GIS3015 - Module 9 - Flow Line Mapping

Worldwide Immigration to the United States By Region in 2007

Hard to believe we have just completed our 9th module in GIS3015!   This week's lab covered Flow Maps.  Our lecture and text discussed the different types of flow maps; distributive, network, radial, continuous, and telecommunication.  For our lab assignment we mapped migration data with a distributive flow map depicting the movement of people between geographic regions.  The entire world is mapped and depicts the flow of people migrating to the United States from other regions across the world.   The precise route is not as important as the direction and magnitude of the migration.  To calculate the varying width/weight of each region’s flow line I chose a maximum line width of 14 (Asia) and applied the formula provided in the lab instructions (Width of line symbol = (maximum line width) x (SQRT value / SQRT maximum value)).  After crunching the numbers the respective line widths for each continent were calculated (North America - 13.169, Europe – 7.858, South America – 7.378, Africa – 6.957, Oceania – 1.766).  When creating the flow line to depict North Americans’ migration to the U.S. I chose to use converging lines to represent the migration populations from the southern part of North America and the northern part of North America.  The flow lines representing Mexico and the Caribbean region were given a weight of 11.852 and Canada and the northern area of North America were weighted 1.317 for a total North American flow weight of 13.169 per the line width formula.  

My first stylistic change to the provided Base Map was to change the color of the worldwide regions.  Using the layer panel, I selected each continent and used the Edit Color, Recolor Artwork to change the continent colors to RGB values of a qualitative color scheme for 6 classes found on Color Brewer.  I chose to keep the color scheme for the United States, provided in the B Base Map, because I felt it adequately contrasted the continent color scheme I had selected. When creating flow lines from each region I originally chose a black stroke.  To keep the flow lines as the main focus of the map, without them becoming overpowering, I chose to modify the transparency opacity value to 40%.   This modification essentially “greyed” the flow lines but also enabled the viewer to see flow line overlap.  By ordering my flow lines in their respective layer I ensured that the smaller South American flow line appeared “on top” of the North American flow line.  Because the flow lines are the main map focal point, I applied a drop shadow to each line.  Finally, I chose to use a 3D Extrude and Bevel Wireframe effect on my map title.   I did not like the 3D effect look for this map so it was more of a fill effect than 3D and I applied a Border Frame from the Brush Library to my Neatline.  

I had to watch a few videos to understand how to use the pen tool and type tools correctly.  With each use of Adobe Illustrator, I discover new features.