Articles | Volume 10, issue 4
https://doi.org/10.5194/esurf-10-797-2022
© Author(s) 2022. 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-10-797-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
02 Aug 2022
Research article |
| 02 Aug 2022
| 02 Aug 2022
Unraveling the hydrology and sediment balance of an ungauged lake in the Sudano-Sahelian region of West Africa using remote sensing
Silvan Ragettli
CORRESPONDING AUTHOR
hydrosolutions Ltd., Venusstrasse 29, 8050 Zurich, Switzerland
Tabea Donauer
hydrosolutions Ltd., Venusstrasse 29, 8050 Zurich, Switzerland
Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
Peter Molnar
Institute of Environmental Engineering, ETH Zurich, Zurich, Switzerland
Ron Delnoije
Caritas Switzerland, Bamako, Mali
Tobias Siegfried
hydrosolutions Ltd., Venusstrasse 29, 8050 Zurich, Switzerland
Institute of Science, Technology and Policy, ETH Zurich, Zurich, Switzerland
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Silvan Ragettli, Tobias Bolch, and Francesca Pellicciotti
The Cryosphere, 10, 2075–2097, https://doi.org/10.5194/tc-10-2075-2016, https://doi.org/10.5194/tc-10-2075-2016, 2016
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This study presents a multi-temporal dataset of geodetically derived elevation changes on debris-free and debris-covered glaciers in the Langtang valley, Nepalese Himalaya. Overall, we observe accelerated glacier wastage, but highly heterogeneous spatial patterns and temporal trends across glaciers. Accelerations in thinning correlate with the presence of supraglacial cliffs and lakes, whereas thinning rates remained constant or declined on stagnating debris-covered glacier areas.
Mosisa Tujuba Wakjira, Nadav Peleg, Johan Six, and Peter Molnar
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2024-37, https://doi.org/10.5194/hess-2024-37, 2024
Revised manuscript accepted for HESS
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While rainwater is a key resource in crop production, its productivity faces challenges from climate change. Using a simple model of climate, water, and crop yield interactions, we found that rain-scarce croplands in Ethiopia are likely to experience decreases in crop yield during the main growing season, primarily due to future temperature increases. These insights are crucial for shaping future water management plans, policies, and informed decision-making for climate adaptation.
Jessica Droujko, Srividya Hariharan Sudha, Gabriel Singer, and Peter Molnar
Earth Surf. Dynam., 11, 881–897, https://doi.org/10.5194/esurf-11-881-2023, https://doi.org/10.5194/esurf-11-881-2023, 2023
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We combined data from satellite images with data measured from a kayak in order to understand the propagation of fine sediment in the Vjosa River. We were able to find some storm-activated and some permanent sources of sediment. We also estimated how much fine sediment is carried into the Adriatic Sea by the Vjosa River: approximately 2.5 Mt per year, which matches previous findings. With our work, we hope to show the potential of open-access satellite images.
Tobias Siegfried, Aziz Ul Haq Mujahid, Beatrice Sabine Marti, Peter Molnar, Dirk Nikolaus Karger, and Andrey Yakovlev
EGUsphere, https://doi.org/10.5194/egusphere-2023-520, https://doi.org/10.5194/egusphere-2023-520, 2023
Preprint archived
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Our study investigates climate change impacts on water resources in Central Asia's high-mountain regions. Using new data and a stochastic soil moisture model, we found increased precipitation and higher temperatures in the future, leading to higher water discharge despite decreasing glacier melt contributions. These findings are crucial for understanding and preparing for climate change effects on Central Asia's water resources, with further research needed on extreme weather event impacts.
Qinggang Gao, Christian Zeman, Jesus Vergara-Temprado, Daniela C. A. Lima, Peter Molnar, and Christoph Schär
Weather Clim. Dynam., 4, 189–211, https://doi.org/10.5194/wcd-4-189-2023, https://doi.org/10.5194/wcd-4-189-2023, 2023
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We developed a vortex identification algorithm for realistic atmospheric simulations. The algorithm enabled us to obtain a climatology of vortex shedding from Madeira Island for a 10-year simulation period. This first objective climatological analysis of vortex streets shows consistency with observed atmospheric conditions. The analysis shows a pronounced annual cycle with an increasing vortex shedding rate from April to August and a sudden decrease in September.
Beatrice Sabine Marti, Aidar Zhumabaev, and Tobias Siegfried
Hydrol. Earth Syst. Sci., 27, 319–330, https://doi.org/10.5194/hess-27-319-2023, https://doi.org/10.5194/hess-27-319-2023, 2023
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Numerical modelling is often used for climate impact studies in water resources management. It is, however, not yet highly accessible to many students of hydrology in Central Asia. One big hurdle for new learners is the preparation of relevant data prior to the actual modelling. We present a robust, open-source workflow and comprehensive teaching material that can be used by teachers and by students for self study.
