Slope risk management using InSAR technology

Interferometric Synthetic Aperture Radar (InSAR) innovative satellite technology is becoming popular for the measurement of displacement and velocity of ground movement over a large area in open cut mining, tunnelling, landslide and infrastructure projects in many parts of the world. Transport for NSW (TfNSW) and Ventia are piloting a trial InSAR project for monitoring slopes and cuttings from five (5) locations across the NSW road and rail corridors. TfNSW is managing about 9000 registered slopes and cuttings across the road and rail corridors with increasing challenges, especially with a rise in slope and cutting failure incidents in recent years in extreme weather conditions (e.g., floods). Traditional investigation methods have limitations and subjectivity which sometimes leading to undetected or unaddressed slope/cutting failures. This paper presents details of InSAR monitoring results from a period of May’23 to April’24 for slopes/cuttings in areas of Waterfall Way, NSW. The results also compare with historical movements/failure of a known down slope. Following the monitoring results, it is found that InSAR is capable of measuring displacement and vector ground movement with times over a large area of slopes/cuttings. The results also suggest that InSAR technology is likely to provide significant values for slope risk management, improved safety for road/rail users, reduced maintenance cost and greater value for money in managing slopes and cuttings of TfNSW.