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All Outputs (27)

Improving predictions of critical shear stress in gravel bed rivers: Identifying the onset of sediment transport and quantifying sediment structure (2024)
Journal Article
Hodge, R. A., Voepel, H. E., Yager, E. M., Leyland, J., Johnson, J. P. L., Sear, D. A., & Ahmed, S. (2024). Improving predictions of critical shear stress in gravel bed rivers: Identifying the onset of sediment transport and quantifying sediment structure. Earth Surface Processes and Landforms, 49(8), 2517-2537. https://doi.org/10.1002/esp.5842

Understanding when gravel moves in river beds is essential for a range of different applications but is still surprisingly hard to predict. Here we consider how our ability to predict critical shear stress (τ c ) is being improved by recent advances... Read More about Improving predictions of critical shear stress in gravel bed rivers: Identifying the onset of sediment transport and quantifying sediment structure.

Pro+: Automated protrusion and critical shear stress estimates from 3D point clouds of gravel beds (2024)
Journal Article
Yager, E. M., Shim, J., Hodge, R., Monsalve, A., Tonina, D., Johnson, J. P. L., & Telfer, L. (2024). Pro+: Automated protrusion and critical shear stress estimates from 3D point clouds of gravel beds. Earth Surface Processes and Landforms, 49(7), 2155-2170. https://doi.org/10.1002/esp.5822

The dimensionless critical shear stress (τ*c) needed for the onset of sediment motion is important for a range of studies from river restoration projects to landscape evolution calculations. Many studies simply assume a τ*c value within the large ran... Read More about Pro+: Automated protrusion and critical shear stress estimates from 3D point clouds of gravel beds.

The influence of bedrock river morphology and alluvial cover on gravel entrainment: Part 1. Pivot angles and surface roughness (2022)
Journal Article
Buechel, M. E., Hodge, R. A., & Kenmare, S. (2022). The influence of bedrock river morphology and alluvial cover on gravel entrainment: Part 1. Pivot angles and surface roughness. Earth Surface Processes and Landforms, 47(14), 3361-3375. https://doi.org/10.1002/esp.5463

Sediment entrainment in bedrock rivers is a key process for river incision and landscape evolution. Bedrock riverbeds are typically comprised of both exposed bedrock and alluvial patches, meaning grains can be entrained from positions on both surface... Read More about The influence of bedrock river morphology and alluvial cover on gravel entrainment: Part 1. Pivot angles and surface roughness.

The influence of bedrock river morphology and alluvial cover on gravel entrainment: Part 2. Modelling critical shear stress (2022)
Journal Article
Hodge, R., & Buechel, M. (2022). The influence of bedrock river morphology and alluvial cover on gravel entrainment: Part 2. Modelling critical shear stress. Earth Surface Processes and Landforms, 47(14), 3348-3360. https://doi.org/10.1002/esp.5462

The critical shear stress (τc) at which grains are entrained on a bedrock surface is important for determining how bedrock rivers evolve through changes in sediment cover and bedrock erosion. The difference in τc for grains on bedrock and alluvial su... Read More about The influence of bedrock river morphology and alluvial cover on gravel entrainment: Part 2. Modelling critical shear stress.

The Influence of In‐Channel Obstacles on River Sound (2022)
Journal Article
Osborne, W. A., Hodge, R. A., Love, G. D., Hawkin, P., & Hawkin, R. E. (2022). The Influence of In‐Channel Obstacles on River Sound. Water Resources Research, 58(4), Article e2021WR031567. https://doi.org/10.1029/2021wr031567

The sound of a river can change from a babbling brook to a thunderous torrent, and we have previously shown that there is the potential to predict river stage from the river's sub-aerial sound. Here, we examined how alterations in channel configurati... Read More about The Influence of In‐Channel Obstacles on River Sound.

Babbling brook to thunderous torrent: Using sound to monitor river stage (2021)
Journal Article
Osborne, W. A., Hodge, R. A., Love, G. D., Hawkin, P., & Hawkin, R. E. (2021). Babbling brook to thunderous torrent: Using sound to monitor river stage. Earth Surface Processes and Landforms, 46(13), 2656-2670. https://doi.org/10.1002/esp.5199

The passive, ambient sound above the water from a river has previously untapped potential for determining flow characteristics such as stage. Measuring sub-aerial sound could provide a new, efficient way to continuously monitor river stage, without t... Read More about Babbling brook to thunderous torrent: Using sound to monitor river stage.

