Combined interpretation of optical and SAR data for landslide mapping
Hölbling, D., Friedl, B., Dittrich, J., Cigna, F., Pedersen, G.B.M.
Sep - 2018

Event Title : 3rd Regional Symposium on Landslides in the Adriatic Balkan Region
Published in: Advances in Landslide Research. Proceedings of the 3rd Regional Symposium on Landslides in the Adriatic-Balkan Region
type: Conference Proceedings

In this study we present three case studies addressing the combination of optical and synthetic aperture radar (SAR) data in integrated landslide mapping by making use of an object-based image analysis (OBIA) framework. For the first test site, located in northern Italy, SPOT-5 imagery was used together with a digital elevation model (DEM) to map landslides with OBIA. Deformation rates were derived using Persistent Scatterer Interferometry (PSI) processing of ERS-1/2, ENVISAT and RADARSAT-1 data. The combined interpretation of landslide boundaries detected through OBIA with PSI-derived surface displacements facilitated the updating of the pre-existing landslide maps. The second example comprises the investigation of typhoon-triggered landslides and debris flows in southern Taiwan. Through the integration of multispectral information (SPOT-5), SAR intensity values (TerraSAR-X) and DEM derivatives in an OBIA environment, landslides could be examined more efficiently than relying on single data sources only. The multiple data analysis was especially useful for delineating single, large-scale landslides. Finally, a third case study was performed in south-east Iceland. We investigated how SAR coherence information and optical imagery could be synergistically used to assist in landslide mapping in glacio-volcanic landscapes.

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