Articles | Volume 4, issue 3
https://doi.org/10.5194/esurf-4-685-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/esurf-4-685-2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| Highlight paper
| 
29 Aug 2016
Research article | Highlight paper |
| 29 Aug 2016
Gravel threshold of motion: a state function of sediment transport disequilibrium?
Joel P. L. Johnson
CORRESPONDING AUTHOR
Department of Geological Sciences, The University of Texas, Austin, TX, USA
Related authors
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.
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.
Related subject area
Physical: Landscape Evolution: modelling and field studies
Refining patterns of melt with forward stratigraphic models of stable Pleistocene coastlines
Optimising global landscape evolution models with 10Be
Self-organization of channels and hillslopes in models of fluvial landform evolution and its potential for solving scaling issues
Stream laws in analog tectonic-landscape models
A control volume finite-element model for predicting the morphology of cohesive-frictional debris flow deposits
Erosion and weathering in carbonate regions reveal climatic and tectonic drivers of carbonate landscape evolution
Patterns and rates of soil movement and shallow failures across several small watersheds on the Seward Peninsula, Alaska
River incision, 10Be production and transport in a source-to-sink sediment system (Var catchment, SW Alps)
Simulating the effect of subsurface drainage on the thermal regime and ground ice in blocky terrain in Norway
Steady-state forms of channel profiles shaped by debris-flow and fluvial processes
An experimental study of drainage network development by surface and subsurface flow in low-gradient landscapes
The push and pull of abandoned channels: how floodplain processes and healing affect avulsion dynamics and alluvial landscape evolution in foreland basins
Climate changes and the formation of fluvial terraces in central Amazonia inferred from landscape evolution modeling
Investigation of stochastic-threshold incision models across a climatic and morphological gradient
Comparing the transport-limited and ξ–q models for sediment transport
Autogenic knickpoints in laboratory landscape experiments
Transmissivity and groundwater flow exert a strong influence on drainage density
Graphically interpreting how incision thresholds influence topographic and scaling properties of modeled landscapes
Escarpment retreat rates derived from detrital cosmogenic nuclide concentrations
Hilltop curvature as a proxy for erosion rate: wavelets enable rapid computation and reveal systematic underestimation
Short communication: Analytical models for 2D landscape evolution
Effect of rock uplift and Milankovitch timescale variations in precipitation and vegetation cover on catchment erosion rates
Modeling glacial and fluvial landform evolution at large scales using a stream-power approach
Topographic disequilibrium, landscape dynamics and active tectonics: an example from the Bhutan Himalaya
Last-glacial-cycle glacier erosion potential in the Alps
The rate and extent of wind-gap migration regulated by tributary confluences and avulsions
Inferring potential landslide damming using slope stability, geomorphic constraints, and run-out analysis: a case study from the NW Himalaya
Groundwater erosion of coastal gullies along the Canterbury coast (New Zealand): a rapid and episodic process controlled by rainfall intensity and substrate variability
Erosional response of granular material in landscape models
Transport-limited fluvial erosion – simple formulation and efficient numerical treatment
Dimensional analysis of a landscape evolution model with incision threshold
Computing water flow through complex landscapes – Part 2: Finding hierarchies in depressions and morphological segmentations
Rivers as linear elements in landform evolution models
Interactions between main channels and tributary alluvial fans: channel adjustments and sediment-signal propagation
Drainage divide networks – Part 1: Identification and ordering in digital elevation models
Drainage divide networks – Part 2: Response to perturbations
Hillslope denudation and morphologic response to a rock uplift gradient
Geomorphic signatures of the transient fluvial response to tilting
The destiny of orogen-parallel streams in the Eastern Alps: the Salzach–Enns drainage system
Statistical modelling of co-seismic knickpoint formation and river response to fault slip
A versatile, linear complexity algorithm for flow routing in topographies with depressions
Can the growth of deltaic shorelines be unstable?
