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UPDATE February 5, 2012
You can visualize the proposed district boundaries that we've mapped (described on this page below) at our new interactive redistricting map for New York State. And The New York World has a great article that uses the maps to highlight examples of gerrymandering in an effort to explain the redistricting process in the Empire State.
UPDATE January 27, 2012
The New York World provides an interactive map based on the GIS files CUR has posted below, highlighting the population disparities between proposed New York State Senate districts in downstate and upstate New York.
The map and related story show how the proposed Senate districts in upstate New York tend to be less populated than in New York City and on Long Island. With more
people in New York City districts than upstate districts, this would effectively diminish the voting power
of city residents. The effect is similar though less pronounced on Long Island.
The map is embedded below:
Original post
The New York State Legislative Task Force on Demographic Research and Reapportionment (commonly known as "LATFOR") has published its proposed new lines for State Senate and Assembly districts based on the decennial 2010 Census.
LATFOR posted its proposed district maps in PDF format, and also provided "block assignment lists" to delineate the proposed districts. The block lists indicate which Census blocks (the smallest level of Census geography) correspond to which district. But the Task Force didn't make the maps available in a format that you can easily use with mapping software or online maps.
In order to enable others to visualize and analyze these districts on maps, the Center for Urban Research (CUR) at the CUNY Graduate Center has converted these lists into two formats compatible with desktop and online mapping applications: "shapefiles" and KML files. (Shapefiles are commonly used by most desktop geographic information system, or GIS, software packages. KML files are used typically in Google Maps, Google Earth, and other online mapping applications.)
- Proposed NYS Senate districts in shapefile [zip] format and KML (KMZ format);
- Proposed NYS Assembly districts in shapefile [zip] format and KML (KMZ format).
Separately we will be posting maps of the districts that display and analyze demographic characteristics.
LATFOR has done a great job this year of posting detailed
demographic and voting data so that organizations and individuals can
analyze how the redistricting process might impact local neighborhoods. Now with CUR's GIS versions of the proposed districts linked above, anyone with mapping software can analyze the patterns in these demographic and voting data files compare with the newly proposed legislative districts.
For more background on the 2010 Census in New York and how it relates to redistricting and other civic issues, CUR has prepared the following resources:
- 2010 population mapped by 2002 (i.e., current) state legislative and Congressional districts across New York State;
- visualizing block-by-block demographic changes from 2000 to 2010 across New York and other major metropolitan areas nationwide;
- a roundup of links and other sources of Census data and maps for New York; and
- an overview of CUR's efforts to analyze and map 2010 Census data and the related American Community Survey.
Technical notes
We used ESRI's ArcGIS Desktop software to join LATFOR's block assignment lists (in DBF format) to the Census 2010 TIGER shapefile of Census blocks for New York State (you can download the block file from the Bureau's FTP site, or directly from this link [187 MB Zip file]). We used ArcGIS's "dissolve" tool to merge the blocks based on common SD or AD district IDs from the DBF files.
In order to convert the shapefiles to KML format, however, we relied on the open source GIS mapping software "QGIS". Thanks to a tip from Tim Henderson of Gannett Newspapers via NICAR, QGIS makes it very easy to save each shapefile as a KML file for quick mapping with Google Maps, Google Earth, etc. QGIS is free and open source, and you don't need to rely on any online services to convert the files. Thanks Tim!
