Articles | Volume 6, issue 1
https://doi.org/10.5194/esurf-6-163-2018
© Author(s) 2018. 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-6-163-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
05 Mar 2018
Research article |
| 05 Mar 2018
| 05 Mar 2018
Topographical change caused by moderate and small floods in a gravel bed ephemeral river – a depth-averaged morphodynamic simulation approach
Department of Geographical and Historical Studies, University of
Eastern Finland, Joensuu, Yliopistokatu 2, P.O. Box 111, 80101 Joensuu,
Finland
Department of Geography and Geology, University of Turku,
20014 Turku, Finland
Mikel Calle
National Museum of Natural Sciences, Spanish Research Council (CSIC),
Madrid, Calle de Serrano 117, 28006 Madrid, Spain
Gerardo Benito
National Museum of Natural Sciences, Spanish Research Council (CSIC),
Madrid, Calle de Serrano 117, 28006 Madrid, Spain
Antero Kukko
Department of Remote Sensing and Photogrammetry, Finnish Geospatial
Research Institute, National Land Survey of Finland, Kirkkonummi,
Geodeetinrinne 2, 02430 Masala, Finland
Department of Built Environment, Aalto University, Espoo,
Vaisalantie 8, P.O. Box 15800, 00076 Aalto, Finland
Harri Kaartinen
Department of Remote Sensing and Photogrammetry, Finnish Geospatial
Research Institute, National Land Survey of Finland, Kirkkonummi,
Geodeetinrinne 2, 02430 Masala, Finland
Department of Geography and Geology, University of Turku,
20014 Turku, Finland
Juha Hyyppä
Department of Remote Sensing and Photogrammetry, Finnish Geospatial
Research Institute, National Land Survey of Finland, Kirkkonummi,
Geodeetinrinne 2, 02430 Masala, Finland
Hannu Hyyppä
Department of Built Environment, Aalto University, Espoo,
Vaisalantie 8, P.O. Box 15800, 00076 Aalto, Finland
Petteri Alho
Department of Remote Sensing and Photogrammetry, Finnish Geospatial
Research Institute, National Land Survey of Finland, Kirkkonummi,
Geodeetinrinne 2, 02430 Masala, Finland
Department of Geography and Geology, University of Turku,
20014 Turku, Finland
Related authors
Reeta Vaahtera, Juha-Matti Välimäki, Tuure Takala, and Eliisa Lotsari
EGUsphere, https://doi.org/10.5194/egusphere-2024-1247, https://doi.org/10.5194/egusphere-2024-1247, 2024
Short summary
Short summary
River ice cover has a significant effect on flow and related processes in a river and the effect can last for months yearly. This impact is dependent on the properties of the ice, particularly its underside. Our study introduces a new approach to studying the underside of river ice, which is typically challenging. The approach allows gaining more information and new insights on river ice and flow during winters which is especially important under environmental change.
Mariana Verdonen, Alexander Störmer, Eliisa Lotsari, Pasi Korpelainen, Benjamin Burkhard, Alfred Colpaert, and Timo Kumpula
The Cryosphere, 17, 1803–1819, https://doi.org/10.5194/tc-17-1803-2023, https://doi.org/10.5194/tc-17-1803-2023, 2023
Short summary
Short summary
The study revealed a stable and even decreasing thickness of thaw depth in peat mounds with perennially frozen cores, despite overall rapid permafrost degradation within 14 years. This means that measuring the thickness of the thawed layer – a commonly used method – is alone insufficient to assess the permafrost conditions in subarctic peatlands. The study showed that climate change is the main driver of these permafrost features’ decay, but its effect depends on the peatland’s local conditions.
Tamir Grodek and Gerardo Benito
Nat. Hazards Earth Syst. Sci. Discuss., https://doi.org/10.5194/nhess-2024-171, https://doi.org/10.5194/nhess-2024-171, 2024
Preprint under review for NHESS
Short summary
Short summary
Check dams, terraces, and trees on steep basins serve to retain sediments, thereby protecting urbanized alluvial fan canals and levees from flooding. However, their effectiveness gradually decreases over time due to sedimentation and aging, which may lead to catastrophic breaching floods. To enhance urban resilience, we propose preserving natural mountain basins and allocating 20–30 % of the alluvial fan for channel migration and sediment deposition corridors.
Reeta Vaahtera, Juha-Matti Välimäki, Tuure Takala, and Eliisa Lotsari
EGUsphere, https://doi.org/10.5194/egusphere-2024-1247, https://doi.org/10.5194/egusphere-2024-1247, 2024
Short summary
Short summary
River ice cover has a significant effect on flow and related processes in a river and the effect can last for months yearly. This impact is dependent on the properties of the ice, particularly its underside. Our study introduces a new approach to studying the underside of river ice, which is typically challenging. The approach allows gaining more information and new insights on river ice and flow during winters which is especially important under environmental change.
Mariana Batista Campos, Leticia Ferrari Castanheiro, Dipal Shah, Yunsheng Wang, Antero Kukko, and Eetu Puttonen
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVIII-1-2024, 43–50, https://doi.org/10.5194/isprs-archives-XLVIII-1-2024-43-2024, https://doi.org/10.5194/isprs-archives-XLVIII-1-2024-43-2024, 2024
Shannon M. Hibbard, Gordon R. Osinski, Etienne Godin, Antero Kukko, Chimira Andres, Shawn Chartrand, Anna Grau Galofre, A. Mark Jellinek, and Wendy Boucher
EGUsphere, https://doi.org/10.5194/egusphere-2024-227, https://doi.org/10.5194/egusphere-2024-227, 2024
Short summary
Short summary
This study investigates a new landform found on Axel Heiberg Island in Nunavut, Canada. Vermicular Ridge Features (VRFs) are comprised of a series of ridges and troughs creating a unique brain-like pattern. We aim to identify how VRFs form and assess the past climate conditions necessary for their formation. We use surface elevation and subsurface data to infer a formation mechanism. We propose VRFs were formed from the burial and removal of glacier ice as the glaciers were retreating.
L. F. Castanheiro, A. M. G. Tommaselli, T. A. C. Garcia, M. B. Campos, and A. Kukko
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVIII-1-W1-2023, 71–77, https://doi.org/10.5194/isprs-archives-XLVIII-1-W1-2023-71-2023, https://doi.org/10.5194/isprs-archives-XLVIII-1-W1-2023-71-2023, 2023
T. Faitli, T. Hakala, H. Kaartinen, J. Hyyppä, and A. Kukko
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVIII-1-W1-2023, 145–150, https://doi.org/10.5194/isprs-archives-XLVIII-1-W1-2023-145-2023, https://doi.org/10.5194/isprs-archives-XLVIII-1-W1-2023-145-2023, 2023
Mariana Verdonen, Alexander Störmer, Eliisa Lotsari, Pasi Korpelainen, Benjamin Burkhard, Alfred Colpaert, and Timo Kumpula
The Cryosphere, 17, 1803–1819, https://doi.org/10.5194/tc-17-1803-2023, https://doi.org/10.5194/tc-17-1803-2023, 2023
Short summary
Short summary
The study revealed a stable and even decreasing thickness of thaw depth in peat mounds with perennially frozen cores, despite overall rapid permafrost degradation within 14 years. This means that measuring the thickness of the thawed layer – a commonly used method – is alone insufficient to assess the permafrost conditions in subarctic peatlands. The study showed that climate change is the main driver of these permafrost features’ decay, but its effect depends on the peatland’s local conditions.
