Use of UVP to investigate the evolution of bed configuration

Ultrasonic Velocity Profiler (UVP) is a widely used instrument which allows the determination of the complete velocity profile. UVP can also measure the echo amplitude in the mean time. In this study, it is intended to use the UVP transducers in an indirect way to detect the bottom surface by orienting them vertically downward. Preliminary experiments were conducted with immobile bed by using uniform, non-uniform sediment as well as wooden and plastic surface. It was appeared that the first remarkable peak corresponds to the bottom surface. The time variations of local bed elevations were registered by applying this technique in order to determine the erosion and deposition around a bridge pier and local scour around a horizontal submerged pipe. It was revealed that the so registered scour depths were in good agreement with those observed during the experiments. Consequently, it is demonstrated that time varied bed elevations can be measured via the first peak value of echo amplitudes by placing UVP transducers vertically.