As a consequence of changing climatic conditions and land-use, large amounts of wood are introduced into streams more frequently. Large wood (LW) represent an important element in rivers, as it provides food and shelter for living organisms and regulates sediment budgets. During floods, the benefits of wood in rivers can quickly turn into challenges, when large amounts of wood are recruited from hillslopes, banks and bars; often affecting fluvial ecosystems, instream structures and human populations. An abundance of mobile wood in rivers increases the probability of collisions (impacts) with instream structures, but also the risk of LW accumulations at critical cross-sections (e.g. bridges, weirs, gorges). Depending on the porosity and packing of such LW accumulations, hydraulic flow conditions are significantly altered. Changing flow conditions may then affect channel morphology, which could increase the risk of flooding (damming effects), or structural failure (erosion, bridge scour).
To date, little knowledge is available about LW dynamics (e.g. roll, rotation, impact forces) and accumulation characteristics (e.g. volume, porosity, structural alignment). However, such knowledge is urgently needed to reduce the risk and damage potential of LW during catastrophic events, and help in the design of more resilient instream structures and well-functioning LW retention racks. This Marie Skłodowska-Curie Action (MSCA), titled “SmartWood_3D”, closes the gap in data availability by employing (1) innovative smart sensors, installed into prototype logs “SmartWood” for quantifying LW dynamics during transport, and (2) an image-based 3D-surveying method “Structure from Motion (SfM) photogrammetry” for the assessment of LW accumulation characteristics via 3D models (digital twin models). The gained data and results allow for novel insights into LW movement behavior, help in the prediction of actual impact forces and significantly advance the assessment of prototype LW accumulations, which will be of relevance for river managers and engineers to maintain the functionality of instream structures and safety for local communities.
The overall objectives of the MSCA are: (1) to introduce state-of-the-art technologies into LW research, in order to advance applicable methodologies and to provide an efficient workflow-pipeline, (2) to generate digital twin models of prototype LW accumulations, allowing for its most accurate assessment, (3) to quantify mobilisation, transport and depositional processes of LW, (4) to determine impact forces from collisions of LW with instream structures and channel boundaries, and (5) to merge the gained results for a more comprehensive understanding of complex flow-sediment-wood interaction processes in rivers.
