U.S. Census Data Options for downloading and importing data into ArcMap Treg Christopher Oct 31, 2008

Types of Census Data Decennial Census ◦ SF1:Sex,Age,Race,Hshld income, size  Info for each field at: ◦ SF2:Similar info as SF1 but detailed for each of 200+ ethnicities  Guide for finding specific info: ◦ SF3:Long form…intensive info from a sample of people from each Block  ◦ SF4:Similar info as SF3 but detailed for many ethnicities Community Surveys Economic Surveys

Census Geographic Files TIGER (Topologically Integrated Geographic Encoding and Referencing ) ◦ Source:  Variety of sources but mainly from1:100,000 USGS topo maps ◦ Positional Accuracy (Horizontal):  National Map Accuracy standards for 1:100k is approx +/- 167 feet  Relationship betw/ scale and acuuracy: ◦ Most sources have already converted these TIGER files into a more usable format (e.g. shapefiles)  If not:  Use Toolbox in ArcMap (Need ArcInfo workstation installed)  Use a 3 rd Party conversion software ◦ Refer to: and for more infohttp://

Census Units Block Group ID: 12 Digits= State (2) + County (3) + Tract (6) + BG (1) So you can always aggregate data and analyses from the single BG ID

Data Sources for Census Data ESRI Geography Network ◦ 00_tigerline/index.html 00_tigerline/index.html Federal GIS Clearinghouse ◦ Vermont Spatial Data (at VCGI) ◦ U.S. Census ◦ American Factfinder at

ESRI Geography Network

Project Workspace Census SF1 Table Census Shapefile

Joining Tables to Shapefiles

Download data for entire state Download data for AOI (Area of Interest)

VCGI Data for Entire State

VCGI Custom Selection

VCGI Custom Selection of B-ton

Data from or

Table Types in ArcMap Tables can be added to ArcMap if they are: ◦ Dbf files ◦ From a database (e.g. Access)  (Doesn’t have to be an ESRI personal geodatabase) DBF not available in Office 2007! ◦ Import xls or csv file directly into Access ◦ Import xls or csv file into Open Office and save as dbf

Import CSV file into Excel or Access Can usually skip this page unless Excel sets wrong data type ID showing as # instead of text

Boundary Files from Don’t use these..they have generalized boundaries (explained at: cob/scale.html ) cob/scale.html

Appending Census Boundaries What to do if you want a single, large coverage from multiple, smaller areas ◦ Copy the largest GIS file (shapefile,pgdb,file gdb) and rename (e.g. “MasterCensusBnd”) ◦ Use the Append command in ArcMap to merge these multiple files

Comments for Projects Indices at: /housing_patterns/app_b.html /housing_patterns/app_b.html Panel/Longitudinal Study? ◦ i.e. how something changes over time? ◦ Be aware that the actual boundaries (and the unit ID ) may change between censuses