HR: 16:15h
AN: B54A-02    [Abstracts]
TI: LEDAPS: A North American Disturbance Record from Landsat Imagery
AU: * Masek, J G
EM: Jeffrey.G.Masek@nasa.gov
AF: NASA Goddard Space Flight Center, Code 923 NASA GSFC, Greenbelt, MD 20771 United States
AU: Hall, F
EM: fghall@ltpmail.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 923 NASA GSFC, Greenbelt, MD 20771 United States
AU: Wolfe, R
EM: rwolfe@pop900.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Code 923 NASA GSFC, Greenbelt, MD 20771 United States
AU: Cohen, W
EM: warren.cohen@oregonstate.edu
AF: USDA Forest Service, 3200 SW Jefferson way, Corvallis, OR 97331 United States
AB: The disturbance regime of forests exerts a strong control on North American terrestrial carbon dynamics. Disturbance events themselves (fire, harvest, insect damage) emit carbon directly to the atmosphere; regrowth following disturbance tends to sequester carbon from the atmosphere. In general, the spatio-temporal patterns of disturbance control the age structure and successional patterns of forests, and thus influence net ecosystem productivity on a regional basis. The Landsat remote sensing program has collected high-resolution (30-80 meter resolution) imagery since 1972, and provides an excellent tool for assessing recent disturbance patterns. To date, however, this archive has not been comprehensively analyzed for such information. To remedy this, the LEDAPS (Landsat Ecosystem Disturbance Adaptive Processing System) project at NASA GSFC is processing decadal Landsat imagery centered on 1975, 1990, and 2000 epochs to map forest disturbance rates and patterns across North America. Landsat imagery is calibrated and atmospherically corrected to surface reflectance using the 6S radiative transfer model. Disturbance patterns are extracted in two phases. First, a simple Disturbance Index (S. Healey, personal communication) is used to map the location of significant biomass loss following a `tasseled cap' radiometric transformation. Second, we are experimenting with the integration of canopy reflectance models to relate pixel radiometry directly to stand attributes (canopy cover, forest type) to better characterize regrowth state. Initial "Beta" products have been released and feedback from the land science community is invited. This presentation will give an overview of the LEDAPS project, and present initial results from reflectance processing and disturbance mapping.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting