HR: 11:15h
AN: NB52E-04    [Abstracts]
TI: Hyporheic and Riparian Exchange of Water and Nitrogen in a Headwater Appalachian Forest Stream.
AU: * DeWalle, D R
EM: drdewalle@psu.edu
AF: School of Forest Resources Penn State University, 107 Land and Water Buuilding, University Park, PA 16802 United States
AU: O'Driscoll, M A
EM: odriscollm@MAIL.ECU.EDU
AF: Geology Department East Carolina University, 104 Graham Building, Greenville, NC 27858 United States
AB: The traditional view of stream baseflow generation and stream chemistry control via upwelling hyporheic groundwater flow did not exist on Baldwin Creek, a 535 hectare headwater forest catchment in the Appalachians of Pennsylvania. Streambed and bank piezometers were installed at 14 points along a 4 km stream length. Head and water chemistry data were collected quarterly during 2000-2001. Stream and piezometer heads consistently showed that the stream was perched and was gradually losing water throughout its length with occasional lateral inputs through its banks. Streamflow gains occurred from numerous surface seepage zones and springs that emanated from sandstone outcrops along the channel and flood plain. Piezometer water showed high ammonium, DON, and DOC concentrations compatible with reducing conditions, while stream water was dominated by nitrate added by individual seeps and springs. Maintenance of riparian ecosystem function in such a setting is as dependent upon protection of seeps, springs, and their source areas as the main stream itself.
DE: 1806 Chemistry of fresh water
DE: 1831 Groundwater quality
DE: 1860 Runoff and streamflow
DE: 1871 Surface water quality
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly