Landslide Susceptibility Assessment in the Alpine and Canyon Areas based on Ascending and Descending InSAR data

[Objective]In recent years, Interferometric Synthetic Aperture Radar (InSAR) data reflecting surface deformation factors have gradually been introduced into landslide susceptibility assessment as factors reflecting surface deformation. However, these studies did not consider differences in SAR images. Especially in the alpine and canyon area, the imaging effect of InSAR ascending and descending varies greatly, and there is a large error in the response to surface deformation. [Methods]In this paper, the reservoir area of Xiangbiling Hydropower Station was selected as the research area. After the correlation analysis of index factors, 11 inducing factors and InSAR deformation data related to landslide in alpine and canyon areas were selected for landslide susceptibility evaluation. [Results]Comparing whether to use deformation data and using different deformation data, it is found that supplementing the sparse ascending data of sampling points in the susceptibility evaluation will reduce the accuracy of susceptibility evaluation, and the descending SAR data with more sampling points can improve the susceptibility accuracy by 2.7% to a certain extent (AUC=0.9248).[Conclusion]Therefore, the introduction of InSAR deformation data as a factor in landslide susceptibility assessment will affect the evaluation results, and it is necessary to select appropriate InSAR deformation data to improve the accuracy of susceptibility evaluation.