Structures Urban Systems & Urban -...
Transcript of Structures Urban Systems & Urban -...
Chapter 11
Urban Systems & Urban Structures
20th century: urbanization process
• 1900: – only 13 cities worldwide > 1,000,000
• 2000: – 411 metropolitan areas > 1,000,000– 19 megacities > 10,000,000
• 2015 projection: – 564 “million cities”
Urban dwellers: proportion increasing
• Differs from continent to continent
• Megacities are increasing
• Mid-size cities are rapidly growing
Conurbations
• Megalopolis – – two large metropolises
merging • Boston to Washington D.C.• Milwaukee/Chicago/Detroit/
Pittsburg• San Diego/Los
Angeles/Santa Barbara
Megalopolis & conurbations
Metropolitan areas of 3 million or more in 2005
Average annual urban population growth rates 1995-2000
Percentage of populationthat is urban or projected to be by 2025
How did urbanization begin?
• First small settlements – villages• 1. temporary markets • 2. permanent markets • 3. development along transport corridor
• Villages transition to urban developments• Trade develops• Not only subsistence existence• Clustering of houses along main road• Become part of system
– ‘system of cities”
Settlement patterns
• Nucleated settlements• Most of world• Village, communal
• Rurally separated, individual
• Only Anglo-American, Northwestern Europe, Australia, New Zealand
Indian rural community
Nepalese summer villageZulu village South Africa
There are many variations of cities
Nature of cities
• Oldest mark of civilization• From 6,000 years, developed around cultural hearths
• Characteristics (functions)• 1. economic base• 2. all part of larger society/economy
– Part of “system of cities”• 3. orderly internal organization of land uses social groups
economic function• 4. experience problems of land use social conflict
environmental concerns
Urban areas provide:
– Retailing – Wholesaling– Manufacturing– Professional services– Government – Personal services
– Entertainment – Political services– Military services – Education – Religion – Transportation
Terms
• Central city – official boundaries of main city surrounded by suburbs
• Urbanized area – continuously built-up landscape
• defined by building & population densities, not political boundaries (physical city)
• Metropolitan area – large scale functional entity
• Urbanized areas operating as integrated economic whole
Terms
• Urban – nucleated, non-agricultural settlements
• Ranging from very small to large
• Town/city – CBD, residential, non-residential uses
• Suburb – subsidiary area, functionally specified
• Not self-sufficient
Defining urbanization
• MSA – metropolitan statistical area– 50,000> major population center/city– 100,000 if no major city
• Two types of counties in the U.S.– metropolitan, non-metropolitan– Over 3,000 counties in the U.S.– 350 + are MSAs
Where are cities located?
• Strategic spots– Ports– River locations– Break-of-bulk points
Function of cities
• Economic Base– Basic sector
• “export” activities, brings in revenue• diversified economy is desirable
– Non-basic sector• Internal functions
Growth & decline in metropolitan areas, 1990-2000
Functional classification
• 1. transportation centers• Sea coasts, rivers, canals, railways
• 2. special function cities• Mining, manufacturing, agglomeration
economies, tourist/recreation
• 3. central places• Rural service, trade functions
Urban hierarchyranking of cities
• First order city – NYC (world city)• Second order cities – Los Angeles,
Chicago• Third order cities – San Francisco,
Houston, Washington D.C.