Inertial drag and lift forces for coarse grains on rough alluvial beds measured using in-grain accelerometers (2020)
Journal Article
Maniatis, G., Hoey, T., Hodge, R., Rickenmann, D., & Badoux, A. (2020). Inertial drag and lift forces for coarse grains on rough alluvial beds measured using in-grain accelerometers. Earth Surface Dynamics, 8, 1067-1099. https://doi.org/10.5194/esurf-8-1067-2020

Quantifying the force regime that controls the movement of a single grain during fluvial transport has historically proven to be difficult. Inertial micro-electromechanical system (MEMS) sensors (sensor assemblies that mainly comprise micro-accelerom... Read More about Inertial drag and lift forces for coarse grains on rough alluvial beds measured using in-grain accelerometers.

X-ray computed tomography reveals that grain protrusion controls critical shear stress for entrainment in fluvial gravels (2019)
Journal Article
Hodge, R., Voepel, H., Leyland, J., Sear, D., & Ahmed, S. (2020). X-ray computed tomography reveals that grain protrusion controls critical shear stress for entrainment in fluvial gravels. Geology, 48(2), 149-153. https://doi.org/10.1130/g46883.1

The critical shear stress (τc) for grain entrainment is a poorly constrained control on bedload transport rates in rivers. Direct calculations of τc have been hindered by the inability to measure the geometry of in situ grains; i.e., the shape and lo... Read More about X-ray computed tomography reveals that grain protrusion controls critical shear stress for entrainment in fluvial gravels.

Development of a vector-based 3D grain entrainment model with application to X-ray computed tomography (XCT) scanned riverbed sediment (2019)
Journal Article
Voepel, H., Leyland, J., Hodge, R., Ahmed, S., & Sear, D. (2019). Development of a vector-based 3D grain entrainment model with application to X-ray computed tomography (XCT) scanned riverbed sediment. Earth Surface Processes and Landforms, 44(15), 3057-3077. https://doi.org/10.1002/esp.4608

Sediment transport equations typically produce transport rates that are biased by orders of magnitude. A causal component of this inaccuracy is the inability to represent complex grain‐scale interactions controlling entrainment. Grain‐scale incipient... Read More about Development of a vector-based 3D grain entrainment model with application to X-ray computed tomography (XCT) scanned riverbed sediment.

Flow resistance and hydraulic geometry in bedrock rivers with multiple roughness length scales (2019)
Journal Article
Ferguson, R., Hardy, R., & Hodge, R. (2019). Flow resistance and hydraulic geometry in bedrock rivers with multiple roughness length scales. Earth Surface Processes and Landforms, 44(12), 2437-2449. https://doi.org/10.1002/esp.4673

Many models of incision by bedrock rivers predict water depth and shear stress from discharge; conversely, palaeoflood discharge is sometimes reconstructed from flow depth markers in rock gorges. In both cases assumptions are made about flow resistan... Read More about Flow resistance and hydraulic geometry in bedrock rivers with multiple roughness length scales.

A probabilistic framework for the cover effect in bedrock erosion (2017)
Journal Article
Turowski, J. M., & Hodge, R. (2017). A probabilistic framework for the cover effect in bedrock erosion. Earth Surface Dynamics, 5(2), 311-330. https://doi.org/10.5194/esurf-5-311-2017

The cover effect in fluvial bedrock erosion is a major control on bedrock channel morphology and long-term channel dynamics. Here, we suggest a probabilistic framework for the description of the cover effect that can be applied to field, laboratory,... Read More about A probabilistic framework for the cover effect in bedrock erosion.

Bed load tracer mobility in a mixed bedrock/alluvial channel (2017)
Journal Article
Ferguson, R., Sharma, B., Hodge, R., Hardy, R., & Warburton, J. (2017). Bed load tracer mobility in a mixed bedrock/alluvial channel. Journal of Geophysical Research: Earth Surface, 122(4), 807-822. https://doi.org/10.1002/2016jf003946

The presence of bare or partially-covered rock in an otherwise alluvial river implies a downstream change in transport capacity relative to supply. Field investigations of this change and what causes it are lacking. We used two sets of magnet-tagged... Read More about Bed load tracer mobility in a mixed bedrock/alluvial channel.

