Image processing system for measuring surface velocities

Image processing techniques for measuring dynamic changes of surface velocities in rill flows are described. Surface velocities were determined by the movement of small wooden beads as they floated past a video camera. The system was evaluated for accuracy using a well defined velocity medium. Algorithms were then tested using water flows in a small rectangular channel. Results indicated that the system was an accurate and efficient technique for measuring surface velocities. The accuracy of the system was estimated as ±10 mm/s.