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Journal Article: ID no. (ISBN etc.):  0034-4257 BibTeX citation key:  Jarlan2008
Jarlan, L., Mangiarotti, S., Mougin, E., Hiernaux, P., Mazzega, P. & Le Dantec, V. (2008) Assimilation of SPOT/VEGETATION NDVI data into a sahelian vegetation dynamics model. IN Remote Sensing of Environment, 112. 1381–1394.
Last Edited by: Deleted user 2009-09-21 09:55:40
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Categories: General
Keywords: Data assimilation, Vegetation
Creators: Hiernaux, Jarlan, Le Dantec, Mangiarotti, Mazzega, Mougin
Collection: Remote Sensing of Environment
Bibliographies: Prior150410

Peer reviewed
Number of views:  1069
Popularity index:  56.56%
Maturity index:  published

 
Abstract
This paper presents a method to monitor the dynamics of herbaceous vegetation in the Sahel. The approach is based on the assimilation of Normalized Difference Vegetation Index (NDVI) data acquired by the VEGETATION instrument on board SPOT 4/5 into a simple sahelian vegetation dynamics model. The study region is located in the Gourma region of Mali. The vegetation dynamics model is coupled with a radiative transfer model (the SAIL model). First, it is checked that the coupled models allow for a realistic simulation of the seasonal and interannual variability of NDVI over three sampling sites from 1999 to 2004. The data assimilation scheme relies on a parameter identification technique based on an Evolution Strategies algorithm. The simulated above-ground herbage mass resulting from NDVI assimilation is then compared to ground measurements performed over 13 study sites during the period 1999–2004. The assimilation scheme performs well with 404 kg DM/ha of average error (n = 126 points) and a correlation coefficient of r = 0.80 (to be compared to the 463 kg DM/ha and r = 0.60 of the model performance without data assimilation). Finally, the sensitivity of the herbage mass model estimates to the quality of the meteorological forcing (rainfall and net radiation) is analyzed thanks to a stochastic approach.
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Last Edited by: Deleted user    Added by: Deleted user