Collaborative Research: Streamflow, Urban Riparian Zones, BMPs, and Impervious Surfaces
EPA Lead: S. Taylor Jarnagin
Streamflow, Urban Riparian Zones, BMPs, and Impervious Surfaces (6pp, 700K, About PDF)
EPA Landscape Ecology Branch, Environmental Sciences Division, USEPA/ORD National Exposure Research Laboratory
Mail Drop E243-05
109 T.W. Alexander Drive
Research Triangle Park, NC 27711
E-mail: jarnagin.taylor@epa.gov
Work Office Telephone: 919-541-1987
Work Fax: 919-541-0864
The U.S. EPA Landscape Ecology Branch (LEB) in Research Triangle Park, North Carolina is currently conducting collaborative landscape/stream ecology research in the Clarksburg Special Protection Area (CSPA) in Montgomery County, Maryland. The CSPA subwatersheds are on the outer edge of the exurban development shockwave expanding outward from the Washington DC metropolitan area and are outlined in yellow on the upper-left of Figure 1. The CSPA is an area of rapid development that we expect will be built out within the next five to ten years. The Montgomery County Department of Environmental Protection (DEP) has been monitoring stream biology and chemistry in the area streams for a decade and the CSPA involves the use of best management practices (BMPs) that are designed to limit the impact of development on water resources. For more information about the Montgomery County programs, see the URL:
http://www.montgomerycountymd.gov/deptmpl.asp?url=/content/dep/SPA/home.asp.![]()
The objective of the LEB research is to correlate the impacts of ongoing development and the mitigating effect of local BMPs on the hydrological, biological, and chemical parameters of the CSPA water resources using a Before-After, Control-Impact (BACI) study design. The project is focused on determining the effectiveness of BMP mitigation on streamflow disturbance, channel erosion and stream sedimentation due to impervious surfaces, sub-surface storm sewers and altered landform due to urbanization.
Our primary research goal is to map development and BMP placement as they occur; both the anthropogenic surface structures such as roads, buildings, parking lots, and changes in surface topography associated with urbanization and the subsurface storm sewer network; and to monitor the physical, chemical, and biological aspects of the associated water resources as that development happens. Changes in streamflow, surface water/groundwater relationships, and the biological and chemical parameters of the CSPA water resources will be correlated with development patterns, anthropogenic alterations of the environment, and the BMPs designed to mitigate the impacts of development. We have obtained four Light Detection And Ranging (LiDAR) overflights of the study area (Figure 2) that greatly increase the spatial resolution of the topographical analyses possible in the CSPA. These overflights and future LiDAR and other remote sensing (RS) collections will be used to determine if RS technology can be used to map changes in stream morphology associated with development as well as to assist in the hydrological modeling and surface mapping of that development. Our research is intended to assess the effectiveness of BMPs by employing both positive and negative controls (stream gauges and monitoring in areas without development and areas developed without the CSPA BMPs) as well as pre- and post development data from areas gauged prior to development within the CSPA (Figure 3).
This research involves two primary components:
1) High resolution watershed mapping over time - topography (LiDAR), aerial photography, satellite imagery, GIS, BMP placement and development mapping and
2) Coordinated monitoring of physical and biological parameters: chemical and biological stream monitoring, streamflow and precipitation gauging, and weather parameters.
To date, the USEPA has:
a) Funded the United States Geological Survey Water Resources Discipline (USGS WRD) for the placement of five stream gauges and a precipitation gauge in the CSPA to complement the existing Montgomery County DEP precipitation gauge,
b) Collected repeat LiDAR data for analysis of stream channel and landform change (Figure 2), and
c) Collected multiple high-resolution satellite data for mapping land-cover change due to development.
This EPA-USGS-DEP collaborative research is an example of a Federal-Local technology-transfer partnership where innovative technologies are researched at the Federal level and the results made available at a local level for neighborhood solutions. This research effort is an example of former EPA Administrator Mike Leavitt's "Enlibra Principles"
, where the "principles of flexibility, innovation, partnership and collaboration ... and other common sense ideas that will accelerate environmental progress" guide the research effort. This research is a collaborative effort where local stakeholders are involved setting research goals and Federal agencies are involved offering expertise and capabilities not available at the local level. Partners in this research are EPA Landscape Ecology Branch, Research Triangle Park, North Carolina; Montgomery County Department of Environmental Protection (DEP), Rockville, Maryland; USGS Water Resources Discipline (WRD), Baltimore, Maryland and Eastern Geographic Science Center (EGSC), Reston, Virginia; University of Maryland, Baltimore County, Maryland (UMBC), Department of Geography and Environmental Systems, and The Center for Urban Environmental Research and Education (CUERE); University of Maryland, College Park, Maryland, Department of Civil & Environmental Engineering and the Behavior, Ecology, Evolution and Systematics (BEES) Program; College of Engineering, Virginia Polytechnic Institute and State University, Blacksburg Virginia; Environmental Systems Analysis, Inc., Annapolis Maryland; and the Maryland-National Capital Park and Planning Commission (M-NCPPC), Silver Spring Maryland.
This paper has been reviewed in accordance with the United States Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. |
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Click image or figure number to view larger size:
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Figure 1: Satellite classification of urban land cover 1970s - 2000. The Clarksburg Special Protection Area (CSPA) subwatersheds (yellow outline) are at the northwest edge of the current development extent of the Washington DC metropolitan area.
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Figure 2: Building a better Digital Elevation Model (DEM). The National Elevation Data (NED), 30-meter pixel spatial resolution at the outer edge of Figure two is compared with a sub-meter DEM derived from a Light Detection And Ranging (LiDAR) overflight of the Clarksburg Special Protection Area. Both images have been processed to the same color elevation scale to graphically illustrate how much more topographical detail is available from the LiDAR imagery and how the mapping of anthropogenic development structures can be assisted with LiDAR. .
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Figure 3: Clarksburg Maryland Special Protection Area showing subwatersheds (in yellow), stream gauges (green circles) and precipitation gauge (pink crosses) locations, and water quality monitoring locations (red stars).
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