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Communication incl. Poster: BibTeX citation key:  Kaptue
Kaptue Tchuente, A. T., Roujean, J.-L. & Faroux, S. 2009. The ECOCLIMAP – II Programme: A new land cover classification at 1 km from MODIS and vegetation data time series over Western Africa in the frame of the AMMA Project. Work presented at Third International AMMA Conference, July 20—24, at Ouagadougou, Burkina Faso.
Added by: roussot 2009-11-04 18:07:06
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Categories: Land surface processes
Keywords: Land use, Vegetation
Creators: Faroux, Kaptue Tchuente, Roujean
Publisher: African Monsoon Multidisciplinary Analyses (Ouagadougou, Burkina Faso)
Collection: Third International AMMA Conference

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Abstract
The ECOCLIMAP database is twofold. First it encompasses a land cover classification per ecosystem based on the principle that they obey to a similar functioning. Secondly, it associated with each ecosystem a dynamic list of useful surface parameters for meteorological studies based on correlation tables. The prescription of a physiographic forcing is important information for the models in the region of West Africa because of farming practices and the modification of ecotones. In the 1st version ECOCLIMAP I, the land cover information (University of Maryland, IGBP) was combined with a global climate mapping (Koeppe and De Lond, FIRS), which led to 215 ecosystems in global and 27 ecosystems on the box [25W, 25E] x [5S, 20N] (http://www. cnrm.meteo.fr/gmme/PROJETS/ECOCLIMAP/page_ecoclimap.htm).
The second version ECOCLIMAP II is more accurate because it relies on information from the latest generation of satellites such as MODIS and VEGETATION which offer a better radiometric and geometric resolution of the order of km. The methodology is to analyze the time series of leaf area index (LAI) and the normalized vegetation index (NDVI) over 8 years (2000-2007). The process of supervised classification includes such factors as climatic zoning (Peel et al., 2007) and topography. The reliability of the 37 classes obtained for the AMMA area shows a good agreement in the order of 75% with the product GLOBCOVER (300 m resolution) and SPOT classification product (20 m resolution) on some contrasting reference sites.
For meteorological applications, the ecosystems of ECOCLIMAP II need to be disaggregated in fraction of vegetation types of the SVAT (Soil Vegetation Atmosphere Transfer) model ISBA used at Météo France. The procedure for disaggregation is based on the identification of pure pixels corresponding to an ISBA type using as disintegrating tool the leaf area index. This leads to the construction of the database of the most relevant biophysical surface variables (leaf area index, albedo, vegetation fraction) for the model ISBA during the period from 2000 to 2007 and the underlining of an inter-annual variability of these biophysical variables for some ecosystems. The physiography of ECOCLIMAP-II which is now a better representation of continental surfaces will enables the analysis of meteorological variables such as evaporation, runoff, moisture and soil temperature using the model SURFEX.
Added by: roussot