The Impacts of Redlining on Urban Heat in New York’s Capital Districts

Abstract

The impact of green space, or lack thereof, on the surface temperature of cities has long been studied through the Urban Heat Island effect. However, the extent to which the historic discriminatory housing policy of redlining influences the temperatures of different neighborhoods in the same city is still being revealed. Here, the researchers investigated how Home Owners’ Loan Corporation (HOLC) maps correspond to land surface temperatures through uneven distribution of tree canopy and impervious surfaces in New York’s Capital District. Using HOLC maps for Albany, Troy, and Schenectady, the researchers calculated percent tree cover and imperviousness for each of the map’s graded blocks, and calculated the land surface temperature for each block using Landsat 8 imagery. Results showed that neighborhoods rated “hazardous” were generally hotter, more impervious, and less tree-covered than those rated “best” in Albany and Schenectady, but not in Troy. The difference between blocks rated “hazardous” and blocks rated “best” was +2.67°C in Albany, +4.18° in Schenectady, and -1.18° in Troy. These results are an example of how discriminatory housing policies are tied to a disproportional distribution of urban heat. Affected communities, like those in the Capital District, should be identified to increase resilience to the environmental, physiological, and social impacts of climate change.

Keywords: Urban Heat Island Effect, Redlining, New York, Housing Policy, Green Space, Urban Tree Cover.