Carmen Quintano Pastor

Radiometric rotation technique to monitor degradation and regeneration features in Brazilian semi-arid region

The objective is to present a technique on “Radiometric rotation controlled by a no-change axis (RCEN)”, using a multi-temporal comparison between ETM+/LANDSAT-7 and CCD/CBERS-2 images. The area under study is located in the central of Brazilian semi-arid region, whose landscape is dominated by steppe savanna (caatinga). The result of RCEN technique is an change detection-image, whose continuous image (floating-point) was transformed into a thematic image through the procedure of slicing and labelling. This allowed the spectral discrimination in five thematic classes: two related to degradation, two referring to regeneration and one of no-change. A map of changes 2001/2004 was generated, illustrating the distribution of these thematic categories mentioned at the caatinga zone , which is under a strong impact due to agriculture activities for subsistence, besides pastureland for goats in the community fields.