L. Zhu, E. Hattula, J. Raninen, and J. Hyyppä
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVIII-4-W1-2022, 561–568, https://doi.org/10.5194/isprs-archives-XLVIII-4-W1-2022-561-2022, https://doi.org/10.5194/isprs-archives-XLVIII-4-W1-2022-561-2022, 2022
P. Rönnholm, S. Wittke, M. Ingman, P. Putkiranta, H. Kauhanen, H. Kaartinen, and M. T. Vaaja
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIII-B2-2022, 633–639, https://doi.org/10.5194/isprs-archives-XLIII-B2-2022-633-2022, https://doi.org/10.5194/isprs-archives-XLIII-B2-2022-633-2022, 2022
C. Jiang, Y. Chen, B. Xu, J. Jia, H. Sun, Z. He, T. Wang, and J. Hyyppä
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLVI-3-W1-2022, 61–66, https://doi.org/10.5194/isprs-archives-XLVI-3-W1-2022-61-2022, https://doi.org/10.5194/isprs-archives-XLVI-3-W1-2022-61-2022, 2022
Gerardo Benito, Olegario Castillo, Juan A. Ballesteros-Cánovas, Maria Machado, and Mariano Barriendos
Hydrol. Earth Syst. Sci., 25, 6107–6132, https://doi.org/10.5194/hess-25-6107-2021, https://doi.org/10.5194/hess-25-6107-2021, 2021
Short summary
Short summary
Climate change is expected to increase the intensity of floods, but changes are difficult to project. We compiled historical and modern flood data of the Rio Duero (Spain) to evaluate flood hazards beyond decadal climate cycles. Historical floods were obtained from documentary sources, identifying 69 floods over 1250–1871 CE. Discharges were calculated from reported flood heights. Flood frequency using historical datasets showed the most robust results, guiding climate change adaptation.
Terhikki Manninen, Kati Anttila, Emmihenna Jääskeläinen, Aku Riihelä, Jouni Peltoniemi, Petri Räisänen, Panu Lahtinen, Niilo Siljamo, Laura Thölix, Outi Meinander, Anna Kontu, Hanne Suokanerva, Roberta Pirazzini, Juha Suomalainen, Teemu Hakala, Sanna Kaasalainen, Harri Kaartinen, Antero Kukko, Olivier Hautecoeur, and Jean-Louis Roujean
The Cryosphere, 15, 793–820, https://doi.org/10.5194/tc-15-793-2021, https://doi.org/10.5194/tc-15-793-2021, 2021
Short summary
Short summary
The primary goal of this paper is to present a model of snow surface albedo (brightness) accounting for small-scale surface roughness effects. It can be combined with any volume scattering model. The results indicate that surface roughness may decrease the albedo by about 1–3 % in midwinter and even more than 10 % during the late melting season. The effect is largest for low solar zenith angle values and lower bulk snow albedo values.
J.-P. Virtanen, A. Julin, H. Handolin, T. Rantanen, M. Maksimainen, J. Hyyppä, and H. Hyyppä
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIV-4-W1-2020, 159–165, https://doi.org/10.5194/isprs-archives-XLIV-4-W1-2020-159-2020, https://doi.org/10.5194/isprs-archives-XLIV-4-W1-2020-159-2020, 2020
M. Campos, P. Litkey, Y. Wang, Y. Chen, H. Hyyti, J. Hyyppä, and E. Puttonen
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLIII-B1-2020, 27–31, https://doi.org/10.5194/isprs-archives-XLIII-B1-2020-27-2020, https://doi.org/10.5194/isprs-archives-XLIII-B1-2020-27-2020, 2020
A. Kukko, H. Kaartinen, G. Osinski, and J. Hyyppä
ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci., V-2-2020, 749–756, https://doi.org/10.5194/isprs-annals-V-2-2020-749-2020, https://doi.org/10.5194/isprs-annals-V-2-2020-749-2020, 2020
Anna Grau Galofre, A. Mark Jellinek, Gordon R. Osinski, Michael Zanetti, and Antero Kukko
The Cryosphere, 12, 1461–1478, https://doi.org/10.5194/tc-12-1461-2018, https://doi.org/10.5194/tc-12-1461-2018, 2018
Short summary
Short summary
Water accumulated at the base of ice sheets is the main driver of glacier acceleration and loss of ice mass in Arctic regions. Previously glaciated landscapes sculpted by this water carry information about how ice sheets collapse and ultimately disappear. The search for these landscapes took us to the high Arctic, to explore channels that formed under kilometers of ice during the last ice age. In this work we describe how subglacial channels look and how they helped to drain an ice sheet.
N. Saarinen, M. Vastaranta, R. Näsi, T. Rosnell, T. Hakala, E. Honkavaara, M. A. Wulder, V. Luoma, A. M. G. Tommaselli, N. N. Imai, E. A. W. Ribeiro, R. B. Guimarães, M. Holopainen, and J. Hyyppä
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-3-W3, 171–175, https://doi.org/10.5194/isprs-archives-XLII-3-W3-171-2017, https://doi.org/10.5194/isprs-archives-XLII-3-W3-171-2017, 2017
S. Junttila, M. Vastaranta, R. Linnakoski, J. Sugano, H. Kaartinen, A. Kukko, M. Holopainen, H. Hyyppä, and J. Hyyppä
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-3-W3, 81–85, https://doi.org/10.5194/isprs-archives-XLII-3-W3-81-2017, https://doi.org/10.5194/isprs-archives-XLII-3-W3-81-2017, 2017
M. Katoh, S. Deng, Y. Takenaka, K. Cheung, K. Oono, M. Horisawa, J. Hyyppä, X. Yu, X. Liang, and Y. Wang
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-3-W3, 95–100, https://doi.org/10.5194/isprs-archives-XLII-3-W3-95-2017, https://doi.org/10.5194/isprs-archives-XLII-3-W3-95-2017, 2017
L. Matikainen, K. Karila, J. Hyyppä, E. Puttonen, P. Litkey, and E. Ahokas
Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLII-3-W3, 119–122, https://doi.org/10.5194/isprs-archives-XLII-3-W3-119-2017, https://doi.org/10.5194/isprs-archives-XLII-3-W3-119-2017, 2017
G. Benito, R. Brázdil, J. Herget, and M. J. Machado
Hydrol. Earth Syst. Sci., 19, 3517–3539, https://doi.org/10.5194/hess-19-3517-2015, https://doi.org/10.5194/hess-19-3517-2015, 2015
Short summary
Short summary
Historical hydrology combines documentary data with hydrological methods to lengthen flow records to the past centuries. We describe the methodological evolution of historical hydrology under the influence of developments in hydraulics and statistics. Analysis of 45 case studies in Europe show that present flood magnitudes are not unusual in the context of the past, whereas flood frequency has decreased, although some rivers show a reactivation of rare floods over the last two decades.
