Last week, we looked at benefits from synergies between unmanned aerial systems (UAS), 3D modeling, Construction Management/General Contractor (CM/GC) project delivery, and e-Construction in Utah. UAS can also create new opportunities for agencies to enhance other critical project activities in ways that benefit both the agency staff and the natural environment.
UAS have been a beneficial tool for the Utah Department of Transportation (UDOT) in its environmental data collection efforts. According to UDOT, UAS allow the department to collect highly accurate, detailed imagery and dense point clouds in surveys. This has increased the quality, speed, and safety of data collection. On past projects, it was difficult for surveyors to navigate through dense vegetation. At times, this required surveyors to crawl under vegetation to find locations where elevation points could be collected. Older surveying technology made it necessary to cut through vegetation to obtain line-of-sight, or to achieve an open sky canopy to collect data. This made it very difficult, if not impossible, to collect data using conventional surveying methods in sensitive areas.
UAS-based light detection and ranging (LiDAR) has been an extremely efficient and valuable tool for the department. UDOT has used LiDAR to penetrate through vegetation, which has drastically increased the quality of data sets. It also allows data collection without disrupting the environment. At the US-40 Strawberry Reservoir passing lanes – wetland mitigation project, the area had thick vegetation and an accurate survey of the stream bank was a project requirement. Conventional surveying methods would have taken a three-person crew several weeks to obtain an accurate survey at this site. Using UAS, UDOT was able to collect the survey data in only a few hours. It also provided a higher density of points, which created a more accurate data set than was ever possible using traditional methods. UDOT plans to continue flying this area periodically to analyze changes over time. By using UAS LiDAR, UDOT predicts saving over $2.5 million within 5 years on transportation projects.
Other States are also interested in using UAS for environmental applications. The Nebraska Department of Transportation has developed a scope of services to build a wetlands predictive model using UAS-collected data (multi-spectral imagery and LiDAR). During the 2020 growing season, they will test this new procedure against conventional processes at five project sites.