Program in GIS

 GEOG 5121 Project 2:
Mapping the Census

Brenton White

 

Zachary Drive and Vicinity
City of Loveland, Larimer County, Colorado
Census 2000 Reference Map
North

South
Scale: 1:14600
(Approx. on 72 dpi screen)

Source:  U.S. Census Bureau, Census 2000.
 
Figure 1: Describe the reference map of your home town, and how you created it. The reference map shows an area of almost 2 square miles (1.6 miles wide by 1.2 miles high) centered on my home location (Zachary Drive).  It shows major roads (e.g., W. Eisenhower Blvd, also known as Highway 34), streets, railroads, streams and water bodies.  It also indicates census references such as tracts, groups, blocks, etc.  It shows school district boundaries as well.  Unfortunately, this maps also shows a railroad going through my back yard that is NOT correct.  This was a railroad right-of-way that was purchased by the city and sold to the developer of my property.  Thus, as a reference map, it may not be a useful as a map with up-to-date data.

I created this reference map by using the American Fact Finder website.  I navigated to the "Maps and Geography" section and then chose "Reference Maps."  This brought me to a default page showing the entire United States with some "Urban Areas" identified on the map.  I then zoomed in on the map until my home street and coverage were as desired.  I then played with the boundaries and features options in the legend, choosing to keep most of the Census Bureau information, as there are no parks, schools, jails, etc. in this area of my home town—in other words, it was a pretty boring map!

What spatial data was the map created from, and what features are shown? The data was derived from the Census 2000 and includes Census tracts, groups, blocks, and place.  It also delineates Census 2000 Urban areas and elementary school boundaries. Major roads, streets, streams and water bodies, and railroads are displayed.

What is the map scale? Approximately 1.6 miles = 500 pixels = 6.9444 inches (at 72 pixels per inch; your screen resolution may be different), so 1 inch = .2304 miles = 1,216.5 feet = 14,598 inches.  Thus, the scale is 1:14598, which I call 1:14600 since the miles are approximate (I don't have that many significant digits).


Percent of Household With Individuals 65 Years and Over
Year 2000
(TM-P024)
 
map 2 legend  North
map 2
South
Scale: 1:365000
(Approx. on 72 dpi screen)

Source:  U.S. Census Bureau, Census 2000 Summary File1, Matrices P15, and P23
 


Percent of Household With Individuals 18 Years and Under
Year 2000
(TM-P019)
 
  North
map 2
South
Scale: 1:365000
(Approx. on 72 dpi screen)

Source:  U.S. Census Bureau, Census 2000 Summary File1, Matrices P1, and P29
 
Figure 2: Describe the choropleth map of your home county, and how you created it. The two maps contrast the percentage of households in Larimer County, Colorado that have individuals in the household that are over 65 (first map) and under 18 (second map).  Both maps show the data aggregated to U.S. Census Block groups, which is small enough to show concentrations without overwhelming the map with unwanted detail.

I created both maps by using the American Fact Finder website. I navigated to the "Maps and Geography" section and then chose "Thematic Maps."  This brought me to a default page showing the entire United States and showing a default dataset (Persons per square mile) from the "Census 2000 Summary File 1 (SF 1) 100-Percent Data, which was the dataset I needed.  I then used the link to Geography to change the map to cover most of Larimer County in Colorado, which involved some zooming in and centering the map.  Next, I clicked on "Theme" in order to choose the data set that I was interested in (P024—persons 65 and over, and P019—persons 18 and under), and I then clicked show map to see the result (performing this for each dataset separately).

Having the data I wanted displayed, I then clicked on the legend in order to try different classification schemes, determine the boundaries and other feature I wanted on the map and elected not to put a title on the map itself.  After trying several options, I kept the default number of classes, color scheme, and classing method (Natural Breaks).  Other options did not add value to the display of the data for what I wanted to show.

From what spatial and attribute data was the map created? U.S. Census Bureau, Census 2000 Summary File1, Matrices P15, and P23, from the Census 2000 Summary File 1 (SF 1) 100-Percent Data Set.  The Universe is "Households."

To what enumeration units are the data aggregated? Block Groups.  I wanted small enough areas to see grouping with enough detail to identify high-concentration areas.

Which classification scheme did you choose, and why did you choose it? Natural Breaks, since it showed the greatest variation in color and relatively equal groups.

What is the map scale?  Approx 40 miles = 500 pixels = 6.94444 inches (at 72 pixels per inch; your screen resolution may be different), so 1 inch = 5.76 miles = 30,413 feet = 364,954 inches.  Thus, scale is 1:364954, which I call 1:365000 since the miles are approximate (I don't have that many significant digits).

What does the map reveal about your home (or adopted) county? Households with high-concentrations of persons over the age of 65 live in a few relatively concentrated areas of the county.  Houses with persons under the age of 18 tend to be located near city centers.  It would be interesting to compare these maps with another that indicates the age of the houses in each block to see if there is a correlation between age of occupant and age of the house.
Sources
U.S. Bureau of the Census (2003) American FactFinder. http://factfinder.census.gov Accessed 6 February 2004 and 18 February 2004.
This document is published in fulfillment of an assignment by a student enrolled in an educational offering of The Pennsylvania State University. The student, named above, retains all rights to the document and responsibility for its accuracy and originality.