HR: 11:20h
AN: H42A-05 [Abstracts]
TI: Effects of Channel Type on Hyporheic Exchange in Mountain River Basins: A Process Hierarchy
AU: * Buffington, J M
EM: jbuffington@fs.fed.us
AF: US Forest Service, Rocky Mountain Research Station, Idaho Water Center, 322 East Front
St, Ste 401, Boise, ID 83702, United States
AU: Tonina, D
EM: dtonina@berkeley.edu
AF: US Forest Service, Rocky Mountain Research Station, Idaho Water Center, 322 East Front
St, Ste 401, Boise, ID 83702, United States
AU: Tonina, D
EM: dtonina@berkeley.edu
AF: Department of Earth and Planetary Science, University of California, 307 McCone Hall,
Berkeley, CA 94720, United States
AB:
Hyporheic exchange is the mixing of surface and shallow subsurface water through porous sediment
surrounding a river and is driven by spatial and temporal variations in channel characteristics (streambed
pressure (a function of bed topography and discharge), sediment composition, alluvial volume, and bed mobility).
The significance of hyporheic exchange in linking fluvial geomorphology, groundwater, and riverine habitat for
aquatic and terrestrial organisms has not been fully appreciated in the past, but has emerged in recent decades
as an important component of conserving, managing, and restoring riverine ecosystems. Here, we provide a
simple mathematical framework for examining the mechanics of hyporheic exchange. We propose that these
mechanisms vary systematically with different channel types and associated fluvial processes that occur in
mountain basins. Furthermore, the spatial distribution of hyporheic environments within mountain catchments
represents a nested hierarchy of process controls; basin physiography (geology, topography, climate, and
geomorphic history) influences successive scales of process domains (Montgomery 1999) and channel type
(e.g., Montgomery and Buffington 1997) which, in turn, affect the local hyporheic environment (scales, rates, and
magnitudes of hyporheic exchange). Consequently, a holistic view of geomorphic processes over a range of
spatial and temporal scales is required for understanding hyporheic ecosystems.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 1813 Eco-hydrology
DE: 1825 Geomorphology: fluvial (1625)
DE: 1829 Groundwater hydrology
DE: 1856 River channels (0483, 0744)
SC: Hydrology [H]
MN: 2007 Fall Meeting