HR: 1340h
AN: H43D-0527    [Abstracts]
TI: Impacts of landscape evolution on hydrology: headwater channels in deglaciated terrain.
AU: * Johnson, A C
EM: ajohnson03@fs.fed.us
AF: PNW Research Station, Forestry Sciences Laboratory, 2770 Sherwood Lane, Suite 2a, Juneau, AK 99801 United States
AU: Edwards, R T
EM: rtedwards@fs.fed.us
AF: PNW Research Station, Forestry Sciences Laboratory, 2770 Sherwood Lane, Suite 2a, Juneau, AK 99801 United States
AU: D'Amore, D
EM: damore@fs.fed.us
AF: PNW Research Station, Forestry Sciences Laboratory, 2770 Sherwood Lane, Suite 2a, Juneau, AK 99801 United States
AU: Fellman, J
EM: fellman@fs.fed.us
AF: University of Fairbanks, P.O. Box 757500, Alaska, AK 99775 United States
AB: We examined nine small headwater channels originating within three vegetation communities on different landforms: sloping bogs, forested wetlands, and upland forests, to quantify relationships between stream type and flow characteristics. Discharge was measured with flumes instrumented with pressure transducers. Average cross-sectional area of the bankfull flow channel was estimated from cross-sections made above and below flumes. Stream hydrographs for forested wetlands and uplands were similar with rapid response to rainfall and rapid return to baseflow. Bog hydrographs were damped relative to the other stream types, presumably due to differences in soil hydrologic conductivity, groundwater input, and slope gradient. Preliminary results suggest that most of our study channels have not acquired their present shape by bankfull flows associated with recent floods. The morphology of some channels may be attributed to debris flow occurrence subsequent to glacial retreat. Other headwater channels, lacking adequate channel incision, overtop banks frequently, and thus, appear to have been formed recently. This work supports concurrent work aimed at calculation of chemical flux rates within a range of wetland and non-wetland settings.
DE: 0483 Riparian systems (0744, 1856)
DE: 1825 Geomorphology: fluvial (1625)
DE: 1856 River channels (0483, 0744)
DE: 1890 Wetlands (0497)
SC: Hydrology [H]
MN: Fall Meeting 2005