Unit 6 - Urban Structure and Patterns Flashcards
1
Q
Land-use zones (12)
A
Commercial zone (CBD) Transition zone (zone of decay) High-density residential zone Light industrial zone Low-income residential zone Suburban shopping zone Suburban office park Heavy industrial zone Informal housing zone High-income residential zone Rural-urban fringe Greenbelt
2
Q
Urban structure
A
Or urban morphology, refers to the external, physical aspects of a city.
3
Q
Internal structure
A
The way in which the various urban functions are arranged within a city.
4
Q
Commercial zone - CBD
A
CBD - Central Business District
- located near city centre, land is scarce and land values are high.
- concentration of high rise buildings due to limited space.
- high order functions and commercial and financial activities
5
Q
Transition zone (zone of decay)
A
- located around the older parts of the CBD
- different functions, retail, commercial and residential.
- run down buildings
- high land values
6
Q
High-density residential zone
A
- found on perimeter of CBD and sometimes in neighboring suburbs.
- consists of high-rise buildings (flat complexes).
- due to urban decay, overcrowded, poorly maintained and a sieve of crime.
7
Q
Light industrial zone
A
- small to medium industries
Eg. Manufacturing of furniture, printing and bakeries. - require good transport networks and quick access to CBD or shopping centers.
- don’t produce much pollution.
8
Q
Low-income residential zone
A
- located near CBD
- located also in outskirts of city.
(If planned, called dormitory towns, if unplanned, squatter camps) - legacy of apartheid and urbanisation created these zones.
9
Q
Suburban shopping zone
A
- situated in residential areas away from CBD.
- customers require parking areas and road works for max accessibility.
- trend is to locate these functions on fringes of cities with rooftop parking or parking garages.
10
Q
Suburban office park
A
- located away from CBD.
- sufficient parking and sometimes in rural-urban fringe.
- attractive zones with landscaped environment and accessible by road transport.
Eg. Century city
11
Q
Heavy industrial zone
A
- located far away from CBD and high income residential areas because of air and Boise pollution, industrial hazards and dangers.
- require heavy transport (rail and road)
- buildings require large areas and land values are lower.
12
Q
Informal housing zone
A
- in the rural urban fringe.
- high desire informal houses l, limited access to basic services, clean water and sanitation.
13
Q
High-income residential zone
A
- located far away from CBD and industrial zones.
- high land values and single dwellings on large plots with pleasant environments and views.
- crime has given rise to cluster housing in security complexes and golf courses.
14
Q
Rural-urban fringe
A
- on outskirts of urban areas.
- mixed functions, need large spaces with lower land values.
Eg. Golf courses, nurseries, cemeteries and airports.
15
Q
Greenbelt
A
- area of parks, farmlands or uncultivated land surrounding or within a city.
16
Q
Urban profile
A
Shows the vertical shape (cross section) of a city skyline when viewed from the side.
17
Q
Reasons for shape of urban profile
A
- concentration of high-rise buildings, located towards centre of city.
- buildings are tall and vertical because of high land values and scarcity of land for building extension.
- cities have a second concentration of buildings away from city centre, usually flat hotel district.
- on outskirts of city, land values are lower. Consists of large buildings that extend horizontally, warehouses and office parks.
- residential areas of mostly single storey houses/ informal settlements.
- vacant areas are located in between because of building restrictions and conservation areas, Greenbelt zones and recreation zones (golf courses).
18
Q
Reasons for division of land-use zones:
A
Centripetal forces
Land values
Centrifugal forces
19
Q
Land-use zone
A
Refers to the type of function (or service) that is found in that area.
20
Q
Centripetal forces
A
Accessibility
Functional magnetism
Functional prestige
Functional convenience
21
Q
Land values
A
Determine where certain functions are located.
CBD most valuable, usually the price of land and rentals is higher in the CBD.
Land on rural-urban fringe is cheapest.
22
Q
Centrifugal forces
A
Congestion High rent High taxes Pollution Crime Lack of sites Lack of facilities
23
Q
Factors influencing the morphological structure of a city:
A
Physical factors
Planning
Transport
24
Q
Physical factors influencing structure of city
A
- relief, steep slopes of a city determine structure.
- microclimate, local climate also influence form of an urban area. Area develops north as the Warner slopes face northwards.
- soil conditions, good soil attracts settlements while poor souls are neglected.
25
Planning factors influencing structure of a city
Planned cities
- planned and built as one unit and has an order structure and modern street plan.
