1. Spatial Measurement of Residential Segregation Flávia F. Feitosa 1, Gilberto Câmara 1, Antônio M. V. Monteiro 1, Thomas Koschitzki 2, Marcelino P. S. Silva 1,3 1 Instituto Nacional de Pesquisas Espaciais 2 Martin-Luther Universität – Institut für Geographie 3 Universidade Estadual do Rio Grande do Norte IV Brazilian Symposium on GeoInformatics. Campos do Jordão, November 22-24, 2004

2. What is Segregation? Segregation is the separation between different social groups

3. Why Measure Segregation? Measure segregation is necessary Understand segregation better Patterns, causes and consequences Useful for public policies Housing policies Infrastructure policies Land speculation control

4. Dimensions of Segregation Evenness/Clustering: Balance of the distribution of population groups Exposure/Isolation: Chance of having members from different groups living side-by-side (Reardon and OSullivan, 2004)

5. Global Measures However, most of these segregation measures are global and nonspatial Global measures Express the segregation degree of the city as a whole But segregation varies along the city Local indices required

6. Nonspatial Measures Nonspatial Measures Nonspatial measures Unable to distinguish different spatial arrangements among population groups Checkerboard Problem

7. Aim of this Work Aim of this Work Build spatial measures of segregation Extend existing measures to enable the use of geographical information in their formulation Propose local measures of segregation Decomposition of the new spatial indices

8. Building Spatial Measures Building Spatial Measures Definition of neighborhoods Proximity functions chosen by the user Neighborhood population count in areal unit i Sum of the population of all areal units, where units are weighted by their proximity to i

9. Building Spatial Measures Building Spatial Measures Spatial version of three nonspatial indices 1) Generalized Dissimilarity Index - Measures the difference between the neighborhood population composition of the units and the population composition of the city as a whole Evenness/clustering dimension

10. Building Spatial Measures Building Spatial Measures Spatial version of three nonspatial indices 2) Exposure/Isolation Index - Average proportion of group n in the neighborhood of each member of group m (or n, if isolation) Exposure/isolation dimension

11. Building Spatial Measures Building Spatial Measures Spatial version of three nonspatial indices 3) Residential Segregation Index -. Segregated city: high Proportion of which is explained by the Evenness/clustering dimension

12. Local Measures of Segregation Local Measures of Segregation Decomposition of spatial measures Local Measures: able to show how much each unit contributes to the composition of the global index Display as maps

13. Nonspatial X Spatial Measures Nonspatial X Spatial Measures Dissimilarity Index Nonspatial 1 1 0 Spatial 0.86 0.05 0 Residential Segregation Index Nonspatial 1 1 0 Spatial 0.82 0.07 0

14. Nonspatial X Spatial Measures Nonspatial X Spatial Measures Dissimilarity Index Nonspatial Dissimilarity Index Spatial

15. Case Study Case Study Segregation in São José dos Campos – SP Years: 1991 and 2000 Income of householders = socioeconomic status of the families Neighborhood population count of each unit

16. Case Study Case Study Generalized Dissimilarity Index INCREASE

17. Case Study Isolation Index of Rich families 1991 Global index = 0.20 2000 Global index = 0.28 INCREASE

18. Results Results New spatial measures Overcome the checkerboard problem Enable the choice of different definitions of neighborhoods Allow complementary views by measuring both dimensions of segregation New local measures Better understanding of global indices results Identify patterns of segregation inside the city Useful tools for public policies

19. Spatial Measurement of Residential Segregation Flávia F. Feitosa 1*, Gilberto Câmara 1, Antônio M. V. Monteiro 1, Thomas Koschitzki 2, Marcelino P. S. Silva 1,3 1 Instituto Nacional de Pesquisas Espaciais 2 Martin-Luther Universität – Institut für Geographie 3 Universidade Estadual do Rio Grande do Norte * E-mail address: flavia@dpi.inpe.br