Drone- and ground-based measurements of velocity, depth, and discharge collected during 2017-18 at the Arkansas and South Platte Rivers in Colorado and the Salcha and Tanana Rivers in Alaska, USA

The U.S. Geological Survey (USGS) is actively investigating the use of innovative remote-sensing techniques to estimate surface velocity and discharge of rivers in ungaged basins and river reaches that lack the infrastructure to install conventional streamgaging equipment. By coupling discharge algorithms and sensors capable of measuring surface velocity, streamgage networks can be established in regions where data collection was previously impractical or impossible. One of the remote-sensing techniques uses a Doppler (velocity) radar (QCam) mounted and integrated on a small unmanned aircraft system (sUAS or drone). QCam measures the along-track surface velocity by spot dwelling in a river cross section at a vertical where the maximum surface velocity is recorded. To evaluate the extensibility of the method, five science flights were conducted on four rivers of varying size including the Arkansas and South Platte Rivers in Colorado and the Salcha and Tanana Rivers in Alaska. QCam surface velocities and QCam river discharges were compared to conventional streamgaging methods.