Articles | Volume 7, issue 4
https://doi.org/10.5194/esurf-7-911-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/esurf-7-911-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
How does the downstream boundary affect avulsion dynamics in a laboratory bifurcation?
Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
Vaughan R. Voller
Department of Civil, Environmental, and Geoengineering, University of Minnesota, Minneapolis, MN, USA
Chris Paola
Department of Earth Sciences, University of Minnesota, Minneapolis, MN, USA
Related authors
Justin A. Nghiem, Gen K. Li, Joshua P. Harringmeyer, Gerard Salter, Cédric G. Fichot, Luca Cortese, and Michael P. Lamb
EGUsphere, https://doi.org/10.5194/egusphere-2024-524, https://doi.org/10.5194/egusphere-2024-524, 2024
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Fine sediment grains in freshwater can cohere into faster settling particles called flocs, but floc settling velocity theory has not been fully validated. Data from the Wax Lake Delta verify a semi-empirical model relying on turbulence and geochemical factors. We showed that the representative grain diameter within flocs relies on floc structure and that floc internal flow follows a model in which flocs consist of permeable grain clusters, thus improving a physics-based settling velocity model.
Meng Zhao, Gerard Salter, Vaughan R. Voller, and Shuwang Li
Earth Surf. Dynam., 7, 505–513, https://doi.org/10.5194/esurf-7-505-2019, https://doi.org/10.5194/esurf-7-505-2019, 2019
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Typically, we think of a shoreline growing with a smooth line separating the land and the water. If the growth is unstable, however, the land–water front will exhibit a roughness that grows with time. Here we ask whether the growth of deltaic shorelines cab be unstable. Through mathematical analysis we show that growth is unstable when the shoreline is building onto an adverse slope. The length scale of the unstable signal in such a case, however, might be obscured by other geomorphic processes.
Justin A. Nghiem, Gen K. Li, Joshua P. Harringmeyer, Gerard Salter, Cédric G. Fichot, Luca Cortese, and Michael P. Lamb
EGUsphere, https://doi.org/10.5194/egusphere-2024-524, https://doi.org/10.5194/egusphere-2024-524, 2024
Short summary
Short summary
Fine sediment grains in freshwater can cohere into faster settling particles called flocs, but floc settling velocity theory has not been fully validated. Data from the Wax Lake Delta verify a semi-empirical model relying on turbulence and geochemical factors. We showed that the representative grain diameter within flocs relies on floc structure and that floc internal flow follows a model in which flocs consist of permeable grain clusters, thus improving a physics-based settling velocity model.
Sam Y. J. Huang, Steven Y. J. Lai, Ajay B. Limaye, Brady Z. Foreman, and Chris Paola
Earth Surf. Dynam., 11, 615–632, https://doi.org/10.5194/esurf-11-615-2023, https://doi.org/10.5194/esurf-11-615-2023, 2023
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We use experiments and a model to study the effects of confinement width and the inflow-to-sediment discharge ratio on the evolution of submarine braided channels. We find that confinement width controls most of the morphological changes. These trends are consistent for submarine braided channels both with and without confinement width effects and similar to fluvial braided rivers. Furthermore, we built a model that can simulate the flow bifurcation and confluence of submarine braided channels.
Tzu-Yin Kasha Chen, Ying-Chen Wu, Chi-Yao Hung, Hervé Capart, and Vaughan R. Voller
Earth Surf. Dynam., 11, 325–342, https://doi.org/10.5194/esurf-11-325-2023, https://doi.org/10.5194/esurf-11-325-2023, 2023
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Predicting the extent and thickness of debris flow deposits is important for assessing and mitigating hazards. We propose a simplified mass balance model for predicting the morphology of terminated debris flows depositing over complex topography. A key element in this model is that the termination of flow of the deposit is determined by prescribed values of yield stress and friction angle. The model results are consistent with available analytical solutions and field and laboratory observations.
Rebecca L. Caldwell, Douglas A. Edmonds, Sarah Baumgardner, Chris Paola, Samapriya Roy, and Jaap H. Nienhuis
Earth Surf. Dynam., 7, 773–787, https://doi.org/10.5194/esurf-7-773-2019, https://doi.org/10.5194/esurf-7-773-2019, 2019
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River deltas are valuable resources that support biodiversity and human habitation. Despite this we do not have a global census of deltas nor do we know the conditions that promote their formation. We surveyed 5399 river mouths greater than 50 m wide and found that 2174 (40 %) create a delta. The conditions that lead to delta formation are high sediment input and low wave and tide conditions. These results can be used to understand how deltas will adapt to environmental changes.
Meng Zhao, Gerard Salter, Vaughan R. Voller, and Shuwang Li
Earth Surf. Dynam., 7, 505–513, https://doi.org/10.5194/esurf-7-505-2019, https://doi.org/10.5194/esurf-7-505-2019, 2019
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Typically, we think of a shoreline growing with a smooth line separating the land and the water. If the growth is unstable, however, the land–water front will exhibit a roughness that grows with time. Here we ask whether the growth of deltaic shorelines cab be unstable. Through mathematical analysis we show that growth is unstable when the shoreline is building onto an adverse slope. The length scale of the unstable signal in such a case, however, might be obscured by other geomorphic processes.
Stephanie S. Day, Karen B. Gran, and Chris Paola
Hydrol. Earth Syst. Sci., 22, 3261–3273, https://doi.org/10.5194/hess-22-3261-2018, https://doi.org/10.5194/hess-22-3261-2018, 2018
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Permanent gullies are deep steep-sided channels that erode as water falls over the upstream end. Erosion of these features is a concern where people and climate change have altered how water moves over the land. This paper analyzes a set of experiments that were used to determine how changing gully flows impact erosion. We found that while increasing the volume of water will increase erosion, changing the flow rate into gullies will not impact the total erosion, but will alter gully shape.
