Long-term land-use and land cover change and their associated impacts pose critical challenges to sustaining vital hydrological ecosystem services for future generations. In this study, a methodology was developed to characterize hydrologic impacts from future urban growth through time. Future growth is represented by housing density maps generated in decadal intervals from 2010 to 2100, produced by the U.S. Environmental Protection Agency (EPA) Integrated Climate and Land-Use Scenarios (ICLUS) project. ICLUS developed future housing density maps by adapting the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) social, economic, and demographic storylines to the conterminous United States. To characterize hydrologic impacts from future growth, the housing density maps were reclassified to National Land Cover Database (NLCD) 2006 land cover classes and used to parameterize the Soil and Water Assessment Tool (SWAT) using the Automated Geospatial Watershed Assessment (AGWA) tool. The objectives of this project were to 1) develop and describe a methodology for adapting the ICLUS data for use in AGWA as an approach to evaluate basin-wide impacts of development on water-quantity and -quality, 2) present initial results from the application of the methodology to evaluate water scenario analyses related to a baseline condition and forecasted changes, and 3) discuss implications of the analysis for the San Pedro River Basin, an arid international watershed on the U.S./Mexico border.

"ARS/294076." Includes bibliographical references (pages 33-36).