The map is a re-creation of Charles Minard’s British Coal Exports in 1864 map. The first run of the script for the flow lines layer shows how there is more coal being sent around Europe, which makes sense as that is where all the coal that is being shipped out starts, centered at Liverpool. Then as it extends out the amount of coal gets less and less as part of it is deposited at places. There are, however, a few larger streams of export that are further away from Europe and even North Africa, such as to the USA, Cuba, Brazil, and Western Asia (more specifically India), areas of importance to Britain. Then with the adjustment of the script making routes flow around countries, we see that in fact, India does not get as much as first perceived, rather the larger flow is directed towards Singapore. The Barriers added then cut off the Panama Canal and the Thai Canal, yet the Thai canal appears to not have been considered a route before as the flow line does not change their route around that Myanmar, Thailand, and Malaysia area. The Panama Canal, on the other hand, exhibits a huge change in flow, forcing it all the way around the bottom of South America. The Suez Canal in Egypt was the one that was not accounted for, that I had to create the barrier for. On my first attempt, one part of the flow was redirected around Africa, but the other part simply maneuvered around the barrier. I then extended the barrier even further and reran the script and it made everything re-route around Africa. One other issue I had with the flow map was how to format the symbology. At first, I wanted graduated symbols to show width proportional to the amount of coal, but there was too much overlap that it was hard to distinguish details of smaller flows. As a result, I changed to using graduated colors to clearly show details and still show how as one gets further away from Europe there is less amount of coal being transported, with exceptions of significant paths (South Africa, USA, etc.). In this, I had to think about using a very distinct color gradient, and a small enough width for the line symbol so that details were observable, yet wide enough to distinguish color.
