GIS 4006 - Module 10 - Dot Mapping

For this weeks module 10 we were tasked with creating a dot density map of South Florida based on information supplied by the U.S. Census Bureau. Dot density mapping involves the use of dots as symbols to identify one or more occurrences. In the case of my map 1 dot is equivalent to 20,000 people. The number of dots change in proportion equivalent to the population field in the supplied census data excel file.

The major advantage of dot mapping is that it is an intuitive concept that a viewer with no map experience can comprehend. A quick glance at the legend to confirm the dot symbol representation and a viewer can see on the map where dots are grouped closely and where they are spread apart. These areas would intuitively register as high and low population areas to an individual with no mapping experience. Another advantage is that dot mapping shows how land is used. In the case of a population map high concentrations of dots indicate a highly populated.

Disadvantages to dot mapping would involve the appearance of the dots themselves. Dots that are weighted to low would barely be visible and dots weighted to high would overlap and obscure. Dots can also be misunderstood if a viewer does not acknowledge the legend. A single dot could be understood as being equivalent to a single person in the case of a population dot density map like in this module.