LANDSLIDE MONITORING THROUGH LIDAR DIFFERENCING ALONG NATURAL GAS PIPELINES IN APPALACHIA

Buried natural gas pipelines throughout Appalachia and the Southeastern United States are vulnerable to geohazard risks, especially landslides. As landslides move, pipelines can bend and rupture, potentially causing human and environmental harm. Using Digital Elevation Models (DEM’s) derived from publicly and privately flown Light Imaging, Detection, and Ranging (LiDAR), we delineate landslide boundaries over thousands of miles of pipeline right of way. We maintain landslide inventory databases in GIS for several oil and gas companies and monitor landslide activity using multiple different tools. One of the most effective monitoring methods for monitoring extensive areas simultaneously is LiDAR Differencing, where high-resolution DEM rasters from two different collection dates are subtracted, displaying a heatmap of potential ground surface movement between the data collection dates. Using examples from a confidential client, the efficacy of this tool and our processes of landslide evaluation and documentation will be presented (identifying areas of suspected ground movement, updating landslide hazard data, and incorporating new landslide hazards into an existing client geodatabase). LiDAR Differencing is beneficial as it can encompass extensive areas of pipeline assets with relative ease. Using LiDAR Differencing rasters, we can isolate areas that have seen anthropogenic, hydrological, and geomorphic changes, including particularly active or newly formed landslides, thereby assisting pipeline operators in determining which of the thousands of mapped landslides pose a significant threat to pipeline integrity. As a result of these evaluations, landslides are visited in person to evaluate threats, and if necessary are mitigated and/or further monitored using other methods.