Multiscale analysis of impervious surface change and environmental equity
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Landscape pattern-focused environmental justice (EJ) research has tended to use high-resolution data. Because of the technical difficulties involved in producing high-resolution land cover data for larger extents or at frequent intervals, this research tends to focus on a snapshot in time and a single city or set of cities. This study compares the relationships between impervious cover (IC) and a socioeconomic EJ indicator, EJScreen’s demographic index (DI), using high-resolution EnviroAtlas Meter Urban Land Cover (MULC) data for 24 communities and 30-meter National Land Cover Database (NLCD) percent impervious cover for the conterminous United States. It also uses the NLCD to examine how change in impervious cover over time relates to DI.
A contingent probability model was used to measure DI response to NLCD 2019 percent IC, NLCD percent IC change, MULC IC, and surface temperature using Census block groups. We found that although the distribution of change across DI values was relatively uniform, vulnerable block groups (those with high DI values) were more likely to experience large changes in impervious cover and experience hotter urban environments.
This research demonstrates that when aggregated by block group, estimates of impervious cover from the NLCD are comparable to estimates from higher-resolution land cover data, and relationships between the DI and impervious cover were similar using both land cover sources. Because the NLCD is available nationwide and updated regularly, this presents opportunities to expand pattern-focused EJ research to a national scale and introduce a temporal component.