CITYgreen Watershed Analysis of Toby Creek: An American Heritage River Tributary

Applications of geospatial technologies such as geographical information systems (GIS) and remote sensing imagery have been relevant for years for both small-scale and large-scale watershed investigations and assessments (e.g., Bruns et al. 1997a, b, O’Neill et al. 1997, and see reviews in Allan 2004 and Bruns 2005). This watershed perspective originally evolved from a general hierarchical approach to spatial scales in environmental analysis (Allen and Starr 1982, O’Neill et al. 1986) for both terrestrial and aquatic ecosystems. Later, O’Neill et al. (1997) recommended the use of GIS and remote sensing data, along with developments in landscape ecology, to assess biotic diversity, watershed integrity, and landscape stability. A useful geospatial perspective on watershed management and assessment is that of the Interagency Stream Restoration Working Group (15 Federal agencies of the U.S.) that developed a manual for applications in stream restoration (Federal Interagency Stream Restoration Working Group 1998) based on a hierarchical approach to watersheds at multiple scales. This team recognized ecosystems at five different spatial scales from regional landscape to local stream reach, stating that watershed units can be delineated at each of these scales, depending on the focus of the analysis and availability of data. We have employed this approach in our GIS environmental plan (Bruns et al. 2001) and related watershed studies (Bruns and Wiersma 2004, Bruns 2005) of the Upper Susquehanna-Lackawanna American Heritage River (US-L AHR), considered in more detail below. In 1998, the US-L watershed was designated as one of 14 American Heritage Rivers by President Clinton (Bruns and Wiersma 2004). Previous studies of a selected subset of tributaries in this AHR watershed resulted in an initial GIS data base on land use, mining impacts, and water quality in the region (Bruns et al. 1997a, b), all of which provided an important impetus to the final AHR designation (U.S. Congressman Paul Kanjorski, personal communication). Based on these GIS data sets (Bruns et al. 1997b), a systems approach to environmental monitoring and assessment (Bruns et al. 1997a, Bruns and Wiersma 2004), and the Interagency Watershed Group’s geospatial scaling model (Federal Interagency Stream Restoration Working Group 1998), we initiated a GIS environmental master plan (Bruns et al. 2001) for the US-L AHR watershed including a research plan to address problems of mining, urbanization, combined sewer overflows, and suburban sprawl in this study area, from 1999 to the present. In this paper, we present selected watershed analyses based on CITYgreen (American Forests 2002), and discuss these in the context of geospatial scaling (Federal Interagency Stream Restoration Working Group 1998) and the economic benefits of ecosystem services (Bennett et al. 2005). CITYgreen utilizes GIS data on soils, slopes, and land use to estimate the economic value of natural ecosystems, especially forests (American Forests, 2002); CITYgreen, a software application intended for environmental land use planning by local communities, represents an important tool in environmental planning and management.