InSAR Evaluation of Landslides and Alternative Transportation Routes

Interferometric Synthetic Aperture Radar (InSAR) was used to monitor ground movement in Badlands National Park. InSAR is an innovative method that can be used to detect, map and measure movement without the need of survey targets or ground-based instruments. Using current and historic data sets, InSAR was applied in observing landslides that impact the Park's access road, and in evaluating possible alternate alignments. Although traditional geotechnical instruments have monitored the road for years, the total area assessed using InSAR is larger than could practically be studied by these instruments. The results are on an interactive website and show that nearby landslides are not interrelated, the boundaries of a large, slow moving landslide agree with data from instruments and observations, and the amount of movement occurring along the existing alignment may be typical for the area. Availability of historic data, unexplainable ground movement and low coherence were some difficulties encountered.