In the first dot density mapping blog, we discussed the workflow for creating dot density maps using ArcMap. In that discussion we emphasized the need for using exclusion or inclusion layers. Here is an example of how we set up the inclusion and exclusion choices for mapping population density in San Bernardino County, the county with the largest land area in the conterminous United States. Because of its size and the fact that population is not evenly distributed throughout the county (rather, it is concentrated in the southwest
corner, around where Redlands is located), this county exemplifies the limitations of dot density mapping without inclusions/exclusions when mapping population density at the county, the state or even the country level. Read More...