M. J. Machado, B. A. Botero, J. López, F. Francés, A. Díez-Herrero, and G. Benito
Hydrol. Earth Syst. Sci., 19, 2561–2576, https://doi.org/10.5194/hess-19-2561-2015, https://doi.org/10.5194/hess-19-2561-2015, 2015
Short summary
Short summary
A flood frequency analysis using a 400-year historical flood record was carried out using a stationary model (based on maximum likelihood estimators) and a non-stationary model that incorporates external covariates (climatic and environmental). The stationary model was successful in providing an average discharge around which value flood quantiles estimated by non-stationary models fluctuate through time.
J. Svensson, A. Virkkula, O. Meinander, N. Kivekäs, H.-R. Hannula, O. Järvinen, J. I. Peltoniemi, M. Gritsevich, A. Heikkilä, A. Kontu, A.-P. Hyvärinen, K. Neitola, D. Brus, P. Dagsson-Waldhauserova, K. Anttila, T. Hakala, H. Kaartinen, M. Vehkamäki, G. de Leeuw, and H. Lihavainen
The Cryosphere Discuss., https://doi.org/10.5194/tcd-9-1227-2015, https://doi.org/10.5194/tcd-9-1227-2015, 2015
Revised manuscript not accepted
Short summary
Short summary
Soot's (including black carbon and organics) negative effect on a natural snow pack is experimentally addressed in this paper through a series of experiments. Soot concentrations in the snow in the range of 200-200 000 ppb verify the negative effects on the albedo, the physical snow characteristics, as well as increasing the melt rate of the snow pack. Our experimental data generally agrees when compared with the Snow, Ice and Aerosol Radiation model.
G. Bussi, X. Rodríguez-Lloveras, F. Francés, G. Benito, Y. Sánchez-Moya, and A. Sopeña
Hydrol. Earth Syst. Sci., 17, 3339–3354, https://doi.org/10.5194/hess-17-3339-2013, https://doi.org/10.5194/hess-17-3339-2013, 2013
Related subject area
Physical: Geomorphology (including all aspects of fluvial, coastal, aeolian, hillslope and glacial geomorphology)
Barchan swarm dynamics from a Two-Flank Agent-Based Model
A landslide runout model for sediment transport, landscape evolution, and hazard assessment applications
Tracking slow-moving landslides with PlanetScope data: new perspectives on the satellite's perspective
Topographic metrics for unveiling fault segmentation and tectono-geomorphic evolution with insights into the impact of inherited topography, Ulsan Fault Zone, South Korea
Acceleration of coastal-retreat rates for high-Arctic rock cliffs on Brøggerhalvøya, Svalbard, over the past decade
The impact of bedrock meander cutoffs on 50 kyr scale incision rates, San Juan River, Utah
How water, temperature, and seismicity control the preconditioning of massive rock slope failure (Hochvogel)
Large structure simulation for landscape evolution models
Terrace formation linked to outburst floods at the Diexi palaeo-landslide dam, upper Minjiang River, eastern Tibetan Plateau
Pliocene shorelines and the epeirogenic motion of continental margins: a target dataset for dynamic topography models
Decadal-scale decay of landslide-derived fluvial suspended sediment after Typhoon Morakot
Role of the forcing sources in morphodynamic modelling of an embayed beach
A machine learning approach to the geomorphometric detection of ribbed moraines in Norway
Overdeepening or tunnel valley of the Aare glacier on the northern margin of the European Alps: Basins, riegels, and slot canyons
Stream hydrology controls on ice cliff evolution and survival on debris-covered glaciers
Time-varying drainage basin development and erosion on volcanic edifices
Geomorphic risk maps for river migration using probabilistic modeling – a framework
Evolution of submarine canyons and hanging-wall fans: insights from geomorphic experiments and morphodynamic models
Riverine sediment response to deforestation in the Amazon basin
Physical modeling of ice-sheet-induced salt movements using the example of northern Germany
Downstream rounding rate of pebbles in the Himalaya
Post-fire Variability in Sediment Transport by Ravel in the Diablo Range
Landscape response to tectonic deformation and cyclic climate change since ca. 800 ka in the southern Central Andes
Examination of Analytical Shear Stress Predictions for Coastal Dune Evolution
A physics-based model for fluvial valley width
Implications for the resilience of modern coastal systems derived from mesoscale barrier dynamics at Fire Island, New York
Quantifying the migration rate of drainage divides from high-resolution topographic data
Validating floc settling velocity models in rivers and freshwater wetlands
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
A simple model for faceted topographies at normal faults based on an extended stream-power law
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
River suspended-sand flux computation with uncertainty estimation, using water samples and high-resolution ADCP measurements
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
Evidence of slow millennial cliff retreat rates using cosmogenic nuclides in coastal colluvium
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
Dominic T. Robson and Andreas C. W. Baas
Earth Surf. Dynam., 12, 1205–1226, https://doi.org/10.5194/esurf-12-1205-2024, https://doi.org/10.5194/esurf-12-1205-2024, 2024
Short summary
Short summary
Barchans are fast-moving sand dunes which form large populations (swarms) on Earth and Mars. We show that a small range of model parameters produces swarms in which dune size does not vary downwind – something that is observed in nature but not when using earlier models. We also show how the shape of dunes and the spatial patterns they form are affected by wind direction. This work furthers our understanding of the interplay between environmental drivers, dune interactions, and swarm properties.
Jeffrey Keck, Erkan Istanbulluoglu, Benjamin Campforts, Gregory Tucker, and Alexander Horner-Devine
Earth Surf. Dynam., 12, 1165–1191, https://doi.org/10.5194/esurf-12-1165-2024, https://doi.org/10.5194/esurf-12-1165-2024, 2024
Short summary
Short summary
MassWastingRunout (MWR) is a new landslide runout model designed for sediment transport, landscape evolution, and hazard assessment applications. MWR is written in Python and includes a calibration utility that automatically determines best-fit parameters for a site and empirical probability density functions of each parameter for probabilistic model implementation. MWR and Jupyter Notebook tutorials are available as part of the Landlab package at https://github.com/landlab/landlab.
Ariane Mueting and Bodo Bookhagen
Earth Surf. Dynam., 12, 1121–1143, https://doi.org/10.5194/esurf-12-1121-2024, https://doi.org/10.5194/esurf-12-1121-2024, 2024
Short summary
Short summary
This study investigates the use of optical PlanetScope data for offset tracking of the Earth's surface movement. We found that co-registration accuracy is locally degraded when outdated elevation models are used for orthorectification. To mitigate this bias, we propose to only correlate scenes acquired from common perspectives or base orthorectification on more up-to-date elevation models generated from PlanetScope data alone. This enables a more detailed analysis of landslide dynamics.
Cho-Hee Lee, Yeong Bae Seong, John Weber, Sangmin Ha, Dong-Eun Kim, and Byung Yong Yu
Earth Surf. Dynam., 12, 1091–1120, https://doi.org/10.5194/esurf-12-1091-2024, https://doi.org/10.5194/esurf-12-1091-2024, 2024
Short summary
Short summary
Topographic metrics were used to understand changes due to tectonic activity. We evaluated the relative tectonic activity along the Ulsan Fault Zone (UFZ), one of the most active fault zones in South Korea. We divided the UFZ into five segments, based on the spatial variation in activity. We modeled the landscape evolution of the study area and interpreted tectono-geomorphic history during which the northern part of the UFZ experienced asymmetric uplift, while the southern part did not.
