Assessing land cover changes in the Brazilian Cerrado between 1990 and 2010 using a remote sensing sampling approach

We present a remote sensing sampling approach to assess land cover changes between years 1990 and 2010 for the Cerrado biome. Despite the fact that natural vegetation cover of this biome has been heavily converted into agricultural lands over the past decades, there is still a lack of detailed and historical information about vegetation cover changes at the biome scale. The sampling design and image processing techniques were developed by the Joint Research Centre (JRC) Tropical Ecosystem Environment Observation by Satellite (TREES- 3) project. A set of 175 regularly distributed sample units (with10 km x 10 km size) located at every full degree confluence point of latitude and longitude were assessed. For each sample unit, (E)TM Landsat images from three target years (1990, 2000 and 2010) were selected, pre-processed, segmented and classified into five land cover classes (Tree Cover - TC, Tree Cover Mosaic - TCM, Other Wooded Land - OWL, Other Land Cover - OLC and Water -W). The results showed that the Cerrado had a net loss of natural vegetation (TC + OWL) of about 12 million hectares between 1990 and 2010, or an average rate of change of -0.6% y -1 . However, the rates of change decreased from the first (1990-2000) to the second (2000-2010) decade. By 2010, the percentage of natural vegetation cover remaining in the Cerrado was 47%.