HR: 0830h
AN: G11A-0242    [PDF]
TI: Application of Local Surface Matching to Multi-Date ALSM Data for Improved Calculation of Flood-Driven Sediment Deposition and Erosion
AU: * Crowell, K J
EM: crowell@lanl.gov
AF: Earth and Environmental Sciences, Los Alamos National Laboratory, PO Box 1663 MS J495, Los Alamos, NM 87545 United States
AU: Wilson, C J
EM: cjw@lanl.gov
AF: Earth and Environmental Sciences, Los Alamos National Laboratory, PO Box 1663 MS J495, Los Alamos, NM 87545 United States
AU: Canfield, H E
EM: ecanfield@tucson.ars.ag.gov
AF: USDA-ARS Southwest Watershed Research Station, 2000 E Allen Rd, Tucson, AZ 85719 United States
AB: The headwaters of Pueblo Canyon, Los Alamos County, New Mexico, were severely burned during the May, 2000 {\it Cerro Grande} Fire, after which occurred a series of floods of significantly increased magnitude compared to pre-fire records. Data from two ALSM missions offered the opportunity to quantify the flood-driven sediment deposition and erosion through the canyon, as well as to aid efforts to model sediment and contaminant transport in the post-fire hydrology. The datasets exhibited an array of processing artifacts and errors but were deemed to be of higher quality than existing photogrammetry-derived elevation data. However, the difference raster exhibited unrealistic patterns of erosion and deposition on hillslopes which were found to be caused by variable horizontal position errors. These combined with background vertical offsets greatly distorted the patterns of sediment deposition and erosion along the stream channel, with a large bias toward deposition throughout. Surface matching over local windows was used to correct the data for sediment volume change calculation. Cross correlation maximization followed by a vertical correction was sufficient to remove the majority of the relative error so that calculated sediment deposition and erosion were consistent with field observations. While the vertical offsets accounted for much of the depositional bias, the horizontal error component of the calculated sediment change volume was not trivial. The effects of this image-based surface matching technique and of an application of iterative point matching as a refinement are presented.
DE: 1224 Photogrammetry
DE: 1294 Instruments and techniques
DE: 1815 Erosion and sedimentation
SC: Geodesy [G]
MN: 2003 Fall Meeting