High-Precision Dam Deformation Monitoring Using Advanced InSAR Techniques: A Review

Interferometric Synthetic Aperture Radar (InSAR) has become a key technology for high-precision dam deformation monitoring, offering millimeter-level accuracy, broad spatial coverage, and all-weather operability. This review systematically synthesizes advancements in several InSAR techniques, including DInSAR, PS-InSAR, SBAS-InSAR, MT-InSAR, and GB-SAR, and illustrates their applications across various dam types through case studies of the Xiaolangdi, Banqiao, Pertusillo, Shuibuya, La Viñuela, Liuduzhai, and Enguri dams. These studies highlight InSAR’s effectiveness in detecting crest deformation, slope instability, settlement patterns, and hydrostatic-thermal responses, with results validated against GNSS and levelling benchmarks. Despite challenges such as atmospheric noise and decorrelation, integrating InSAR with numerical modeling and multi-sensor data fusion has significantly improved diagnostic reliability. With the advent of new satellite missions and artificial intelligence-based time-series analysis, InSAR is poised to become a cornerstone of modern dam safety frameworks, enabling proactive risk management through near-real-time deformation intelligence.