ABSTRACT
Besides enhancing the ecological diversity of fluvial environments, large wood (LW) abundance in rivers heavily affects channel morphology and flow hydraulics. The formation of LW accumulations at constricted cross-sections in the channel and the resulting local geomorphic effects are still poorly understood to date. In this study, a flume experiment was conducted using live-bed conditions that are representative of a New Zealand headwater river. The model includes an abundance of scaled LW elements (wooden dowels) and a one-lane bridge with 3-pier row. Model runs leveraged the use of novel SmartWood - scaled LW elements with embedded nine-degree-of-freedom smart sensors - for quantification of LW transport and accumulation dynamics. We use novel Structure from Motion (SfM) data for accurate quantification of changes in channel morphology and for providing information about scour depth and net volume change. Results have revealed that, during low discharges, logs are more likely to be accumulated at an orientation perpendicular to the flow direction. Otherwise, logs seem to be suitable to accumulate at a random orientation during high discharges. This study aims to improve our current understanding of complex interaction processes between flow, wooden elements and sediments.
