Links to Data, Cleaning and Analysis Scripts, RMarkdown HTML Pages
- The entire codebase for this analysis, including R markdown cleaning and analysis scripts – and the raw and cleaned data needed to reproduce the cleaning and analysis, is available through the Howard Center’s GitHub.
- A site with HTML versions of the R markdown files, for fact-checking the completed the analysis.
- NPR has made available a separate GitHub repo for nationwide analysis on urban heat islands available here.
Definitions
Geographic Units: Several geographic units are used throughout the analysis. The geographic units are:
- U.S. Census block: The smallest geographic area tracked by the U.S. Census bureau. Shapefiles downloaded from Census.gov.
- ZCTAs - ZIP Code Tabulation Areas: A U.S. Census proxy for postal ZIP Code units. Shapefiles downloaded from Census.gov.
- NSAs - Neighborhood Statistical Areas: Areas created by Baltimore City to represent Baltimore neighborhoods, comprised of custom groupings of U.S. Census blocks. This grouping is considered by Baltimore City and this analysis as the best representation of true Baltimore neighborhoods. Shapefiles provided by the Baltimore City Department of Planning.
- CSAs - Community Statistical Areas: Groupings of neighborhoods, created and used by the Baltimore Neighborhood Indicators Alliance (BNIA). In some cases, there is one neighborhood per CSA; in others, it’s multiple. Recent demographic data is only available by CSA. Shapefiles downloaded from the Baltimore Neighborhood Indicators Alliance Vital Signs project.
- Redlined geographic units: Between 1935 and 1940, local real estate lenders, developers and real estate appraisers assigned grades to residential neighborhoods based on the perceived risk for banks to grant loans. This process was based in part on the race of residents and is known today as “redlining.” The “Mapping Inequality” project, conducted by teams at four different universities, generated interactive maps of cities across the U.S., including Baltimore, and made their shapefiles available by city.
A Note About ZCTAs:
- There are some slight differences in the exact boundaries between ZCTA shapefiles pulled from Census.gov when pulled county-by-county and for MD as a whole. All ZCTA groups are from the state-level ZCTA files.
- The Mid-Atlantic Terminal at Dundalk (sometimes included as part of the 21222 ZCTA) is not included.
- All calculations for included ZCTAs are done over the entire ZCTA, even when the ZCTA expands past the city boundary, with one exception. 21226 is cut off at the city boundary due to limitations the in treecover and heat maps. In addition, a small peninsula in that same ZCTA was removed for ease in computing.
- 4 ZCTAs (‘21208’, ‘21228’, ‘21234’, ‘21236’) encroach slightly into Baltimore City, but were not included due to limitations in treecover and heat maps.
- 3 included ZCTAs (‘21227’, ‘21222’, ‘21237’) only encroach slightly into Baltimore City but were included because the treecover and heat maps encompass them.
- An insignificant portion of the north end of 21237 is not included on the treecover map and is therefore missing from calculations made for that ZCTA.
- ZCTA lists for reference:
- Complete list of Baltimore ZCTAs: ‘21201’, ‘21202’, ‘21205’, ‘21206’, ‘21207’, ‘21208’, ‘21209’, ‘21210’, ‘21211’, ‘21212’, ‘21213’, ‘21214’, ‘21215’, ‘21216’, ‘21217’, ‘21218’, ‘21222’, ‘21223’, ‘21224’, ‘21225’, ‘21226’, ‘21227’, ‘21228’, ‘21229’, ‘21230’, ‘21231’, ‘21234’, ‘21236’, ‘21237’, ‘21239’, ‘21251’
- ZCTAs removed from list (for untrimmed): ‘21208’, ‘21228’, ‘21234’, ‘21236’
- Complete list of ZCTAs used (for untrimmed): ‘21201’, ‘21202’, ‘21205’, ‘21206’, ‘21207’, ‘21209’, ‘21210’, ‘21211’, ‘21212’, ‘21213’, ‘21214’, ‘21215’, ‘21216’, ‘21217’, ‘21218’, ‘21222’, ‘21223’, ‘21224’, ‘21225’, ‘21226’, ‘21227’, ‘21229’, ‘21230’, ‘21231’, ‘21237’, ‘21239’, ‘21251’