Preliminary analysis of MODIS vegetation indices over the LBA sites in the Cerrado region, Brazil

The Brazilian Cerrado, the second largest biome in South America, is marked by a distinct seasonal contrast and comprises an intricate mosaic of land cover types, vertically structured as grassland, shrubland, and woodland. Due to intensive agricultural and grazing occupation, the Cerrado is today the most severely threatened biome in Brazil. Therefore, the discrimination of the major Cerrado types, the monitoring of the vegetation conditions, as well as the identification of the current distribution of land-cover types and occurrences of land use intensification, play a major role in the Global Land-Cover and Land-Use Change Strategy within the scope of the NASA Earth Observing System (EOS) program. In fact, different studies have already demonstrated the potential of the optical vegetation indices to monitor the Cerrado vegetation and condition. These investigations, mainly based on temporal AVHRR data sets converted to the normalized difference vegetation index (NDVI), indicate that the dominant land cover types may be grouped into three spatial domains, encompassing the savanna formation and pasture sites, the forested areas, and the agricultural crops. In relation to the recently launched MODIS, the key instrument onboard the Terra platform, the expectation is that performing the NDVI, a continuity index, as well as the EVI (Enhanced Vegetation Index), will result in more precise and accurate measures of the vegetative cover. The extent, to which such sensor and VI concept improvements will directly impact biophysical parameter estimations and vegetation mapping in the Cerrado biome, is the main focus of this investigation