You are working at a small-to-midsize county planning department in the 48 contiguous United States. (For the purposes of this exercise, it’s a county of your choice). The department is in the early stages of developing a new comprehensive plan—which will set new directions for issues ranging from housing and transportation to economic development and energy consumption. Of course, these early efforts include looking at recent trends in basic variables, such as population change and density. Further, given the size of the county, the departmental leadership is very interested in developing regional strategies (coordinating with neighboring counties) whenever possible.
In working toward the eventual plan, you must analyze the overall change in population density across the county from 2010 to 2015. In addition to calculating this change, you must prepare a presentation slide—with one or more maps—situating these changes regionally (in the context of surrounding counties). In other words, your map(s) should answer the following questions:
Complete the exercise below, answering the embedded questions.
Following the exercise, create one map composition that situates the changes in population density for your chosen county relative to changes nationwide. The map composition should be landscape-oriented and formatted as a presentation slide (one that might be used internally within the department and later in public hearings or community-engagement meetings).
In choosing a county, you should consider the population of the county relative to those across the country. Recall the scenario specifies “a small-to-midsize county planning department,” and large cities generally have their own planning agencies. (Thus, choosing a metropolitan area would be inappropriate for this assignment).
<aside> 💾 Download and unzip the exercise data package from google drive, saving it to your working directory.
Exercise data packages are accessible with a Columbia University login. If you would like a copy of the full course materials, see here.
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The exercise uses three data sets from the US Census Bureau: a table of population estimates by county in the United States in 2015, a table of population change estimates by county from 2010 to 2015, and the TIGER/line shapefile of county boundaries. The 2015 county boundary shapefile is provided as it was downloaded from the US Census Bureau website.
US Census Bureau. “PEPTCOMP – Estimates of the Components of Resident Population Change: April 1, 2010 to July 1, 2015” [dataset]. Population Estimates. 2016.
-----. 2015 American Community Survey 5-year Estimates “Total Population by county” [dataset]. 2016.
-----. 2015 TIGER/Line Shapefiles “Counties and County Equivalents” [shapefile]. 2015. Subset created by L Meisterlin. December 2016.
The exercise requires two separate but related analyses: We must first map population size, change, and density across the country to choose an appropriate county for the fictional scenario. Then we must create at least one thematic map of population density change within that county relative to its surrounding region.
Because we will be calculating population and population density, it is important that we use (and understand) an appropriate projection. The early portions of this exercise will examine different projections at the national (across the continent) level, comparing a few common projections with the help of some simple geometric calculations. The latter portions will calculate population change and density.
To set up, launch your GIS software and create a new, blank map project. Add the county boundary shapefile as a layer in your map project. It is located in the \vector\ folder and called tl_2015_us_county.shp.
Save your new project.
Working with geospatial information in GIS software means working with coordinate systems and usually (but not always) projected data. Before we get started, there are a few software-related concepts to cover.