Scientists Create Satellite Map To Show Chesapeake Bay Urban Development
How buildings, roads, parking lots and other components of the built environment are integrated into communities impact a wide range of biogeochemical and hydrological processes. Among other effects, increased pollution discharge into streams has significant implications for the health of ecosystems.
Scientists at the Woods Hole Research Center announced on April 11 they have developed new high resolution maps of the built environment, expressed in terms of impervious surface cover, for the 168,000-square-kilometer Chesapeake Bay watershed, a region that has been highly altered by human land use.
According to Scott Goetz, a senior scientist at the Woods Hole Research Center (WHRC) and lead author of an article in the current edition of Eos describing the work, "The information captured in these maps can be used to help mitigate impacts associated with the impervious nature of built environments, including reduced water quality, impoverished stream biota, and increased flood risk."
The new maps were developed for the region at 30-square-meter spatial resolution, and are currently being used for baseline monitoring and modeling activities in the Chesapeake Bay Program restoration effort. The Eos article focuses on use of the regional maps to assess the quality of a new national impervious cover map available at coarser (one-square-kilometer) resolution for the entire conterminous United States.
Patrick Jantz, a research assistant at WHRC and doctoral student at the University of California - Santa Barbara, notes that "the national map provides a unique view of the built environment from which useful information relevant to water quality can be derived, particularly applications related to monitoring land transformation and assessing watershed impacts."
Goetz adds "These maps provide a unique view of the extent and intensity of the built environment, and the urbanization process which continues to rapidly evolve as exurban development expands into traditionally more rural areas."
Goetz and Jantz used the maps of impervious cover change between 1990 and 2000 to document the loss of forest and crop lands to expanding residential and commercial development. Goetz and colleagues also documented how impervious cover impacted stream biology in hundreds of small watersheds.
In the same way that the regional map has informed various Chesapeake Bay watershed restoration efforts, the national impervious cover map has utility for incorporating landscape configuration information into large-area hydrological models and for improving a range of watershed management efforts. Current maps of the built environment provide a baseline data set upon which ongoing regional and national mapping efforts can be developed to better inform environmental policy, particularly those related to human modification of the landscape that have multiple impacts on aquatic ecosystems and water quality.
Woods Hole Research Center: http://www.whrc.org
Scott Goetz: http://www.whrc.org/about_us/whos_who/CV/sgoetz.htm