Pauline Delorme, Vaughan Voller, Chris Paola, Olivier Devauchelle, Éric Lajeunesse, Laurie Barrier, and François Métivier
Earth Surf. Dynam., 5, 239–252, https://doi.org/10.5194/esurf-5-239-2017, https://doi.org/10.5194/esurf-5-239-2017, 2017
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Alluvial fans are sedimentary deposits that take place at the outlet of mountain range. This location makes them the first sedimentary archive where sediments, eroded from mountains, are deposed. Their morphology is controlled by the water and sediment discharges and sediment characteristics. By using controlled laboratory experiments, we show that an alluvial fan composed of two distinct sediments has a characteristic shape; it can be decomposed into two fans made up of one sediment.
J.-L. Grimaud, C. Paola, and V. Voller
Earth Surf. Dynam., 4, 11–23, https://doi.org/10.5194/esurf-4-11-2016, https://doi.org/10.5194/esurf-4-11-2016, 2016
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Knickpoints represent localized steps along a river profile (e.g. waterfalls or rapids) that are commonly interpreted as the geomorphic response of river systems to external changes. We used a simple experiment to show that knickpoints may not only respond to external base-level change but are also able to self-organize. We highlight the effect of alluvial cover in delaying knickpoint formation and show that river bed strength controls both retreat velocity and geometry of knickpoints.
M. Liang, V. R. Voller, and C. Paola
Earth Surf. Dynam., 3, 67–86, https://doi.org/10.5194/esurf-3-67-2015, https://doi.org/10.5194/esurf-3-67-2015, 2015
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In this work we present DeltaRCM, a reduced-complexity model for river delta formation. It is a rule-based cellular morphodynamic model, in contrast to reductionist models based on detailed computational fluid dynamics. DeltaRCM is able to resolve channel dynamics and to produce stratigraphy. We also explain the meaning of complexity reduction, especially the essential processes to be included in modeling deltas.
Related subject area
Physical: Geomorphology (including all aspects of fluvial, coastal, aeolian, hillslope and glacial geomorphology)
Long-term monitoring (1953–2019) of geomorphologically active sections of Little Ice Age lateral moraines in the context of changing meteorological conditions
Coevolving edge rounding and shape of glacial erratics: the case of Shap granite, UK
Dimensionless argument: a narrow grain size range near 2 mm plays a special role in river sediment transport and morphodynamics
Path length and sediment transport estimation from DEMs of difference: a signal processing approach
Influence of cohesive clay on wave–current ripple dynamics captured in a 3D phase diagram
Statistical characterization of erosion and sediment transport mechanics in shallow tidal environments – Part 1: Erosion dynamics
Statistical characterization of erosion and sediment transport mechanics in shallow tidal environments – Part 2: Suspended sediment dynamics
Geomorphological and hydrological controls on sediment export in earthquake-affected catchments in the Nepal Himalaya
Optimization of passive acoustic bedload monitoring in rivers by signal inversion
Stochastic properties of coastal flooding events – Part 2: Probabilistic analysis
Field monitoring of pore water pressure in fully and partly saturated debris flows at Ohya landslide scar, Japan
Analysis of autogenic bifurcation processes resulting in river avulsion
Bedload transport fluctuations, flow conditions, and disequilibrium ratio at the Swiss Erlenbach stream: results from 27 years of high-resolution temporal measurements
Stochastic properties of coastal flooding events – Part 1: convolutional-neural-network-based semantic segmentation for water detection
Coexistence of two dune scales in a lowland river
Alpine hillslope failure in the western US: insights from the Chaos Canyon landslide, Rocky Mountain National Park, USA
Using repeat UAV-based laser scanning and multispectral imagery to explore eco-geomorphic feedbacks along a river corridor
Numerical modelling of the evolution of a river reach with a complex morphology to help define future sustainable restoration decisions
Method to evaluate large-wood behavior in terms of the convection equation associated with sediment erosion and deposition
Effects of seasonal variations in vegetation and precipitation on catchment erosion rates along a climate and ecological gradient: insights from numerical modeling
On the use of convolutional deep learning to predict shoreline change
Riverine Sediment Response to Deforestation in the Amazon Basin
On the use of packing models for the prediction of fluvial sediment porosity
Automated riverbed composition analysis using deep learning on underwater images
Marsh-induced backwater: the influence of non-fluvial sedimentation on a delta's channel morphology and kinematics
Spatial and temporal variations in rockwall erosion rates derived from cosmogenic 10Be in medial moraines at five valley glaciers around Pigne d'Arolla, Switzerland
Downstream rounding rate of pebbles in the Himalaya
Building a bimodal landscape: bedrock lithology and bed thickness controls on the morphology of Last Chance Canyon, New Mexico, USA
Geotechnical controls on erodibility in fluvial impact erosion
Linear-stability analysis of plane beds under flows with suspended loads
Stream hydrology controls on ice cliff generation, evolution, and survival on debris-covered glaciers
Estimating surface water availability in high mountain rock slopes using a numerical energy balance model
Sediment source and sink identification using Sentinel-2 and a small network of turbidimeters on the Vjosa River
Spatiotemporal bedload transport patterns over two-dimensional bedforms
Ice-buttressing-controlled rock slope failure on a cirque headwall, Lake District, UK
The probabilistic nature of dune collisions in 2D
Shape still matters: rockfall interactions with trees and deadwood in a mountain forest uncover a new facet of rock shape dependency
A process-based model for fluvial valley width
Quantifying the migration rate of drainage divides from high-resolution topographic data
Earthquake contributions to coastal cliff retreat