Top of hierarchy – world citiesNYC London Tokyo
• These cities provide organization & management of global system of finance– Dominate control points:
• 1. international production • 2. international marketing • 3. international finance
• Secondary world cities:– Osaka, Rhine-Ruhr, Chicago, Paris, Frankfurt,
Zurich
Rankings
• Rank-size rule – usually complex economies, urbanized– 1/nth the size of the largest city
• (second largest city = ½ largest city)
• Primate city – often developing countries– more than twice the size of 2nd ranked city– often no obvious “second city”
Bangkok, Thailand
Missouri, USA
Primate city evolution
Central Place TheoryWalter Christaller
• 1. towns of the same size (functional level) will be evenly spread
• 2. larger towns (higher-order places) will be further apart than smaller ones
• “threshold” = • higher farther to travel for product/service/entertainment• lower is much closer
Threshold points
• Range: maximum distance customers will travel– Highest order good: 2 million population– Lowest order: gas stations, grocery, 1 mile or <
• Hierarchical marginal good– Cut off point, next city down doesn’t have– “breaking point”
• Threshold of 500 people– Boom at 1,000 population– Cluster of services
Complementary regions and the pattern of central places
Internal structure of cities
• American cities– First cities:
• Intense land use: compact, high residential & structural density
• Walking cities/later mass transit, but limited range of accessible land
• Sharp demarcation between urban/rural• Transportation lines radiated out, dictating development
High density housing, Brooklyn NY
Land bidding
• Land accessibility, based on economics– Transportation convergence lines – center– Transit junctions– Along transit lines
• Location factors: – Stores: near customers, easily reached– Factories: near workers, materials, resources, supply lines– Residents: connect to jobs, transit lines, stores, schools
Changing landscape: rail lines to freeways
1872 Boston 1994
CBDcentral business district
• Peak-Land value intersection – most costly location of the CBD, most accessible by mass transit
• 1. widest variety of goods/services• 2. highest order of goods• 3. expensive rent
– High value products/services– Small space
• Jewelry• Finance
– Development of office towers = build up
Transition/fringe zone• 1. low income residential
• high density• Immigrants – succession invasion
• 2. whole sale businesses• 3. light industries
• textiles• Bus depots, cargo routes, transients
• Low density residences • Agricultural – intensive farming, dairy
Models of urban land-use
• All models have CBD• A framing core/fringe area• Residential land-use
Concentric Zone Model – 1920s
• CBD• Wholesale, light manufacturing• A zone in transition, deteriorating older
houses– high density, immigrants, low-income slums
• A zone of independent working people – blue collar, second generation Americans
• Single family homes, high-rent apts• Commuter’s zone, low density
• Sector Model– Develops along major transportation lines
• High-rent housing– Low-income housing along manufacturing districts– “filtering down” system
• Multiple-Nuclei Model
– Large cities develop from several nodes– Distinct high-rise development– Independent
Sector Models
Social areas of cities
• In hunter-gather societies identified with tribe/families
• Today we sort ourselves/ find where we fit by several variables
Social status
• 1. income• 2. education (years of schooling)• 3. occupation• 4. house value/rent• 5. home ownership
Family
• 1. gender• 2. marital status• 3. number of children• 4. age• 5 household size (extended family)
• Usually as distance increases from city center, adult residents age gets younger (land is cheaper for families)
Ethnicity
• *sometimes this is a more important determinant than social or family status
• Race > • ethnicity (culture) > • country of origin > • language/dialect > • religion
Social space of American & Canadian cities
Institutional controls
• 1. land-use planning• 2. subdivision control• 3. zoning ordinances• 4. building, health, safety codes
Suburbanization
• Development of the automobile• Acceptance of 40-hour work week• Federal Housing Administration established
• Guaranteed creditors security of mortgage loans• Veterans benefits • “baby boom” – demand for housing exploded 1950-1970
• Interstate Highway system • Late 1950s to 1996• Assembly-line, fordism• By end of 1930s, a national network of paved roads
Resulting patterns
• Metropolitanization (urbanized)
• Suburbanization
