Applied Sciences / Assessment of landslide-induced geomorphological changes in Hítardalur Valley, Iceland, using Sentinel-1 and Sentinel-2 data

• Published in: Applied Sciences
• Main Authors: Dabiri, Zahra, Hölbling, Daniel, Abad, Lorena, Helgason, Jón Kristinn, Sæmundsson, Þorsteinn, Tiede, Dirk
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: object-based image analysis; Sentinel-1; Sentinel-2; digital elevation model; InSAR; landslide; landslide-dammed lake; river; Iceland; Dammed Lake; Hítará; Hítardalur
• Online Access: https://resolver.obvsg.at/urn:nbn:at:at-ubs:3-18933; https://doi.org/10.3390/app10175848; https://eplus.uni-salzburg.at/doi/10.3390/app10175848

Landslide mapping and analysis are essential aspects of hazard and risk analysis. Landslides can block rivers and create landslide-dammed lakes, which pose a significant risk for downstream areas. In this research, we used an object-based image analysis approach to map geomorphological features and related changes and assess the applicability of Sentinel-1 data for the fast creation of post-event digital elevation models (DEMs) for landslide volume estimation. We investigated the Hítardalur landslide, which occurred on the 7 July 2018 in western Iceland, along with the geomorphological changes induced by this landslide, using optical and synthetic aperture radar data from Sentinel-2 and Sentinel-1. The results show that there were no considerable changes in the landslide area between 2018 and 2019. However, the landslide-dammed lake area shrunk between 2018 and 2019. Moreover, the Hítará river diverted its course as a result of the landslide. The DEMs, generated by ascending and descending flight directions and three orbits, and the subsequent volume estimation revealed that—without further post-processing—the results need to be interpreted with care since several factors influence the DEM generation from Sentinel-1 imagery.