Effects of large wood (LW) blockage on bedload connectivity in the presence of a hydraulic structure

Large wood (LW) commonly forms log jams, influencing bed composition and biota via complex flow-sediment-wood interactions. A LW blockage, often induced by river-crossing infrastructure, can strongly alter channel hydraulics sediment transport patterns, thus inducing a ‘forced’ morphology. For studying the deposition of bedload gravel fractions in presence rigid jam, novel experimental setup is presented. Using mobile stream table, effects channel-spanning blockage (a ‘dam jam’), resting at bridge pier, on scour dynamics are examined. Changes morphology were measured using Structure from Motion (SfM) photogrammetry manually obtained measurements. experiment without accumulation place, natural was observed over entire length - about 20% fed colour recovered trap outlet, while total interruption occurred accumulation, resulting trapping all material upstream obstructed cross-section. The volumetric deviation between SfM manual measurements less than 0,4%. porosity characteristics analysed meshing techniques. With our experiments, we demonstrated that relatively high jam has significant impact By interrupting hydraulic energy gradient, movement coarse damped, forcing initiating development wedge infrastructure. Our quantitative results provide new insights into how force (particularly storage) through alteration hydraulics. We further elaborate laboratory-based techniques be used to enhance current understanding interaction processes engineered in-stream structures.