Journal Articles
Norriss, W,
Baynes, E, Hillier, J, Lague, D, Steer, P (2026)
Knickpoint morphology in homogenous substrates controlled by sediment cover and base-level fall rate,
Earth Surface Processes and Landforms, 51(8), e70389, ISSN: 0197-9337. DOI:
10.1002/esp.70389.
Prasojo, O, Leenman, A,
Baynes, E (2026)
Non-linear morphodynamic response of deltas to extreme events,
Geophysical Research Letters, 53(10), e2025GL120954, ISSN: 0094-8276. DOI:
10.1029/2025GL120954.
Whitfield, D,
Baynes, E, Rice, S, Jeffries, R (2026)
Fundamental hydraulic geometry relations as an accessible tool for identifying channel instability over national scales,
River Research and Applications, 42(7), pp.1500-1519, ISSN: 1535-1459. DOI:
10.1002/rra.70154.
Baynes, E, Dingle, E, Warburton, J (2026)
Carbonate bedrock channel erosion dynamics inhibit weathering effect on bedrock erodibility, DOI:
10.5194/egusphere-egu26-4890.
Whitfield, D,
Baynes, E, Rice, S, Mathers, K (2026)
Influence of grain arrangement on particle mobility and patterns of variability between gravel bed rivers,
Journal of Geophysical Research (JGR): Earth Surface, 131(3), e2025JF008842, ISSN: 2169-9003. DOI:
10.1029/2025JF008842.
Stanton, T, Law, A, Somers, C, Worne, S, Sheridan, KJ, Kechi-Okafor, C, Wheat, A, Wood, A, Bateman, A, Richardson, N,
Baynes, E, Ryves, DB, Gaca, P, Cundy, A, McKay, D (2026)
‘Natural’ fibres in lakes: a 150-year sedimentary perspective on persistence,
iScience, 29(3), 114904, ISSN: 2589-0042. DOI:
10.1016/j.isci.2026.114904.
Nicholls, H, Sanders, C, Ryves, D,
Baynes, E, Sheridan, KJ, Stanton, T (2025)
Flowing fibers: subsurface sampling is key to understanding natural and plastic textile fiber pollution in rivers,
ACS ES&T Water, 6(1), pp.263-272, ISSN: 2690-0637. DOI:
10.1021/acsestwater.5c00998.
Wells, G, Saemundsson, T,
Baynes, E, Beach, T, Luzzader-Beach, S (2025)
Early holocene jökulhlaup chronology and deglaciation dynamics in central Iceland,
Boreas, 55(2), pp.340-355, ISSN: 0300-9483. DOI:
10.1111/bor.70028.
Whitfield, D,
Baynes, E, Hodge, R, Rice, S, Yager, E (2025)
The influence of gravel-bed structure on grain mobility thresholds: Comparison of force-balance approaches,
Journal of Geophysical Research (JGR): Earth Surface, 130(5), e2025JF008333, ISSN: 2169-9003. DOI:
10.1029/2025JF008333.
H. Dingle, E,
Baynes, E, Hall, A, Warburton, J (2025)
Erosion dynamics in carbonate bedrock channels inhibit weathering processes,
Earth Surface Processes and Landforms, 50(5), e70067, ISSN: 0197-9337. DOI:
10.1002/esp.70067.
Baynes, E, Whitfield, D, Rice, S, Jeffries, R, Mathers, K (2025)
Exploring Variabilities in Gravel Mobility Using Force-Balance Models, DOI:
10.5194/egusphere-egu25-11412.
Stanton, T, Stanes, E, Gwinnett, C, Lei, X, Cauilan-Cureg, M, Ramos, M, Sallach, JB, Harrison, E, Osborne, A, Sanders, CH,
Baynes, E, Law, A, Johnson, M, Ryves, DB, Sheridan, KJ, Blackburn, RS, McKay, D (2023)
Shedding off-the-grid: The role of garment manufacturing and textile care in global microfibre pollution,
Journal of Cleaner Production, 428, pp.139391-139391, ISSN: 0959-6526. DOI:
10.1016/j.jclepro.2023.139391.
Baynes, E, Kincey, M, Warburton, J (2023)
Extreme flood sediment production and export controlled by reach-scale morphology,
Geophysical Research Letters, 50(10), e2023GL103042, ISSN: 0094-8276. DOI:
10.1029/2023GL103042.