Morphologic and morphometric differences between gullies formed in different substrates on Mars: new insights into the gully formation processes
Testing the sensitivity of the CAESAR-Lisflood landscape evolution model to grid cell size
Development of a machine learning model for river bed load
Modeling the spatially distributed nature of subglacial sediment transport and erosion
Confinement width and inflow-to-sediment discharge ratio control the morphology and braiding intensity of submarine channels: insights from physical experiments and reduced-complexity models
The influence of dune lee side shape on time-averaged velocities and turbulence
Implications for the Resilience of Modern Coastal Systems Derived from Mesoscale Barrier Dynamics at Fire Island, New York
Synoptic-scale to mesoscale atmospheric circulation connects fluvial and coastal gravel conveyors and directional deposition of coastal landforms in the Dead Sea basin
Initial shape reconstruction of a volcanic island as a tool for quantifying long-term coastal erosion: the case of Corvo Island (Azores)
Geospatial modelling of large-wood supply to rivers: a state-of-the-art model comparison in Swiss mountain river catchments
Moritz Altmann, Madlene Pfeiffer, Florian Haas, Jakob Rom, Fabian Fleischer, Tobias Heckmann, Livia Piermattei, Michael Wimmer, Lukas Braun, Manuel Stark, Sarah Betz-Nutz, and Michael Becht
Earth Surf. Dynam., 12, 399–431, https://doi.org/10.5194/esurf-12-399-2024, https://doi.org/10.5194/esurf-12-399-2024, 2024
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We show a long-term erosion monitoring of several sections on Little Ice Age lateral moraines with derived sediment yield from historical and current digital elevation modelling (DEM)-based differences. The first study period shows a clearly higher range of variability of sediment yield within the sites than the later periods. In most cases, a decreasing trend of geomorphic activity was observed.
Paul A. Carling
Earth Surf. Dynam., 12, 381–397, https://doi.org/10.5194/esurf-12-381-2024, https://doi.org/10.5194/esurf-12-381-2024, 2024
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Edge rounding in Shap granite glacial erratics is an irregular function of distance from the source outcrop in northern England, UK. Block shape is conservative, evolving according to block fracture mechanics – stochastic and silver ratio models – towards either of two attractor states. Progressive reduction in size occurs for blocks transported at the sole of the ice mass where the blocks are subject to compressive and tensile forces of the ice acting against a bedrock or till surface.
Gary Parker, Chenge An, Michael P. Lamb, Marcelo H. Garcia, Elizabeth H. Dingle, and Jeremy G. Venditti
Earth Surf. Dynam., 12, 367–380, https://doi.org/10.5194/esurf-12-367-2024, https://doi.org/10.5194/esurf-12-367-2024, 2024
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River morphology has traditionally been divided by the size 2 mm. We use dimensionless arguments to show that particles in the 1–5 mm range (i) are the finest range not easily suspended by alluvial flood flows, (ii) are transported preferentially over coarser gravel, and (iii), within limits, are also transported preferentially over sand. We show how fluid viscosity mediates the special status of sediment in this range.
Lindsay Marie Capito, Enrico Pandrin, Walter Bertoldi, Nicola Surian, and Simone Bizzi
Earth Surf. Dynam., 12, 321–345, https://doi.org/10.5194/esurf-12-321-2024, https://doi.org/10.5194/esurf-12-321-2024, 2024
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We propose that the pattern of erosion and deposition from repeat topographic surveys can be a proxy for path length in gravel-bed rivers. With laboratory and field data, we applied tools from signal processing to quantify this periodicity and used these path length estimates to calculate sediment transport using the morphological method. Our results highlight the potential to expand the use of the morphological method using only remotely sensed data as well as its limitations.
Xuxu Wu, Jonathan Malarkey, Roberto Fernández, Jaco H. Baas, Ellen Pollard, and Daniel R. Parsons
Earth Surf. Dynam., 12, 231–247, https://doi.org/10.5194/esurf-12-231-2024, https://doi.org/10.5194/esurf-12-231-2024, 2024
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The seabed changes from flat to rippled in response to the frictional influence of waves and currents. This experimental study has shown that the speed of this change, the size of ripples that result and even whether ripples appear also depend on the amount of sticky mud present. This new classification on the basis of initial mud content should lead to improvements in models of seabed change in present environments by engineers and the interpretation of past environments by geologists.
Andrea D'Alpaos, Davide Tognin, Laura Tommasini, Luigi D'Alpaos, Andrea Rinaldo, and Luca Carniello
Earth Surf. Dynam., 12, 181–199, https://doi.org/10.5194/esurf-12-181-2024, https://doi.org/10.5194/esurf-12-181-2024, 2024
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Sediment erosion induced by wind waves is one of the main drivers of the morphological evolution of shallow tidal environments. However, a reliable description of erosion events for the long-term morphodynamic modelling of tidal systems is still lacking. By statistically characterizing sediment erosion dynamics in the Venice Lagoon over the last 4 centuries, we set up a novel framework for a synthetic, yet reliable, description of erosion events in tidal systems.
Davide Tognin, Andrea D'Alpaos, Luigi D'Alpaos, Andrea Rinaldo, and Luca Carniello
Earth Surf. Dynam., 12, 201–218, https://doi.org/10.5194/esurf-12-201-2024, https://doi.org/10.5194/esurf-12-201-2024, 2024
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Reliable quantification of sediment transport processes is necessary to understand the fate of shallow tidal environments. Here we present a framework for the description of suspended sediment dynamics to quantify deposition in the long-term modelling of shallow tidal systems. This characterization, together with that of erosion events, allows one to set up synthetic, yet reliable, models for the long-term evolution of tidal landscapes.
