The Wyoming DOT (WYDOT) recently contracted with Woolpert to perform aerial mapping services to assess three landslide-prone areas along a 10-mile stretch of U.S. 26 in the northwest part of the state.
The region is near the Shoshone National Forest boundary, east of Togwotee Pass and west of Dubois. The site is close to Yellowstone National Park and along the Continental Divide.
According to Woolpert, geologic conditions have caused multiple landslides in this region over the past decade, with some areas showing up to a foot of geologic movement during that span. Woolpert was brought in to utilize the firm’s aircraft, its Leica TerrainMapper LiDAR sensor and its in-house acquisition services to deliver classified LiDAR data and aerial imagery, which WYDOT can use to evaluate, prioritize, and mitigate possible landslide events.
“Multiple passes were made over these three areas to collect data that met or exceeded the requested 50 points per square meter,” Woolpert Project Manager Chris Raml said in a statement. “The extremely dense, raw, and bare-earth point clouds that we produced enabled WYDOT’s Photogrammetry and Surveys Section to create well-defined digital terrain models and triangulated irregular network models specific to the needs of the department.”
These models created a detailed baseline of valuable data that will be compared to models created through future acquisitions to determine the slide movement, volume, and rate at which the earth is moving. TerrainMapper’s integrated RCD30 camera simultaneously acquired high-definition, 3-in. ground sample distance imagery that was rectified and used to colorize the LiDAR point cloud.
According to Woolpert, advanced mapping data like this has become essential to multiple local, state, and federal applications, including disaster resilience.