UTILIZING INSAR FOR GEOTECHNICAL ASSET MANAGEMENT OF LANDSLIDES IN COLORADO

Interferometric Synthetic Aperture Radar (InSAR) is a satellite-based remote sensing technique that has the ability to observe ground deformation at a centimeter-scale. Currently, AMEC Environment & Infrastructure, Inc is performing a Landslide Asset Management Pilot Project for the Colorado Department of Transportation (CDOT) to assess the applicability of incorporating InSAR technology into a risk based Geotechnical Asset Management plan. The goal of this project is to evaluate InSAR as a method for monitoring ground displacement. A primary objective is to determine if InSAR can be used as an indicator of slope or other geological hazard-related movement that could affect the conditions of highways or indicate a potential for a geotechnical asset condition change. For the pilot study, CDOT select three existing landslides to evaluate: 1) Slide Creek Slide (I-70 milepost 212), 2) Vail Golf Course Slide (I-70 milepost 177), and 3) Jackson Mountain Slide (US 160 milepost 151). The ground deformation interpreted by InSAR in this preliminary analysis has been shown to closely match existing data, including inclinometer data, for the three pilot areas and is able to delineate areas experiencing known and potentially unrecognized ground deformation. InSAR is also able to quantify a rate of movement as defined by line of site from the satellite that should prove to be useful in geotechnical asset management. Preliminary results including interferograms and deformation maps for the three pilot study locations will be discussed and indicate that InSAR can be a valuable tool for geotechnical asset management of landslides.