Emma L. S. Graf, Hugh D. Sinclair, Mikaël Attal, Boris Gailleton, Basanta Raj Adhikari, and Bishnu Raj Baral
Earth Surf. Dynam., 12, 135–161, https://doi.org/10.5194/esurf-12-135-2024, https://doi.org/10.5194/esurf-12-135-2024, 2024
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Using satellite images, we show that, unlike other examples of earthquake-affected rivers, the rivers of central Nepal experienced little increase in sedimentation following the 2015 Gorkha earthquake. Instead, a catastrophic flood occurred in 2021 that buried towns and agricultural land under up to 10 m of sediment. We show that intense storms remobilised glacial sediment from high elevations causing much a greater impact than flushing of earthquake-induced landslides.
Mohamad Nasr, Adele Johannot, Thomas Geay, Sebastien Zanker, Jules Le Guern, and Alain Recking
Earth Surf. Dynam., 12, 117–134, https://doi.org/10.5194/esurf-12-117-2024, https://doi.org/10.5194/esurf-12-117-2024, 2024
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Hydrophones are used to monitor sediment transport in the river by listening to the acoustic noise generated by particle impacts on the riverbed. However, this acoustic noise is modified by the river flow and can cause misleading information about sediment transport. This article proposes a model that corrects the measured acoustic signal. Testing the model showed that the corrected signal is better correlated with bedload flux in the river.
Byungho Kang, Rusty A. Feagin, Thomas Huff, and Orencio Durán Vinent
Earth Surf. Dynam., 12, 105–115, https://doi.org/10.5194/esurf-12-105-2024, https://doi.org/10.5194/esurf-12-105-2024, 2024
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We provide a detailed characterization of the frequency, intensity and duration of flooding events at a site along the Texas coast. Our analysis demonstrates the suitability of relatively simple wave run-up models to estimate the frequency and intensity of coastal flooding. Our results validate and expand a probabilistic model of coastal flooding driven by wave run-up that can then be used in coastal risk management in response to sea level rise.
Shunsuke Oya, Fumitoshi Imaizumi, and Shoki Takayama
Earth Surf. Dynam., 12, 67–86, https://doi.org/10.5194/esurf-12-67-2024, https://doi.org/10.5194/esurf-12-67-2024, 2024
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The monitoring of pore water pressure in fully and partly saturated debris flows was performed at Ohya landslide scar, central Japan. The pore water pressure in some partly saturated flows greatly exceeded the hydrostatic pressure. The depth gradient of the pore water pressure in the lower part of the flow was generally higher than the upper part of the flow. We conclude that excess pore water pressure is present in many debris flow surges and is an important mechanism in debris flow behavior.
Gabriele Barile, Marco Redolfi, and Marco Tubino
Earth Surf. Dynam., 12, 87–103, https://doi.org/10.5194/esurf-12-87-2024, https://doi.org/10.5194/esurf-12-87-2024, 2024
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River bifurcations often show the closure of one branch (avulsion), whose causes are still poorly understood. Our model shows that when one branch stops transporting sediments, the other considerably erodes and captures much more flow, resulting in a self-sustaining process. This phenomenon intensifies when increasing the length of the branches, eventually leading to branch closure. This work may help to understand when avulsions occur and thus to design sustainable river restoration projects.
Dieter Rickenmann
Earth Surf. Dynam., 12, 11–34, https://doi.org/10.5194/esurf-12-11-2024, https://doi.org/10.5194/esurf-12-11-2024, 2024
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Field measurements of the bedload flux with a high temporal resolution in a steep mountain stream were used to analyse the transport fluctuations as a function of the flow conditions. The disequilibrium ratio, a proxy for the solid particle concentration in the flow, was found to influence the sediment transport behaviour, and above-average disequilibrium conditions – associated with a larger sediment availability on the streambed – substantially affect subsequent transport conditions.
Byungho Kang, Rusty A. Feagin, Thomas Huff, and Orencio Durán Vinent
Earth Surf. Dynam., 12, 1–10, https://doi.org/10.5194/esurf-12-1-2024, https://doi.org/10.5194/esurf-12-1-2024, 2024
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Coastal flooding can cause significant damage to coastal ecosystems, infrastructure, and communities and is expected to increase in frequency with the acceleration of sea level rise. In order to respond to it, it is crucial to measure and model their frequency and intensity. Here, we show deep-learning techniques can be successfully used to automatically detect flooding events from complex coastal imagery, opening the way to real-time monitoring and data acquisition for model development.
Judith Y. Zomer, Bart Vermeulen, and Antonius J. F. Hoitink
Earth Surf. Dynam., 11, 1283–1298, https://doi.org/10.5194/esurf-11-1283-2023, https://doi.org/10.5194/esurf-11-1283-2023, 2023
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Secondary bedforms that are superimposed on large, primary dunes likely play a large role in fluvial systems. This study demonstrates that they can be omnipresent. Especially during peak flows, they grow large and can have steep slopes, likely affecting flood risk and sediment transport dynamics. Primary dune morphology determines whether they continuously or intermittently migrate. During discharge peaks, the secondary bedforms can become the dominant dune scale.
Matthew C. Morriss, Benjamin Lehmann, Benjamin Campforts, George Brencher, Brianna Rick, Leif S. Anderson, Alexander L. Handwerger, Irina Overeem, and Jeffrey Moore
Earth Surf. Dynam., 11, 1251–1274, https://doi.org/10.5194/esurf-11-1251-2023, https://doi.org/10.5194/esurf-11-1251-2023, 2023
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In this paper, we investigate the 28 June 2022 collapse of the Chaos Canyon landslide in Rocky Mountain National Park, Colorado, USA. We find that the landslide was moving prior to its collapse and took place at peak spring snowmelt; temperature modeling indicates the potential presence of permafrost. We hypothesize that this landslide could be part of the broader landscape evolution changes to alpine terrain caused by a warming climate, leading to thawing alpine permafrost.
