Early Detection of Geological Hazards in Longmenshan-Dadu River Area Using Various InSAR Techniques

Interferometric synthetic aperture radar (InSAR) technology is an important method to detect surface deformation. However, differential InSAR (D-InSAR), small baseline subset InSAR (SBAS-InSAR) and permanent scatters InSAR (PS-InSAR) have their own advantages and disadvantages in the early investigation of geological hazards. 127 ALOS-2 images and 96 Sentinel-1 images are processed by different InSAR techniques, and 840 surface deformations are interpreted in Longmenshan-Dadu River area. Through field investigation, it is found that about 70% of the interpreted areas show signs of deformation. The relationship between the distribution of deformation area, stratum structure, lithology and active fault is analyzed. The different InSAR monitoring results in typical deformation area are compared and analyzed. The consistency, accuracy and reliability of different InSAR technologies in the application of surface deformation monitoring are verified. We provide a reference for the engineering application in early detection of geological hazards using various InSAR techniques.