Since 1988, Brazil National Institute of Space Research (INPE) has developed a deforestation mapping program in the Amazon that became a world reference for tropical forest monitoring (PRODES).
The first monitoring system that gave manually and later digitally annual deforestation rate estimations for the overall Brazilian Amazon based on LANDSAT images was recently improved to provide near real time deforestation areas detection (DETER). This system made possible a large deforestation control program in Brazil that limited significantly the progression of deforestation in the region. These monitoring programs are essential for the conservation of the tropical biodiversity but it is now considered that a specific monitoring of the areas already deforested should complement such effort. This monitoring is essential to define and apply specific conservation strategies for the regions that have a human-impacted landscape. In recent studies, certain types of human-modified areas such as secondary forest, agroforestry or even pasture have shown a high biodiversity conservation capacity for plants, trees and fauna. On the opposite, some landscapes are devastating the biodiversity such as soybean fields, sugarcane or palm oil plantations. To take in account this biodiversity gradient within the human-modified areas and prepare future conservation strategies, it is then necessary to provide up-to-date land cover maps of the so-called "deforested areas".
Description of the test sites
Two study sites were defined in the western part of the Legal Amazon region. Each test site is defined by the window of a LANDSAT image of 120 km x 120 km.
The first test site is located around Santarem. Santarem is a town located in the western part of the Para State at the confluence of the Amazon and Tapajos rivers. While conservation of primary forest should represent 80% of the lands according to Brazilian laws, the deforestation has continued and even increased with the recent installation of a port facility for processing soybean in Santarem what enhanced soybean production in the region. This test site is particularly interesting since it concentrates a high diversity of land cover situations with small patches of deforestation. It is considered as a complex region to map the land cover of the human-modified areas because of the large diversity of situations and the high landscape fragmentation.
The second test site is located in the north part of the Tucurui Lake between Belem and Maraba. It is a region where deforestation was very intense partly because of the presence of steel-making centres that use primary forest to produce charcoal. In this region, eucalyptus plantations have grown to produce more sustainable charcoal and avoid deforestation. It is also an area where pasture degradation is common. The mapping of the actual land cover situation will be also useful to plan reforestation forest in this particular region.
For both test sites the products delivered by BIO_SOS will allow to discriminate pastures, agricultural fields, remnant primary growth forest patches, riparian strips, secondary forests and agroforestry.