Data analysis and visuals for NYCC 10.22.20 'Oversight - Improving the Equity of Green Space throughout the City in Light of the COVID Epidemic' hearing.
- Walk-to-a-Park Service Area
- Open Space (Parks)
- Parks Properties
- Waterfront Access Map: Publicly Owned Waterfront
- 2010 Census Tracts
- 2010 ZCTA to Census Tract Relationship File
- NYC DOHMH Geographic Resources
- 2018 5-Year ACS Survey: *We used R package censusapi to get demographic data
- Parks Closure Status Due to COVID-19:
- Calculate how much square feet of park space individuals in NYC have access to at the census tract and zipcode level.
- See if there are geographic & income disparities in access to park space & the relation to COVID cases.
From the Open Space (Parks), Parks Properties and Waterfront Access Map datasets, features that were within 50 ft of an access point from the Walk-to-a-Park Service Area were included as the set of parks, open space and recreation areas for analysis. This excludes cemeteries. For more information on what parks were included in NYC Parks Walk-to-a-Park Service Area dataset, please view their data dictionary.
Using the access points from Walk-to-a-Park Service Area dataset, we created isochrone polygons or time-distance areas for each point. We used mapbox api for this process and selected a 10 minute walking distance parameter. If the center of a census tract is within 10-minutes walking of any access point associated with a given park, then it is designated as having access to that park.
If a census tract is designated as having access to a park, then it is assigned the square footage of that park. The square footage is summed for all the parks a census tract has access to. The total square footage is then divided by the census tract population to get square feet per capita. For larger parks, we do not assign the full square footage of the park to a census tract. The maximum amount assigned from a park is capped at 7,000,000 square feet. This number is roughly equivalent to 0.25 square miles and is 3 standard deviations above the average square footage of all the parks in NYC.
To compare the COVID-19 data to our open space access data, we aggregate the census tracts up to the MODZCTA level. Census tract data is first aggregated to ZCTA5 level using the Census crosswalk relationship file and doing a population-weighted assignment of square footage. Refer to the technical document for more information.
The data is then aggregated to the MODZCTA level using the NYC DOHMH files. The MODZCTA square feet value is a population-weighted average of each nested ZCTA value.
This script determines which open space access points are within 10 minutes walking from each census tract, assigns square footage per capita, and aggregates the data up to the zip code level. It is also used to plot and map COVID-19 case rate, income, and access data at the MODZCTA level. This script imports data from the other scripts, noted in the comments of the code.