Christopher Tomsett and Julian Leyland
Earth Surf. Dynam., 11, 1223–1249, https://doi.org/10.5194/esurf-11-1223-2023, https://doi.org/10.5194/esurf-11-1223-2023, 2023
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Vegetation influences how rivers change through time, yet the way in which we analyse vegetation is limited. Current methods collect detailed data at the individual plant level or determine dominant vegetation types across larger areas. Herein, we use UAVs to collect detailed vegetation datasets for a 1 km length of river and link vegetation properties to channel evolution occurring within the study site, providing a new method for investigating the influence of vegetation on river systems.
Rabab Yassine, Ludovic Cassan, Hélène Roux, Olivier Frysou, and François Pérès
Earth Surf. Dynam., 11, 1199–1221, https://doi.org/10.5194/esurf-11-1199-2023, https://doi.org/10.5194/esurf-11-1199-2023, 2023
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Predicting river morphology evolution is very complicated, especially for mountain rivers with complex morphologies such as the Lac des Gaves reach in France. A 2D hydromorphological model was developed to reproduce the channel's evolution and provide reliable volumetric predictions while revealing the challenge of choosing adapted sediment transport and friction laws. Our model can provide decision-makers with reliable predictions to design suitable restoration measures for this reach.
Daisuke Harada and Shinji Egashira
Earth Surf. Dynam., 11, 1183–1197, https://doi.org/10.5194/esurf-11-1183-2023, https://doi.org/10.5194/esurf-11-1183-2023, 2023
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This paper proposes a method for describing large-wood behavior in terms of the convection equation and the storage equation, which are associated with active sediment erosion and deposition. Compared to the existing Lagrangian method, the proposed method can easily simulate the behavior of large wood in the flow field with active sediment transport. The method is applied to the flood disaster in the Akatani River in 2017, and the 2-D flood flow computations are successfully performed.
Hemanti Sharma and Todd A. Ehlers
Earth Surf. Dynam., 11, 1161–1181, https://doi.org/10.5194/esurf-11-1161-2023, https://doi.org/10.5194/esurf-11-1161-2023, 2023
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Seasonality in precipitation (P) and vegetation (V) influences catchment erosion (E), although which factor plays the dominant role is unclear. In this study, we performed a sensitivity analysis of E to P–V seasonality through numerical modeling. Our results suggest that P variations strongly influence seasonal variations in E, while the effect of seasonal V variations is secondary but significant. This is more pronounced in moderate and least pronounced in extreme environmental settings.
Eduardo Gomez-de la Peña, Giovanni Coco, Colin Whittaker, and Jennifer Montaño
Earth Surf. Dynam., 11, 1145–1160, https://doi.org/10.5194/esurf-11-1145-2023, https://doi.org/10.5194/esurf-11-1145-2023, 2023
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Predicting how shorelines change over time is a major challenge in coastal research. We here have turned to deep learning (DL), a data-driven modelling approach, to predict the movement of shorelines using observations from a camera system in New Zealand. The DL models here implemented succeeded in capturing the variability and distribution of the observed shoreline data. Overall, these findings indicate that DL has the potential to enhance the accuracy of current shoreline change predictions.
Anuska Narayanan, Sagy Cohen, and John Robert Gardner
EGUsphere, https://doi.org/10.5194/egusphere-2023-2271, https://doi.org/10.5194/egusphere-2023-2271, 2023
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This study investigates Amazon deforestation's profound impact on sediment dynamics. Novel remote sensing data and statistical analyses reveal significant changes, especially in heavily deforested regions, with rapid effects within a year. In less disturbed areas, a 1- to 2-year lag occurs, influenced by natural sediment shifts and human activities. These findings highlight the need to understand human activities' consequences for our planet's future.
Christoph Rettinger, Mina Tabesh, Ulrich Rüde, Stefan Vollmer, and Roy M. Frings
Earth Surf. Dynam., 11, 1097–1115, https://doi.org/10.5194/esurf-11-1097-2023, https://doi.org/10.5194/esurf-11-1097-2023, 2023
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Packing models promise efficient and accurate porosity predictions of fluvial sediment deposits. In this study, three packing models were reviewed, calibrated, and validated. Only two of the models were able to handle the continuous and large grain size distributions typically encountered in rivers. We showed that an extension by a cohesion model is necessary and developed guidelines for successful predictions in different rivers.
Alexander A. Ermilov, Gergely Benkő, and Sándor Baranya
Earth Surf. Dynam., 11, 1061–1095, https://doi.org/10.5194/esurf-11-1061-2023, https://doi.org/10.5194/esurf-11-1061-2023, 2023
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A novel, artificial-intelligence-based riverbed sediment analysis methodology is introduced that uses underwater images to identify the characteristic sediment classes. The main novelties of the procedure are as follows: underwater images are used, the method enables continuous mapping of the riverbed along the measurement vessel’s route contrary to conventional techniques, the method is cost-efficient, and the method works without scaling.
Kelly M. Sanks, John B. Shaw, Samuel M. Zapp, José Silvestre, Ripul Dutt, and Kyle M. Straub
Earth Surf. Dynam., 11, 1035–1060, https://doi.org/10.5194/esurf-11-1035-2023, https://doi.org/10.5194/esurf-11-1035-2023, 2023
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River deltas encompass many depositional environments (like channels and wetlands) that interact to produce coastal environments that change through time. The processes leading to sedimentation in wetlands are often neglected from physical delta models. We show that wetland sedimentation constrains flow to the channels, changes sedimentation rates, and produces channels more akin to field-scale deltas. These results have implications for the management of these vulnerable coastal landscapes.
