Title: Using GIS and Aerial Photography to Determine a Historical Impervious Surface/Streamflow Relationship.

Abstract: Impervious surfaces are a leading contributor to non-point-source water pollution in urban watersheds. These surfaces include such features as roads, parking lots, rooftops and driveways. Arcview GIS and the Image Analysis extension have been utilized to geo-register and map impervious surface area from six dates of digital historical photography (1949 -1994) in the upper Accotink Creek subwatershed located in northern Virginia. These data, along with concurrent streamflow and climate data, were then utilized to assess the historical relationship between the growth of impervious surfaces and changes in streamflow. The integration of historical aerial photography and GIS can reveal historical changes in landscape pattern and shows promise as a tool for understanding long-term changes in ecosystem function.

Notice: The views expressed here are those of the individual authors and do not necessarily reflect the views and policies of the U.S. Environmental Protection Agency (EPA). The Abstract was prepared by scientists in EPAs Office of Research and Development (ORD) and has been administratively reviewed and approved for publication.