ernest W. Burgess between 1925 and 1929. Burgess looked at the growth of Chicago in the late 19th and early 20th century. Many people moved to Chicago at that time. 
The model was the first to explain why certain groups of people lived in certain areas of the city. Burgess said that there were circles around the center of the city. The circle a piece of land was in determined how it was used. Burgess saw different zones, starting at the center:
Burgess saw that richer people tended to live farther away from the city center. When the city grew, the city center would grow; the rings would also shift outwards.
The model also has some problems, for example: