Spatial Measurement of Residential Segregation Flávia F. Feitosa 1, Gilberto Câmara 1, Antônio M. V. Monteiro 1, Thomas Koschitzki 2, Marcelino P. S. Silva.

Spatial Measurement Spatial Measurement of Residential of Residential SegregationSegregation

Flávia F. Feitosa1, Gilberto Câmara1, Antônio M. V. Monteiro1, Thomas Koschitzki2, Marcelino P. S. Silva1,3

1 Instituto Nacional de Pesquisas Espaciais2 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

What is Segregation?What is Segregation?

Segregation is the separation between different social groups

Why Measure Segregation?Why Measure Segregation?

Measure segregation is necessary

Understand segregation betterPatterns, causes and consequences

Useful for public policiesHousing policiesInfrastructure policiesLand speculation control

Dimensions of SegregationDimensions 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 O’Sullivan, 2004)

Global MeasuresGlobal 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

Nonspatial MeasuresNonspatial Measures

Nonspatial measures Unable to distinguish different spatial

arrangements among population groups Checkerboard Problem

Aim of this WorkAim 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

Building Spatial MeasuresBuilding 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

Building Spatial MeasuresBuilding 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

Building Spatial MeasuresBuilding 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

Building Spatial MeasuresBuilding 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

Local Measures of SegregationLocal 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

Nonspatial X Spatial MeasuresNonspatial X Spatial Measures

Dissimilarity IndexNonspatial 1 1 0Spatial 0.86 0.05 0

Residential Segregation IndexNonspatial 1 1 0Spatial 0.82 0.07 0

Nonspatial X Spatial MeasuresNonspatial X Spatial Measures

Dissimilarity Index

Nonspatial

Dissimilarity Index

Spatial

Case StudyCase 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

Case StudyCase StudyGeneralized Dissimilarity Index

INCREASE

Case StudyCase Study

Isolation Index of “Rich families”1991

Global index = 0.20

2000

Global index = 0.28

INCREASE

ResultsResults

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

Spatial Measurement Spatial Measurement of Residential of Residential SegregationSegregation

Flávia F. Feitosa1*, Gilberto Câmara1, Antônio M. V. Monteiro1, Thomas Koschitzki2, Marcelino P. S. Silva1,3

1 Instituto Nacional de Pesquisas Espaciais2 Martin-Luther Universität – Institut für Geographie

3 Universidade Estadual do Rio Grande do Norte

*E-mail address: [email protected]