Juditha Aga, Livia Piermattei, Luc Girod, Kristoffer Aalstad, Trond Eiken, Andreas Kääb, and Sebastian Westermann
Earth Surf. Dynam., 12, 1049–1070, https://doi.org/10.5194/esurf-12-1049-2024, https://doi.org/10.5194/esurf-12-1049-2024, 2024
Short summary
Short summary
Coastal rock cliffs on Svalbard are considered to be fairly stable; however, long-term trends in coastal-retreat rates remain unknown. This study examines changes in the coastline position along Brøggerhalvøya, Svalbard, using aerial images from 1970, 1990, 2010, and 2021. Our analysis shows that coastal-retreat rates accelerate during the period 2010–2021, which coincides with increasing storminess and retreating sea ice.
Aaron T. Steelquist, Gustav B. Seixas, Mary L. Gillam, Sourav Saha, Seulgi Moon, and George E. Hilley
Earth Surf. Dynam., 12, 1071–1089, https://doi.org/10.5194/esurf-12-1071-2024, https://doi.org/10.5194/esurf-12-1071-2024, 2024
Short summary
Short summary
The rates at which rivers erode their bed can be used to interpret the geologic history of a region. However, these rates depend significantly on the time window over which you measure. We use multiple dating methods to determine an incision rate for the San Juan River and compare it to regional rates with longer timescales. We demonstrate how specific geologic events, such as cutoffs of bedrock meander bends, are likely to preserve material we can date but also bias the rates we measure.
Johannes Leinauer, Michael Dietze, Sibylle Knapp, Riccardo Scandroglio, Maximilian Jokel, and Michael Krautblatter
Earth Surf. Dynam., 12, 1027–1048, https://doi.org/10.5194/esurf-12-1027-2024, https://doi.org/10.5194/esurf-12-1027-2024, 2024
Short summary
Short summary
Massive rock slope failures are a significant alpine hazard and change the Earth's surface. Therefore, we must understand what controls the preparation of such events. By correlating 4 years of slope displacements with meteorological and seismic data, we found that water from rain and snowmelt is the most important driver. Our approach is applicable to similar sites and indicates where future climatic changes, e.g. in rain intensity and frequency, may alter the preparation of slope failure.
Julien Coatléven and Benoit Chauveau
Earth Surf. Dynam., 12, 995–1026, https://doi.org/10.5194/esurf-12-995-2024, https://doi.org/10.5194/esurf-12-995-2024, 2024
Short summary
Short summary
The aim of this paper is to explain how to incorporate classical water flow routines into landscape evolution models while keeping numerical errors under control. The key idea is to adapt filtering strategies to eliminate anomalous numerical errors and mesh dependencies, as confirmed by convergence tests with analytic solutions. The emergence of complex geomorphic structures is now driven exclusively by nonlinear heterogeneous physical processes rather than by random numerical artifacts.
Jingjuan Li, John D. Jansen, Xuanmei Fan, Zhiyong Ding, Shugang Kang, and Marco Lovati
Earth Surf. Dynam., 12, 953–971, https://doi.org/10.5194/esurf-12-953-2024, https://doi.org/10.5194/esurf-12-953-2024, 2024
Short summary
Short summary
In this study, we investigated the geomorphology, sedimentology, and chronology of Tuanjie (seven terraces) and Taiping (three terraces) terraces in Diexi, eastern Tibetan Plateau. Results highlight that two damming and three outburst events occurred in the area during the late Pleistocene, and the outburst floods have been a major factor in the formation of tectonically active mountainous river terraces. Tectonic activity and climatic changes play a minor role.
Andrew Hollyday, Maureen E. Raymo, Jacqueline Austermann, Fred Richards, Mark Hoggard, and Alessio Rovere
Earth Surf. Dynam., 12, 883–905, https://doi.org/10.5194/esurf-12-883-2024, https://doi.org/10.5194/esurf-12-883-2024, 2024
Short summary
Short summary
Sea level was significantly higher during the Pliocene epoch, around 3 million years ago. The present-day elevations of shorelines that formed in the past provide a data constraint on the extent of ice sheet melt and the global sea level response under warm Pliocene conditions. In this study, we identify 10 escarpments that formed from wave-cut erosion during Pliocene times and compare their elevations with model predictions of solid Earth deformation processes to estimate past sea level.
Gregory A. Ruetenik, Ken L. Ferrier, and Odin Marc
Earth Surf. Dynam., 12, 863–881, https://doi.org/10.5194/esurf-12-863-2024, https://doi.org/10.5194/esurf-12-863-2024, 2024
Short summary
Short summary
Fluvial sediment fluxes increased dramatically in Taiwan during Typhoon Morakot in 2009, which produced some of the heaviest landsliding on record. We analyzed fluvial discharge and suspended sediment concentration data at 87 gauging stations across Taiwan to quantify fluvial sediment responses since Morakot. In basins heavily impacted by landsliding, rating curve coefficients sharply increased during Morakot and then declined exponentially with a characteristic decay time of <10 years.
Nil Carrion-Bertran, Albert Falqués, Francesca Ribas, Daniel Calvete, Rinse de Swart, Ruth Durán, Candela Marco-Peretó, Marta Marcos, Angel Amores, Tim Toomey, Àngels Fernández-Mora, and Jorge Guillén
Earth Surf. Dynam., 12, 819–839, https://doi.org/10.5194/esurf-12-819-2024, https://doi.org/10.5194/esurf-12-819-2024, 2024
Short summary
Short summary
The sensitivity to the wave and sea-level forcing sources in predicting a 6-month embayed beach evolution is assessed using two different morphodynamic models. After a successful model calibration using in situ data, other sources are applied. The wave source choice is critical: hindcast data provide wrong results due to an angle bias, whilst the correct dynamics are recovered with the wave conditions from an offshore buoy. The use of different sea-level sources gives no significant differences.
Thomas J. Barnes, Thomas V. Schuler, Simon Filhol, and Karianne S. Lilleøren
Earth Surf. Dynam., 12, 801–818, https://doi.org/10.5194/esurf-12-801-2024, https://doi.org/10.5194/esurf-12-801-2024, 2024
Short summary
Short summary
In this paper, we use machine learning to automatically outline landforms based on their characteristics. We test several methods to identify the most accurate and then proceed to develop the most accurate to improve its accuracy further. We manage to outline landforms with 65 %–75 % accuracy, at a resolution of 10 m, thanks to high-quality/high-resolution elevation data. We find that it is possible to run this method at a country scale to quickly produce landform inventories for future studies.
Fritz Schlunegger, Edi Kissling, Dimitri Tibo Bandou, Guilhem Amin Douillet, David Mair, Urs Marti, Regina Reber, Patrick Fabian Schläfli, and Michael Alfred Schwenk
EGUsphere, https://doi.org/10.5194/egusphere-2024-683, https://doi.org/10.5194/egusphere-2024-683, 2024
Short summary
Short summary
Overdeepenings are bedrock depressions filled with sediment. We combine the results of a gravity survey with drilling data to explore the morphology of such a depression beneath the city of Bern. We find that the target overdeepening comprises two basins >200 m deep. They are separated by a bedrock riegel that itself is cut by narrow canyons up to 150 m deep. We postulate that these structures formed underneath a glacier, where erosion by subglacial meltwater caused the formation of the canyons.
