Day 12: Population – Nobody Lives Here: Unpopulated Places in Alaska
My #30DayMapChallenge theme for today is population and I wanted to show places without people. I decided to map unpopulated areas of Alaska, which is both the largest and least densely populated state in the United States (Wyoming actually has the lowest population). I have seen a few of these kinds of maps on mapping blogs and elsewhere and find them eye catching. While it may sound like a challenging map to produce, it is surprisingly easy to make this type of map using open source 2020 US Census Bureau data.
Approach
To make my map, I downloaded a shapefile of US Census blocks for Alaska, which included population data from the United States census of 2020. A census block is the smallest geographic unit that the US Census Bureau uses for collecting and tabulating decennial census data (that is, the national census required by US Constitution to be performed every ten years). The census block data can be downloaded directly from the US Census Bureau’s website or imported into ArcGIS Pro via a quick search in Esri’s Living Atlas.
Once I had my block data for Alaska, I reviewed the attribute table and found a field called Total Population that included the total population for each of census block, as of the 2020 decennial census. I then set a display filter in ArcGIS Pro to have the Total Population field value equal to zero. This resulted in limiting my data to only show empty, unpopulated census blocks. Below is my map:
The areas in green represent census blocks that are completely devoid of people.