Use of elevation models for landform analysis by SEASAT-SAR imagery

Abstract

Within the framework of a long-term project aimed at the development of methods and techniques for regional land evaluation and land-use planning, an attempt has been made to assess the potential of SAR imagery as a source of information regarding landform characteristics which are directly or indirectly related to slope instability. In fact, geomorphic features, such as elevation, slope angle, local relief and drainage network, strongly control radar signature. Hence the feasibility of applying radar imagery to qualitatively and quantitatively detect and classify landslide and erosional phenomena. However, in hilly and mountainous areas very large geometrical and radiometrical distortions hamper to a great extent the interpretation of SAR data. Therefore, the development of efficient and suitable techniques is necessary for the correction of lay-over and shadowing, mainly due to local relief and ground slope. A numerical procedure has been implemented using both SEASAT-SAR data and a digital terrain model of a sample area, the Buonamico basin, Aspromonte, Southern Italy. Geometrical operators and interpolation functions have been employed in order to resample radar pixels into a new, topographically referenced, network. In addition, simple models have been applied to accomplish empirical radiometrical calibrations. As a result, some geomorphic features associated with slope instability phenomena have been detected.