HR: 09:00h
AN: G11B-05 INVITED     [Abstracts]
TI: Using airborne laser swath mapping to quantify sediment production and transport processes
AU: * Roering, J J
EM: jroering@uoregon.edu
AF: University of Oregon, Dept. of Geological Sciences, Eugene, OR 97403-1272 United States
AU: McKean, J
EM: jmckean@fs.fed.us
AF: USFS, Rocky Mtn. Res. Station, 316 East Myrtle Street, Boise, ID 83702 United States
AU: Dietrich, W E
EM: bill@seismo.berkeley.edu
AF: Univ. of California, Berkeley, Dept. of Earth and Planetary Sci., Berkeley, CA 94703-4767 United States
AU: Kirchner, J W
EM: kirchner@seismo.berkeley.edu
AF: Univ. of California, Berkeley, Dept. of Earth and Planetary Sci., Berkeley, CA 94703-4767 United States
AB: Since Gilbert, Agassiz, and other pioneers of geomorphology viewed the shape of landscapes as a reflection of surficial processes, earth scientists have embraced the process-form linkage as an important tool in the quantification of sediment production and transport processes. Testing the rich pool of geomorphic models has been difficult due to the lack of topographic data at the process scale. Emerging datasets acquired from airborne laser swath mapping (ALSM) are enabling earth scientists to marry state-of-the-art theoretical models with high-resolution topographic information. Here, we describe examples of how ALSM data can be used for: 1) geomorphic model testing and calibration, 2) prediction of erosion rates, and 3) deciphering the chronology of mass movement over millennial timescales. Models describing the movement of soil on hillslopes generate distinctive morphologic predictions. Analyses of ALSM datasets illustrate that soil-mantled hillslopes in the Oregon Coast Range (OCR) become increasingly convex with steepness, consistent with proposed nonlinear, slope-dependent transport models. Given assumptions regarding background erosion rates or field-based measurements, such transport models can be calibrated and used to predict the spatial distribution of erosion rates using ALSM datasets. Our analysis of post-fire erosion on OCR hillslopes demonstrates that subtle variations in topographic form are important for determining the spatial pattern of soil stripping and bedrock emergence. The seemingly jumbled and chaotic topographic form of large landslide complexes contains a wealth of information regarding the history and mechanics of slide movement. Statistical analyses of ALSM datasets for slide-dominated terrain can identify unstable areas and distinguish the chronology and style of internal deformation features. These projects emphasize the need to both carefully consider how we estimate standard topographic properties (such as slope and curvature) and explore new methods for quantifying the form of the earth's surface.
DE: 1824 Geomorphology (1625)
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2004 AGU Fall Meeting