Development of proglacial lakes and evaluation of related outburst susceptibility at the Adygine ice-debris complex, northern Tien Shan
Reconstruction of four-dimensional rockfall trajectories using remote sensing and rock-based accelerometers and gyroscopes
Short communication: flow as distributed lines within the landscape
Morphological effects of vegetation on the tidal–fluvial transition in Holocene estuaries
Scaling and similarity of a stream-power incision and linear diffusion landscape evolution model
A lattice grain model of hillslope evolution
On the Holocene evolution of the Ayeyawady megadelta
Numerical modelling of landscape and sediment flux response to precipitation rate change
Patrick Boyden, Paolo Stocchi, and Alessio Rovere
Earth Surf. Dynam., 11, 917–931, https://doi.org/10.5194/esurf-11-917-2023, https://doi.org/10.5194/esurf-11-917-2023, 2023
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Preservation bias often hampers the extraction of sea level changes from the stratigraphic record. In this contribution, we use a forward stratigraphic model to build three synthetic subtropical fringing reefs for a site in southwestern Madagascar (Indian Ocean). Each of the three synthetic reefs represents a different ice sheet melt scenario for the Pleistocene. We then evaluate each resultant reef sequence against the observed stratigraphic record.
Gregory A. Ruetenik, John D. Jansen, Pedro Val, and Lotta Ylä-Mella
Earth Surf. Dynam., 11, 865–880, https://doi.org/10.5194/esurf-11-865-2023, https://doi.org/10.5194/esurf-11-865-2023, 2023
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We compare models of erosion against a global compilation of long-term erosion rates in order to find and interpret best-fit parameters using an iterative search. We find global signals among exponents which control the relationship between erosion rate and slope, as well as other parameters which are common in long-term erosion modelling. Finally, we analyse the global variability in parameters and find a correlation between precipitation and coefficients for optimised models.
Stefan Hergarten and Alexa Pietrek
Earth Surf. Dynam., 11, 741–755, https://doi.org/10.5194/esurf-11-741-2023, https://doi.org/10.5194/esurf-11-741-2023, 2023
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The transition from hillslopes to channelized flow is typically attributed to a threshold catchment size in landform evolution models. Here we propose an alternative concept directly based on topography. Using this concept, channels and hillslopes self-organize, whereby the catchment size of the channel heads varies over some range. Our numerical results suggest that this concept works better than the established idea of a strict threshold catchment size.
Riccardo Reitano, Romano Clementucci, Ethan M. Conrad, Fabio Corbi, Riccardo Lanari, Claudio Faccenna, and Chiara Bazzucchi
Earth Surf. Dynam., 11, 731–740, https://doi.org/10.5194/esurf-11-731-2023, https://doi.org/10.5194/esurf-11-731-2023, 2023
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Tectonics and surface processes work together in shaping orogens through their evolution. Laboratory models are used to overcome some limitations of direct observations since they allow for continuous and detailed analysis of analog orogens. We use a rectangular box filled with an analog material made of granular materials to study how erosional laws apply and how erosion affects the analog landscape as a function of the applied boundary conditions (regional slope and rainfall rate).
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.
Richard Ott, Sean F. Gallen, and David Helman
Earth Surf. Dynam., 11, 247–257, https://doi.org/10.5194/esurf-11-247-2023, https://doi.org/10.5194/esurf-11-247-2023, 2023
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We compile data on carbonate denudation, the sum of mechanical erosion and chemical weathering, from cosmogenic nuclides and use them in conjunction with weathering data to constrain the partitioning of denudation into erosion and weathering. We show how carbonate erosion and weathering respond to different climatic and tectonic conditions and find that variations in denudation partitioning can be used to explain the vastly different morphology of carbonate landscapes on Earth.
Joanmarie Del Vecchio, Emma R. Lathrop, Julian B. Dann, Christian G. Andresen, Adam D. Collins, Michael M. Fratkin, Simon Zwieback, Rachel C. Glade, and Joel C. Rowland
Earth Surf. Dynam., 11, 227–245, https://doi.org/10.5194/esurf-11-227-2023, https://doi.org/10.5194/esurf-11-227-2023, 2023
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In cold regions of the Earth, thawing permafrost can change the landscape, impact ecosystems, and lead to the release of greenhouse gases. In this study we used many observational tools to better understand how sediment moves on permafrost hillslopes. Some topographic change conforms to our understanding of slope stability and sediment transport as developed in temperate landscapes, but much of what we observed needs further explanation by permafrost-specific geomorphic models.
Carole Petit, Tristan Salles, Vincent Godard, Yann Rolland, and Laurence Audin
Earth Surf. Dynam., 11, 183–201, https://doi.org/10.5194/esurf-11-183-2023, https://doi.org/10.5194/esurf-11-183-2023, 2023
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We present new tools in the landscape evolution model Badlands to simulate 10Be production, erosion and transport. These tools are applied to a source-to-sink system in the SW French Alps, where the model is calibrated. We propose a model that fits river incision rates and 10Be concentrations in sediments, and we show that 10Be in deep marine sediments is a signal with multiple contributions that cannot be easily interpreted in terms of climate forcing.
