Evaluation of Landsat 8 and Sentinel-2A data on the correlation between geological mapping and NDVI

This paper presents an experimental evaluation of the Normalized Difference Vegetation Index (NDVI), comparing results obtained with images from the Operational Land Imager (OLI) onboard Landsat 8 satellite, Multispectral Instrument (MSI) onboard Sentinel-2A satellite, and data acquired through field surveys applied in a semi-detailed geological mapping of the Campo Formoso region in Brazil. Large areas of vegetation have predominantly been determined by climatic factors but this classification changes when zones of smaller dimensions are considered, as they may share similar climatic characteristics. Within the framework of the thematic mapping performed, the aspect with the greatest influence in forming associated vegetation is the nature of the lithotypes, whose influences determine the direct interferences of soil genesis. From a comparison of the results, it was possible to effectuate a quantified correlation between NDVI values of the distinct sensors and qualitatively suggest the magnitude of the proximity between the distribution of different phytophysiognomies and their intrinsic relationship with lithogeological expressions.