MAPPING OF LAVA FLOWS THROUGH SPOT IMAGES - AN EXAMPLE OF THE SABANCAYA VOLCANO (PERU)

SPOT XS and Panchromatic images are used jointly in order to map the l ava flows of the Nevado Sabancaya volcano (southern Peru). This mappin g is achieved through two types of processing: the unsupervised multis pectral clustering applied to the XS image, and some specific methods of image analysis (mathematical morphology, convolution filtering) app lied to the Panchromatic image. The resulting images allowed us to ide ntify flows and the two main morphological features of the flow areas: lava reliefs and flow lines. Therefore, our experience shows that ima ge analysis can be a tool for thematic mapping which displays more cap abilities than photointerpretation.