HR: 0830h
AN: H41A-02    [Abstracts]
TI: Inferring floodplain subsurface flowpaths using remote sensing vegetation indices
AU: * O'Daniel, S J
EM: sodaniel@icess.ucsb.edu
AF: Confederated Tribes of the Umatilla Indian Reservation, 72329 Confederated Way, Pendleton, OR United States
AU: Poole, G C
EM: gcp7@cornell.edu
AF: Eco-metrics, 2520 Pine Lake Lane, Tucker, GA United States
AU: Mertes, L A
EM: leal@geog.ucsb.edu
AF: University of California at Santa Barbara, Institute for Computational Earth System Science and Geography Department, 3611 Ellison Hall, Santa Barbara, CA United States
AU: Woessner, W W
EM: www@selway.umt.edu
AF: Department of Geology, 32 Campus Dr. #1296, Missoula, MT United States
AB: Floodplain vegetation directly responds to water availability in the alluvial aquifer. Variation in plant water stress, both spatially and across the growing season, may indicate preferential flowpaths in alluvial floodplains. We use aerial and satellite remote sensing data to monitor change of a semi-arid floodplain through the summer season. Combining several remote sensing instruments in a 2004 campaign, we collected images at multiple spatial scales from 4/2005 to 9/2005. We evaluated several vegetation indices, including Normalized Difference Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI) and Red-edge Stress Vegetation Index (RSVI) and compared them to local floodplain topography. Initial results suggest that RSVI is the most robust index and the least sensitive to atmospheric conditions. Apparent surface reflectance was calculated from each data set and aerial hyperspectral images were convolved to satellite images. By standardizing units in this way, we can directly compare spectra across multiple basins and identify patterns of water stress in riparian vegetation at multiple spatial scales. Corroborating these results with 3-dimensional model outputs and field tracer tests should identify areas where vegetation responds directly to patterns of hydrologic connectivity.
DE: 1640 Remote sensing
SC: Hydrology [H]
MN: 2005 Joint Assembly