No planning
- an urban area that develops quickly, no specific city centre or street pattern.
Piecemeal planning
- settlement in which each new suburb may have a different appearance, but there is evidence of urban planning.
26
Transport influencing structure of a city
Transport plays vital role in development of a city's structure.
As transport systems improve and more people are able to buy cars, towns become less compact.
People could live away from the city centre and commute to their work places.
As a result, urban sprawl is evident along transport networks in cities.
27
Perimeter shapes of cities
Circular shape
- city developed around focal point, church or market.
Geometrical shape
- characterized by Middle Ages, planned as fortress cities
Stellar/star shape
- new extensions radiating outwards in different directions along transport routes.
Linear shape
- due to relief barriers, along a river, coastline or between two mountains.
Satellite shape
- developed where commuter towns are close to the city.
28
Main factors that determine shape of a city
- physical site
- land values
- transport routes
- economic factors
- origin
- growth
- function
- relief barrier
- human activity
29
Street patterns
Streets are regarded as skeleton of an urban settlement.
Used to identify different zones and age of settlement.
Street patterns are a result of:
- age, planning and relief.
30
Different kinds of street patterns?
Grid or gridiron pattern
Irregular (planned or unplanned)
Radial pattern
31
Grid or gridiron pattern
Streets intersect at right angles to each other.
Typical to older settlements in CBD, because pedestrian traffic was important.
32
Advantages and disadvantages of GRID IRON patterns
Advantages:
- easy to survey, plan and extend.
- easy to subsided land into plots and construct buildings.
- easier to laud own networks for water, electricity and telephones.
Disadvantages:
- many intersections lead to traffic congestion.
- not suitable where land is steep.
33
Irregular (planned or unplanned) pattern
Planned irregular
- more typical of modern era, used to break the monotonous gridiron pattern
- newer suburbs have circles, in hilly areas where the relief influences such planning.
Unplanned irregular
- result of lack of planning
- results in maze of streets with various widths and directions.
- street blocks of all shapes and sizes.
- found in rural or informal settlements.
34
Advantages and disadvantages of IRREGULAR patterns
Planned irregular advantage:
- allows for smooth, uninterrupted traffic flow.
Unplanned irregular disadvantage:
- streets are shaking steep gradients and result in pedestrian and transport flow problems.
35
Radial pattern
All roads lead to a central accessible point.
36
Advantages and disadvantages of RADIAL pattern
Advantages:
Ensures smooth flow of traffic.
Disadvantages:
Confusing and easy to get lost.
37
Models of urban structure:
| land-use zone models
Concentric zone model
Sector model
Multiple nuclei model
38
Concentric zone model
Burgess
1925
Land use zone is arranged in concentric rings or zones around the city centre (CBD).
Idea is that the city has grown outwards a in all directions.
Process is like the growth of a tree. The oldest rings/zones in the centre.
39
Sector model
Hoyt
1939
Zones in sectors radiating from CBD.
Growth follows in a linear pattern along major transport routes or physical features like river valleys.
One particular type of land use establishes itself in an area, it attracts similar activities (industry) and repels dissimilar ones (high stays housing).
40
Multiple nuclei model
Harris/Ullman
1945
Various nuclei (small areas) with CBD not centrally placed.
Distinctive land uses form nuclei such as CBD, housing and industrial estates, office and retail parks.
Often similar activities/types of land-use benefit from being clustered together.
41
Criticism of urban structure models
- not totally realistic, they don't take into account social policies like apartheid.
- lower income earners tend to live closer to CBD than wealthier people.
- wealthy people often live some distance from CBD, in areas with good views and large ground.
- industrial areas and high income areas are not compatible.
- new trends, like loft living in CBD, aren't taken into account.
42
Modern American - western city
Developed as a result of rural-urban migration.
All western cities have orderly structure.
You can find the different functions and particular zones in more or less the same part of the city.
Multi-nodal city, old CBD, new secondary cores and large suburbs, gated estates, and edge cities.
Businesses move away from inner city to secondary nodes and suburbs.
43
The Third world city
Develop their own distinctive pattern.
CBD is main urban core.
Surrounded by housing and industrial areas.
Large informal settlements are located on outskirts of city.
Rapid growth due to high rates of population increase.
44
The South African City
SA has an unnatural system of land-use as a result of apartheid policies.
Group Areas Act of 1953, divide SA cities into separate racial area. Black peoples were removed from homes and relocated in outlying townships.
Large townships and informal settlements are found in most parts of SA.