Cas Renette, Kristoffer Aalstad, Juditha Aga, Robin Benjamin Zweigel, Bernd Etzelmüller, Karianne Staalesen Lilleøren, Ketil Isaksen, and Sebastian Westermann
Earth Surf. Dynam., 11, 33–50, https://doi.org/10.5194/esurf-11-33-2023, https://doi.org/10.5194/esurf-11-33-2023, 2023
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One of the reasons for lower ground temperatures in coarse, blocky terrain is a low or varying soil moisture content, which most permafrost modelling studies did not take into account. We used the CryoGrid community model to successfully simulate this effect and found markedly lower temperatures in well-drained, blocky deposits compared to other set-ups. The inclusion of this drainage effect is another step towards a better model representation of blocky mountain terrain in permafrost regions.
Luke A. McGuire, Scott W. McCoy, Odin Marc, William Struble, and Katherine R. Barnhart
Earth Surf. Dynam. Discuss., https://doi.org/10.5194/esurf-2022-47, https://doi.org/10.5194/esurf-2022-47, 2022
Revised manuscript accepted for ESurf
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Debris flows are mixtures of mud and rocks that can travel at high speeds across steep landscapes. Here, we propose a new model to describe how landscapes are shaped by debris flow erosion over long timescales. Model results demonstrate that the shapes of channel profiles are sensitive to uplift rate, meaning that it may be possible use topographic data from steep channel networks to infer how erosion rates vary in space across a landscape.
Brian G. Sockness and Karen B. Gran
Earth Surf. Dynam., 10, 581–603, https://doi.org/10.5194/esurf-10-581-2022, https://doi.org/10.5194/esurf-10-581-2022, 2022
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To study channel network development following continental glaciation, we ran small physical experiments where networks slowly expanded into flat surfaces. By changing substrate and rainfall, we altered flow pathways between surface and subsurface. Initially, most channels grew by overland flow. As relief increased, erosion through groundwater sapping occurred, especially in runs with high infiltration and low cohesion, highlighting the importance of groundwater in channel network evolution.
Harrison K. Martin and Douglas A. Edmonds
Earth Surf. Dynam., 10, 555–579, https://doi.org/10.5194/esurf-10-555-2022, https://doi.org/10.5194/esurf-10-555-2022, 2022
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River avulsions (rivers suddenly changing course) redirect water and sediment. These floods can harm people and control how some landscapes evolve. We model how abandoned channels from older avulsions affect where, when, and why future avulsions occur in mountain-front areas. We show that abandoned channels can push and pull avulsions, and the way they heal controls landscapes. Avulsion models should include abandoned channels; we also highlight opportunities for future field workers.
Ariel Henrique do Prado, Renato Paes de Almeida, Cristiano Padalino Galeazzi, Victor Sacek, and Fritz Schlunegger
Earth Surf. Dynam., 10, 457–471, https://doi.org/10.5194/esurf-10-457-2022, https://doi.org/10.5194/esurf-10-457-2022, 2022
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Our work is focused on describing how and why the terrace levels of central Amazonia were formed during the last 100 000 years. We propose to address this question through a landscape evolution numerical model. Our results show that terrace levels at lower elevation were established in response to dry–wet climate changes and the older terrace levels at higher elevations most likely formed in response to a previously higher elevation of the regional base level.
Clément Desormeaux, Vincent Godard, Dimitri Lague, Guillaume Duclaux, Jules Fleury, Lucilla Benedetti, Olivier Bellier, and the ASTER Team
Earth Surf. Dynam., 10, 473–492, https://doi.org/10.5194/esurf-10-473-2022, https://doi.org/10.5194/esurf-10-473-2022, 2022
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Landscape evolution is highly dependent on climatic parameters, and the occurrence of intense precipitation events is considered to be an important driver of river incision. We compare the rate of erosion with the variability of river discharge in a mountainous landscape of SE France where high-magnitude floods regularly occur. Our study highlights the importance of the hypotheses made regarding the threshold that river discharge needs to exceed in order to effectively cut down into the bedrock.
Jean Braun
Earth Surf. Dynam., 10, 301–327, https://doi.org/10.5194/esurf-10-301-2022, https://doi.org/10.5194/esurf-10-301-2022, 2022
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By comparing two models for the transport of sediment, we find that they share a similar steady-state solution that adequately predicts the shape of most depositional systems made of a fan and an alluvial plain. The length of the fan is controlled by the size of the mountain drainage area feeding the sedimentary system and its slope by the incoming sedimentary flux. We show that the models differ in their transient behavior to external forcing and are characterized by different response times.
