The emergence of Vegetation Index, in 1960, contributes to the acquisition of important environmental information. Since then, several experts have worked on the improvement of this technique, in order to generate results closer to reality. The index most commonly used is the NDVI, which includes the range -1 to 1, varying with the density of vegetation. His improvement culminates in the SAVI, which employs a constant adjustment of the substrate L canopy. The present study aimed at comparing both indexes, applied in the caatinga biome, in order to conclude which one yields the best results. The study area is located at Embrapa Semi-Arid, Petrolina, Pernambuco. It was sought to demonstrate the importance of improvement of the indexes, with an emphasis on rigor and selectivity in choosing the most appropriate rate for the study area. For this, the bibliographic databases are guided with a greater emphasis on Ponzoni and Shimabukuro (2009) and Jensen (2009). The results show that the SAVI discriminate targets better, presenting a greater number of classes. NDVI, however, accused some peculiarities, such as saturation their values in relation to leaf area index and the influence of shadows of the plants. The details of the research is showed bellow.Pages: 1828-183
