Early Registration Deadline
12 February 2010

Travel Award & Grant Recipients Notified
March 2010

Authors Notified
April 2010

Schedule Posted
January 2010

Wondzell, S. M., USDA Forest Service, Pacific Northwest Research Station, Olympia, USA, swondzell@fs.fed.us
Zarnetske, J. P., Oregon State University, Corvallis, USA, zarnetsj@geo.oregonstate.edu
Haggerty, R. ., Oregon State University, Corvallis, USA, haggertr@geo.orst.edu
Payn, R. A., Montana State University, Bozeman, USA, robpayn@gmail.com
Gooseff, M. N., Pennsylvania State University, State College, USA, mgooseff@engr.psu.edu
McGlynn, B. L., Montana State University, Bozeman, USA, bmcglynn@montana.edu

LIMITATIONS OF THE STREAM TRACER APPROACH FOR HYPORHEIC INVESTIGATIONS

Stream tracer studies and subsequent analyses with transient storage models have long been a mainstay of hyporheic investigations. These stream tracer studies are appealing. They are easier than methods that rely on direct observations from wells and appear to provide estimates of the size of the hyporheic zone. Stream tracer methods have many limitations however. Some are well known, for example, the “window of detection”; other limitations are less well known, for example, how the spatial ordering of gains and losses can influence estimates of lateral groundwater inputs. To illustrate these limitations we contrast tracer-based methods with well-network based methods. We show that, in most streams, tracer studies are only sensitive to very short residence time exchange flows and thus fail to characterize portions of the residence time distribution important to many biogeochemical processes. We suggest that all stream tracer studies should (1) conduct mass balances on recovered tracer mass and (2) use numerous wells to document the spatial extent of the hyporheic zone actually measured in any given tracer study. In summary: Transient storage does not equal hyporheic exchange.

Poster presentation

Session #:S20
Date: 06-10-10
Time: 17:30 - 19:30

Presentation is given by student: No