Variáveis geomorfométricas locais e sua relação com a vegetação da região do interflúvio Madeira-Purus (AM-RO)

The objective of this work was to assess the potential of geomorphometric variables, derived from SRTM (Shuttle Radar Topographic Mission) data, to help identify vegetation types in the Amazonian Madeira-Purus interfluvio region. A RADAMBRASIL project vegetation map was used as a reference and the geomorphometric variables (elevation, slope, aspect and profile and plan curvatures) were compared to the mapped units. Analyses indicated vegetation types easily discriminated, depending on the topographic position. The variables of elevation, slope and aspect were the most important for their high discrimination power of the vegetation types. Although geomorphometric data are recognized as having strong potential for characterizing vegetation, this was not shown in the results, due to the mismatching of variability scales between the two sources of data; large units tend to exhibit similar distribution patterns of geomorphometry, and comprise classes with different responses for geomorphometric constraints. Discriminant analyses of geomorphometric variables permitted vegetation mapping up to the sub-physiognomy levels.