HR: 1340h
AN: B53B-1197 [Abstracts]
TI: Remote Estimation of Gross Primary Production in Crops at Field and Regional Levels
AU: * Gitelson, A A
EM: gitelson@calmit.unl.edu
AF: University of Nebraska, 303 hardin Hall, Lincoln, NE 68583-0973, United States
AU: Vina, A
EM: avina@calmit.unl.edu
AF: University of Nebraska, 303 hardin Hall, Lincoln, NE 68583-0973, United States
AU: Verma, S B
EM: sverma@unlnotes.unl.edu
AF: University of Nebraska, 303 hardin Hall, Lincoln, NE 68583-0973, United States
AU: Rundquist, D C
EM: drundquist@calmit.unl.edu
AF: University of Nebraska, 303 hardin Hall, Lincoln, NE 68583-0973, United States
AB:
Accurate estimation of spatially distributed CO2 fluxes is of great importance for regional and global studies of
carbon balance. We have found that in irrigated and rainfed crops (maize and soybean), GPP is closely related to
total crop chlorophyll content. The finding allowed development of a new technique for remote estimation of crop
chlorophyll specifically for assessing gross primary production. The technique is based on reflectance in two
spectral channels: the near-infrared and either the green or the red-edge. The technique provided accurate
estimations of daily GPP in both crops. Validation using independent datasets for irrigated and rainfed maize and
soybean documented the robustness of the technique. We report also about applying the developed technique
for GPP retrieval from data acquired by both an airborne imaging spectrometer (AISA-Eagle) and Landsat ETM+.
The Chlorophyll Index, retrieved from Landsat ETM+ data, was found to be an accurate surrogate measure for
daily crop GPP with a root mean square error of GPP prediction of less than 1.58 g C m-2d-1 in a GPP range of
1.88 g C m-2d-1 to 23.1 g C m-2d-1. These results suggest new possibilities for analyzing the spatio-temporal
variation of the GPP of crops using not only the extensive archive of Landsat Thematic Mapper imagery acquired
since the early 1980s but also the 500-m/pixel data currently being acquired by MODIS.
DE: 0402 Agricultural systems
DE: 0428 Carbon cycling (4806)
DE: 0438 Diel, seasonal, and annual cycles (4227)
DE: 0480 Remote sensing
SC: Biogeosciences [B]
MN: 2007 Fall Meeting