Investigating the Deformation History and Failure Mechanism of Heifangtai Loess Landslide, China with Multi-Source Sar Data

Abstract

Multi-source Synthetic Aperture Radar (SAR) datasets are used to investigate the deformation history and failure mechanism of small-scale loess landslide in the Heifangtai loess terrace, Gansu province, China. A total of 65 SAR datasets acquired by L-band ascending ALOS/PALSAR, X-band descending TerraSAR-X and C-band descending Sentinel-1A/B covering the different periods of Heifangtai terrace are fully exploited. In addition, groundwater level data are also involved to analyze the failure mechanism of loess landslide. The displacements occurred during the past eleven years were quantitatively identified for firstly by InSAR technique. The results show that three slopes, failed on October 1, 2017 had large cumulative deformations from January 2016 to November 2016. The acceleration dates of the deformation for the three slopes were successfully captured by Sentinel-1A/B data. Furthermore, the result shows that the magnitude of the landslide deformation is closely correlated to the groundwater level variation.