Models of urban structure
Urban / Services FYI 1. Cities have many 3. There are only 3 issues to deal with World Cities: NYC, Race relations London, Tokyo Traffic • Other cities are Water delivery/ ranked based on infrastructure importance to their Pol ution service areas (SEP) Sprawl 4. Primate cities have 2. Cities are ranked in 2x the amount of a hierarchy: hamlet population as the next to megalopolis largest city in the • Largest megalopolis same country in USA = NYC area (London, Paris, (Bos – Wash) Buenos Aires….)
5. The USA has 3 basic models of urban structure: – Concentric Zones/ Burgess, – Sectors/Hoyt, – Multiple Nuclei/ Ullman and Harris 6. Continents have different urban characteristics: • Europe-older/more historic cities, poor in suburbs, not inner cities…. • Asia-cities are built as ports for trade b/c of colonialism • Latin America-High income houses are built on a spine from the CBD • Africa-3 separate CBDs: colonial, modern, market zone (pre-colonial)
7. All cities fit w/in Christaller’s central place theory. • Some have greater ranges and need bigger thresholds.
Burgess – Concentric Zone model A model describing land uses as a series of circular belts or rings around a core central business district, each ring housing a distinct type of land use. Studied 1920’s Chicago to make this model• 5 concentric zones• Immigrants lived in inner zones causing affluent residents to move further out Weaknesses–does not allow for change in the citydoes not allow for physical geographic barriers like mtns, rivers, etc..
Sector model/Hoyt A description of urban land uses as wedge-shaped sectors radiating outward from the central business district along transportation corridors. Answered drawbacks of Burgess Model Growth creates PIE shaped urban structures CBD isn’t as important is Burgess says it was Sectors develop along transport routes (hwy, RR, etc)
The Sector Model -Homer Hoyt (1939) There tends to be a filtering down process as older areas are abandoned by the outward movement of their original inhabitants, with the lowest-income population becoming the dubious beneficiaries of the least desirable vacated a reas.
Multiple Nuclei Model – Harris and Ullman (1945)The postulate that largecities develop by peripheralspread not from one centralbusiness district. There are several nodes of growth,each of specialized use. The separately expandinguse districts eventuallycoalesce at their margins.
Urban Realms Model • Modeled after L.A. in the 1990’s • Post WWII cities grew increasingly outward • Nuclei or Realms become less dependent on each other, and much less on the CBD • Realms became largely self- sufficient in most cases • Regional shopping centers became like the CBD Construction ‘ring roads’ created growth explosions at major highway intersections in outer areas Leads to emergence of EDGE CITIES (Woodlands)
Models of urban structure Color code the map using 10 colors or patterns so you can distinguish the zones in each model. 1. Central Business District2. Wholesale/Light manufacturing3. Low-class residential4. Medium-clas residential5. High-class residential6. Heavy manufacturing7. Outlying business district8. Residential suburb 9. Industrial suburb 10.Commuter zone
Edge Cities • Edge Cities – Joel Garreau Nodal concentrations of shopping and office space that are situated on the outer fringes of metropolitan areas,typical y near major highwayintersections.
The Concentric Zone Model – Ernest Burgess(1925) 1. CBD is primary and at the center, CBD is also divided into districts (financial, retail, fashion, etc) 2. Zone in transition – residential deterioration and encroachment by business and light manufacturing 3. Independent workers homes – closely 4. Better residences – spaced homes, middle class/white typical y blue col ar collar homes 5. Commuter zone – suburban ring
The Sector Model -Homer Hoyt (1939) Sector 1 – high rent2 Intermediate rent 3. Low Rent residential 4. Education and recreation 5. Transportation6. Industrial7. Core
The Concentric Zone Model – Ernest Burgess(1925) It recognizes four concentric circles of mostly residential diversity at increasing distance in all directions from the wholesaling, warehousing, and light industry border of the high-density CBD core. A zone in transition is marked by the deterioration of old residential structures abandoned, as the city expanded, by the former wealthier occupants and now containing high-density, low income slums, warehouses and (in some areas) gentrified buildings.
Other Urban models info The Galactic City Squatter Settlements As suburbs continue to An area within a city in a sprawl they spawn less many suburban developed country in which nucleations, which people are simply multiple illegally establish downtowns and residences on land special function nodes and corridors, they do not own or rent which are linked by and erect the metropolitan homemade structures. expressway system. Density GradientThe change in density in an urban area from the center to the periphery.
GentrificationThe movement into the inner portions of American cities of middle- and upper- income people who replace low- income populations, rehabilitate the structures they occupied, and change the social character of neighborhoods.