HR: 13:55h
AN: H23J-02 INVITED    [Abstracts]
TI: Channel-Streambed Interactions Over and Under Ice
AU: * Gooseff, M N
EM: mgooseff@engr.psu.edu
AF: Pennsylvania State University, Department of Civil & Environmental Engineering 212 Sackett Building, University Park, PA 16802, United States
AU: Cardenas, M B
EM: cardenas@mail.utexas.edu
AF: University of Texas, Department of Geological Sciences 1 University Station C1100, Austin, TX 78712-0254, United States
AU: Zarnetske, J P
EM: zarnetsj@science.oregonstate.edu
AF: Oregon State University, Department of Geosciences 104 Wilkinson Hall, Corvallis, OR 97331-5506,
AU: Bowden, W B
EM: breck.bowden@uvm.edu
AF: University of Vermont, Rubenstein School of Environment & Natural Resources 304 Aiken Center, Burlington, VT 05405, United States
AU: Greenwald-Johnston, M
EM: morgan.johnston@uvm.edu
AF: University of Vermont, Rubenstein School of Environment & Natural Resources 304 Aiken Center, Burlington, VT 05405, United States
AU: McNamara, J P
EM: jmcnamar@boisestate.edu
AF: Department of Geosciences, Boise State University, Boise, ID 83725, United States
AU: Bradford, J H
EM: jbradfor@boisestate.edu
AF: Department of Geosciences, Boise State University, Boise, ID 83725, United States
AU: Brosten, T R
EM: troybrosten@mail.boisestate.edu
AF: Department of Geosciences, Boise State University, Boise, ID 83725, United States
AB: An overwhelming set of studies in temperate streams has noted that exchanges of water, solutes, and heat across streambeds are very important to stream ecosystem structure and function. We have postulated that similar dependence is likely in streams affected by ice. In particular, streams underlain by permafrost have a finite potential aquifer with which to exchange (i.e., constrained by the depth of annual thaw), and streams that maintain an ice-cover for any period of time experience a modified hydraulic condition (compared to open water conditions) that affects channel-streambed exchanges. Here we present findings from field and modeling studies of streams underlain by permafrost and from modeling studies of ice-covered channels. Our results from these studies indicate that, 1) in general, sub-channel thaw does not limit exchange potential, rather it is the morphology of the streambed that controls exchange potential and extent, 2) these exchanges facilitate nutrient regeneration, and 3)for the same discharge, exchange fluxes are generally enhanced by the presence of an ice- cover, though the depth of exchange is diminished. These findings indicate that while ice may be an important component of these systems, streambed form and composition are primary controls on exchange processes.
DE: 1804 Catchment
DE: 1825 Geomorphology: fluvial (1625)
DE: 1830 Groundwater/surface water interaction
DE: 1856 River channels (0483, 0744)
SC: Hydrology [H]
MN: 2007 Fall Meeting