Environmental Justice: A Case Study into the Heat Vulnerable Neighborhoods of Philadelphia

Studies have shown that low-income communities and communities of color are more likely to live in neighborhoods experiencing multiple environmental burdens and disproportionate vulnerability to the impacts of climate change in American cities. The practice of redlining in Philadelphia, Pennsylvania has caused environmental injustice in ways that might not have been obvious at that time however there are neighborhoods that are still affected by this practice. These areas have the lowest median household incomes, lowest life expectancies, and highest population of African American people compared to the rest of the city. The main objective of this research is to map the heat vulnerable neighborhoods in Philadelphia and suggest ways to mitigate urban heat island. Mapping heat vulnerability shows the areas that are more susceptible to the exacerbating effects of heat. The research began with mapping factors that determine vulnerability, such as heat exposure, access to green space/tree coverage, median household income, life expectancy, and race. Mapping these indicators allowed the vulnerable neighborhoods to be pinpointed. The most vulnerable neighborhoods chosen were Tioga and Carroll Park. To conduct a better analysis the least vulnerable neighborhood, Chestnut Hill, was chosen to compare to. Further, overlaying the Homeowners Loan Corporation redlining map to find out that the “hazardous” neighborhoods overlap with the most vulnerable neighborhoods. To continue the analysis with simulations, Rhino and Grasshopper (Ladybug Tools) were used to quantify the urban heat island indicators such as Direct Sun Hours, Universal Thermal Climate Index (UTCI) and Heat Stress Hours in both public spaces and streets. In summary, this research proposes design interventions, including strategies of adding greenery, to mitigate the urban heat island effect. The simulations showed that the neighborhoods that are the most heat vulnerable would have to drastically change their environment to mitigate the urban heat island.