Léopold de Lavaissière, Stéphane Bonnet, Anne Guyez, and Philippe Davy
Earth Surf. Dynam., 10, 229–246, https://doi.org/10.5194/esurf-10-229-2022, https://doi.org/10.5194/esurf-10-229-2022, 2022
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Rivers are known to record changes in tectonic or climatic variation through long adjustment of their longitudinal profile slope. Here we describe such adjustments in experimental landscapes and show that they may result from the sole effect of intrinsic geomorphic processes. We propose a new model of river evolution that links long profile adjustment to cycles of river widening and narrowing. This result emphasizes the need to better understand control of lateral erosion on river width.
Elco Luijendijk
Earth Surf. Dynam., 10, 1–22, https://doi.org/10.5194/esurf-10-1-2022, https://doi.org/10.5194/esurf-10-1-2022, 2022
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The distance between rivers is a noticeable feature of the Earth's surface. Previous work has indicated that subsurface groundwater flow may be important for drainage density. Here, I present a new model that combines subsurface and surface water flow and erosion, and demonstrates that groundwater exerts an important control on drainage density. Streams that incise rapidly can capture the groundwater discharge of adjacent streams, which may cause these streams to become dry and stop incising.
Nikos Theodoratos and James W. Kirchner
Earth Surf. Dynam., 9, 1545–1561, https://doi.org/10.5194/esurf-9-1545-2021, https://doi.org/10.5194/esurf-9-1545-2021, 2021
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We examine stream-power incision and linear diffusion landscape evolution models with and without incision thresholds. We present a steady-state relationship between curvature and the steepness index, which plots as a straight line. We view this line as a counterpart to the slope–area relationship for the case of landscapes with hillslope diffusion. We show that simple shifts and rotations of this line graphically express the topographic response of landscapes to changes in model parameters.
Yanyan Wang and Sean D. Willett
Earth Surf. Dynam., 9, 1301–1322, https://doi.org/10.5194/esurf-9-1301-2021, https://doi.org/10.5194/esurf-9-1301-2021, 2021
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Although great escarpment mountain ranges are characterized by high relief, modern erosion rates suggest slow rates of landscape change. We question this interpretation by presenting a new method for interpreting concentrations of cosmogenic isotopes. Our analysis shows that erosion has localized onto an escarpment face, driving retreat of the escarpment at high rates. Our quantification of this retreat rate rationalizes the high-relief, dramatic landscape with the rates of geomorphic change.
William T. Struble and Joshua J. Roering
Earth Surf. Dynam., 9, 1279–1300, https://doi.org/10.5194/esurf-9-1279-2021, https://doi.org/10.5194/esurf-9-1279-2021, 2021
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We used a mathematical technique known as a wavelet transform to calculate the curvature of hilltops in western Oregon, which we used to estimate erosion rate. We find that this technique operates over 1000 times faster than other techniques and produces accurate erosion rates. We additionally built artificial hillslopes to test the accuracy of curvature measurement methods. We find that at fast erosion rates, curvature is underestimated, raising questions of measurement accuracy elsewhere.
Philippe Steer
Earth Surf. Dynam., 9, 1239–1250, https://doi.org/10.5194/esurf-9-1239-2021, https://doi.org/10.5194/esurf-9-1239-2021, 2021
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How landscapes respond to tectonic and climatic changes is a major issue in Earth sciences. I have developed a new model that solves for landscape evolution in two dimensions using analytical solutions. Compared to numerical models, this new model is quicker and more accurate. It can compute in a single time step the topography at equilibrium of a landscape or be used to describe its evolution through time, e.g. during changes in tectonic or climatic conditions.
Hemanti Sharma, Todd A. Ehlers, Christoph Glotzbach, Manuel Schmid, and Katja Tielbörger
Earth Surf. Dynam., 9, 1045–1072, https://doi.org/10.5194/esurf-9-1045-2021, https://doi.org/10.5194/esurf-9-1045-2021, 2021
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We study effects of variable climate–vegetation with different uplift rates on erosion–sedimentation using a landscape evolution modeling approach. Results suggest that regardless of uplift rates, transients in precipitation–vegetation lead to transients in erosion rates in the same direction of change. Vegetation-dependent erosion and sedimentation are influenced by Milankovitch timescale changes in climate, but these transients are superimposed upon tectonically driven uplift rates.