Eric Petersen, Regine Hock, and Michael G. Loso
Earth Surf. Dynam., 12, 727–745, https://doi.org/10.5194/esurf-12-727-2024, https://doi.org/10.5194/esurf-12-727-2024, 2024
Short summary
Short summary
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, 33 % of ice cliffs are actively influenced by streams, while nearly half are within 10 m of streams.
Daniel O'Hara, Liran Goren, Roos M. J. van Wees, Benjamin Campforts, Pablo Grosse, Pierre Lahitte, Gabor Kereszturi, and Matthieu Kervyn
Earth Surf. Dynam., 12, 709–726, https://doi.org/10.5194/esurf-12-709-2024, https://doi.org/10.5194/esurf-12-709-2024, 2024
Short summary
Short summary
Understanding how volcanic edifices develop drainage basins remains unexplored in landscape evolution. Using digital evolution models of volcanoes with varying ages, we quantify the geometries of their edifices and associated drainage basins through time. We find that these metrics correlate with edifice age and are thus useful indicators of a volcano’s history. We then develop a generalized model for how volcano basins develop and compare our results to basin evolution in other settings.
Brayden Noh, Omar Wani, Kieran B. J. Dunne, and Michael P. Lamb
Earth Surf. Dynam., 12, 691–708, https://doi.org/10.5194/esurf-12-691-2024, https://doi.org/10.5194/esurf-12-691-2024, 2024
Short summary
Short summary
In this paper, we propose a framework for generating risk maps that provide the probabilities of erosion due to river migration. This framework uses concepts from probability theory to learn the river migration model's parameter values from satellite data while taking into account parameter uncertainty. Our analysis shows that such geomorphic risk estimation is more reliable than models that do not explicitly consider various sources of variability and uncertainty.
Steven Y. J. Lai, David Amblas, Aaron Micallef, and Hervé Capart
Earth Surf. Dynam., 12, 621–640, https://doi.org/10.5194/esurf-12-621-2024, https://doi.org/10.5194/esurf-12-621-2024, 2024
Short summary
Short summary
This study explores the creation of submarine canyons and hanging-wall fans on active faults, which can be defined by gravity-dominated breaching and underflow-dominated diffusion processes. The study reveals the self-similarity in canyon–fan long profiles, uncovers Hack’s scaling relationship and proposes a formula to estimate fan volume using canyon length. This is validated by global data from source-to-sink systems, providing insights into deep-water sedimentary processes.
Anuska Narayanan, Sagy Cohen, and John R. Gardner
Earth Surf. Dynam., 12, 581–599, https://doi.org/10.5194/esurf-12-581-2024, https://doi.org/10.5194/esurf-12-581-2024, 2024
Short summary
Short summary
This study investigates the profound impact of deforestation in the Amazon 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 the consequences of human activity for our planet's future.
Jacob Hardt, Tim P. Dooley, and Michael R. Hudec
Earth Surf. Dynam., 12, 559–579, https://doi.org/10.5194/esurf-12-559-2024, https://doi.org/10.5194/esurf-12-559-2024, 2024
Short summary
Short summary
We investigate the reaction of salt structures on ice sheet transgressions. We used a series of sandbox models that enabled us to experiment with scaled-down versions of salt bodies from northern Germany. The strongest reactions occurred when large salt pillows were partly covered by the ice load. Subsurface salt structures may play an important role in the energy transition, e.g., as energy storage. Thus, it is important to understand all processes that affect their stability.
Prakash Pokhrel, Mikael Attal, Hugh D. Sinclair, Simon M. Mudd, and Mark Naylor
Earth Surf. Dynam., 12, 515–536, https://doi.org/10.5194/esurf-12-515-2024, https://doi.org/10.5194/esurf-12-515-2024, 2024
Short summary
Short summary
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 the size of ancient Himalaya. Results show that the ancient river network was larger than the modern one, indicating that there has been river capture.
Hayden L. Jacobson, Danica L. Roth, Gabriel Walton, Margaret Zimmer, and Kerri Johnson
EGUsphere, https://doi.org/10.5194/egusphere-2023-2694, https://doi.org/10.5194/egusphere-2023-2694, 2024
Short summary
Short summary
Loose grains travel farther after a fire because no vegetation is left to stop them. This matters since loose grains at the base of a slope can turn into a debris flow if it rains. To find if grass growing back after a fire had different impacts on grains of different sizes on slopes of different steepness, we dropped thousands of natural grains and measured how far they went. Large grains went farther 7 months after the fire than 11 months after, and small grain movement didn’t change much.
Elizabeth Orr, Taylor Schildgen, Stefanie Tofelde, Hella Wittmann, and Ricardo Alonso
EGUsphere, https://doi.org/10.5194/egusphere-2024-784, https://doi.org/10.5194/egusphere-2024-784, 2024
Short summary
Short summary
Fluvial terraces and alluvial fans in the Toro Basin, NW Argentina record river evolution and global climate cycles over time. Landform dating reveals lower-frequency climate cycles (100-kyr) preserved downstream and higher-frequency cycles (21/40-kyr) upstream, supporting theoretical predications that longer rivers filter out higher-frequency climate signals. This finding improves our understanding of the spatial distribution of sedimentary paleoclimate records within landscapes.
Orie Cecil, Nicholas Cohn, Matthew Farthing, Sourav Dutta, and Andrew Trautz
EGUsphere, https://doi.org/10.5194/egusphere-2024-855, https://doi.org/10.5194/egusphere-2024-855, 2024
Short summary
Short summary
Using computational fluid dynamics, we analyze the error trends of an analytical shear stress distribution model used to drive aeolian transport for coastal dunes which are an important line of defense against storm related flooding hazards. We find that compared to numerical simulations, the analytical model results in a net overprediction of the landward migration rate. Additionally, two data-driven approaches are proposed for reducing the error while maintaining computational efficiency.
Jens Martin Turowski, Aaron Bufe, and Stefanie Tofelde
Earth Surf. Dynam., 12, 493–514, https://doi.org/10.5194/esurf-12-493-2024, https://doi.org/10.5194/esurf-12-493-2024, 2024
Short summary
Short summary
Fluvial valleys are ubiquitous landforms, and understanding their formation and evolution affects a wide range of disciplines from archaeology and 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.
Daniel J. Ciarletta, Jennifer L. Miselis, Julie C. Bernier, and Arnell S. Forde
Earth Surf. Dynam., 12, 449–475, https://doi.org/10.5194/esurf-12-449-2024, https://doi.org/10.5194/esurf-12-449-2024, 2024
Short summary
Short summary
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.
Chao Zhou, Xibin Tan, Yiduo Liu, and Feng Shi
Earth Surf. Dynam., 12, 433–448, https://doi.org/10.5194/esurf-12-433-2024, https://doi.org/10.5194/esurf-12-433-2024, 2024
Short summary
Short summary
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.
