Diversity of global slum conditions is a universal spatial definition of slums feasible?

Transcription

1 Diversity of global slum conditions is a universal spatial definition of slums feasible? Richard Sliuzas ITC Expert Group Meeting on Slum Mapping May 2008 INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION

2 Contents Slum dwellers indicators Different types of slums and informal development processes Key spatial characteristics that may have potential for slum mapping

3 The 5 characteristics of slum dwellers UN-Habitat Global Report on Slums Access to improved water ( access to sufficient amount of water for family use, at an affordable price, available to household members without being subject to extreme effort); 2. Access to improved sanitation ( access to an excreta disposal system, either in the form of a private toilet or a public toilet shared with a reasonable number of people);

4 The 5 characteristics of slum dwellers UN-Habitat Global Report on Slums Durability of housing ( permanent and adequate structure in non-hazardous location) 4. Sufficient living area (not more than two people sharing the same room). 5. Security of tenure ( evidence of documentation to prove secure tenure status or de facto or perceived protection from evictions )

5 Spatial aspects Access to improved water: proximity to water delivery points and system capacity Access to improved sanitation: location and capacity of sanitary system Durability of housing: type and level of hazard (natural and technological) building quality? Sufficient living area: house size (in relation to occupants) Security of tenure: boundaries of parcels (and tenure type)

6 Typical spatial characteristics of slums High density Lack of spatial order Lack of access (quantity and quality of infrastructure) Lack of public facilities (schools, health, cemeteries, parks and sport fields) Hazardous locations Advantageous locations (employment, low travel costs)

7 Phases of development (informal) Infancy: initial occupation of land and construction Consolidation: Bridge-headers expand and improve housing and individual services; increasing subdivision, construction and tenancy Maturity: private space maximised at expense of public space; total build out, congestion and infrastructure improvement only at expense of demolition Increasing physical development > population density increase exceeds improvements in physical development and services Formal slum development result of different process associated with filtering and physical decline of buildings and infrastructure

8 What variety is to be found and what sort of development processes can be identified? INTERNATIONAL INSTITUTE FOR GEO-INFORMATION SCIENCE AND EARTH OBSERVATION

9 The life and motion of informal (slum) areas incremental & unstructured Vacant piece of land 1 building 2 buildings 2 buildings T0 T1 APPEAR T2 APPEAR T3 Grow n buildings 13 buildings 2 buildings T5 APPEAR T4 Reduce T6 Expand & consolidate (SETTLEMENT) (BLDG > SETTLEMENT)

10 Dar es Salaam, Tanzania

11 Phola Park, Cape Town The layout in Phola Park 17/03/2004 Housing in a Social Context 5 (Abbott)

12 The pilot project area: New Rest

13 Rio de Janeiro (Brazil) (Vidigal) (Abbott)

14 The life and motion of informal (slum) areas incremental & structured Vacant piece of land 1 building 2 buildings 4 buildings T0 T1 APPEAR T2 GROW T3 GROW x buildings Expand & consolidate (SETTLEMENT)

15 Cairo slum development on agricultural lands

16 Cairo slum development on agricultural lands

17 Examples from Cairo (Ikonos) Multi-storey high density informal Former Agricultural land Incremental / structured Desert land Incremental / unstructured

18 Urban Villages in Cairo Fringe location In planned area

19 Land use map prepared from Ikonos satellite images for Ministry of Planning Egypt Greater Cairo Land Use 2000 LEGEND Study Area Land Use 2000 Core Villages Informal Residential Vacant Pocket Formal Residential Other Urban Ring Road Road Under Construction Construction sites Agriculture Desert Nile and other water bodies SOURCE OF DATA This land use map of Greater Cairo was produced at the ITC, The Netherlands using a mosaic of Ikonos imagery from the period June The initial interpretation of informal settlements was carried out by students of the Urban Planning and Land Adminitstration programme from June to September Additional interpretation was carried out by Chris Hecker. The interpretation was supevised by Walid Belal and Richard Sliuzas. Data of 1991 and 1998 produced by CEDEJ, Cairo provided the basis for the delineations. The Greater Cairo Land Use Map is a collaborative project involving the following organisations: GTZ, ITC, CEDEJ,and the Ministry of Planning, CAPMAS, Ministry of Local Government, Egypt. Information about this project can be obtained from Dieter Bohnet (Dieter.Bohnet@Bohnet-Consulting.de) or the GTZ office Cairo (mopgtz@link.net). N Meters

20 Matare 4, Nairobi high degree of commercial room rental ref: Richard Sliuzas

21 The life and motion of informal (slum) areas Invasion settlements - sudden & structured Vacant piece of land x buildings & settlement T0 T1 APPEAR T2 Evolve - grow T3 Evolve - grow

22 Peru: Invasion settlements

23 Vizag, India Urban villages on hillsides and in gullies providing economic opportunities such as manufacturing or household services

24 New Delhi, India

25 Reflections on these examples Diversity Contexts / cultures / histories Buildings: styles, sizes, densities, materials Building quality Physical site characteristics Neighbourhood characteristics Phases of development

26 Reflections Using remote sensing alone only relatively data about some of the physical characteristics of slums can be collected Existing GIS data and local knowledge can considerably enhance the data extraction process

27 Reflections Need to differentiate between different development stages (process of slum formation not just the end state) Size, density and quality of housing may be such that even 40-60cm resolution is insufficient for detailed mapping