Stefan Hergarten
Earth Surf. Dynam., 9, 937–952, https://doi.org/10.5194/esurf-9-937-2021, https://doi.org/10.5194/esurf-9-937-2021, 2021
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This paper presents a new approach to modeling glacial erosion on large scales. The formalism is similar to large-scale models of fluvial erosion, so glacial and fluvial processes can be easily combined. The model is simpler and numerically less demanding than established models based on a more detailed description of the ice flux. The numerical implementation almost achieves the efficiency of purely fluvial models, so that simulations over millions of years can be performed on standard PCs.
Martine Simoes, Timothée Sassolas-Serrayet, Rodolphe Cattin, Romain Le Roux-Mallouf, Matthieu Ferry, and Dowchu Drukpa
Earth Surf. Dynam., 9, 895–921, https://doi.org/10.5194/esurf-9-895-2021, https://doi.org/10.5194/esurf-9-895-2021, 2021
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Elevated low-relief regions and major river knickpoints have for long been noticed and questioned in the emblematic Bhutan Himalaya. We document the morphology of this region using morphometric analyses and field observations, at a variety of spatial scales. Our findings reveal a highly unstable river network, with numerous non-coeval river captures, most probably related to a dynamic response to local tectonic uplift in the mountain hinterland.
Julien Seguinot and Ian Delaney
Earth Surf. Dynam., 9, 923–935, https://doi.org/10.5194/esurf-9-923-2021, https://doi.org/10.5194/esurf-9-923-2021, 2021
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Ancient Alpine glaciers have carved a fascinating landscape of piedmont lakes, glacial valleys, and mountain cirques. Using a previous supercomputer simulation of glacier flow, we show that glacier erosion has constantly evolved and moved to different parts of the Alps. Interestingly, larger glaciers do not always cause more rapid erosion. Instead, glacier erosion is modelled to slow down during glacier advance and peak during phases of retreat, such as the one the Earth is currently undergoing.
Eitan Shelef and Liran Goren
Earth Surf. Dynam., 9, 687–700, https://doi.org/10.5194/esurf-9-687-2021, https://doi.org/10.5194/esurf-9-687-2021, 2021
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Drainage basins are bounded by water divides (divides) that define their shape and extent. Divides commonly coincide with high ridges, but in places that experienced extensive tectonic deformation, divides sometimes cross elongated valleys. Inspired by field observations and using simulations of landscape evolution, we study how side channels that drain to elongated valleys induce pulses of divide migration, affecting the distribution of water and erosion products across mountain ranges.
Vipin Kumar, Imlirenla Jamir, Vikram Gupta, and Rajinder K. Bhasin
Earth Surf. Dynam., 9, 351–377, https://doi.org/10.5194/esurf-9-351-2021, https://doi.org/10.5194/esurf-9-351-2021, 2021
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Despite a history of landslide damming and flash floods in the NW Himalaya, only a few studies have been performed. This study predicts some potential landslide damming sites in the Satluj valley, NW Himalaya, using field observations, laboratory analyses, geomorphic proxies, and numerical simulations. Five landslides, comprising a total landslide volume of 26.3 ± 6.7 M m3, are found to have the potential to block the river in the case of slope failure.
Aaron Micallef, Remus Marchis, Nader Saadatkhah, Potpreecha Pondthai, Mark E. Everett, Anca Avram, Alida Timar-Gabor, Denis Cohen, Rachel Preca Trapani, Bradley A. Weymer, and Phillipe Wernette
Earth Surf. Dynam., 9, 1–18, https://doi.org/10.5194/esurf-9-1-2021, https://doi.org/10.5194/esurf-9-1-2021, 2021
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We study coastal gullies along the Canterbury coast of New Zealand using field observations, sample analyses, drones, satellites, geophysical instruments and modelling. We show that these coastal gullies form when rainfall intensity is higher than 40 mm per day. The coastal gullies are formed by landslides where buried channels or sand lenses are located. This information allows us to predict where coastal gullies may form in the future.
Riccardo Reitano, Claudio Faccenna, Francesca Funiciello, Fabio Corbi, and Sean D. Willett
Earth Surf. Dynam., 8, 973–993, https://doi.org/10.5194/esurf-8-973-2020, https://doi.org/10.5194/esurf-8-973-2020, 2020
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Looking into processes that occur on different timescales that span over thousands or millions of years is difficult to achieve. This is the case when we try to understand the interaction between tectonics and surface processes. Analog modeling is an investigating technique that can overcome this limitation. We study the erosional response of an analog landscape by varying the concentration of components of analog materials that strongly affect the evolution of experimental landscapes.