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Stefan Hergarten
EGUsphere, https://doi.org/10.5194/egusphere-2024-336, https://doi.org/10.5194/egusphere-2024-336, 2024
Short summary
Short summary
Faceted topographies are impressing footprints of active tectonics in geomorphology. This paper investigates the evolution of faceted topographies at normal faults and its interaction with the river network theoretically and numerically. As a main result beyond several relations for the the geometry of facets, the horizontal displacement associated to normal faults is crucial for the dissection of initially polygonal facets into triangular facets bounded by almost parallel rivers.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Jessica Laible, Guillaume Dramais, Jérôme Le Coz, Blaise Calmel, Benoît Camenen, David J. Topping, William Santini, Gilles Pierrefeu, and François Lauters
EGUsphere, https://doi.org/10.5194/egusphere-2023-2348, https://doi.org/10.5194/egusphere-2023-2348, 2024
Short summary
Short summary
Suspended-sand fluxes in rivers vary with time and space, complicating their measurement. The proposed method captures the vertical and lateral variations of suspended-sand concentration throughout a river cross section. It merges water samples taken at various positions throughout the cross section with high-resolution acoustic velocity and discharge measurements. The method also determines the sand flux uncertainty and can be easily applied to other sites using the available open-source code.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Rémi Bossis, Vincent Regard, Sébastien Carretier, and Sandrine Choy
EGUsphere, https://doi.org/10.5194/egusphere-2023-3020, https://doi.org/10.5194/egusphere-2023-3020, 2024
Short summary
Short summary
The erosion of rocky coasts occurs episodically through wave action and landslides, constituting a major natural hazard. Documenting the factors that control the coastal retreat rate over millennia is fundamental to evidencing any change in time. However, the known rates to date are essentially representative of the last few decades. Here, we present a new method using the concentration of an isotope, 10Be in sediment eroded from the cliff to quantify its retreat rate averaged over millennia.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cited articles
Acrement, G. J. and Schneider, V. R.: Guide for Selecting Manning's Roughness Coefficients for Natural Channels and Flood Plains, United States Geological Survey Water-Supply Paper, 2339, 1–38, 1984.
An, C., Fu, X., Wang, G., and Parker, G.: Effect of grain sorting on gravel bed river evolution subject to cycled hydrographs: Bed load sheets and breakdown of the hydrograph boundary layer, J. Geophys. Res.-Earth, 122, 1513–1533 https://doi.org/10.1002/2016JF003994, 2017a.
An, C., Cui, Y., Fu, X., and Parker, G.: Gravel-bed river evolution in earthquake-prone regions subject to cycled hydrographs and repeated sediment pulses, Earth Surf. Proc. Land., 42, 2426–2438, https://doi.org/10.1002/esp.4195, 2017b.
Bagnold, R. A.: An Approach to the Sediment Transport Problem from General Physics, Geological Survey Professional Paper 422-I, United States Government Printing Office, Washington, 1966.
Bagnold, R. A.: An empirical correlation of bedload transport rates in flumes and natural rivers, P. Roy. Soc Lond. A Mat., 372, 453–473, https://doi.org/10.1098/rspa.1980.0122, 1980.
Barry, J. I., Buffington, J. M., and King J. G.: A general power equation for predicting bed load transport rates in gravel bed rivers, Water Resour. Res., 40, W10401, https://doi.org/10.1029/2004WR003190, 2004.
Benito, G., Thorndycraft, V. R., Rico, M. T., Sánchez-Moya, Y., Sopeña, A., Botero, B. A., Machado, M. J., Davis, M., and Pérez-González, A.: Hydrological response of a dryland ephemeral river to southern African climatic variability during the last millennium, Quaternary Res., 75, 471–482, https://doi.org/10.1016/j.yqres.2011.01.004, 2011.
Billi, P.: Flash flood sediment transport in a steep sand-bed ephemeral stream, Int. J. Sediment Res., 26, 193–209, https://doi.org/10.1016/S1001-6279(11)60086-3, 2011.
Bunte, K. and Abt, S. R.: Sampling surface and subsurface particle-size distributions in wadable gravel- and cobble-bed streams for analyses in sediment transport, hydraulics, and streambed monitoring, Gen. Tech. Rep. RMRS-GTR-74, Fort Collins, CO, US Department of Agriculture, Forest Service, Rocky Mountain Research Station, 1–428, 2001.
Calle, M., Lotsari, E., Kukko, A., Alho, P., Kaartinen, H., Rodriguez-Lloveras, X., and Benito, G.: Morphodynamics of an ephemeral gravel-bed stream combining mobile laser scanner, hydraulic simulations and geomorphological indicators, Z. Geomorphol. Supp., 59, 33–57, https://doi.org/10.1127/zfg_suppl/2015/S-59196, 2015.
Cao, Z., Hu, P., and Pender, G.: Reconciled bedload sediment transport rates in ephemeral and perennial rivers, Earth Surf. Proc. Land., 35, 1655–1665, https://doi.org/10.1002/esp.2005, 2010.
Casas, A., Lane, S. N., Yu, D., and Benito, G.: A method for parameterising roughness and topographic sub-grid scale effects in hydraulic modelling from LiDAR data, Hydrol. Earth Syst. Sci., 14, 1567–1579, https://doi.org/10.5194/hess-14-1567-2010, 2010a.
Casas, M. A, Lane, S. N., Hardy, R. J., Benito, G., and Whiting, P. J.: Reconstruction of subgrid-scale topographic variability and its effect upon the spatial structure of three-dimensional river flow, Water Resour. Res., 46, W03519, https://doi.org/10.1029/2009WR007756, 2010b.
Chow, V. T.: Open Channel Hydraulics, McGraw-Hill Book Company, New York, USA, 1959.
Croke, J., Fryirs, K., and Thompson, C.: Channel–floodplain connectivity during an extreme flood event: implications for sediment erosion, deposition, and delivery, Earth Surf. Proc. Land., 38, 1444–1456, https://doi.org/10.1002/esp.3430, 2013
Deltares: Delft3D-FLOW, Simulation of Multi-dimensional Hydrodynamic Flows and Transport Phenomena, Including Sediments, User Manual: Hydro-Morphodynamics, Delft, the Netherlands, 2011.
Dietrich, W. E. and Smith, J. D.: Influence of the point bar on flow through curved channels, Water Resour. Res., 19, 1173–1192, 1983.
Engelund, F. and Hansen, E.: A Monograph on Sediment Transport in Alluvial Streams, Technical University of Denmark, Teknisk Forlag, Copenhagen, 1967.
Euler, T., Herget, J., Schlömer, O., and Benito, G.: Hydromorphological processes at submerged solitary boulder obstacles in streams, Catena, 157, 250–267, https://doi.org/10.1016/j.catena.2017.05.028, 2017.
Ferguson, R. I.: Understanding braiding processes in gravel-bed rivers: progress and unsolved problems, in: Braided Rivers, Geological Society Special Publication No. 75, edited by: Best, J. L. and Bristow, CS, 73–87, 1993.
Gendaszek, A. S., Magirl, C. S., Czuba, C. R., and Konrad, C. P.: The timing of scour and fill in a gravel-bedded river measured with buried accelerometers, J. Hydrol., 495, 186–196, https://doi.org/10.1016/j.jhydrol.2013.05.012, 2013.
Graf, W. L.: Transport and deposition of plutonium-contaminated sediments by fluvial processes, Los Alamos Canyon, New Mexico, Geol. Soc. Am. Bull., 108, 1342–1355, https://doi.org/10.1130/0016-7606(1996)108<1342:TADOPC>2.3.CO;2, 1996.
