Dot Marks The Spot (GIS 3015/3015L- Cartographic Skills)

This week we jumped into dot maps. Although it seems like a simple procedure, there is plenty of depth within the subject. The map we were tasked to create displays the population density of southern Florida in urban areas. Major cities in this part of the state along with water bodies and wetlands are also displayed. What is accomplished is the ability to view the spatial variation in dot density.

Although the dots appear random, this is not the case. Utilizing ArcMap's masking ability, the software was told to not place the dots in water bodies and only place them in urban areas. Without the proper information, however, this would not have been possible.

The legend included was created in Adobe Illustrator since that would allow for more control compared to ArcMap. It was created by drawing the squares and placing the dots inside them. One dot is equal to 20,000 people and the three squares show an example of what 100,000 to 800,000 would look like.

Although simplistic enough, ArcMap was a bear to work with when it came to implementing the mask. It would either not apply the mask after being told to do so or simply crash before the operation could start. But as with many things in ArcMap, a work around is usually possible.

I also have a relevant picture that I think sums up how everyone felt during this exercise when working with the mask utility.


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