HR: 1330h
AN: B33E-16    [Abstracts]
TI: Developing a Method for Partitioning Transient Storage into Hyporheic and In-Channel Dead Zone Components
AU: * Baker, M A
EM: mbaker@biology.usu.edu
AF: Department of Biology and Ecology Center, Utah State University, Logan, UT 84322 United States
AU: Arp, C D
EM: carp@biology.usu.edu
AF: Department of Biology and Ecology Center, Utah State University, Logan, UT 84322 United States
AU: Gooseff, M N
EM: mgooseff@mines.edu
AF: Department of Geology and Geophysical Engineering, Colorado School of Mines, Golden, CO 80401 United States
AU: Hall, R O
EM: bhall@uwyo.edu
AF: Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071 United States
AB: Transient storage is often represented as characterizing the hyporheic zone, but it may also represent storage in the channel. We attempted to separate the size and exchange rate of both storage types using a combination of rhodamine WT tracer injections and cross-sectional flow velocity measurements, coupled with inverse modeling using STAMMT-L (a one dimensional transient storage model that simulates a variety of different residence time distributions) and one- and two-compartment models of OTIS. Experiments comparing stream reach breakthrough curves were conducted while concurrently measuring lateral velocity profiles. Exchange rates between the main channel and in-channel dead zones were calculated with shear velocities and lateral eddy diffusion. The one-compartment OTIS model best described in-channel storage in reaches with pools and eddies while STAMMT-L better described storage due to hyporheic exchange. The two-compartment OTIS model was a good compromise between these models and adequately quantified in-channel and hyporheic storage when constrained by empirical data. The ability to separate hyporheic and in-channel storage can improve our understanding of nutrient cycling in streams that differ geomorphically because these storage zones differ in the rates and types of nutrient transformations.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2005 Joint Assembly