Mapping with
flow lines provides a very simple graphic illustration of geographical movement
of some phenomena. In this module a flow map was created to show the origins of
and number of persons coming from other regions and obtaining legal permanent United States
resident status. A choropleth map of the United States was created to show
the percentage of immigrants to each of the fifty states. The graphic
representations were based on fiscal year 2007 statistics obtained from the US
Department of Homeland Security. Flow lines on flow maps must be hand drawn due
to their individual and unique nature. Because of this, Adobe Illustrator was
used exclusively to create the flow map.
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| preliminary sketch - horizontal |
Far more than
any other map created to date, this flow map took the most preparation to
determine the best layout before even starting Adobe Illustrator. First in the process
was sketching out two possibilities ~ a horizontal format and a vertical format,
each one showing the location of the continents with flow line placement,
location of the choropleth map and the legend. For each map a list of pros and
cons was also created. The horizontal format allowed plenty of room to place
the US in the center with
the regions placed around the US
with large flow lines directed to it. The horizontal layout seemed less busy, was
very clear, and required shorter flow lines. The cons of the horizontal layout were that the regions were
not viewed in their normal relationships to each other, and the map was very
US-centric giving the impression that the US is of greater importance than
the rest of the world. Although the purpose and focus of the map is to show
immigration to the US
from all other regions, the US-centric format was rejected eventually. On the other hand, the vertical format kept the US
and the other regions of the world in their proper relationships, and the US was kept at the
same scale as the other countries.
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| preliminary sketch - vertical |
Negative aspects of this format were that the
flow line showing immigration from other parts of North America to the US was
split and had to be joined near the arrowhead, and either the South American
flow line had to cross the flow line coming from the region of Mexico/Central
America or it would have to be placed in the already congested area of the east
coast. That would be dealt with later, as this still seemed like the better
layout choice.
The next step
in the flow map-making process was to print out a preliminary layout for a
working sketch. This involved placing the world map and choropleth map in an AI
document and printing it out.
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| working sketch |
Questions, notes, ideas, RGB colors for matching
purposes, additions/deletions, and information that came up in discussion board
postings as well as the flow lines were marked on this map or the initial
hand-drawn sketch. This provided a way to keep all the necessary information
and lab requirements organized and to minimize the possibility of leaving information
out unintentionally. It was also a way to think out different ways of presenting
the information prior to committing to making changes in Illustrator. With flow
lines sized proportionally and matching the regions by color, the resultant map
provides an easy to interpret comparison of immigration from different regions
of the world. For specific immigration numbers, viewers can consult the chart
included in the map. Ideally this chart would have included the color and size
of flow line attributed to each region, but time constraints and other obligations precluded that this time.
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Persons Obtaining Legal Permanent
U.S. Resident Status (By Region of Birth, FY 2007) |
Choropleth
colors were chosen to match the color of North America
in the flow map. Normally the bar scale for a map would be placed lower than
the legend of the map, but in this particular case it was placed closer to the
map for ease of use. The orange color scheme of the choropleth map and the
legend along with the size of the rectangles in the legend attract one’s
attention directly to the legend from the choropleth map, so it still appears
to rank higher visually if not physically.
While some
aspects of using AI are becoming familiar, there is so much more to learn.
Creating the flow lines was extremely difficult with each one requiring several
attempts. Applying some of the special effects to the flow lines changed either
the color, length or position of the flow lines with the longer lines impacted
more severely than shorter lines. Because of this, only drop shadow was applied
to the lines, and that had to be adjusted where the lines come together at the
east coast of the US.
Some workarounds for the other issues may be discovered with more practice. Throughout
this map-making exercise, numerous copies of the map were saved at different
stages to provide backup in case a special effect could not be undone for some
reason. This exercise exemplified the extensive capabilities of Adobe Illustrator
for creating or enhancing maps.
