HR: 17:15h
AN: H34B-05 INVITED     [Abstracts]
TI: Mapping Channel Morphology and Stream Habitat With a Full Waveform Green Lidar
AU: * McKean, J
EM: jmckean@fs.fed.us
AF: USDA Forest Service, 316 E. Myrtle St., Boise, ID 83702 United States
AU: Wright, W
EM: wright@lidar.net
AF: NASA, Goddard Space Flight Center, Wallops Flight Facility, Code 972, Wallops Island, VA 23337-5099 United States
AB: Basic topographic mapping and objective description of physical habitat in channels remains problematic using standard methods of cross section and thalweg surveying. Even with ground GPS surveys, detailed maps of bedforms and banks are normally only attempted for short stream reaches on the order of 100 m. The Experimental Advanced Airborne Research Lidar (EAARL) is a full waveform lidar, operating at 532 nm, with the potential to seamlessly map riparian vegetation, floodplain topography, and channel banks and bedforms over whole stream networks. We have used EAARL to map channel topography continuously over 85 km of streams in the watershed of the Middle Fork Salmon River, Idaho. The data are being compared to control field surveys in six reaches of plane bed and pool/riffle channels to assess their accuracy. In 15- to 50-meter-wide channels, EAARL data support fundamental hydrologic measures such as bankfull depth, pool and riffle definition, residual pool volumes, channel cross-sectional area and slope, bedform hydraulic roughness, and water turbidity. We are also using EAARL data to classify channels based on their morphometry and inferred processes and to objectively define the physical habitat for Chinook salmon and other species from derived metrics such as available spawning surface area, bedform amplitude, and locations, dimensions, and hydrologic connection of off-channel rearing areas. The continuous nature of the data allows us to study network scale habitat connectivity and explore controls on the spatio-temporal distribution of whole salmon populations. Continuous thalweg profiles have been interpreted in the frequency domain using wavelet analyses to investigate periodicity of channel topography at a variety of spatial scales. The wavelet analyses accurately map transitions in channel types and in one stream segment closely define historic preferred spawning sites. Future work is planned to exploit the three-dimensional bed topography mapped by EAARL and refine local predictions of bed shear stress and bed mobility, substrate median grain size, and hyporheic exchange over whole stream networks.
DE: 1209 Tectonic deformation (6924)
DE: 1294 Instruments and techniques
DE: 1625 Geomorphology and weathering (0790, 1824, 1825, 1826, 1886)
DE: 1824 Geomorphology: general (1625)
DE: 1886 Weathering (0790, 1625)
SC: Hydrology [H]
MN: Fall Meeting 2005