Baynes, E, Lague, D, Steer, P, Davy, P (2022)
Dynamic bedrock channel width during knickpoint retreat enhances undercutting of coupled hillslopes,
Earth Surface Processes and Landforms, 47(15), pp.3629-3640, ISSN: 0197-9337. DOI:
10.1002/esp.5477.
Wells, G, Dugmore, A, Beach, T,
Baynes, E, Sæmundsson, Þ, Luzzadder-Beach, S (2022)
Reconstructing glacial outburst floods (jökulhlaups) from geomorphology: challenges, solutions, and an enhanced interpretive framework,
Progress in Physical Geography, 46(3), pp.398-421, ISSN: 0309-1333. DOI:
10.1177/03091333211065001.
Hicks, DM, Baynes, E, Measures, R, Stecca, G, Tunnicliffe, J, Friedrich, H (Accepted for publication) Morphodynamic research challenges for braided river environments: Lessons from the iconic case of New Zealand, Earth Surface Processes and Landforms, esp.5014, ISSN: 0197-9337. DOI: 10.1002/esp.5014.
Baynes, E, Lague, D, Steer, P, Bonnet, S, Illien, L (2020)
Sediment flux driven channel geometry adjustment of bedrock and mixed gravel‐bedrock rivers,
Earth Surface Processes and Landforms, esp.4996, ISSN: 0197-9337. DOI:
10.1002/esp.4996.
Baynes, E, Bardin, C, Friedrich, H (2020)
Fluvial evacuation of landslide material from bedrock-confined channels under controlled experimental conditions,
Geomorphology, 368, 107359, ISSN: 0169-555X. DOI:
10.1016/j.geomorph.2020.107359.
Duran, S, Coulthard, TJ,
Baynes, ERC (2019)
Knickpoints in Martian channels indicate past ocean levels ,
Scientific Reports, 9(1), 15153, DOI:
10.1038/s41598-019-51574-2.
Steer, P, Croissant, T,
Baynes, E, Lague, D (2019)
Statistical modelling of co-seismic knickpoint formation and river response to fault slip,
Earth Surface Dynamics, 7(3), pp.681-706, DOI:
10.5194/esurf-7-681-2019.
Baynes, ERC, Lague, D, Kermarrec, J-J (2018)
Supercritical river terraces generated by hydraulic and geomorphic interactions,
Geology, 46(6), pp.499-502, ISSN: 0091-7613. DOI:
10.1130/g40071.1.
Baynes, E, Lague, D, Attal, M, Gangloff, A, Kirstein, LA, Dugmore, AJ (2018)
River self-organisation inhibits discharge control on waterfall migration,
Scientific Reports, 8, 2444, DOI:
10.1038/s41598-018-20767-6.
Baynes, ER, Van de Lageweg, WI, McLelland, SJ, Parsons, DR, Aberle, J, Dijkstra, JT, Henry, P-Y, Rice, S, Thom, M, Moulin, FY (2018)
Beyond equilibrium: Re-evaluating physical modelling of fluvial systems to represent climate changes,
Earth-Science Reviews, 181, pp.82-97, ISSN: 0012-8252. DOI:
10.1016/j.earscirev.2018.04.007.
Baynes, ERC, Attal, M, Dugmore, AJ, Kirstein, LA, Whaler, KA (2015)
Catastrophic impact of extreme flood events on the morphology and evolution of the lower Jökulsá á Fjöllum (northeast Iceland) during the Holocene,
Geomorphology, 250, pp.422-436, ISSN: 0169-555X. DOI:
10.1016/j.geomorph.2015.05.009.
Baynes, ERC, Attal, M, Niedermann, S, Kirstein, LA, Dugmore, AJ, Naylor, M (2015)
Erosion during extreme flood events dominates Holocene canyon evolution in northeast Iceland,
Proceedings of the National Academy of Sciences, 112(8), pp.2355-2360, ISSN: 0027-8424. DOI:
10.1073/pnas.1415443112.
