A Methodology to Support the Analysis of Environmental Degradation Using Noaa Avhrr Data

This work proposes a particular approach to assess information about soil degradation from NOAA/AVHRR data. As erosive processes change physical and chemical properties of the soil, altering, consequently, the superficial color, monitoring the change in color over time can help to identify and analyze those processes. A methodology for the determination of soil color from NOAA/AVHRR data was devised, based on a theoretical model that establishes the relationship among the soil color, described in the Munsell Color System, vegetation indices, surface temperature and emissivity. The test area of the methodology was the Upper Taquari Basin, in the central region of Brazil, where the lack of land use planning and soil conservation practices have been causing severe erosion and siltation of the water bodies, increasing the spatial and temporal significance of flood events over the Brazilian Pantanal region. The tests showed that the methodology was efficient in determining soil color using the NDVI, MSAVI and PAVI vegetation indices. Best results were obtained for the hue color component. To further test the methodology, the calculated digital color models were compared with the characteristic color of soil classes in the Upper Taquari Basin.