Evaluation of UAS photogrammetry and comparison to ground and aerial surveys for monitoring geomorphic condition of fine sediment deposits along the Colorado River
At the Grand Canyon Monitoring and Research Center (GCMRC), we are looking for affordable and efficient alternatives and augmentations to our current approaches to monitoring the geomorphic condition of sandbars, terraces and other fine-sediment deposits along the Colorado River in the Grand Canyon region, Arizona.
We use topographic change detection to monitor erosion and deposition of fine-grained fluvial sandbars and terraces. In-channel sandbars typically aggrade during periodic controlled floods from Glen Canyon Dam and erode during intervening dam operations. Terraces erode by gullying and aeolian (wind) processes. Monitoring is currently accomplished with a combination of topographic survey methods including conventional total station, ground-based lidar, and lidar and digital photogrammetry from manned aerial platforms. We are specifically interested in using structure from motion (SfM) photogrammetry using imagery collected from UAV platforms to derive DEMs of our study areas along the river. This will be a less expensive and more efficient approach to acquire digital topographic data from near-nadir perspectives at greater spatial extent than ground-based lidar, and less expensive at comparable resolution to aerial lidar and/or automated digital photogrammetry. It will require fewer technicians on the ground and result in less site disturbance by trampling than conventional surveys and ground-based lidar. We propose that the USGS UAS program acquire data at monitoring sites on the Colorado River in Glen Canyon and produce DEMs for us to evaluate relative to our current data for monitoring topographic change. If through the proposed proof of concept demonstration by the USGS UAS program, the UAS-based SfM method proves to be complementary to, better, more affordable, or more efficient than our current methods, this would allow us to adopt the method within our operations at GCMRC and in conjunction with the USGS UAS program. In addition to monitoring terraces and fine-sediment deposits along the Colorado River in Glen Canyon, we have active sandbar, riparian, and cultural resource monitoring programs that extend from Glen Canyon Dam downriver through Grand Canyon to Lake Mead that would be poised to adopt affordable and efficient UAS monitoring.
At the Grand Canyon Monitoring and Research Center (GCMRC), we are looking for affordable and efficient alternatives and augmentations to our current approaches to monitoring the geomorphic condition of sandbars, terraces and other fine-sediment deposits along the Colorado River in the Grand Canyon region, Arizona.
We use topographic change detection to monitor erosion and deposition of fine-grained fluvial sandbars and terraces. In-channel sandbars typically aggrade during periodic controlled floods from Glen Canyon Dam and erode during intervening dam operations. Terraces erode by gullying and aeolian (wind) processes. Monitoring is currently accomplished with a combination of topographic survey methods including conventional total station, ground-based lidar, and lidar and digital photogrammetry from manned aerial platforms. We are specifically interested in using structure from motion (SfM) photogrammetry using imagery collected from UAV platforms to derive DEMs of our study areas along the river. This will be a less expensive and more efficient approach to acquire digital topographic data from near-nadir perspectives at greater spatial extent than ground-based lidar, and less expensive at comparable resolution to aerial lidar and/or automated digital photogrammetry. It will require fewer technicians on the ground and result in less site disturbance by trampling than conventional surveys and ground-based lidar. We propose that the USGS UAS program acquire data at monitoring sites on the Colorado River in Glen Canyon and produce DEMs for us to evaluate relative to our current data for monitoring topographic change. If through the proposed proof of concept demonstration by the USGS UAS program, the UAS-based SfM method proves to be complementary to, better, more affordable, or more efficient than our current methods, this would allow us to adopt the method within our operations at GCMRC and in conjunction with the USGS UAS program. In addition to monitoring terraces and fine-sediment deposits along the Colorado River in Glen Canyon, we have active sandbar, riparian, and cultural resource monitoring programs that extend from Glen Canyon Dam downriver through Grand Canyon to Lake Mead that would be poised to adopt affordable and efficient UAS monitoring.