How Just is Sprawl? Links among Density and Environmental Justice in US Territories

Sprawl is broadly described as “low density development on the edges of cities; poorly planned, land-consumptive, automobile dependent and designed without regard to its surroundings (Moe, 1997).” It is considered to... [ view full abstract ]

Sprawl is broadly described as “low density development on the edges of cities; poorly planned, land-consumptive, automobile dependent and designed without regard to its surroundings (Moe, 1997).” It is considered to account for various social and environmental crises, including health consequences, erosion of social capital, environmentally sensitive land damage, and global warming. Numerous researchers have suggested “working” definitions and subsequently, measures and indices to inform practice, including a sprawl/compactness index supported by Smart Growth America, which incorporates various density dimensions (Ewing, 2014). Although popular in research, the 2014 version of this index has not been quite examined yet, especially in regard to its relationship with social capital and the environment.

While sprawl’s consequences are not limited to environmental injustice, emerging issues like climate change and associated inequalities are increasingly used to frame and inform urban systems research and evaluate sprawl’s impacts (Wilson, 2013). In addition, it is critical to understand that the interconnectedness of human and natural structures demands greater consideration in urban planning decisions (Wilson, 2013). To that end, EPA has recently released an environmental justice (EJ) index, a mapping and data reporting tool that links environmental and demographic indicators from US areas, in the form of EJ indexes (EPA, 2016).

The present study brings together the aforementioned sprawl/compactness index and selected EJ indicators on air pollution-Ozone and Air Toxics- (and associated datasets) in a cross-scale analysis from the county to the census tract level; first in 994 US counties and then in a zoomed-in investigation of those counties most vulnerable to injustice, for the purpose of statistically examining possible sprawl effects on social capital and the environment. Cross-sectional associations between urban sprawl/compactness and environmental justice will answer whether there are consistent patterns and will reveal correlations that could potentially contribute to the ongoing discussion of unsustainable spatial forms and their implied environmental and social consequences. This hypothesis is well supported by theory, since there have been numerous studies from urban theorists and sustainability researchers during the last three or so decades, which analyze complications of sprawl, including increased sociodemographic inequalities and severe environmental damages. To the best of the authors’ knowledge however, few studies have focused on large US samples and none have linked the sprawl and EJ indices discussed above. The statistical analysis to be utilized, along with appropriate mapping visualizations, will potentially advance current knowledge in the field, and highlight the crucial role of sustainable systems when designing human-natural communities with long-term, effective adaptation in mind.

References

• Ewing, R. and Hamidi, S. (2014). Measuring Urban Sprawl and Validating Sprawl Measures. Report from National Cancer Institute, National Institutes of Health, Ford Foundation and Smart Growth America.
• Moe, R., & Wilkie, C. (1997). Changing Places: Rebuilding Community in the Age of Sprawl. Henry Holt & Company.
• U.S. Environmental Protection Agency (EPA), (2016). EJSCREEN: Environmental Justice and Screening Tool. EJSCREEN Technical Documentation.
• Wilson, B., & Chakraborty, A. (2013). The Environmental Impacts of Urban Sprawl: Integrating New Evidence and Emergent Issues. Sustainability, 5 (8) (2013), pp. 3302–3327