Greenbaum, N. and Bergman, N.: Formation and evacuation of a large gravel-bar deposited during a major flood in a Mediterranean ephemeral stream, Nahal Me'arot, NW Israel, Geomorphology, 77, 169–186, https://doi.org/10.1016/j.geomorph.2006.01.016, 2006.
Grodek, T., Jacoby, Y., Morin, E., and Katz, O.: Effectiveness of exceptional rainstorms on a small Mediterranean basin, Geomorphology, 159/160, 156–168, https://doi.org/10.1016/j.geomorph.2012.03.016, 2012
Hassan, M. A., Marren, P. M., and Schwartz, U.: Bar structure in an arid ephemeral stream, Sediment. Geol., 221, 57–70, https://doi.org/10.1016/j.sedgeo.2009.07.012, 2009.
Hauer, C. and Habersack, H.: Morphodynamics of a 1000-year flood in the Kamp River, Austria, and impacts on floodplain morphology, Earth Surf. Proc. Land., 34, 654–682, https://doi.org/10.1002/esp.1763, 2009.
Hjulström, F.: Studies of the Morphological Activity of Rivers as Illustrated by the River Fyris – Inaugural Dissertation, Almqvist & Wiksells, 1935.
Hooke, J.: Morphological impacts of flow events of varying magnitude on ephemeral channels in a semiarid region, Geomorphology, 252, 128–143, https://doi.org/10.1016/j.geomorph.2015.07.014, 2016a.
Hooke, J.: Geomorphological impacts of an extreme flood in SE Spain, Geomorphology, 263, 19–38, https://doi.org/10.1016/j.geomorph.2016.03.021, 2016b.
Hooke, J. M. and Mant, J. M.: Geomorphological impacts of a flood event on ephemeral channels in SE Spain, Geomorphology, 34, 163–180, https://doi.org/10.1016/S0169-555X(00)00005-2, 2000.
Hooke, J. M., Brookes, C. J., Duane, W., and Mant, J. M.: A simulation model of morphological, vegetation and sediment changes in ephemeral streams, Earth Surf. Proc. Land., 30, 845–866, https://doi.org/10.1002/esp.1195, 2005.
Ikeda, S.: Incipient Motion of Sand Particles on Side Slopes, J. Hydr. Eng. Div.-ASCE, 108, 95–114, 1982.
Kaitna, R., Chiari, M., Kerschbaumer, M., Kapeller, H., Zlatic-Jugovic, J., Hengl, M., and Huebl, J.: Physical and numerical modelling of a bedload deposition area for an Alpine torrent, Nat. Hazard. Earth Sys., 11, 1589–1597, https://doi.org/10.5194/nhess-11-1589-2011, 2011.
Kasvi, E., Alho, P., Lotsari, E., Wang, Y., Kukko, A., Hyyppä, H., and Hyyppä, J.: Two-dimensional and three-dimensional computational models in hydrodynamic and morphodynamic reconstructions of a river bend: sensitivity and functionality, Hydrol. Process., 29, 1604–1629, https://doi.org/10.1002/hyp.10277, 2014.
Kasvi, E., Vaaja, M., Kaartinen, H., Kukko, A., Jaakkola, A., Flener, C., Hyyppä, H., Hyyppä, J., and Alho, P.: Sub-bend scale flow–sediment interaction of meander bends – A combined approach of field observations, close-range remote sensing and computational modelling, Geomorphology, 238, 119–134, https://doi.org/10.1016/j.geomorph.2015.01.039, 2015.
Kukko, A., Kaartinen, H., and Zanetti, M.: Backpack Personal Laser Scanning System for Grain-Scale Topographic Mapping, 46th Lunar and Planetary Science Conference, The Woodlands, TX, USA, 2015.
Li, Z., Cao, Z., Liu, H., and Pender, G.: Graded and uniform bed load sediment transport in a degrading channel, Int. J. Sediment Res., 31, 376–385, https://doi.org/10.1016/j.ijsrc.2016.01.004, 2016.
Limerinos, J. T.: Determination of the Manning coefficient from measured bed roughness in natural channels, Geological survey water-supply paper, 1898-B, US Department of the Interior, prepared in cooperation with the California Department of Water Resources, United States Government Printing Office, Washington, 1970.
Lisle, T. E. and Madej, M. A.: Spatial variation in armouring in a channel with high sediment supply, in: Dynamics of Gravel-bed Rivers, edited by: Billi, P., Hey, R. D., Thorne, C. R., and Tacconi, P., John Wiley & Sons Ltd., Chichester, 277–293, 1992.
Long, A. J.: Hydrograph separation for karst watersheds using a two-domain rainfall–discharge model, J. Hydrol., 364, 249–256, https://doi.org/10.1016/j.jhydrol.2008.11.001, 2009
Lotsari, E., Wainwright, D., Corner, G. D., Alho, P., and Käyhkö, J.: Surveyed and modelled one-year morphodynamics in the braided lower Tana River, Hydrol. Process., 28, 2685–2716, https://doi.org/10.1002/hyp.9750, 2014a.
Lotsari, E., Vaaja, M., Flener, C., Kaartinen, H., Kukko, A., Kasvi, E., Hyyppä, H., Hyyppä, J., and Alho, P.: Annual bank and point bar morphodynamics of a meandering river determined by high-accuracy multitemporal laser scanning and flow data, Water Resour. Res., 50, 5532–5559, https://doi.org/10.1002/2013WR014106, 2014b.
Lotsari, E., Thorndycraft, V., and Alho, P.: Prospects and challenges of simulating river channel response to future climate change, Prog. Phys. Geogr., 39, 483–513, https://doi.org/10.1177/0309133315578944, 2015.
Lloyd, C. E. M., Freer, J. E., Johnes, P. J., and Collins, A. L.: Using hysteresis analysis of high-resolution water quality monitoring data, including uncertainty, to infer controls on nutrient and sediment transfer in catchments, Sci. Total Environ., 543, 388–404, https://doi.org/10.1016/j.scitotenv.2015.11.028, 2016
Lucía, A., Recking, A., Martín-Duque, J. F., Storz-Peretz, Y., and Laronne, J. B.: Continuous monitoring of bedload discharge in a small, steep sandy channel, J. Hydrol., 497, 37–50, https://doi.org/10.1016/j.jhydrol.2013.05.034, 2013.
Meyer-Peter, E. and Müller, R.: Formula for bed load transport, Proceedings of the 2nd Meeting, Int. Assoc. Hydraulic Structures Res. (IAHR), Stockholm, Sweden, 39–64, 1948.
Milan, D. J., Heritage, G. L., and Hetherington, D.: Application of a 3D laser scanner in the assessment of erosion and deposition volumes and channel change in a proglacial river, Earth Surf. Proc. Land., 32, 1657–1674, https://doi.org/10.1002/esp.1592, 2007.
Müller, E. R. and Pitlick, J.: Sediment supply and channel morphology in mountain river systems: 1. Relative importance of lithology, topography, and climate, J. Geophys. Res.-Earth, 118, 2325–2342, https://doi.org/10.1002/2013JF002843, 2013.
Nardi, L. and Rinaldi, M.: Spatio-temporal patterns of channel changes in response to a major flood event: the case of the Magra River (central–northern Italy), Earth Surf. Proc. Land., 40, 326–339, https://doi.org/10.1002/esp.3636, 2015.
