Final answer:
The question discusses a city's central business district and its surrounding residential areas as defined by urban models such as the Concentric Ring Model and the Multiple Nuclei Model. The CBD is a hub for commerce and business, while residential zones vary based on economic class. New Urbanism seeks to revitalize urban areas by integrating business and residential amenities.
Step-by-step explanation:
The central business district (CBD) is often found at the center of a city and serves as the focal point for business and commerce. Surrounding the CBD, as outlined in the Concentric Ring Model by Ernest Burgess, are various zones, including residential areas that reflect different economic classes. The CBD is characterized by a high density of businesses and tall buildings, with commercial land uses and residences such as high-rise apartments or tenements in nearby zones. Over time, and as highlighted by the Multiple Nuclei Model, additional smaller business districts or nuclei can develop in various parts of a city, sometimes competing with the historic CBD for businesses involved in finance, insurance, real estate, and legal affairs. The Central Place Theory indicates that centrally located businesses tend to grow and attract more customers, leading to the expansion of some villages into cities, while others do not thrive. To rejuvenate urban cores and associated suburbs, a movement known as New Urbanism promotes mixed-use development, often centered around public transportation to encourage a blend of living, working, and recreational spaces.