ABSTRACT
A novel pressure sensing system specialized for ecohydraulic field measurement, “sphera”, was developed to record synchronized three-point absolute pressure measurement at 20 or 50 Hz. Three pressure sensors were embedded into a concrete body with a cobble-like shape. The device was used to record the pressure time series of the near-bed pressure field. Two sphera devices were used to investigate the flow feature in a Japanese gravel bed river with engineering works recently implemented to activate morphological change at the site. In conjunction with sphera, hydrophones were used to detect the acoustic signatures caused by bedload transport. The method was applied in a field campaign during a controlled water release from a dam. Near-bed pressure time series profiles and sediment transport processes were deduced by the recorded synchronized pressure signatures and the sediment transport signatures.
