Mapping the agricultural frontier in Mato Grosso based on remote sensing data.
Résumé
An active agricultural frontier is moving forward in the Brazilian Amazon area, especially in the State of Mato Grosso where crop expansion has been considered as a main driver of deforestation for more than 30 years. Geographical concepts of the agricultural frontier assume that its progress is carried out through five stages (pre-settlement, occupation, consolidation, intensification and intensive stages), corresponding to the evolution of three frontiers (deforestation, economic and intensification frontiers). This paper aims at proposing a remote sensing-based methodology to map the spatio-temporal evolution of these frontiers and the evolution stages of the agricultural frontier in Mato Grosso. The method is based on the definition of an agrarian locality scale and on land-use based indices. The quality of the method is then dependent on the accuracy of the input data used. Here deforestation (provided by INPE and SEMA-MT) and classification maps (computed on MODIS EVI time series) are used. The results allow to visualize the evolution of three important phenomena in Mato Grosso during the 2000-2006 period: increase in deforestation, crop expansion and agricultural intensification. Final maps highlight the fact that few areas have reached the final intensive stage of the agricultural frontier, reminding that Mato Grosso is still experiencing a very active colonization process.