OVERVIEW

This layer was produced by MassGIS for display purposes when mapping any of the other Census 2000 layers. The town boundary and coastline features developed by the Census Bureau do not match those in MassGIS' own Towns layer, and these spatial discrepancies become more apparent at larger scales. MassGIS recommends the use of this layer when plotting municipal boundaries with the other Census 2000 layers. Two shapefiles are available, one for polygons and one for arcs.

PRODUCTION

The polygon layer was produced by dissolving the Census 2000 Blocks layer (without offshore zero-population polygons) on the TOWN_ID field. Population fields were added by joining to the polygon attribute table in the MassGIS Towns layer. The Arc layer was generated from the polygon layer using XTools for ArcMap 8.1 Version 3.0. The resulting polylines were converted to an ArcInfo coverage and the lines were coded for coastline, municipal boundaries, and state outline. The coverage was then converted to a shapefile.

The polygon attributes (census2000towns_poly.dbf) for the Census 2000 Towns shapefiles distributed by MassGIS contain the following items:
 

ITEM NAME		TYPE / WIDTH		DESCRIPTION
TOWN_ID		N / 4		MassGIS Town ID
TOWN		C / 21		Town Name
POP1980		N / 6		1980 Population
POP1990		N / 6		1990 Population
POP2000		N / 6		2000 Population
POPCH80_90		N / 5		Population Change, 1980-1990
POPCH90_00		N / 5		Population Change, 1990-2000
AREA		F / 19		Area of polygon(s) in square meters
PERIMETER		F / 19		Perimeter of polygon(s) in meters
ACRES		F / 19		Area of polygon(s) in acres
SQ_MI		N / 11		Area of polygon(s) in square miles

The Area, Perimeter, and Acres fields were calculated by XTools for ArcMap 8.1 Version 3.0. The Sq_Mi field was calculated by multiplying the Acres field by 0.0015625.

The arc attributes (census2000towns_arc.dbf) contains an item added called OUTLINE, which enables differentiation of line type (e.g. dashed lines inside the state and solid for the outside). OUTLINE codes are:
 - 1 = Interstate boundaries
 - 17 = Internal boundaries
 - 4 = Coastline

MAINTENANCE

MassGIS is maintaining this layer. Minor updates to the geometry of both the polygon and arc feature classes were made in May 2003.

• OVERVIEW
• WHAT MASSGIS PROVIDES
• Census 2000 Blocks
• Census 2000 Block Groups
• Census 2000 Tracts
• Census 2000 TIGER Linework
• Census 2000 TIGER Water Bodies
• Census 2000 TIGER Towns
• Environmental Justice Populations
• CONSIDERATIONS WHEN USING TIGER DATA
• OTHER RESOURCES

 

Last Updated 7/31/2003
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