Flooding is one of the most common and destructive disaster types in the United States.  As climate change intensifies, urban areas are becoming increasingly vulnerable to flooding and face an urgent need for adaptive urban planning and mitigation. A Philadelphia-focused case study conducted by Princeton researcher Sina Razzaghi Asl explores the relationship between high flood risk communities and green spaces.

Green spaces, which include forests, parks, gardens, and other areas with vegetation, mitigate flooding by enhancing water absorption and decreasing runoff from heavy rainfall and storms. As rapid urbanization increases, environmental justice researchers are growing increasingly concerned with the lack of green spaces and flood protections in vulnerable urban communities. Using social and geophysical data from the National Risk Index (NRI), the U.S. Geological Survey (USGS), Web Soil Survey (WSS), and the American Community Survey (ACS), Razzaghi Asl analyzed census block groups in eight townships and boroughs within the Philadelphia Metropolitan Area to examine the relationship between  flood vulnerability and green space density.

“Philadelphia was chosen for this study due to its moderate-to-high projected flood risk, high population growth, and diverse green spaces,” says Razzaghi Asl, a postdoctoral researcher at C-PREE. “These factors make it an ideal area to examine flood vulnerability and green space density.”

The results emphasize the urgent need for targeted flood interventions for urban areas,  especially those with limited green spaces.  Prof. Eric Tate, a C-PREE faculty member and flooding expert, highlights the need for integrated flood management and the policy implications moving forward.     

“The study adds to the empirical evidence that intersections of environmental hazards and lack of amenities often occur in low-income communities,” explains Prof. Eric Tate, a faculty member at Princeton’s School of Public and International Affairs.  “Focusing adaptation investments on places with such compounding burdens is likely to yield environmental and social co-benefits.”