Characterizing landscape and land clover in the Azores with RADARSAT-1 imagery

Landscape and land cover patterns of a selected group of islands in the Azores Archipelago have been assessed on the basis of synthetic aperture radar (SAR) image data of Canada's RADARSAT-1 satellite. These data were acquired as part of RADARSAT-1 baseline data acquisitions called Background Mission. RADARSAT-1 SAR allows for the discrimination of landcover units associated with steep coastal cliffs, dense montane forests, localized areas of intense agriculture, recently active volcanic terrain, and narrow gravel beaches. Human dwellings often appear as distinct targets of bright radar response and can be easily delineated. Despite the presence of a continuous veneer of vegetation, the underlying volcanic terrane and associated landforms, particularly the Holocene caldera structures, are discernable on RADARSAT-1 images. The erosional signatures of gullies and other drainage systems are apparent, as are escarpments with local slopes at or above the angle of repose. Residual cloud forests on several of the islands are mappable, although there is evidence for spatial fragmentation. The all-weather, multi-mode imaging capabilities make RADARSAT-1 a useful tool for studying landcover variations of anthropogenic and natural causes in this perennially cloud-covered region of the world.