Metodologia para mapeamento retroativo do desflorestamento na Amazônia brasileira

This paper aims at introduce a methodology developed to recover the Amazon deforestation occurred before 1997. The official mapping performed by FUNCATE team along PRODES project since 1988 was built initially by visual interpretation over printed maps in order to compute the overall deforestation rates. After 1997, the deforestation maps were developed by a computer aid process, hereafter producing digital deforestation maps available year by year until today. Even the deforestation monitoring exists since 1988, the amount of deforested area was large mainly in decade of 1970. Thus, deriving deforestation maps for years prior to 1988 is crucial to social, environmental, climatic and ecologic studies. Given the cost and labor intensity of the visual interpretation performed by PRODES, it is of great value to apply an effective methodology in order to recover this untouched information to support studies about issues so far unaddressed. The methodology consists in download images with fine quality and correction and compare this data with data provided by PRODES. The main aim of the proposed deforestation detection maps is to develop a mapping very similar to the one executed by PRODES team, keeping confidence and consonance with their results, but automatically made. The results were after spread through a WEBSIG system developed by the project specially to address the social demand.