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Evaluation of satellite based indices for primary production estimates in a sparse savanna in the Sudan
M. Sjöström1, J. Ardö1, L. Eklundh1, B. A. El-Tahir2, H. A. M. El-Khidir2, P. Pilesjö1, and J. Seaquist1
1Department of Physical Geography and Ecosystem Analysis, Lund, Sweden
2Agricultural Research Corporation, El Obeid, Sudan
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Abstract. One of the more frequently applied methods for integrating controls on
primary production through satellite data is the Light Use Efficiency (LUE)
approach. Satellite indices such as the Enhanced Vegetation Index (EVI) and
the Shortwave Infrared Water Stress Index (SIWSI) have previously shown
promise as predictors of primary production in several different
environments. In this study, we evaluate EVI and SIWSI derived from the
Moderate Resolution Imaging Spectroradiometer (MODIS) satellite sensor
against in-situ measurements from central Sudan in order to asses their
applicability in LUE-based primary production modelling within a water
limited environment. Results show a strong correlation between EVI against
gross primary production (GPP), demonstrating the significance of EVI for
deriving information on primary production with relatively high accuracy at
similar areas. Evaluation of SIWSI however, reveal that the fraction of
vegetation apparently is to low for the index to provide accurate
information on canopy water content, indicating that the use of SIWSI as a
predictor of water stress in satellite data-driven primary production
modelling in similar semi-arid ecosystems is limited.
Discussion Paper (PDF, 3309 KB) Interactive Discussion (Closed, 4 Comments) Final Revised Paper (BG)
Citation: Sjöström, M., Ardö, J., Eklundh, L., El-Tahir, B. A., El-Khidir, H. A. M., Pilesjö, P., and Seaquist, J.: Evaluation of satellite based indices for primary production estimates in a sparse savanna in the Sudan, Biogeosciences Discuss., 5, 2985-3011, 2008. Bibtex EndNote Reference Manager
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