Hi! Elizabeth,

Please check the information here to see if it can clarify your question:

http://www.federalregister.gov/articles/2010/08/24/2010-20808/proposed-urban-area-criteria-for-the-2010-census

"All proposed criteria based on land area, population, and population density, reflect the information contained in the Census Bureau's Master Address File/Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB) at the time of the initial delineation. All calculations of population density include only land; the areas of water contained within census tracts and census blocks are not used to calculate population density."

Thanks!

Juyin Chen, AICP
Senior Modeling Systems Analyst
Virginia Department of Transportation
Transportation & Mobility Planning Division
Office: (804) 225-3564
Fax: (804) 225-4785
Website: http://www.virginiadot.org/vtm/

From: ctpp-news-bounces@chrispy.net [mailto:ctpp-news-bounces@chrispy.net] On Behalf Of Elizabeth Hassett
Sent: Friday, May 20, 2011 2:04 PM
To: ctpp-news@chrispy.net
Subject: [CTPP] Census population density calculations

Hello all,

I am finding discrepancies between population densities that I’m calculating in ArcGIS using Census 2010 population data and the TIGER geography shapefiles (in my case for the county and state level), and population density numbers posted on Census websites. The discrepancy is from the square mileage calculation, in particular. Does anyone know if this is because water bodies are subtracted from the total square mileage for the density calculation (or if there is another reason for the discrepancy)?

Thank you,

Elizabeth

Elizabeth Hassett

Syracuse Metropolitan Transportation Council

100 Clinton Square

126 N. Salina Street, Suite 100

Syracuse, NY 13202

ehassett@smtcmpo.org

(P) 315-422-5716

(F) 315-422-7753

Elizabeth Hassett

Syracuse Metropolitan Transportation Council

100 Clinton Square

126 N. Salina Street, Suite 100

Syracuse, NY 13202

ehassett@smtcmpo.org

(P) 315-422-5716

(F) 315-422-7753