Other
Norriss, W,
Baynes, E, Hillier, J, Lague, D, Steer, P (2026)
Modelling and understanding knickpoint dynamics in homogenous substrates,
In fluvial environments, knickpoints are key geomorphological landscapes exerting a disproportionate control on landscape evolution. Their influence extends both along the fluvial network and into adjacent hillslopes through coupled channel–hillslope processes. Despite this, previous studies focus on individual elements of knickpoint retreat (retreat rate, height, occurrence rate) with little focus on how they come together to wholly govern knickpoint retreat and the impact this has on wider channel evolution. We present a geometric model to illustrate the ways in which a channel can respond to changing forcing conditions – by changing knickpoint retreat rate, knickpoint spacing or knickpoint height. To evaluate our model, we conducted 22 analogue experiments in the Bedrock River Experimental Incision Tank at the Université de Rennes. To emulate bedrock, we use a silica paste of 45 μm silica, glass beads, and 18% water, with the ratio of silica to glass beads controlling substrate strength. Sediment was fed into the channel (±2% tolerance) via an infinite screw feeder, and base-level fall was simulated by a constant speed motor lowering a movable outlet gate. Conditions were constant throughout each of the experiments with sediment flux ranging from 0 g min-1 to 30 g min-1, base-level fall rate from 2.5 cm hr-1 to 5.0 cm hr-1 and silica to beads ratio from 2.5:1 (weakest) to 4:1 (strongest). A terrestrial laser scanner with a green water-penetrating laser scanned the bathymetry of the channel every 2 minutes, and the 2mm resolution digital elevation models (gridded point cloud data) used as input topography for the FLOODOS hydrodynamic model. Using Z-score normalised multi-variate regression we find knickpoint spacing is set primarily by base-level fall rate where base-level fall rate has 2.41x the impact of sediment flux and 3.61x the impact of bedrock strength. This results from the rate the channel can go through the cycle of initiating knickpoints. We find knickpoint retreat rate is set almost exclusively by bedrock strength explained by the impact of excess shear stress, with bedrock strength having 2.15x the impact of base-level fall rate and 3.61x the impact of sediment flux. Finally, knickpoint height is found to be set by base-level fall rate with base-level fall rate having 3.92x the impact of sediment flux and 4.59x the impact of bedrock strength. Next, the study looks at the impact of knickpoint dynamics on reach scale width and slope and find that these factors are governed by knickpoint morphology, with implications for channel-hillslope interactions. We find that vertical, steep knickpoints impact channel width and slope on a local scale, compared to long, elongated steepened reaches where knickpoint impacts extend beyond the local scale, reducing both overall channel width and slope. Overall, this study enhances the of understanding holistic knickpoint dynamics by assessing the interplay between multiple factors. This is important due to the broader implications for hillslope processes and landscape evolution resulting from knickpoint migration.. DOI:
10.5194/egusphere-egu26-17457.
Norriss, W,
Baynes, E, Hillier, J, Lague, D, Steer, P (2025)
Understanding the impact of sediment supply, base-level fall rate and bedrock strength on knickpoint dynamics in fluvial environments,
Knickpoints are prominent geomorphic features, and despite being localized (i.e. 10s of m) within longitudinal river profiles they profoundly influence landscape evolution with impacts occurring both within the channel system and outside of it due to channel-hillslope interactions. Because of this, a thorough mechanistic understanding of knickpoint dynamics is imperative to understanding landscapes, yet the study of knickpoints remains limited. The long geological timescales over which knickpoints evolve in natural settings makes in-situ measurements of knickpoints challenging. The Bedrock River Experimental Incision Tank at the Université de Rennes 1 was used to perform analogue experiments to provide a comprehensive dataset assessing the impact of sediment supply, base-level fall rate and bedrock strength on knickpoint dynamics. Experiments were conducted with a homogenous lithology made up of a mixture of silica and glass beads with ratios ranging from 2.5:1 to 4:1. The mixture was combined with water and used to simulate bedrock, eroded by clear water flow, with the strength of the material set by the ratio of silica to glass beads. The experiments were run with constant water discharge (1.5 l min-1), sediment supply ranging from 0 g l-1 to 20 g l-1,and base-level fall rates between 1.5 cm hr-1 and 5 cm hr-1. We find that knickpoint retreat exists between two end member states: knickpoint replacement and headward migration. It is illustrated that sediment supply impacts the channel’s ability to diffuse the knickpoint lip, whilst protecting the base, and base-level fall rate impacts the time the channel has to tend towards headward migration. Furthermore, we construct a phase diagram to illustrate the intricate interplay of sediment supply and base-level fall rate in shaping knickpoint morphology. Secondly, we find that lithology is the key determinant of knickpoint retreat rate where harder bedrock strengths result in lower knickpoint retreat rates, and channels respond to faster base level fall rates by generating more knickpoints rather than knickpoints retreating faster. This study provides a key insight into important controls on knickpoint morphology and retreat rate and provides a starting point for accurately modelling how knickpoint morphology varies as it migrates through a channel system.. DOI:
10.5194/egusphere-egu25-1576.