Katharina Wetterauer and Dirk Scherler
Earth Surf. Dynam., 11, 1013–1033, https://doi.org/10.5194/esurf-11-1013-2023, https://doi.org/10.5194/esurf-11-1013-2023, 2023
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In glacial landscapes, debris supply rates vary spatially and temporally. Rockwall erosion rates derived from cosmogenic 10Be concentrations in medial moraine debris at five Swiss glaciers around Pigne d'Arolla indicate an increase in erosion from the end of the Little Ice Age towards deglaciation but temporally more stable rates over the last ∼100 years. Rockwall erosion rates are higher where rockwalls are steep and north-facing, suggesting a potential slope and temperature control.
Prakash Pokhrel, Mikael Attal, Hugh D. Sinclair, Simon M. Mudd, and Mark Naylor
EGUsphere, https://doi.org/10.5194/egusphere-2023-2157, https://doi.org/10.5194/egusphere-2023-2157, 2023
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Pebbles become increasingly rounded during downstream transport in rivers due to abrasion. This study quantifies pebble roundness along the length of two Himalayan rivers. We demonstrate that roundness increases with downstream distance and that the rates are dependent on rock type. We apply this to reconstructing travel distances, and hence size of ancient Himalayan. Results show that the ancient river network was larger than the modern indicating that there has been river capture.
Sam Anderson, Nicole Gasparini, and Joel Johnson
Earth Surf. Dynam., 11, 995–1011, https://doi.org/10.5194/esurf-11-995-2023, https://doi.org/10.5194/esurf-11-995-2023, 2023
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We measured rock strength and amount of fracturing in the two different rock types, sandstones and carbonates, in Last Chance Canyon, New Mexico, USA. Where there is more carbonate bedrock, hills and channels steepen in Last Chance Canyon. This is because the carbonate-type bedrock tends to be more thickly bedded, is less fractured, and is stronger. The carbonate bedrock produces larger boulders than the sandstone bedrock, which can protect the more fractured sandstone bedrock from erosion.
Jens M. Turowski, Gunnar Pruß, Anne Voigtländer, Andreas Ludwig, Angela Landgraf, Florian Kober, and Audrey Bonnelye
Earth Surf. Dynam., 11, 979–994, https://doi.org/10.5194/esurf-11-979-2023, https://doi.org/10.5194/esurf-11-979-2023, 2023
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Rivers can cut into rocks, and their strength modulates the river's erosion rates. Yet, which properties of the rock control its response to erosive action is poorly understood. Here, we describe parallel experiments to measure rock erosion rates under fluvial impact erosion and the rock's geotechnical properties such as fracture strength, elasticity, and density. Erosion rates vary over a factor of a million between different rock types. We use the data to improve current theory.
Koji Ohata, Hajime Naruse, and Norihiro Izumi
Earth Surf. Dynam., 11, 961–977, https://doi.org/10.5194/esurf-11-961-2023, https://doi.org/10.5194/esurf-11-961-2023, 2023
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We investigated the influence of sediment transport modes on the formation of bedforms using theoretical analysis. The results of the theoretical analysis were verified with published data of plane beds obtained by fieldwork and laboratory experiments. We found that suspended sand particles can promote the formation of plane beds on a fine-grained bed, which suggests that the presence of suspended particles suppresses the development of dunes under submarine sediment-laden gravity currents.
Eric Petersen, Regine Hock, and Michael G. Loso
EGUsphere, https://doi.org/10.5194/egusphere-2023-1913, https://doi.org/10.5194/egusphere-2023-1913, 2023
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Ice cliffs are melt hot spots that increase melt rates on debris-covered glaciers which otherwise see a reduction in melt rates. In this study, we show how surface runoff streams contribute to the generation, evolution, and survival of ice cliffs by carving into the glacier and transporting rocky debris. On Kennicott Glacier, Alaska, 31.4 % of streams are actively influenced by streams, while nearly half are within 10 m of streams.
Matan Ben-Asher, Florence Magnin, Sebastian Westermann, Josué Bock, Emmanuel Malet, Johan Berthet, Ludovic Ravanel, and Philip Deline
Earth Surf. Dynam., 11, 899–915, https://doi.org/10.5194/esurf-11-899-2023, https://doi.org/10.5194/esurf-11-899-2023, 2023
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Quantitative knowledge of water availability on high mountain rock slopes is very limited. We use a numerical model and field measurements to estimate the water balance at a steep rock wall site. We show that snowmelt is the main source of water at elevations >3600 m and that snowpack hydrology and sublimation are key factors. The new information presented here can be used to improve the understanding of thermal, hydrogeological, and mechanical processes on steep mountain rock slopes.
Jessica Droujko, Srividya Hariharan Sudha, Gabriel Singer, and Peter Molnar
Earth Surf. Dynam., 11, 881–897, https://doi.org/10.5194/esurf-11-881-2023, https://doi.org/10.5194/esurf-11-881-2023, 2023
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We combined data from satellite images with data measured from a kayak in order to understand the propagation of fine sediment in the Vjosa River. We were able to find some storm-activated and some permanent sources of sediment. We also estimated how much fine sediment is carried into the Adriatic Sea by the Vjosa River: approximately 2.5 Mt per year, which matches previous findings. With our work, we hope to show the potential of open-access satellite images.
