The Effect of Roughness Spacing and Size on the Lateral Deflection of Bedload Particles

Abstract

Bedrock erosion can be divided into the vertical incision and lateral erosion. Vertical incision deepens the valleys, steepens the hillslopes, and is thus a primary process for landscapes to respond to spatial-temporal variations of tectonic deformation (e.g.,

Influence of Rarely Mobile Boulders on Channel Width and Slope: Theory and Field Application

“…The sideward deflection length d is expected to vary in space and time and likely depends on channel hydraulics, roughness, and sediment supply (Beer et al, 2017;Fuller et al, 2016;He et al, 2021;Li et al, 2020;Turowski, 2018Turowski, , 2020. However, for simplicity, the current analysis assumes that d is constant and uniform.…”

“…A field study in a bedrock channel gorge in Switzerland showed that wall erosion increases in proximity to roughness elements (Beer et al., 2017). Although recent studies proposed a positive relationship between lateral erosion and channel roughness (Fuller et al., 2016; He et al., 2021; Li et al., 2020; Turowski, 2018), the precise nature of this relationship and its relation to large boulders remains to be explored (Turowski, 2020).…”

“…The tools, cover, and "tools and cover" models additionally scale linearly with the square root of boulder-bed to boulder-free deflection lengths, which we assumed to be one, that is, d b = d. However, previous research implies that the deflection length ratio could differ from one (Beer et al, 2017;Fuller et al, 2016;He et al, 2021;Li et al, 2020). The influence of boulder concentration on sediment deflection is unknown, but a positive correlation may account for channel widening for the above-discussed models beyond the predictions with d b = d.…”

Numerical Simulation of Flow Resistance due to the Limnoperna fortunei Attachment

“…In Chen et al (2019)'s study, different sizes of streambed sediment were scanned and reconstructed based on structure-from-motion (SfM) photogrammetry, and they discovered that the stream flow resistance was mainly controlled by the standard deviation of the bed elevation normalized by water depth. As for these aquatic organisms, the species, sizes, densities and distribution may play important roles in flow resistance (Ghisalberti, 2009;Wang et al, 2010;Mossa et al, 2017;He et al, 2021). Therefore, some hydraulic models incorporate the geometric features of the roughness elements to increase the prediction of flow resistance (D'Ippolito et al, 2021).…”