Satellite maps show Chesapeake Bay urban development

Abstract

The extent, density, and configuration of the built environment—such as buildings, roads, parking lots, and other materials constructed for human use—have an impact on a wide range of biogeochemical and hydrological processes. These built areas, which are impervious to water infiltration, modify hydrology through the combined influence of increased peak flows, reduced base flows, flashier stream hydrographs (decreased lag times between storm events and peak discharge), and changes in bank and streambed erosion [Nilsson et al., 2003]. Additionally, increasing impervious cover has long been known to amplify point source pollution discharges into streams, including chemical runoff from parking lots and roads [Schuelen 1994]. Two maps of the built environment, expressed in terms of impervious surface area, have been derived for areas that encompass the 168,000‐square‐kilometer Chesapeake Bay watershed (Figure l), a region that has been highly altered by human land use [Goetz et al., 2004; Jantz et al., 2005]. One map was developed for the region at fine (30‐square‐meter) spatial resolution, and the other covers the extent of the conterminous United States at one‐square‐kilometer resolution [Elvidge et al., 2004].A finer‐resolution regional map was used to assess the quality of the national map, demonstrating the utility the latter map for a range of applications related to monitoring land transformation and assessing watershed impacts.

Connectivity Conservation

“…We independently analyzed the accuracy of the OLS-NLCD impervious cover maps in earlier work and found them comparable to spatially aggregated higher resolution impervious cover maps generated directly from Landsat image reflectance data (Goetz & Jantz, 2006;Jantz et al, 2005). Nonetheless, we note again here that finer scale maps of proportional impervious cover have since been derived as part of the NLCD, but were not yet available for the analysis reported here and are still undergoing independent accuracy assessment.…”

Managing Water Quality in the Face of Uncertainty: A Robust Decision Making Demonstration for EPA's National Water Program

“…The CBLCM uses U.S. Census data and a growth allocation model to project future urban area at each watershed segment. Then, for each segment, the proportions of urban growth that affect other land uses (e.g., farmland, forest, sewer, septic) are estimated using a stochastic cellular automata model customized for the Chesapeake Bay that extrapolates historic patterns of urban growth into the future (Goetz and Jantz, 2006;Claggett et al, 2008). CBLCM parameters were adjusted to reflect two plausible future land use patterns:…”

Quantitative land cover change analysis using fuzzy segmentation

“…In addition, a continuous classification seems to be an appealing way to represent the spectral hetereogeneity within land cover classes present in imagery at several spatial resolutions (Fisher and Arnot, 2007). Examples of successful application of continuous classification of land cover include urbanization monitoring in urban and suburban watersheds (Clapham, 2005;Goetz and Jantz, 2006).…”