Kate C. P. Leary, Leah Tevis, and Mark Schmeeckle
Earth Surf. Dynam., 11, 835–847, https://doi.org/10.5194/esurf-11-835-2023, https://doi.org/10.5194/esurf-11-835-2023, 2023
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Despite the importance of bedforms (e.g., ripples, dunes) to sediment transport, the details of sediment transport on a sub-bedform scale are poorly understood. This paper investigates sediment transport in the downstream and cross-stream directions over bedforms with straight crests. We find that the patterns of bedload transport are highly variable on the sub-bedform scale, which is important for our understanding of the evolution of bedforms with complex crest geometries.
Paul A. Carling, John D. Jansen, Teng Su, Jane Lund Andersen, and Mads Faurschou Knudsen
Earth Surf. Dynam., 11, 817–833, https://doi.org/10.5194/esurf-11-817-2023, https://doi.org/10.5194/esurf-11-817-2023, 2023
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Many steep glaciated rock walls collapsed when the Ice Age ended. How ice supports a steep rock wall until the ice decays is poorly understood. A collapsed rock wall was surveyed in the field and numerically modelled. Cosmogenic exposure dates show it collapsed and became ice-free ca. 18 ka ago. The model showed that the rock wall failed very slowly because ice was buttressing the slope. Dating other collapsed rock walls can improve understanding of how and when the last Ice Age ended.
Paul A. Jarvis, Clement Narteau, Olivier Rozier, and Nathalie M. Vriend
Earth Surf. Dynam., 11, 803–815, https://doi.org/10.5194/esurf-11-803-2023, https://doi.org/10.5194/esurf-11-803-2023, 2023
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Sand dune migration velocity is inversely proportional to dune size. Consequently, smaller, faster dunes can collide with larger, slower downstream dunes. Such collisions can result in either coalescence or ejection, whereby the dunes exchange mass but remain separate. Our numerical simulations show that the outcome depends probabilistically on the dune size ratio, which we describe through an empirical function. Our numerical predictions compare favourably against experimental observations.
Adrian Ringenbach, Peter Bebi, Perry Bartelt, Andreas Rigling, Marc Christen, Yves Bühler, Andreas Stoffel, and Andrin Caviezel
Earth Surf. Dynam., 11, 779–801, https://doi.org/10.5194/esurf-11-779-2023, https://doi.org/10.5194/esurf-11-779-2023, 2023
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Swiss researchers carried out repeated rockfall experiments with rocks up to human sizes in a steep mountain forest. This study focuses mainly on the effects of the rock shape and lying deadwood. In forested areas, cubic-shaped rocks showed a longer mean runout distance than platy-shaped rocks. Deadwood especially reduced the runouts of these cubic rocks. The findings enrich standard practices in modern rockfall hazard zoning assessments and strongly urge the incorporation of rock shape effects.
Jens Martin Turowski, Aaron Bufe, and Stefanie Tofelde
EGUsphere, https://doi.org/10.5194/egusphere-2023-1770, https://doi.org/10.5194/egusphere-2023-1770, 2023
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Fluvial valleys are ubiquitous landforms, and understanding their formation and evolution affects a wide range of disciplines, from archaeology over geology to fish biology. Here, we develop a model to predict the width of fluvial valleys for a wide range of geographic conditions. In the model, fluvial valley width is controlled by the two competing factors of lateral channel mobility and uplift. The model complies with available data and yields a broad range of quantitative predictions.
Chao Zhou, Xibin Tan, Yiduo Liu, and Feng Shi
EGUsphere, https://doi.org/10.5194/egusphere-2023-1428, https://doi.org/10.5194/egusphere-2023-1428, 2023
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The drainage divide stability provides new insights into both the river network evolution and the tectonic and/or climatic changes. Several methods have been proposed to determine the direction of drainage-divide migration. However, how to quantify the migration rate of drainage divides remains challenging. In this paper, we propose a new method to calculate the migration rate of drainage divides from high-resolution topographic data.
Colin K. Bloom, Corinne Singeisen, Timothy Stahl, Andrew Howell, and Chris Massey
Earth Surf. Dynam., 11, 757–778, https://doi.org/10.5194/esurf-11-757-2023, https://doi.org/10.5194/esurf-11-757-2023, 2023
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Earthquakes can cause damaging coastal cliff retreat, but we have a limited understanding of how these infrequent events influence multidecadal retreat. This makes hazard planning a challenge. In this study, we use historic aerial images to measure coastal cliff-top retreat at a site in New Zealand. We find that earthquakes account for close to half of multidecadal retreat at this site, and our results have helped us to develop tools for estimating the influence of earthquakes at other sites.
Rishitosh K. Sinha, Dwijesh Ray, Tjalling De Haas, Susan J. Conway, and Axel Noblet
Earth Surf. Dynam., 11, 713–730, https://doi.org/10.5194/esurf-11-713-2023, https://doi.org/10.5194/esurf-11-713-2023, 2023
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Our detailed investigation of Martian gullies formed in different substrates in 29 craters distributed between 30°–75° S latitude suggests that they can be differentiated from one another in terms of (1) morphology and length of alcoves and (2) mean gradient of the gully fans. The comparison between the Melton ratio, alcove length, and fan gradient of Martian and terrestrial gullies suggests that Martian gullies were likely formed by terrestrial debris-flow-like processes in the past.
Christopher J. Skinner and Thomas J. Coulthard
Earth Surf. Dynam., 11, 695–711, https://doi.org/10.5194/esurf-11-695-2023, https://doi.org/10.5194/esurf-11-695-2023, 2023
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Landscape evolution models allow us to simulate the way the Earth's surface is shaped and help us to understand relevant processes, in turn helping us to manage landscapes better. The models typically represent the land surface using a grid of square cells of equal size, averaging heights in those squares. This study shows that the size chosen by the modeller for these grid cells is important, with larger sizes making sediment output events larger but less frequent.
