HR: 14:30h
AN: H42I-04    [PDF]
TI: A Comparison of Fluvial Geomorphic Structure, Transient Storage Residence Time Distributions, and Nitrate Cycling Along a Gradient of Impacted Streams In and Around Grand Teton National Park, Wyoming
AU: * Gooseff, M N
EM: michael.gooseff@usu.edu
AF: Utah State University, Department of Aquatic, Watershed, & Earth Resources, Logan, UT 84322-5210 United States
AU: Hall, R O
EM: bhall@uwyo.edu
AF: University of Wyoming, Department of Zoology and Physiology, Laramie, WY 82071 United States
AU: Tank, J L
EM: tank.1@nd.edu
AF: University of Notre Dame, Department of Biological Sciences, Notre Dame, IN 46556 United States
AB: Stream fluvial geomorphic structure establishes patterns of surface water and subsurface head distributions, often driving hyporheic exchange through steps, riffles, and meanders. Exchanges of stream water through hyporheic zones provide substrate for hyporheic biogeochemical transformations (e.g. denitrification). In this study, stream tracer experiments and topographic surveys were performed on three streams, one agricultural stream, one urban stream, and one pristine stream, to investigate the control of stream fluvial geomorphic structure on water residence time distributions and nitrate cycling in relation to land use. Urban and agricultural streams had very little streambed elevation variation (near constant slopes along thalwegs), and very short conservative tracer residence time distributions with average reach residence times of 8.53 and 31.41 s/m stream length. The pristine stream had a much more complex geomorphic structure with several riffles, pools, steps and splits. Consequently, the pristine stream residence time distribution was longer (average residence time was 79.03 s/m), indicating greater transient storage within this reach. The results of this study suggest that land-use influences upon fluvial geomorphic structure directly impact transient storage processes and nitrate cycling in streams.
DE: 1800 HYDROLOGY
DE: 1824 Geomorphology (1625)
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1860 Runoff and streamflow
SC: Hydrology [H]
MN: 2003 Fall Meeting