HR: 1340h
AN: H13A-0966    [Abstracts]
TI: Baltimore WATERS Test Bed -- Quantifying Groundwater in Urban Areas
AU: * Welty, C
EM: weltyc@umbc.edu
AF: UMBC, Center for Urban Envir Research and Education, Baltimore, MD 21250,
AU: Miller, A J
EM: miller@umbc.edu
AF: UMBC, Center for Urban Envir Research and Education, Baltimore, MD 21250,
AU: Ryan, R J
EM: rjryan@temple.edu
AF: Temple University, Dept of Civil and Envir Eng, Philadelphia, PA 19122,
AU: Crook, N
EM: ncrook@pangea.Stanford.edu
AF: Stanford University, Dept of Geophysics, Stanford, CA 94305,
AU: Kerchkof, T
EM: tkerchk1@umbc.edu
AF: UMBC, Center for Urban Envir Research and Education, Baltimore, MD 21250,
AU: Larson, P
EM: plarson@umbc.edu
AF: UMBC, Center for Urban Envir Research and Education, Baltimore, MD 21250,
AU: Smith, J
AF: Princeton University, Dept of Civil and Envir Eng, Princeton, NJ 08544,
AU: Baeck, M L
EM: mlbaeck@Princeton.EDU
AF: Princeton University, Dept of Civil and Envir Eng, Princeton, NJ 08544,
AU: Kaushal, S
EM: kaushal@cbl.umces.edu
AF: University of Maryland, Chesapeake Biological Lab, Solomons, MD 20688,
AU: Belt, K
EM: kbelt@fs.fed.us
AF: Urban Forestry Ecol. Research Unit, NE/USDA Forest Service, UMBC, Baltimore, MD 21227,
AU: McGuire, M
EM: mikemcguire@umbc.edu
AF: UMBC, Center for Urban Envir Research and Education, Baltimore, MD 21250,
AU: Scanlon, T
EM: tms2v@virginia.edu
AF: University of Virginia, Dept of Envir Sciences, Charlottesville, VA 22903,
AU: Warner, J
EM: juying@umbc.edu
AF: UMBC, Center for Urban Envir Research and Education, Baltimore, MD 21250,
AU: Shedlock, R
EM: rjshedlo@usgs.gov
AF: US Geological Survey MD-DE-DC Water Science Center, 5522 Research Park Drive, Baltimore, MD 21228,
AU: Band, L
EM: lband@email.unc.edu
AF: University of North Carolina, Dept of Geography, Chapel Hill, NC 27599,
AU: Groffman, P
EM: groffmanp@ecostudies.org
AF: Institute of Ecosystem Studies, Box AB 65 Sharon Turnpike, Millbrook, NY 12545,
AB: The purpose of this project is to quantify the urban water cycle, with an emphasis on urban groundwater, using investigations at multiple spatial scales. The overall study focuses on the 171 sq km Gwynns Falls watershed, which spans an urban to rural gradient of land cover and is part of the Baltimore Ecosystem Study LTER. Within the Gwynns Falls, finer-scale studies focus on the 14.3 sq km Dead Run and its subwatersheds. A coarse-grid MODFLOW model has been set up to quantify groundwater flow magnitude and direction at the larger watershed scale. Existing wells in this urban area are sparse, but are being located through mining of USGS NWIS and local well data bases. Wet and dry season water level synoptics, stream seepage transects, and existing permeability data are being used in model calibration. In collaboration with CUAHSI HMF Geophysics, a regional-scale microgravity survey was conducted over the watershed in July 2007 and will be repeated in spring 2008. This will enable calculation of the change in groundwater levels for use in model calibration. At the smaller spatial scale (Dead Run catchment), three types of data have been collected to refine our understanding of the groundwater system. (1) Multiple bromide tracer tests were conducted along a 4 km reach of Dead Run under low-flow conditions to examine groundwater- surface water exchange as a function of land cover type and stream position in the watershed. The tests will be repeated under higher base flow conditions in early spring 2008. Tracer test data will be interpreted using the USGS OTIS model and results will be incorporated into the MODFLOW model. (2) Riparian zone geophysical surveys were carried out with support from CUAHSI HMF Geophysics to delineate depth to bedrock and the water table topography as a function of distance from the stream channel. Resistivity, ground penetrating radar, and seismic refraction surveys were run in ten transects across and around the stream channels. (3) A finer-scale microgravity survey was conducted over this area and will be repeated in spring. Efforts to quantify other components of the water cycle include: (1) deployment of an eddy covariance station for ET measurement; (2) mining flow metering records; (3) evaluation of long-term stream-flow data records; and (4) processing precipitation fields. The objective of the precipitation analysis is to obtain rainfall fields at a spatial scale of 1 sq km for the study area. Analyses are based on rain gage observations and radar reflectivity observations from the Sterling, Virginia WSR-88D radar. Radar rainfall analyses utilize the HydroNEXRAD system. Data is being managed using the CUAHSI HIS Observations Data Model housed on a HIS server. The dataset will be made accessible through web services and the Data Access System for Hydrology.
DE: 1829 Groundwater hydrology
DE: 1830 Groundwater/surface water interaction
DE: 1876 Water budgets
DE: 1879 Watershed
DE: 1894 Instruments and techniques: modeling
SC: Hydrology [H]
MN: 2007 Fall Meeting