Stefan Hergarten
Earth Surf. Dynam., 8, 841–854, https://doi.org/10.5194/esurf-8-841-2020, https://doi.org/10.5194/esurf-8-841-2020, 2020
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Many contemporary models of large-scale fluvial erosion focus on the detachment-limited regime where all material entrained by the river is immediately excavated. This limitation facilitates the comparison with real river profiles and strongly reduces the numerical complexity. Here a simple formulation for the opposite case, transport-limited erosion, and a new numerical scheme that achieves almost the same numerical efficiency as detachment-limited models are presented.
Nikos Theodoratos and James W. Kirchner
Earth Surf. Dynam., 8, 505–526, https://doi.org/10.5194/esurf-8-505-2020, https://doi.org/10.5194/esurf-8-505-2020, 2020
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We non-dimensionalized a commonly used model of landscape evolution that includes an incision threshold. Whereas the original model included four parameters, we obtained a dimensionless form with a single parameter, which quantifies the relative importance of the incision threshold. Working with this form saves computational time and simplifies theoretical analyses.
Richard Barnes, Kerry L. Callaghan, and Andrew D. Wickert
Earth Surf. Dynam., 8, 431–445, https://doi.org/10.5194/esurf-8-431-2020, https://doi.org/10.5194/esurf-8-431-2020, 2020
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Maps of elevation are used to help predict the flow of water so we can better understand landslides, floods, and global climate change. However, modeling the flow of water is difficult when elevation maps include swamps, lakes, and other depressions. This paper explains a new method that overcomes these difficulties, allowing models to run faster and more accurately.
Stefan Hergarten
Earth Surf. Dynam., 8, 367–377, https://doi.org/10.5194/esurf-8-367-2020, https://doi.org/10.5194/esurf-8-367-2020, 2020
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Models of fluvial erosion have a long history in landform evolution modeling. Interactions between rivers and processes acting at hillslopes (e.g., landslides) are receiving growing interest in this context. While present-day computer capacities allow for applying such coupled models, there is still a scaling problem when considering rivers to be linear elements on a topography. Based on a reinterpretation of old empirical results, this study presents a new approach to overcome this problem.
Sara Savi, Stefanie Tofelde, Andrew D. Wickert, Aaron Bufe, Taylor F. Schildgen, and Manfred R. Strecker
Earth Surf. Dynam., 8, 303–322, https://doi.org/10.5194/esurf-8-303-2020, https://doi.org/10.5194/esurf-8-303-2020, 2020
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Fluvial deposits record changes in water and sediment supply. As such, they are often used to reconstruct the tectonic or climatic history of a basin. In this study we used an experimental setting to analyze how fluvial deposits register changes in water or sediment supply at a confluence zone. We provide a new conceptual framework that may help understanding the construction of these deposits under different forcings conditions, information crucial to correctly inferring the history of a basin.
Dirk Scherler and Wolfgang Schwanghart
Earth Surf. Dynam., 8, 245–259, https://doi.org/10.5194/esurf-8-245-2020, https://doi.org/10.5194/esurf-8-245-2020, 2020
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Drainage divides are believed to provide clues about divide migration and the instability of landscapes. Here, we present a novel approach to extract drainage divides from digital elevation models and to order them in a drainage divide network. We present our approach by studying natural and artificial landscapes generated with a landscape evolution model and disturbed to induce divide migration.
Dirk Scherler and Wolfgang Schwanghart
Earth Surf. Dynam., 8, 261–274, https://doi.org/10.5194/esurf-8-261-2020, https://doi.org/10.5194/esurf-8-261-2020, 2020
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Drainage divides are believed to provide clues about divide migration and the instability of landscapes. Here, we present a novel approach to extract drainage divides from digital elevation models and to order them in a drainage divide network. We present our approach by studying natural and artificial landscapes generated with a landscape evolution model and disturbed to induce divide migration.
Vincent Godard, Jean-Claude Hippolyte, Edward Cushing, Nicolas Espurt, Jules Fleury, Olivier Bellier, Vincent Ollivier, and the ASTER Team
Earth Surf. Dynam., 8, 221–243, https://doi.org/10.5194/esurf-8-221-2020, https://doi.org/10.5194/esurf-8-221-2020, 2020
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Slow-slipping faults are often difficult to identify in landscapes. Here we analyzed high-resolution topographic data from the Valensole area at the front of the southwestern French Alps. We measured various properties of hillslopes such as their relief and the shape of hilltops. We observed systematic spatial variations of hillslope morphology indicative of relative changes in erosion rates. These variations are potentially related to slow tectonic deformation across the studied area.