Parker, G.: Surface-based bedload transport relation for gravel rivers, J. Hydraul. Res., 28, 417–436, https://doi.org/10.1080/00221689009499058, 1990.
Pelletier, J. D., Mayer, L., Pearthree, P. A., House, P. K., Demsey, K. A., Klawon, J. E., and Vincent, K. R.: An integrated approach to flood hazard assessment on alluvial fans using numerical modeling, field mapping, and remote sensing, Geol. Soc. Am. Bull., 117, 1167–1180, https://doi.org/10.1130/B25544.1, 2005.
Petersen, M. S.: Impacts of Flash Floods, in: Coping With Flash Floods, edited by: Gruntfest, E. and Handmer, J., NATO Science Series (Series 2. Environmental Security), vol. 77, Springer, Dordrecht, 2001.
Pitlick, J.: Response and recovery of a subalpine stream following a catastrophic flood, Geol. Soc. Am. Bull., 105, 657–670, 1993.
Reid, I., Frostick, L. E., and Layman, J. T.: The incidence and nature of bedload transport during flood flows in coarse-grained alluvial channels, Earth Surf. Proc. Land., 10, 33–44, https://doi.org/10.1002/esp.3290100107, 1985.
Reid, I., Powell, D. M., and Laronne, J. B.: Prediction of bed-load transport by desert flash floods, J. Hydraul. Eng., 122, 170–173, https://doi.org/10.1061/(ASCE)0733-9429(1996)122:3(170), 1996.
Rodriguez-Lloveras, X., Bussi, G., Francés, F., Rodriguez-Caballero, E., Solé-Benet, A., Calle, M., and Benito, G.: Patterns of runoff and sediment production in response to land-use changes in an ungauged Mediterranean catchment, J. Hydrol., 531, 1054–1066, https://doi.org/10.1016/j.jhydrol.2015.11.014, 2015.
Sanyal, J.: Predicting possible effects of dams on downstream river bed changes of a Himalayan river with morphodynamic modelling, Quatern. Int., 453, 48–62, https://doi.org/10.1016/j.quaint.2017.03.063, 2017.
Schuurman, F., Marra, W. A., and Kleinhans, M. G.: Physics-based modeling of large braided sand-bed rivers: bar pattern formation, dynamics and sensitivity, J. Geophys. Res.-Earth, 118, 2509–2527, https://doi.org/10.1002/2013jf002896, 2013.
Segura-Beltrán, F. and Sanchis-Ibor, C.: Assessment of channel changes in a Mediterranean ephemeral stream since the early twentieth century, The Rambla de Cervera, eastern Spain, Geomorphology, 201, 199–214, https://doi.org/10.1016/j.geomorph.2013.06.021, 2013.
Singh, U., Crosato, A., Giri, S., and Hicks, M.: Sediment heterogeneity and mobility in the morphodynamic modelling of gravel-bed braided rivers, Adv. Water Resour., 104, 127–144, https://doi.org/10.1016/j.advwatres.2017.02.005, 2017.
Thompson, C. and Croke, J.: Geomorphic effects, flood power, and channel competence of a catastrophic flood in confined and unconfined reaches of the upper Lockyer valley, southeast Queensland, Australia, Geomorphology, 197, 156–169, https://doi.org/10.1016/j.geomorph.2013.05.006, 2013.
Tooth, S.: Process, form and change in dryland rivers: a review of recent research, Earth-Sci. Rev., 51, 67–107, https://doi.org/10.1016/S0012-8252(00)00014-3, 2000.
Vaaja, M., Hyyppä, J., Kukko, A., Kaartinen, H., Hyyppä, H., and Alho, P.: Mapping Topography Changes and Elevation Accuracies Using a Mobile Laser Scanner, Remote Sens., 3, 587–600, https://doi.org/10.3390/rs3030587, 2011.
van Rijn, L. C.: Principles of Sediment Transport in Rivers, Estuaries and Coastal Seas, 1993 Edn., Aqua Publications, the Netherlands, 1993.
Verhaar, P. M., Biron, P. M., Ferguson, R. I., and Hoey, T. B.: A modified morphodynamic model for investigating the response of rivers to short-term climate change, Geomorphology, 101, 674–682, https://doi.org/10.1016/j.geomorph.2008.03.010, 2008.
Viparelli, E., Gaeuman, D., Wilcock, P., and Parker, G.: A model to predict the evolution of a gravel bed river under an imposed cyclic hydrograph and its application to the Trinity River, Water Resour. Res., 47, W02533, https://doi.org/10.1029/2010WR009164, 2011.
Walling, D. E.: Suspended sediment and solute yields from a small catchment prior to urbanisation, in: Fluvial Processes in Instrumented Watersheds, edited by: Gregory, K. J. and Walling, D. E., Special Publication 6, Institute of British Geographers, 169–192, 1974.
Wang, Y., Liang, X., Flener, C., Kukko, A., Kaartinen, H., Kurkela, M., Vaaja, M., Hyyppä, H., and Alho, P.: 3D Modeling of Coarse Fluvial Sediments Based on Mobile Laser Scanning Data, Remote Sens., 5, 4571–4592, https://doi.org/10.3390/rs5094571, 2013.
Wheaton, J., Brasington, J., Darby, S. E., Kasprak, A., Sear, D., and Vericat, D.: Morphodynamic signatures of braiding mechanisms as expressed through change in sediment storage in a gravel-bed river, J. Geophys. Res.-Earth, 118, 759–779, https://doi.org/10.1002/jgrf.20060, 2013.
Williams, R. D., Brasington, J., Hicks, M., Measures, R., Rennie, C. D., and Vericat, D.: Hydraulic validation of two-dimensional simulations of braided river flow with spatially continuous ADCP data, Water Resour. Res., 49, 5183–5205, https://doi.org/10.1002/wrcr.20391, 2013.
Williams, R. D., Rennie, C. D., Brasington, J., Hicks, D. M., and Vericat, D.: Linking the spatial distribution of bed load transport to morphological change during high-flow events in a shallow braided river, J. Geophys. Res.-Earth, 120, 604–622, https://doi.org/10.1002/2014JF003346, 2015.
Williams, R. D., Brasington, J., and Hicks D. M.: Numerical Modelling of Braided River Morphodynamics: Review and Future Challenges, Geography Compass, 10, 102–127, https://doi.org/10.1111/gec3.12260, 2016a.
Williams, R. D., Measures, R., Hicks, D. M., and Brasington J.: Assessment of a numerical model to reproduce event-scale erosion and deposition distributions in a braided river, Water Resour. Res., 52, 6621–6642, https://doi.org/10.1002/2015WR018491, 2016b.
Wolman, M. G.: A method of sampling coarse river-bed material, Transactions of the American Geophysical Union, 35, 951–956, 1954.
Short summary
This paper analyses the timing of topographical changes of a gravel bed ephemeral river channel during consecutive and moderate- and low-magnitude floods by applying a morphodynamic model calibrated with pre- and post-event surveys using RTK-GPS and mobile laser scanning. The channel acted as a braided river during lower flows but as a meandering river during higher flows. The channel changes can be greater during the long-lasting receding phase than during the rising phase of the floods.
This paper analyses the timing of topographical changes of a gravel bed ephemeral river channel...