Hossein Hosseiny, Claire C. Masteller, Jedidiah E. Dale, and Colin B. Phillips
Earth Surf. Dynam., 11, 681–693, https://doi.org/10.5194/esurf-11-681-2023, https://doi.org/10.5194/esurf-11-681-2023, 2023
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It is of great importance to engineers and geomorphologists to predict the rate of bed load in rivers. In this contribution, we used a large dataset of measured data and developed an artificial neural network (ANN), a machine learning algorithm, for bed load prediction. The ANN model predicted the bed load flux close to measured values and better than the ones obtained from four standard bed load models with varying degrees of complexity.
Ian Delaney, Leif Anderson, and Frédéric Herman
Earth Surf. Dynam., 11, 663–680, https://doi.org/10.5194/esurf-11-663-2023, https://doi.org/10.5194/esurf-11-663-2023, 2023
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This paper presents a two-dimensional subglacial sediment transport model that evolves a sediment layer in response to subglacial sediment transport conditions. The model captures sediment transport in supply- and transport-limited regimes across a glacier's bed and considers both the creation and transport of sediment. Model outputs show how the spatial distribution of sediment and water below a glacier can impact the glacier's discharge of sediment and erosion of bedrock.
Sam Y. J. Huang, Steven Y. J. Lai, Ajay B. Limaye, Brady Z. Foreman, and Chris Paola
Earth Surf. Dynam., 11, 615–632, https://doi.org/10.5194/esurf-11-615-2023, https://doi.org/10.5194/esurf-11-615-2023, 2023
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We use experiments and a model to study the effects of confinement width and the inflow-to-sediment discharge ratio on the evolution of submarine braided channels. We find that confinement width controls most of the morphological changes. These trends are consistent for submarine braided channels both with and without confinement width effects and similar to fluvial braided rivers. Furthermore, we built a model that can simulate the flow bifurcation and confluence of submarine braided channels.
Alice Lefebvre and Julia Cisneros
Earth Surf. Dynam., 11, 575–591, https://doi.org/10.5194/esurf-11-575-2023, https://doi.org/10.5194/esurf-11-575-2023, 2023
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Underwater dunes are found in various environments with strong hydrodynamics and sandy sediment. Using a numerical model, we investigated how the dune shape influences flow velocity and turbulence. We propose a classification with three types of dunes, depending on their mean lee side angles (low-angle dunes, intermediate-angle dunes and high-angle dunes). We discuss the implications of this classification on the interaction between dune morphology, flow and sediment transport.
Daniel Ciarletta, Jennifer Miselis, Julie Bernier, and Arnell Forde
EGUsphere, https://doi.org/10.5194/egusphere-2023-1307, https://doi.org/10.5194/egusphere-2023-1307, 2023
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We reconstructed the evolution of Fire Island, a barrier island in New York, USA, to identify drivers of landscape change. Results reveal Fire Island was once divided into multiple inlet-separated islands with distinct features. Later, inlets closed, and Fire Island’s landscape became more uniform as human activities intensified. The island is now less mobile and less likely to resist and recover from storm impacts and sea-level rise. This vulnerability may exist for other stabilized barriers.
Haggai Eyal, Moshe Armon, Yehouda Enzel, and Nadav G. Lensky
Earth Surf. Dynam., 11, 547–574, https://doi.org/10.5194/esurf-11-547-2023, https://doi.org/10.5194/esurf-11-547-2023, 2023
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Extracting paleoenvironmets from sedimentologic and geomorphic records is a main goal in Earth sciences. We study a chain of processes connecting causative Mediterranean cyclones, coeval floods, storm waves generated by mesoscale funneled wind, and coastal gravel transport. This causes northward dispersion of gravel along the modern Dead Sea coast, which has also persisted since the late Pleistocene, resulting in beach berms and fan deltas always being deposited north of channel mouths.
Rémi Bossis, Vincent Regard, and Sébastien Carretier
Earth Surf. Dynam., 11, 529–545, https://doi.org/10.5194/esurf-11-529-2023, https://doi.org/10.5194/esurf-11-529-2023, 2023
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This study presents a method to calculate the volume of rock eroded by the sea on volcanic islands, by reconstructing their pre-erosion shape and size. The method has been applied on Corvo Island (Azores). We show that before the island was eroded, it was roughly 8 km wide and 1 km high. The island has lost more than 6 km3 of rock and 80 % of its surface. We also show that the erosion of sea cliffs is mainly due to the moderate and most frequent waves.
Nicolas Steeb, Virginia Ruiz-Villanueva, Alexandre Badoux, Christian Rickli, Andrea Mini, Markus Stoffel, and Dieter Rickenmann
Earth Surf. Dynam., 11, 487–509, https://doi.org/10.5194/esurf-11-487-2023, https://doi.org/10.5194/esurf-11-487-2023, 2023
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Various models have been used in science and practice to estimate how much large wood (LW) can be supplied to rivers. This contribution reviews the existing models proposed in the last 35 years and compares two of the most recent spatially explicit models by applying them to 40 catchments in Switzerland. Differences in modelling results are discussed, and results are compared to available observations coming from a unique database.
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Short summary
Bifurcations are the switches that steer water and sediment in delta and multithread river networks, playing an important role in shaping the landscape. In lab experiments, we found that when the downstream branches grow through time, frequent switching in the water and sediment partitioning occurs. In contrast, once sediment freely exits the downstream boundary, long periods of time when one branch dominates occur; however, unlike our theoretical prediction, these are not permanent.
Bifurcations are the switches that steer water and sediment in delta and multithread river...