Flow resistance and hydraulic geometry in contrasting reaches of a bedrock channel (2017)
Journal Article
Ferguson, R., Sharma, B., Hardy, R., Hodge, R., & Warburton, J. (2017). Flow resistance and hydraulic geometry in contrasting reaches of a bedrock channel. Water Resources Research, 53(3), 2278-2293. https://doi.org/10.1002/2016wr020233

Assumptions about flow resistance in bedrock channels have to be made for mechanistic modeling of river incision, paleoflood estimation, flood routing, and river engineering. Field data on bedrock flow resistance are very limited and calculations gen... Read More about Flow resistance and hydraulic geometry in contrasting reaches of a bedrock channel.

Calculating the explicit probability of entrainment based on inertial acceleration measurements (2016)
Journal Article
Maniatis, G., Hoey, T., Hassan, M., Sventek, J., Hodge, R., Drysdale, T., & Valyrakis, M. (2017). Calculating the explicit probability of entrainment based on inertial acceleration measurements. Journal of Hydraulic Engineering, 143(4), Article 04016097. https://doi.org/10.1061/%28asce%29hy.1943-7900.0001262

A new method for the approximation of the explicit probability of entrainment for individual coarse particles is presented. The method is based on the derivation of inertial acceleration measurements, space-state approximation of the dynamics close t... Read More about Calculating the explicit probability of entrainment based on inertial acceleration measurements.

A Froude-scaled model of a bedrock-alluvial channel reach: 1. Hydraulics (2016)
Journal Article
Hodge, R., & Hoey, T. (2016). A Froude-scaled model of a bedrock-alluvial channel reach: 1. Hydraulics. Journal of Geophysical Research: Earth Surface, 121(9), 1578-1596. https://doi.org/10.1002/2015jf003706

The controls on hydraulics in bedrock-alluvial rivers are relatively poorly understood, despite the importance of the flow in determining rates and patterns of sediment transport and consequent erosion. To measure hydraulics within a bedrock-alluvial... Read More about A Froude-scaled model of a bedrock-alluvial channel reach: 1. Hydraulics.

A Froude-scaled model of a bedrock-alluvial channel reach: 2. Sediment cover (2016)
Journal Article
Hodge, R., & Hoey, T. (2016). A Froude-scaled model of a bedrock-alluvial channel reach: 2. Sediment cover. Journal of Geophysical Research: Earth Surface, 121(9), 1597-1618. https://doi.org/10.1002/2015jf003709

Previous research into sediment cover in bedrock-alluvial channels has focussed on total sediment cover, rather than the spatial distribution of cover within the channel. The latter is important because it determines the bedrock areas that are protec... Read More about A Froude-scaled model of a bedrock-alluvial channel reach: 2. Sediment cover.

Formation and erosion of sediment cover in an experimental bedrock-alluvial channel (2016)
Journal Article
Hodge, R., Hoey, T., Maniatis, G., & Leprêtre, E. (2016). Formation and erosion of sediment cover in an experimental bedrock-alluvial channel. Earth Surface Processes and Landforms, 41(10), 1409-1420. https://doi.org/10.1002/esp.3924

Sediment grains in a bedrock-alluvial river will be deposited within or adjacent to a sediment patch, or as isolated grains on the bedrock surface. Previous analysis of grain geometry has demonstrated that these arrangements produce significant diffe... Read More about Formation and erosion of sediment cover in an experimental bedrock-alluvial channel.

Spatial variations in surface sediment structure in riffle-pool sequences: a preliminary test of the Differential Sediment Entrainment Hypothesis (DSEH) (2013)
Journal Article
Hodge, R., Sear, D., & Leyland, J. (2013). Spatial variations in surface sediment structure in riffle-pool sequences: a preliminary test of the Differential Sediment Entrainment Hypothesis (DSEH). Earth Surface Processes and Landforms, 38(5), 449-465. https://doi.org/10.1002/esp.3290

Riffle–pool sequences are maintained through the preferential entrainment of sediment grains from pools rather than riffles. This preferential entrainment has been attributed to a reversal in the magnitude of velocity and shear stress under high flow... Read More about Spatial variations in surface sediment structure in riffle-pool sequences: a preliminary test of the Differential Sediment Entrainment Hypothesis (DSEH).