Mason, R, Delorme, P, Murphy, B, McLelland, S,
Baynes, E, Polvi, L, Rice, S, Parsons, D (2025)
Effect of incision on river response to floods: Insights from flume experiments,
Flood risk is increasing worldwide, however, studies on river geomorphological responses to floods often lack explicit consideration of anthropogenic impacts on rivers. A pervasive impact of human modification has been the conversion of anabranching riverscapes to incised, single thread, so called ‘fire-hose’ channels. However, the consequences of such modification for river functioning are poorly understood, restricting our ability to manage flood risk in modified systems or restore these riverscapes. Therefore, we aim to determine how incision of gravel bed rivers modifies their geomorphological response to flood events. We undertook an experiment in a large hydraulic flume, designed to simulate an alluvial gravel-bed river. The flume was filled with loose sand and seeded with alfalfa to represent riparian vegetation. Under our initial conditions of low flow and sediment input, a fully equilibrium anabranching channel developed. Subsequently, we simulated both small and large flood events. We then prompted incision by lowering the downstream base level, allowed the channel to reach a new equilibrium state, and conducted the same flood sequence. We compare the response of the anabranching and incised treatments to floods, in terms of geomorphic work done, morphological response and sediment output. First, we found that for the same input conditions, both anabranching and incised, single thread, equilibrium states existed, determined by the historical changes in base level modification. However, the two equilibrium states responded very differently to flood events. Riparian vegetation played a critical role in this process, reducing widening and channel migration associated with incision in non-vegetated experiments. Instead, channel morphological changes to high flows after incision were predominantly through adjustments to river depth. Second, incision reduced flooding because even the largest flows were fully contained within the channel. However, sediment export from the incised channel during floods was nearly double that of the anabranching treatment. Consequently, incision reduced flood extents locally, but may exacerbate flood risk overall by transporting water quickly downstream and exporting much greater amounts of sediment which could reduce channel capacity at other parts of the river network.. DOI:
10.5194/egusphere-egu25-15572.
Whitfield, D,
Baynes, E, Rice, S, Jeffries, R (2023)
Hydraulic Geometry of ‘Equilibrium’ Channels: From Theory to Application at the National Scale,
Interactions between sediment mobility and transport capacity are one of the key controls over the geometry and morphology of gravel bed rivers; these drivers are temporally variable, fluctuating in response to changes in channel hydrology - for example, with climate change - and sediment supply - for example, via land use change. Quasi-stable, equilibrium channels occur when transport capacity and bed mobility are in balance. In both field and experimental flume studies, various efforts have been made to predict the relationship between channel hydrology (bankfull discharge, Qbf) and the equilibrium dimensions (channel width and depth). Similarly, recent studies seek to quantify equilibrium state by approximating the ratio of dimensionless bankfull shear stress to dimensionless critical shear stress (τ*bf/τ*c). If robust, these theories can offer a useful approach towards identifying channels that are sensitive to present and future aggradation and/or degradation, and can therefore be valuable tools in applications such as predicting the impacts of climate change and flood risk management. Despite their widespread use in the identification and comparison of channel stability at regional scales, these quantitative methods remain uncertain when investigating the equilibrium state of individual channels, particularly when applied to semi-managed reaches.Through completing a UK-wide assessment of upland channel stability, this study aims to field-validate hydraulic geometry theories and critically evaluate their appropriateness in river management applications within a UK context. A dataset comprising 50 upland reaches of various sizes (Qbf varied from ~2 to 270 m3s-1) was collected through field survey. Observed evidence for recent aggradation and degradation was compared against hydraulic geometry theory. Where τ*bf << τ*c, channels are predicted to aggrade, typically resulting in geometries wider and shallower than expected (and vice versa for degradational regimes, where τ*bf >> τ*c). However, when compared against field observations, predictions do not always coincide with reality. Here, we identify case study exceptions, and explore process complexities (for example, sediment supply, confinement and bank reinforcement) that lead to deviation from the predicted aggradational/degradational regime. Additionally, to account for deviations from expected channel morphology, we consider temporal variations in bed structure and sediment mobility thresholds under different hydrological regimes.. DOI:
10.5194/egusphere-egu23-6241.