• 1970s: developers converted open land @ 200 acres per hour
• End of 1990s: 50 acres and fill in
History of urban sprawl
Suburbanization & landscape
• Unfocused sprawl – no constraints• Mass transit lines defined location, roads = no form• Massive relocation of retail business
• “edge cities” • 5 million sq. ft. of office space/ 500,000 sq. ft. of retail• Built on fringe of central city• Development of self-sufficiency• Basic sector developed: generators of employment/income
• Today’s suburbs: gaining independence from central city residents are self-contained, no ties to central city
Gated communities
Unfocused urban sprawlLas Vegas
Central city change
• Eastern American cities• Confined & central city urban decay
• Western American cities• Huge, expanding urban sprawl, auto-culture
• Redistribution of population• Younger, wealthy, higher-educated – moved to suburbs (more space & cheaper land)• Older, poorer, least-advantaged – remained in central city
• Spatial mis-match• Low-paying, low skill jobs in suburbs, McDonalds, retail, service jobs• Immigrants, unskilled workers in central city ghettos, neighborhoods
• Inner city abandoned• Private investors gone• Loss of tax base to inner city with out-migration of wealthy residents• Housing Act of 1949 – to initiate urban renewal• Massive clearance of slums reduced housing for poor
Public housing
• 1950s & 60s • Concentrated
poverty• Apartments
abandoned– Vandalism– High crime rates 2 miles long development
28 identical 16-story buildings4321 apartmentsAll but 2 demolished in 2004
Chicago
Changing prospect of central cities in 1990s
• Two factors:– Revised economic
opportunity/employment
– Residential for young & trendy, affluent, educated, home seekers - gentrification
Central cities revitalized
• Metropolitan cores provide:• Telecommunication• Investors, • Skilled labor• Research • Education
• Attractive to economic centralizing market• Knowledge base• Finance• Entertainment• Health care• Corporate management
Key factors
• 1. by direct funding from governments• 2. by influx of 15 million new immigrants
(1980-2000) into “gateway” cities – increasing urban labor force
• 3. gentrification – rehabilitation of housing in oldest, deteriorated inner-city
• Gravity & multiplier effect
Trends of cities today
• Western cities:– Problems of unfocused urban sprawl
– No restrictions on growth – No infrastructure $$$ (police & fire depts, schools, water
facilities, sewage)
• Solutions for both Eastern & Western cities– Increasingly restricted physical growth– Diverting some $$$ from highway spending to
mass transit– Resisting expansion of freeways/highways
World cities
• Canadian city (more European style)– More compact (higher
density)– Less suburbanization– More service/ more
dependent on rapid transit
– Higher proportion of foreign born
– Inner city core maintained
Toronto
Western European cities
• Pattern imprints date back to Roman times – Remnants of older
development, just like East Coast U.S. cities
– Irregular systems of narrow streets
– Main streets radiate from city center
– Circumferential “ring roads”
– From Renaissance ideals
Paris
Western European cities
• Not inner core deterioration; Not: “succession/invasion”– outskirts/fringe : immigrants, public housing groups
• Characteristics: – broad throughfares, public parks, plazas, compact (occupy less
land than U.S. cities), most are apt. dwellers, front/side/back yards are rare, developed for pedestrians
• City skylines are low– predates steel frames & elevators (Paris: 3-5 stories)
• Lifestyles: work is close; walking; bicycling– auto is not as important
Eastern European citiesCommunist period 1945-1990
• Ideals:– Limited size for cities– Internal structure of neighborhood equality/self-
sufficiency– Strict land use/segregation
• Characteristics:• compact city, high density, apt. dwelling, dependence
upon public transportation, sharp break between urban/rural land, central cultural district (CCD), large central square, micro districts (assemblages of uniform apt block housing & full neighborhood)
Bucharest, Romania
Poprad, Slovakia
Cities in the developing world• Cities vary tremendously• Commonalities:
• massive in-migration from rural areas
• high rates of natural increase
• ringed by vast squatter settlements
• lack public facilities/services
• populations are greater than formal employment can support
• large group of “informal” sector (street vendors, etc.)
• modern centers of commerce/ like the Western cities
• usually primate city effect
Guanajuato, Mexico
Nairobi, Kenya
Brasilia, Brazil
Mexico City