TABLE 5 - uploaded by Renata Libonati
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Pearson r correlation values between burn scars and active fires for the different 32-day study periods.
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![Figure 2.5. Atmospheric transmittance attenuation [%] on MODIS VIS to...](profile/Renata-Libonati/publication/236321047/figure/fig3/AS:669400432660483@1536608908519/Atmospheric-transmittance-attenuation-on-MODIS-VIS-to-MIR-channels-for_Q320.jpg)
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Citations
... On a second hand, spectral response to fire in the MIR (around 3.75 -3.9 µm) is similar to that observed in the visible region, but with a larger increase in brightness and with an unequivocal reduction of sensitivity to atmospheric effects. As stressed out by Libonati et al. (2010), this is special relevant over the Amazon and Cerrado regions, where BA mapping is a challenging task due to the ephemeral character of the radiative signal and the presence of aerosols that prevent using classical approaches e.g. based on visible channels information. In this study, we evaluate the performance of the new BA index derived by Libonati (2010) in identifying burned surfaces in the Brazilian Amazon and Cerrado using the NIR/MIR bi-spectral region of MODIS channels. ...
... As stressed out by Libonati et al. (2010), this is special relevant over the Amazon and Cerrado regions, where BA mapping is a challenging task due to the ephemeral character of the radiative signal and the presence of aerosols that prevent using classical approaches e.g. based on visible channels information. In this study, we evaluate the performance of the new BA index derived by Libonati (2010) in identifying burned surfaces in the Brazilian Amazon and Cerrado using the NIR/MIR bi-spectral region of MODIS channels. Moreover, it is shown a comparison of the ability in discriminating burned and unburned surfaces when using traditional indices and the new proposed index. ...
Although the Brazilian Amazonia together with Cerrado region presents one of the highest numbers of occurrences of fire events, hardly any studies aiming to design burned area (BA) indices specifically for these regions have been attempted. This issue is of particular interest since the accuracy of BA maps is closed related to the characteristics of the location (e.g., pre-fire land-cover type and conditions, background soil, fire severity, post-fire processes, and atmospheric conditions) and in addition, index thresholds are often subjective or vary from region to region. Accordingly, a new spectral index, specifically designed for burned land discrimination in Amazon and Cerrado regions using the middle/near-infrared spectral domain, was tested on sets of Moderate Resolution Imaging Spectroradiometer (MODIS) images. The utility of the new index for burned land discrimination was assessed against other widely used spectral indices: Normalized Difference Vegetation Index (NDVI), Burned Area Index (BAI) and Global Environmental Monitoring Index (GEMI), defined in the red/near infrared space and the modified version on them, namely VI20, BAI20 and GEMI20 defined in the middle/near-infrared space of MODIS sensor. The ability of each index to discriminate between burned and unburned surfaces was assessed by means of a discrimination index. The new proposed (V,W) index works better than the traditional indices in all three cases analyzed, with the advantage of not requiring water masks, which is not true for the remaining indices.
