1 proposed urban area criteria for the 2010 census michael ratcliffe geography division u.s. census...
DESCRIPTION
3 Urban Area Definitions Represent densely developed territory, encompassing residential, commercial, and other non-residential urban land uses in which social and economic interactions occur. Represent the “Urban Footprint” Structure has been explicitly defined through measures based primarily on population counts and residential population density Criteria have also accounted for non-residential urban land uses that are functionally part of the urban landscapeTRANSCRIPT
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Proposed Urban Area Criteria for the 2010 Census
Michael RatcliffeGeography Division U.S. Census BureauLet’s Focus on Census Geography WorkshopGIS-TApril 11, 2010
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Urban and Rural Classification
• The Census Bureau identifies and classifies urban and rural areas after each decennial census.
• Urban areas of at least 2,500 people have been identified since 1906.
• Urbanized areas of 50,000 or more people were first defined for the 1950 Census. Urban places of at least 2,500 people were identified outside urbanized areas. Urban clusters of 2,500 - 49,999 were first defined after Census 2000.
• The Census Bureau identifies urban and rural areas solely for the purpose of tabulating and presenting statistical data.
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Urban Area Definitions• Represent densely developed territory, encompassing
residential, commercial, and other non-residential urban land uses in which social and economic interactions occur.
• Represent the “Urban Footprint”
• Structure has been explicitly defined through measures based primarily on population counts and residential population density
• Criteria have also accounted for non-residential urban land uses that are functionally part of the urban landscape
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Census 2000 Urban Areas
• For Census 2000, an urban area consists of a densely settled core created from census block groups, census blocks, and the adjacent densely settled surrounding territory that together have a minimum population of 2,500 people
• Two types of urban areas:
• urbanized areas of 50,000 or more population;
• urban clusters of 2,500 – 49,999.
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Census 2000 Basic Urban Core Delineation
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Census 2000 Basic Urban Core Delineation
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2010 Urban Area Program
• Remain committed to an objective, equitable, and consistent nationwide urban area delineation.
• Retain decennial comparability by building upon 2000 criteria.
• All potential modifications are refinements, or supplements to address deficiencies encountered for Census 2000.
Qualifying census tract ≥ 1,000 ppsm
Qualifying census tract ≥ 500 ppsm contiguous to initial coreCensus tract not contiguous to an initial core census tract ≥ 1,000 ppsmCensus tract > 3 sq. miles
Initial Census Tract Core Based on Population and Size Criteria
1,600 ppsm
1,300 ppsm
750 ppsm
550 ppsm
560 ppsm
700 ppsm
800 ppsm
Initial Core Using Census Tract Analysis Units
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Cincinnati UA Qualifying Core Employment Tract
Employment TractsCensus 2000 Cincinnati UA
Qualifying census tract ≥ 1,000 wpsm
Qualifying census tract ≥ 500 ppsm contiguous to initial coreCensus tract not contiguous to an initial core census tract ≥ 1,000 wpsmCensus tract > 5 sq. miles and < 15 sq. miles
Initial Census Tract Core Based on Employment and Size Criteria
1,600 wpsm
1,300 wpsm
750 wpsm
550 wpsm
560 wpsm
15,000 workers
And
1,200 wpsm
800 wpsm
Initial Core Using Census Tract Analysis Units
Initial Core Test Delineation Regions
Tract as Analysis Unit Block Group as Analysis Unit
Population Land Area (sq. miles)
Number of Initial Urban Cores
Population Land Area (sq. miles)
Number of Initial Urban Cores
42,252,474 14,779 918 42,384,952 15,027 904
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Splitting Large Urban Agglomerations
Census 2000 San Francisco-Oakland and San Jose Split
Commuting core A ≥ 50,000 persons
Commuting core B ≥ 50,000 personsLargest worker flow to commuting core A
No commuting association and largest adjacency with urban area B
Largest worker flow to commuting core B
Splitting Large Urban Agglomerations Using Commuting Patterns
Urban area A after split
Urban area B after split
Urban split
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Concord/Livermore UA Split
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2000 Urban Area ´Urban Area Boundary Using Impervious Land Cover
Impervious Land CoverCensus Blocks
0 0.2 0.40.1Miles
Boundary Using Proposed Impervious Criteria
Wetlands as an Additional Exempted Territory
Distance from core to wetlands is 0.7 mile
Distance over wetlands is 0.5 mile
Distance over river is 0.6 mile
Distance over wetlands is 0.7 mile
Distance from wetlands to noncontiguous qualifying area is 0.7 mile
Total jump distance is 3.2 miles
Urban Core
Noncontiguous qualifying territory
Jump census block
Road connection
Total exempted distance is 1.8 miles
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5 0 5 10 Miles
Polygons w/slope greater than 40%Proposed 2010 Cumberland UA2000 Cumberland UAN
EW
S
Cumberland, MD and Surrounding Area
Exempted slope jumps
Steep Slope as Exempted Territory
Qualification of Airports for Inclusion in Urban Areas
Merced Municipal/MacCready Field, Merced CA
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Prison Urban Clusters
Abilene North (Robertson Unit), TX Population: 4,650Urban: 4,650Group Quarters: 4,650Institutional: 4,650Correctional: 4,650Density: 94,589 ppsm
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Central Places
• Central places are not necessary for UA or UC delineation
• Principal cities defined within CBSAs:
• capture same concept
• classification based on different criteria
• Lack of consideration of place boundaries in delineation process results in central places split between urban and rural portions.
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Questions? Comments?
Vincent OsierChiefGeographic Standards and Criteria BranchGeography DivisionU.S. Census [email protected](301) 763-9039
Chris HenrieGeographic Standards and Criteria BranchGeography DivisionU.S. Census [email protected](301) 763-9086