Helen W. Beeson and Scott W. McCoy
Earth Surf. Dynam., 8, 123–159, https://doi.org/10.5194/esurf-8-123-2020, https://doi.org/10.5194/esurf-8-123-2020, 2020
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We used a computer model to show that, when a landscape is tilted, rivers respond in a distinct way such that river profiles take on unique forms that record tilt timing and magnitude. Using this suite of river forms, we estimated tilt timing and magnitude in the Sierra Nevada, USA, and results were consistent with independent measures. Our work broadens the scope of tectonic histories that can be extracted from landscape form to include tilting, which has been documented in diverse locations.
Georg Trost, Jörg Robl, Stefan Hergarten, and Franz Neubauer
Earth Surf. Dynam., 8, 69–85, https://doi.org/10.5194/esurf-8-69-2020, https://doi.org/10.5194/esurf-8-69-2020, 2020
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The evolution of the drainage system in the Eastern Alps is inherently linked to different tectonic stages. This leads to a situation in which major orogen-parallel alpine rivers, such as the Salzach and the Enns, are characterized by elongated east–west-oriented catchments. We investigate the stability of present-day drainage divides and the stability of reconstructed paleo-drainage systems. Our results indicate a progressive stability of the network towards the present-day situation.
Philippe Steer, Thomas Croissant, Edwin Baynes, and Dimitri Lague
Earth Surf. Dynam., 7, 681–706, https://doi.org/10.5194/esurf-7-681-2019, https://doi.org/10.5194/esurf-7-681-2019, 2019
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We use a statistical earthquake generator to investigate the influence of fault activity on river profile development and on the formation of co-seismic knickpoints. We find that the magnitude distribution of knickpoints resulting from a purely seismic fault is homogeneous. Shallow aseismic slip favours knickpoints generated by large-magnitude earthquakes nucleating at depth. Accounting for fault burial by alluvial cover can modulate the topographic expression of earthquakes and fault activity.
Guillaume Cordonnier, Benoît Bovy, and Jean Braun
Earth Surf. Dynam., 7, 549–562, https://doi.org/10.5194/esurf-7-549-2019, https://doi.org/10.5194/esurf-7-549-2019, 2019
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We propose a new algorithm to solve the problem of flow routing across local depressions in the topography, one of the main computational bottlenecks in landscape evolution models. Our solution is more efficient than the state-of-the-art algorithms, with an optimal linear asymptotic complexity. The algorithm has been designed specifically to be used within landscape evolution models, and also suits more generally the efficient treatment of large digital elevation models.
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.
Kristyna Falatkova, Miroslav Šobr, Anton Neureiter, Wolfgang Schöner, Bohumír Janský, Hermann Häusler, Zbyněk Engel, and Vojtěch Beneš
Earth Surf. Dynam., 7, 301–320, https://doi.org/10.5194/esurf-7-301-2019, https://doi.org/10.5194/esurf-7-301-2019, 2019
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In the last 50 years the Adygine glacier has been subject to relatively fast recession comparable to other glaciers in Tien Shan. As a consequence, a three-level cascade of glacial lakes formed, two of which were categorised as having medium outburst susceptibility. By 2050, the glacier is expected to have shrunk to 56–73 % of its 2012 extent. Further development of the site will result in formation of new lakes and probably also increase of outburst susceptibility due to permafrost degradation.
Andrin Caviezel, Sophia E. Demmel, Adrian Ringenbach, Yves Bühler, Guang Lu, Marc Christen, Claire E. Dinneen, Lucie A. Eberhard, Daniel von Rickenbach, and Perry Bartelt
Earth Surf. Dynam., 7, 199–210, https://doi.org/10.5194/esurf-7-199-2019, https://doi.org/10.5194/esurf-7-199-2019, 2019
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In rockfall hazard assessment, knowledge about the precise flight path of assumed boulders is vital for its accuracy. We present the full reconstruction of artificially induced rockfall events. The extracted information such as exact velocities, jump heights and lengths provide detailed insights into how rotating rocks interact with the ground. The information serves as future calibration of rockfall modelling tools with the goal of even more realistic modelling predictions.
