Historical reconstruction of land use in the Brazilian Amazon (1940-1995)

The construction of geographically precise, high-resolution time series of historical changes in land use is an important step in constructing more realistic models of biogeophysical and bio-geochemical interactions with the atmosphere. However, such data are rarely available due to the typically imprecise nature of historical land use surveys and the relatively recent advent of sufficiently sensitive satellite remote sensing technology. In this article, we reconstruct and validate a geographically explicit historical database of land use in Amazonia for the period 1940-1995, at a 5' x 5' spatial resolution, through a fusion of historical census data and a contemporary land use classification. The reconstruction indicates that the main changes in the land use occurred in the south and southeast regions of the Amazon in the states of Tocantins, Goia ' s, and Mato Grosso. These states were characterized by an intensification of planted pasture during the study period, accelerating after 1970, although in many areas planted pasture replaced natural pasture rather than natural vegetation because it was considered more productive for raising cattle. Croplands were observed to expand significantly in Goia ' s and Mato Grosso, but were almost absent in the state of Amazonas. More generally, within the study region land use change was greatest in regions of pioneer occupation in the Amazon and near the main roads such as the trans-Amazonian highway.