Census Geography: Maps & Apps
description
Transcript of Census Geography: Maps & Apps
Census Geography: Maps
& AppsJoe Germuska
NewsApps DeveloperChicago Tribune
0:00
Census Geographies
http://www.census.gov/geo/www/geodiagram.pdf
1:30
SUMLEV
3:03
Key Summary Levels
• Block (~ 8M): basis for all tabulated data
• Block Group (~211K): smallest geography for which sample data is published
• Tract (~74K): relatively permanent; 1200-8000 people (optimum: 4000)
• County (3,143)
• State (52)
• Division (9)
• Region (4)
• Nation (1) (and then there are the “Island Areas”)
4:57
Other Groupings
•Place (7,438): Incorporated and Census Designated (CDP)
•County Subdivision (36,642)
•Core Based Statistical Areas (942)
7:20
Geographic Components
•about 100 different geographic components, with most focusing on urban/rural or metropolitan/non-metropolitan distinctions
•Nation
•Region
•Division
•State
•CBSA
9:00
TIGER Shapefiles
9:46
Shapefiles
•In addition to tabulation geographies:
•Roads
•Hydrography
•Landmarks
•Military Installations
10:40
Gazetteer• Delimited text files provide IDs, names, area, centroid for:
• 111th Congressional Districts
• Census Tracts
• Counties
• County Subdivisions
• School Districts - Elementary, Secondary, Unified
• State Legislative Districts - Lower & Upper
• Places
• ZIP Code Tabulation Areas
• GeoID not always exact match for shapefile (prefix, etc)
11:10
Keep in Mind
• Geos can change between “vintages”: compare with caution. Consult “crosswalk”
• Know which geos are contained by larger geos and which can “overlap”
• Choose your summary level carefully
• 080 “Census Tract” ≠ 140 “Census Tract”
• Exercise extreme caution when aggregating to non-census geographies
11:50
Population Change Map
14:54
WNYC Map
15:28
Know Spokane
15:35
Options
Chicago Tribune
WNYCSpokesman-
Review
Tile MillGoogle Fusion
TablesGeoDjango + Google Maps
15:44
Tile Mill
16:17
Tile Mill
•Can be entirely hosted on any simple web server (Amazon S3)
•Tile generation can be slow, especially for close zoom levels
•Evolving rapidly, especially interactivity
18:14
Fusion Tables
19:33
Fusion Tables
•Can import KML for shapes, sometimes data
•More often, KML for shapes, then join with data
•Easy to embed
20:10
GeoDjango
21:02
GeoDjango
•Highly customizable
•Well-documented, healthy user community
•Hosting adds extra layer of complexity
21:37
22:32
23:45
24:00
24:04
24:15
census.ire.org
•Browse and compare
•Correctly computed changes since 2010
•Export as CSV, JSON, KML
•JSON available for web apps
26:30
Example JSON datahttp://…/15/1571550.jsonp*
27:12
You can join the fun
• CENSUS-L » http://www.ire.org/join/listserv.html
• https://github.com/ireapps/census
29:17
Questions?
•Links for this presentation:
•http://j.mp/muCTyM
•http://blog.apps.chicagotribune.com
•Twitter:
•@JoeGermuska
•@TribApps
32:07
Links• Census Geographic Resources
•http://www.census.gov/geo/www/tiger/tgrshp2010/tgrshp2010.html
•http://www.census.gov/geo/www/2010census/gtc_10.html
•http://www.census.gov/geo/www/2010census/GTC_10.pdf
• Example Apps
•http://media.apps.chicagotribune.com/census-2010/population-change/index.html
•http://data.spokesman.com/census/2010/washington/
•http://project.wnyc.org/census-maps/2010pop.html
• How-tos:
•http://blog.apps.chicagotribune.com/2010/02/17/quick-install-pythonpostgis-geo-stack-on-snow-leopard/
•http://blog.apps.chicagotribune.com/2011/03/08/making-maps-1/
•http://blog.apps.chicagotribune.com/2010/02/17/hello-newsroom-a-simple-geodjango-application/
• http://www.ire.org/census/
• https://github.com/ireapps/census
• http://www.ire.org/join/listserv.html32:17