Spatial profile of three South African cities

Transcription

1 Spatial Outcomes Workshop South African Reserve Bank Conference Centre Pretoria September 29-30, 2009 Spatial profile of three South African cities by Alain Bertaud September 29 Web site : 1

2 Outline A. South African urban structures: issues and opportunities B. Metropolitan spatial development issues: South African cities compared to other cities in the world C. Households land consumption, formal and informal, shape South African cities D. Is it possible to modify urban spatial pattern in South Africa? 2

3 A. South African urban structures: issues and opportunities Gauteng, Cape Town and ethekwini Different structures but one thing in common: Low densities in center, high densities in far away suburbs (except in ethekwini) High land consumption by both the rich and the poor more compatible with individual car as main mean of transportation than with transit Informal sector shows trade off between distance and land consumption in the absence of subsidies 3

4 Analytical approach Spatial indicators and the geometry of spatial structures are important, but Historical factors are difficult to reverse and make urban structures path dependent Cultural factors are extremely important in land use: solutions will have to satisfy both a quantitative approach (more compact cities) and be compatible with local culture 4

5 Looking simultaneously at both the macro and micro level To be operationally relevant it is necessary to look at cities at the macro level (metropolitan spatial structures) and at the micro level (design of projects). In the first part of this presentation we will concentrate on the analysis of South African urban spatial structures In the second part we will look at housing projects parameters in the formal and informal sector 5

6 B. Metropolitan spatial development issues Cities as a labor market: less than one hour from anyplace to any other place in polycentric cities less than 1 hour to the main center for monocentric cities Trade off between transport cost and land consumption Substituting capital for land (Floor Area Ratio) 6

7 Labor markets and urban spatial structures Large labor markets are the raison d'être of large cities Large labor markets provide economic opportunities for both employees and employers A labor market is efficient when it is integrated, when it is fragmented it looses its efficiency. Integration of labor markets requires that all jobs be potentially physically accessible to all adults within a reasonable commuting time (say, 1 hour one way) and at a reasonable cost (say, below 8% of income) A deficient city spatial structure fragments labor markets, and contributes to a high unemployment rate for the poor. 7

8 Does a city spatial structure matters for the poor? The poor cannot fully participate in the labor market when They are spatially dispersed beyond 1 hour commuting time from employment areas or when transport costs represent more than about 8% of income; Spatial dispersion decreases economic opportunity for the poor and reduces the economic efficiency of the entire city. 8

9 Urban spatial structures: How to define them? Why do they matter? 9

10 A city spatial structure is defined by: The average density (consumption of land per person) the spatial distribution of densities and population The pattern of daily trips It is deficient when: Commuting distances for a significant part of the population are too long to be travelled within a reasonable travel time or/and at a reasonable cost The spatial distribution of population and the pattern of trips are incompatible with the main mode of transport affordable to the poor 10

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12 Defining a city spatial structure: Average population density in the built-up area The population density of a city is an indicator of land consumption. For a given population, the lower the density, the larger is the city built-up area, and as a consequence the longer is the commuting distance; There are no optimum densities, but low densities are incompatible with transit, and high densities are incompatible with private cars as a main mean of transport. 12

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15 Defining spatial structure: the pattern of trips 15

16 The urban structure of South African cities as compared to other cities structures in the rest of the world 16

17 Gauteng, Cape Town and ethekwini spatial structures: Differ from most other major metropolis urban structures in the world Have evolved over the last 18 years but the impact of apartheid has not disappeared Main characteristics: Extremely large footprint for their population size High density residential settlements far away from employment areas Employment areas dispersed in clusters through the region Large empty buffer zones between settlements However Gauteng, Cape Town and ethekwini have important structural differences due to history, culture and topography 17

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19 The spatial distribution of densities: One of the major issue in South African cities 19

20 Gauteng population density in built up area 20

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31 The spatial distribution of jobs 31

32 Jobs in Gauteng are concentrated in the center and north but spread over a wide area at low job densities. 50% of jobs are located in areas where the job density is lower than 10 jobs per hectare. 32

33 3D representation of the spatial distribution of jobs in Gauteng area showing the dispersion of jobs on a very wide area mostly in the center and North. 33

34 The spatial concentration of jobs in Gauteng, New York and Paris metropolitan areas represented at the same scale 34

35 Looking at the micro level: land consumption per household, design and standards of specific residential settlements 35

36 The spatial structure of South African cities will evolve project by project 36

37 B. Households land consumption - formal and informal sectors 37

38 The land consumption in the formal and informal sector 38

39 Gauteng south of Benrose informal settlement 39

40 Gauteng -Sebokeng 40

41 Cape Town - Guguletu 41

42 ethekwini - Acorn -informal 42

43 ethekwini Emagezeni informal 43

44 The tradition of leaving buffers between projects 44

45 45 The households income numbers presented in this graph are only illustrative and do not correspond to any specific South African city

46 The limits between the formal and informal sector is established by minimum standard regulations. Move the standards up and the number of households in the informal sector increases Move the standards down and it decreases 46

47 The minimum land use standards set the limits between formal and informal markets High land use standards have several consequences: 1. They increase the number of households requiring subsidies 2. They have an impact on the spatial distribution of population as they increase the land consumption of low income households 3. They obliged the housing institutions to make an implicit trade-off between increased land consumption and reducing commuting distance in favor of consumption. 47

48 D. Is it possible to modify urban spatial pattern in South Africa? 1. General land use regulations and planning Review status of buffers zone between settlements Allow densification of high income area Develop standard for low income housing based on clusters rather than on individual plots Allow and actively promote the concentration of employment Upgrade and increase the amenities in the central parts of cities 2. Low cost Housing policy Allow households to make the trade-off between land consumption and distance Institute portable housing subsidies that are not project specific More flexible standards for suppliers: emphasis should be on minimum floor space and infrastructure not on minimum land consumption. 3. Transport Public transport will be viable only if and when employment concentration is possible Taxis here to stay, better roads network to avoid congestion 48