UP206A: Introduction to GIS

» When was the first census? ˃1790 » How many people were counted? ˃3.9 million » How many states did we have then? ˃13 original states, plus the districts of Kentucky, Maine, Vermont, and the Southwest Territory » What questions were asked? ˃name of head of family ˃number of persons in each household of the following descriptions: +Free White males 16 years and upward, +free White males under 16 years, +free White females, +all other free persons (by sex and color) and slaves

» When was it taken? ˃April 1, 2000 » How many people were counted? ˃281,421,906 (13.2 percent increase over the 248,709,873 in 1990) » Questionnaire included seven questions for each household: ˃name ˃sex ˃age ˃relationship ˃Hispanic origin ˃race ˃owner/renter

» When was it taken? ˃April 1, 2010 » How many people were counted? ˃308,745,538 (9.7 percent increase over the 281,421,906 in 2000) » Questionnaire included ten questions for each household: ˃ form.phphttp://2010.census.gov/2010census/about/interactive- form.php » Release schedule Release schedule

» Apportionment of representatives among the states ˃census determines how the 435 seats in the U.S. House of Representatives are divided among the 50 states

» Census data directly affect how more than $300 billion per year in federal funding is allocated to local, state and tribal governments – $3 trillion over a decade. » draw legislative districts » evaluate success of programs or identify populations in need of services

Before 2010…

» When was the long form introduced? ˃1940 census » How many people got the long form? ˃17 percent of the households (1 out of every 6 households) » What questions were asked? ˃ancestry ˃income ˃mortgage ˃size of the housing unit ˃disability ˃etc

» Meet the American Community Survey Meet the American Community Survey » The form The form » Replaces the long form ˃ie, [old long form] = [new American community survey] » From once in 10 years, to every year! (started in 2005) » 1, 3, and 5 year estimates ˃Which to choose? ˃ » You are in luck… the data is JUST becoming available, just in time for your final projects

» counts and basic cross-tabulations of information collected from all people and housing units. ˃race, age, household size, owner/renter » Lowest level geography: ˃Blocks

» contains tables with social, economic and housing characteristics compiled from a sample of approximately 19 million housing units (about 1-in-6 households) that received the Census 2000 long-form questionnaire. Many tables are given for nine major race and Hispanic or Latino groups. » Lowest level geography: ˃Block Groups/Census Tracts

UP206A: Introduction to GIS

» Counties in 48 States » Independent Cities in 4 States » Parishes in Louisiana » Cities and Boroughs in Alaska » 58 » 58 counties in California » 3,141 » 3,141 counties in the US

Incorporated Places (i.e. municipalities) Census Designated Places (i.e. unincorporated areas) 1,081 1,081 places in California 25,150 25,150 places in the US

Cover the nation (65,000 Census tracts across U.S.) Relatively homogenous population characteristics 4,000 Size: optimally 4,000 people, range between 1,000 and 8,000 2,054 2,054 census tracts in Los Angeles County 65,344 65,344 census tracts in the US

Groups of blocks (share the same first digit) Smallest areas for which sample data available 1,500 Size: optimally 1,500 people, but range between 300 to 3,000 6,351 6,351 block groups in Los Angeles County 208, ,689 block groups in the US

Smallest units of data tabulation Cover the entire nation Do not cross census tracts or counties Generally bounded by visible features and legal boundaries 100 Size: average about 100 people 89,614 89,614 blocks in Los Angeles County 8.2 million 8.2 million blocks in the US

» Densely settled areas with population of at least 50,000 » Geographic core of block groups or blocks that have a population density of at least 1,000 people per square mile – Urban Cluster

» ZCTAs: ZIP Code Tabulation Areas » Approximate area representations of USPS ZIP Code service areas » Based on Census 2000 blocks » To address difficulties in mapping USPS ZIP Codes » May represent either a five or three-digit USPS ZIP Code »

» How ZIP Code Tabulation Areas Are Created » Determine the majority ZIP Code for each census block with addresses.

» FIPS – Federal Information Processing Standards STATECOUNTY CENSUS TRACT BLOCK GROUP

» Topologically Integrated Geographic Encoding and Referencing » developed at the U.S. Census Bureau to support its mapping needs for the Decennial Census and other Bureau programs » coverage of the United States, Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the Midway Islands »

» The larger the census geographic unit, the greater the amount of data available (i.e. Single years of data by County) » The smaller the census geographic unit, the less data available (i.e., Age in five-year categories for Census Tracts)