Data Management,
Preservation and Access
The primary data generated
in this study included children’s observations in their community,
the routes taken to school by children, and safety-related observations
by University of Texas students. Secondary data obtained during
the project included information on facilities with hazardous materials
provided by the Texas Commission on Environmental Quality and pedestrian
accident information provided by the City of Austin.
Our data management considerations
included:
-how to organize information to allow for efficient data entry and
analysis
-how to allow for data access, data entry and data storage by community
partners
-how to most faithfully preserve and represent children’s observation
Children’s observations
were entered into ESRI ArcGIS shapefiles to allow for cartographic
presentation and spatial analysis. We grouped the attribute fields
into the following categories: 1) information about the observer,
2) information defining the location of the observation, 3) information
on the observer’s perceptions, and 4) information on methods of
collection. This structure allowed each record to unfold as a story
while emphasizing the role of the child observer, and facilitates
the preservation of raw or un-manipulated datasets. The attribute
tables were exported into Excel spreadsheets for easy presentation
of the data to members of the community without access to GIS. Shapefiles
modified during analysis and map generation were stored separately,
and all datasets will be burned to CDs and distributed and archived.
Observation Location
vs. Location of the Observed
During data
input to GIS, a high-quality aerial photograph was used to locate
the observation on the sidewalk nearest to the workshop-mapped point.
This was to recognize that the observation did not occur within
an industrial facility or park, and to emphasize that these data
sets represent children’s perceptions, not the actual location
of the perceived location. The object or location observed was captured
in the “Point Name” attribute field and in the “Address” field.
Symbology
We explored many different
symbol combinations to represent children’s perceptions and industrial
activity around their elementary school. Effective communication
of this information required a balance between clarity and quantity,
while considering the needs of the audience, purpose of the symbol,
the rhetorical impact of different colors and symbols, and visual
harmony with other symbols.
Children’s Perceptions
To display the six perceptions
collected during the workshops (sight, smell, sound, safety, cleanliness,
and “fun”) while still respecting the individuality of the children’s
observations, we decided to give each perception its own map. Our Industry and Children’s Perception of Safety Near Zavala Elementary School by Point and Block map uses pie charts to capture each child’s perception by giving
them their own slice of the pie. Varying sizes of pie charts was
used to show the number of children at the observation point. We
used red to symbolize negative feelings of safety, which matched
the color used to represent the perception of safety for each block.
This allows the map user to quickly see the areas around Zavalla
Elementary that the children perceive as unsafe.
Line Categories
For our map, Industy, Hazardous Materials, and Children's Walking Routes to Zavala Elementary School,
we needed to show the number of children walking on each block.
We chose to use color categories to represent this information because
it allows for both easy comparison between features and interpretation
with the legend. The use of color categories required us to choose
a color that allowed comparison between lines. For our map, we chose
differing shades of blue. This was partly because the other features
on our map were hazmat sites, which we felt required a harsher,
less-natural color such as red and yellow.
Hazmat Points:
Representative Marker vs. Color Categories
The categories of hazmat
sites (i.e. “Auto Repair,” “Tire Repair,” “Petroleum Storage
Tanks”) seemed at first to be perfect for representative markers,
such as a picture of an automobile, tire, or tank. However, this
resulted in difficulties of interpretation when points were overlapping
or in close proximity to each other. We chose to simply use circles
with different colors to show categories. Although this caused the
map user to rely heavily on the legend to match a hazmat site with
the category, it was preferred since it gave equal visual weight
to the children walking routes layer also displayed on the same
map.
Historic Race Patterns in Austin
The controversial 1927 Property Use Map displays the racial distribution
of Austin at that time. We have attempted to display the information
from that map and show that the present-day race and industry spatial
distribution patters are a product the past.
To capture the 1927 racial distribution of Austin, a scanned image
of the 1927 Property Use Map of Austin was georeferenced in GIS.
The 1927 image did not provide easy distinction between white residential
property (cross-hatched polygons) and miscellaneous residential
property (stipple-filled polygons). Because of this and considering
our maps will be focused on citywide patterns with a scale of 1:48,000,
the white property and miscellaneous property were captured in a
polygon shapefile. Business property was not captured as part of
this analysis since the category was broad and included commercial
and office as well as industrial. It is obvious that the miscellaneous
residential property was used to display housing for nonwhites. Below
is a map showing the white and nonwhite housing in 1927. Recent
spatial information, including road centerlines (2006) and the Colorado
River (1999) were added to our maps to allow users the ability to
orient the 1927 information to the present city.
It is apparent that the majority of nonwhite residential property
is located in East Austin, with a few small pockets scattered west
and south. The below table displays basic information pertaining
to the housing composition of Austin in 1927, which contained a
much greater amount of white residences when compared to nonwhite.
Austin Housing in
1927 |
Residential Type |
Acres |
Number of Parcels |
White |
1,400 |
843 |
Nonwhite |
360 |
301 |
To allow for easier comparison with other polygon layers, buffer
zones were for of the 1927 residential types were created. The use
of buffer zones also compensated to a degree the spatial errors
created during the georeferencing process. Common errors were noted
to be 150 feet in some areas, which was the amount chosen for our
buffers. Three buffer zone categorizes were created that included
white, nonwhite, and combined. The combined category captured areas
that were within the 150-foot buffer of both a white and nonwhite
property. The buffers were then merged into these three categories
to allow for easy visual interpretation. Below is our map displaying
the residential (buffer) zones we created from this process.

Current Race Distribution compared with 1927 Residential
Zones
Census tracts with a nonwhite racial composition of greater than
50% were selected from the 2000 City of Austin Census data. The
resulting polygon was merged and compared to the 1927 residential
zones created earlier. Below is a map showing that information.
It is apparent that the present distribution of nonwhite populations
has a similar spatial pattern as the 1927 residential zones. Nonwhite
populations apparently expanded east after 1927.

2003 Industrial Land Use compared with 1927 Residential
Zones
A potential relationship between residential distribution in 1927
and the distribution of present-day industrial land use was explored
in this section. We compared the 2003 industrial land use to the
1927 residential zones, with the resulting map displayed below.
A shapefile of the 2003 industrial land use was clipped to the 1927
City of Austin Boundary to simplify our map.
The 2003 industrial parcels that intersect residential zones
were selected and the following table was generated.
It is apparent that present-day industrial parcels are more likely
to occur near residences that housed non-white residents in 1927. According to
our results, industry was more than twice as likely to occur near
an area historically used for housing by non-white residents.
A comparison of 2003
industrial land use near residential zones in Austin |
Residential Zone (1927) |
Acres of Residential Zone (1927) |
Acres of Industrial Use (2003) |
Acres of Industrial/
Acres of Zone |
Nonwhite |
1,123 |
310 |
0.276 |
White |
3,543 |
384 |
0.108 |
Combined |
429 |
180 |
0.420 |
|