John J. Armitage
Earth Surf. Dynam., 7, 67–75, https://doi.org/10.5194/esurf-7-67-2019, https://doi.org/10.5194/esurf-7-67-2019, 2019
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Landscape evolution models (LEMs) aim to capture an aggregation of the processes of erosion and deposition and predict evolving topography. A key aspect of any LEM is how water is chosen to be routed down the surface, which can impact the model results and, importantly, the numerical accuracy. I find that by treating flow as lines within the model domain and by distributing water down all slopes, the results are independent of resolution, pointing to a new method to model landscape evolution.
Ivar R. Lokhorst, Lisanne Braat, Jasper R. F. W. Leuven, Anne W. Baar, Mijke van Oorschot, Sanja Selaković, and Maarten G. Kleinhans
Earth Surf. Dynam., 6, 883–901, https://doi.org/10.5194/esurf-6-883-2018, https://doi.org/10.5194/esurf-6-883-2018, 2018
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In estuaries, mud sedimentation enhances salt marsh accretion. Here we explore system-scale effects of plants and mud on planform shape and size of estuaries. We coupled Delft3D for hydromorphodynamics with our vegetation model and ran controls for comparison. Effects are greatest at the fluvial–tidal transition, where for the first time in a model, a bedload convergence zone formed. Regardless of local vegetation effects, mud and vegetation cause gradual filling of estuaries over time.
Nikos Theodoratos, Hansjörg Seybold, and James W. Kirchner
Earth Surf. Dynam., 6, 779–808, https://doi.org/10.5194/esurf-6-779-2018, https://doi.org/10.5194/esurf-6-779-2018, 2018
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We perform dimensional analysis on a frequently used landscape evolution model (LEM). Defining characteristic scales in a novel way, we significantly simplify the LEM and develop an efficient numerical modeling approach. Our characteristic scales are physically meaningful; they quantify competitions between landscape-forming processes and are related to salient properties of landscape topography. Dimensional analyses of other LEMs may benefit from our approach in defining characteristic scales.
Gregory E. Tucker, Scott W. McCoy, and Daniel E. J. Hobley
Earth Surf. Dynam., 6, 563–582, https://doi.org/10.5194/esurf-6-563-2018, https://doi.org/10.5194/esurf-6-563-2018, 2018
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This article presents a new technique for computer simulation of slope forms. The method provides a way to study how events that disturb soil or turn rock into soil add up over time to produce landforms. The model represents a cross section of a hypothetical landform as a lattice of cells, each of which may represent air, soil, or rock. Despite its simplicity, the model does a good job of simulating a range of common of natural slope forms.
Liviu Giosan, Thet Naing, Myo Min Tun, Peter D. Clift, Florin Filip, Stefan Constantinescu, Nitesh Khonde, Jerzy Blusztajn, Jan-Pieter Buylaert, Thomas Stevens, and Swe Thwin
Earth Surf. Dynam., 6, 451–466, https://doi.org/10.5194/esurf-6-451-2018, https://doi.org/10.5194/esurf-6-451-2018, 2018
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Here we provide the first results on the evolution of the Ayeyarwady delta, the last unstudied megadelta of Asia. In addition to its intrinsic value as a founding study on the Holocene development of this region, we advance new ideas on the climate control of monsoonal deltas as well as describe for the first time a feedback mechanism between tectonics and tidal hydrodynamics that can explain the peculiarities of the Ayeyarwady delta.
John J. Armitage, Alexander C. Whittaker, Mustapha Zakari, and Benjamin Campforts
Earth Surf. Dynam., 6, 77–99, https://doi.org/10.5194/esurf-6-77-2018, https://doi.org/10.5194/esurf-6-77-2018, 2018
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We explore how two landscape evolution models respond to a change in climate. The two models are developed from a divergent assumption on the efficiency of sediment transport. Despite the different resulting mathematics, both numerical models display a similar functional response to a change in precipitation. However, if we model sediment transport rather than assume it is instantaneously removed, the model responds more rapidly, with a response time similar to that observed in nature.
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Short summary
Accurately predicting gravel transport rates in mountain rivers is difficult because of feedbacks with channel morphology. River bed surfaces evolve during floods, influencing transport rates. I propose that the threshold of gravel motion is a state variable for channel reach evolution. I develop a new model to predict how transport thresholds evolve as a function of transport rate, and then use laboratory flume experiments to calibrate and validate the model.
Accurately predicting gravel transport rates in mountain rivers is difficult because of...
