Gis for Environmental Justice - an Example
INVESTIGATING THE SCALES OF ENVIRONMENTAL JUSTICE THROUGH
GEOGRAPHIC INFORMATION SYSTEMS (GIS) AND SPATIAL ANALYSIS FOR
AIR TOXICS IN WEST OAKLAND, CALIFORNIA (Fisher et al, 2006)
The paper under analysis characterizes the spatial point pattern of air toxics in the U.S.
Environmental Protection Agency (EPA) designated Environmental Justice area of West Oak-land,
California. Integrating a GIS framework and an interdisciplinary statistical technique called Ripley’s
K-function, Fisher et al. verify the neighborhood as an environmental justice site across multiple spatial scales, and by means of an air dispersion model, identify the number of people potentially affected by a particular facility, and engage the problem of non-point sources of diesel emissions with an analysis of the street network (Fisher, 2003; Fisher et al, 2006).
DATA SOURCES
The data used in this study was mainly obtained from two different sources:
1. US Census Bureau’s 2000 survey, referred to as census 2000, and spatially referenced by means of TIGER digital files.
2. Toxic Releases Inventory (TRI; volume and location of emissions from facilities).
The census is a statistical method to collect data about every unit within a population or universe. The information does not need to be transformed to be statistically useful, unlike what happens with administrative data sources. The advantages and disadvantages of the census in comparison to other methods are commented below (based on Glejberman, 1997).
Between the strengths: * Total coverage of the population aimed (sampling variance is zero). *“Cross-tabulation of a wide range of demographic, social and economic data” (Vidler, 2001) *The results can be presented per administrative units or smaller classification criteria
(national to local scale), thus the level of aggregation can be chosen. * The census represent a reference for countinous
GEOGRAPHIC INFORMATION SYSTEMS (GIS) AND SPATIAL ANALYSIS FOR
AIR TOXICS IN WEST OAKLAND, CALIFORNIA (Fisher et al, 2006)
The paper under analysis characterizes the spatial point pattern of air toxics in the U.S.
Environmental Protection Agency (EPA) designated Environmental Justice area of West Oak-land,
California. Integrating a GIS framework and an interdisciplinary statistical technique called Ripley’s
K-function, Fisher et al. verify the neighborhood as an environmental justice site across multiple spatial scales, and by means of an air dispersion model, identify the number of people potentially affected by a particular facility, and engage the problem of non-point sources of diesel emissions with an analysis of the street network (Fisher, 2003; Fisher et al, 2006).
DATA SOURCES
The data used in this study was mainly obtained from two different sources:
1. US Census Bureau’s 2000 survey, referred to as census 2000, and spatially referenced by means of TIGER digital files.
2. Toxic Releases Inventory (TRI; volume and location of emissions from facilities).
The census is a statistical method to collect data about every unit within a population or universe. The information does not need to be transformed to be statistically useful, unlike what happens with administrative data sources. The advantages and disadvantages of the census in comparison to other methods are commented below (based on Glejberman, 1997).
Between the strengths: * Total coverage of the population aimed (sampling variance is zero). *“Cross-tabulation of a wide range of demographic, social and economic data” (Vidler, 2001) *The results can be presented per administrative units or smaller classification criteria
(national to local scale), thus the level of aggregation can be chosen. * The census represent a reference for countinous