jgoodall / us-maps

GeoJSON and TopoJSON map files

Creation process

The maps here were created using the following steps.

Get raw shape files

Census

Census files have to be downloaded from a browser. This assumes they are downloaded to ~/Downloads. us-state/zip/county Available: http://www.census.gov/cgi-bin/geo/shapefiles2010/main

States

• Open a browser to: https://www.census.gov/cgi-bin/geo/shapefiles2010/main
• Choose 'States (and equivalent)' and 'Submit'
• Choose 'All states in one national file' for 'State and Equivalent (2010)' and click 'Download'

Then unzip the files:

mkdir -p raw/state && cd raw/state && unzip ~/Downloads/tl_2010_us_state10.zip && cd ../..

Counties

• Open a browser to: https://www.census.gov/cgi-bin/geo/shapefiles2010/main
• Choose 'Counties (and equivalent)' and 'Submit'
• Choose 'All states in one national file' for 'County and Equivalent (2010)' and click 'Download'

Then unzip the files:

mkdir -p raw/county && cd raw/county && unzip ~/Downloads/tl_2010_us_county10.zip && cd ../..

Zip codes

• Open a browser to: https://www.census.gov/cgi-bin/geo/shapefiles2010/main
• Choose 'Zip Code Tabulation Areas' and 'Submit'
• Choose 'All states in one national file' for '5-Digit ZIP Code Tabulation Area (2010)' and click 'Download'

Then unzip the files:

mkdir -p raw/zcta5 && cd raw/zcta5 && unzip ~/Downloads/tl_2010_us_zcta510.zip && cd ../..

Zip Code Tabulated Areas (ZCTA)

• Open a browser to: http://udsmapper.org/zcta-crosswalk.cfm
• Click the link named ZIP Code to ZCTA Crosswalk to download the 2016 mappings of zip codes to ZCTA's.
• That file is an Excel Spreadsheet, which can be exported to a CSV format, as done in this repo.

Medicare

Medicare files can be downloaded directly from Dartmouth Atlas hrr/hsa Available: http://www.dartmouthatlas.org/Tools/Downloads.aspx?tab=35

Hospital Referral Regions

curl -O http://www.dartmouthatlas.org/downloads/geography/hrr_bdry.zip
mkdir -p raw/hrr && cd raw/hrr && unzip ../../hrr_bdry.zip && cd ../..

Hospital Service Area

curl -O http://www.dartmouthatlas.org/downloads/geography/hsa_bdry.zip
mkdir -p raw/hsa && cd raw/hsa && unzip ../../hsa_bdry.zip && cd ../..

Clean up .zip files as needed.

Convert to GeoJSON

Convert using gdal. On a Mac, you can install gdal with homebrew: brew install gdal.

ogr2ogr -f "GeoJSON" hsa.geo.json ./raw/hsa/HSA_Bdry.SHP HSA_Bdry
ogr2ogr -f "GeoJSON" hrr.geo.json ./raw/hrr/HRR_Bdry.SHP HRR_Bdry
ogr2ogr -f "GeoJSON" state.geo.json ./raw/state/tl_2010_us_state10.shp tl_2010_us_state10
ogr2ogr -f "GeoJSON" county.geo.json ./raw/county/tl_2010_us_county10.shp tl_2010_us_county10
ogr2ogr -f "GeoJSON" zcta5.geo.json ./raw/zcta5/tl_2010_us_zcta510.shp tl_2010_us_zcta510

Move the GeoJSON files into the geojson directory

mkdir -p geojson && mv *.geo.json geojson

Convert to TopoJSON

TopoJSON is an extension to GeoJSON that encodes toplogy, resulting in much smaller files. Nodejs is required to run the script. Install topojson using npm install topojson -g. No simplification is done on these files. None of the files are combined either, although that is possible. ZCTA file fails when trying to use topojson to convert.

mkdir -p topojson
topojson --properties HRRCITY --id-property HRRNUM --out ./topojson/hrr.topo.json ./geojson/hrr.geo.json
topojson --properties HSANAME --id-property HSA93 --out ./topojson/hsa.topo.json ./geojson/hsa.geo.json
topojson --properties NAME10 --properties STUSPS10 --id-property GEOID10 --out ./topojson/state.topo.json ./geojson/state.geo.json
topojson --properties NAME10 --properties NAMELSAD10 --id-property GEOID10 --out ./topojson/county.topo.json ./geojson/county.geo.json
topojson --id-property GEOID10 --out ./topojson/zcta5.topo.json ./geojson/zcta5.geo.json

Unify and simplify

I wanted some of these files combined into a single TopoJSON, and simplified somewhat to make the size of the map smaller. To do so, the following command was used:

topojson --out ./topojson-simplified/us.topo.json ./topojson/state.topo.json ./topojson/hrr.topo.json ./topojson/county.topo.json
topojson -s 1 --out ./topojson-simplified/us-s1.topo.json ./topojson/state.topo.json ./topojson/hrr.topo.json ./topojson/county.topo.json
topojson -s 3 --out ./topojson-simplified/us-s3.topo.json ./topojson/state.topo.json ./topojson/hrr.topo.json ./topojson/county.topo.json

A simplification threshold of 3 retained 150581 / 549117 points (27%), while a level of 1 retained 231768 / 549117 points (42%).

Reference files

The reference directory has lookup files to get names for each of the IDs, as well as getting parent information (e.g. which state is a HRR in).