Fabian Walter, Elias Hodel, Erik S. Mannerfelt, Kristen Cook, Michael Dietze, Livia Estermann, Michaela Wenner, Daniel Farinotti, Martin Fengler, Lukas Hammerschmidt, Flavia Hänsli, Jacob Hirschberg, Brian McArdell, and Peter Molnar
Nat. Hazards Earth Syst. Sci., 22, 4011–4018, https://doi.org/10.5194/nhess-22-4011-2022, https://doi.org/10.5194/nhess-22-4011-2022, 2022
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Debris flows are dangerous sediment–water mixtures in steep terrain. Their formation takes place in poorly accessible terrain where instrumentation cannot be installed. Here we propose to monitor such source terrain with an autonomous drone for mapping sediments which were left behind by debris flows or may contribute to future events. Short flight intervals elucidate changes of such sediments, providing important information for landscape evolution and the likelihood of future debris flows.
Elena Leonarduzzi, Brian W. McArdell, and Peter Molnar
Hydrol. Earth Syst. Sci., 25, 5937–5950, https://doi.org/10.5194/hess-25-5937-2021, https://doi.org/10.5194/hess-25-5937-2021, 2021
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Landslides are a dangerous natural hazard affecting alpine regions, calling for effective warning systems. Here we consider different approaches for the prediction of rainfall-induced shallow landslides at the regional scale, based on open-access datasets and operational hydrological forecasting systems. We find antecedent wetness useful to improve upon the classical rainfall thresholds and the resolution of the hydrological model used for its estimate to be a critical aspect.
Jacob Hirschberg, Alexandre Badoux, Brian W. McArdell, Elena Leonarduzzi, and Peter Molnar
Nat. Hazards Earth Syst. Sci., 21, 2773–2789, https://doi.org/10.5194/nhess-21-2773-2021, https://doi.org/10.5194/nhess-21-2773-2021, 2021
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Debris-flow prediction is often based on rainfall thresholds, but uncertainty assessments are rare. We established rainfall thresholds using two approaches and find that 25 debris flows are needed for uncertainties to converge in an Alpine basin and that the suitable method differs for regional compared to local thresholds. Finally, we demonstrate the potential of a statistical learning algorithm to improve threshold performance. These findings are helpful for early warning system development.
Marius G. Floriancic, Wouter R. Berghuijs, Tobias Jonas, James W. Kirchner, and Peter Molnar
Hydrol. Earth Syst. Sci., 24, 5423–5438, https://doi.org/10.5194/hess-24-5423-2020, https://doi.org/10.5194/hess-24-5423-2020, 2020
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Low river flows affect societies and ecosystems. Here we study how precipitation and potential evapotranspiration shape low flows across a network of 380 Swiss catchments. Low flows in these rivers typically result from below-average precipitation and above-average potential evapotranspiration. Extreme low flows result from long periods of the combined effects of both drivers.
Elena Leonarduzzi and Peter Molnar
Nat. Hazards Earth Syst. Sci., 20, 2905–2919, https://doi.org/10.5194/nhess-20-2905-2020, https://doi.org/10.5194/nhess-20-2905-2020, 2020
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Landslides are a natural hazard that affects alpine regions. Here we focus on rainfall-induced shallow landslides and one of the most widely used approaches for their predictions: rainfall thresholds. We design several comparisons utilizing a landslide database and rainfall records in Switzerland. We find that using daily rather than hourly rainfall might be a better option in some circumstances, and mean annual precipitation and antecedent wetness can improve predictions at the regional scale.
Giulia Battista, Peter Molnar, and Paolo Burlando
Earth Surf. Dynam., 8, 619–635, https://doi.org/10.5194/esurf-8-619-2020, https://doi.org/10.5194/esurf-8-619-2020, 2020
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Suspended sediment load in rivers is highly uncertain because of spatial and temporal variability. By means of a hydrology and suspended sediment transport model, we investigated the effect of spatial variability in precipitation and surface erodibility on catchment sediment fluxes in a mesoscale river basin.
We found that sediment load depends on the spatial variability in erosion drivers, as this affects erosion rates and the location and connectivity to the channel of the erosion areas.
Nadav Peleg, Chris Skinner, Simone Fatichi, and Peter Molnar
Earth Surf. Dynam., 8, 17–36, https://doi.org/10.5194/esurf-8-17-2020, https://doi.org/10.5194/esurf-8-17-2020, 2020
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Extreme rainfall is expected to intensify with increasing temperatures, which will likely affect rainfall spatial structure. The spatial variability of rainfall can affect streamflow and sediment transport volumes and peaks. The sensitivity of the hydro-morphological response to changes in the structure of heavy rainfall was investigated. It was found that the morphological components are more sensitive to changes in rainfall spatial structure in comparison to the hydrological components.
Anna Costa, Daniela Anghileri, and Peter Molnar
Hydrol. Earth Syst. Sci., 22, 3421–3434, https://doi.org/10.5194/hess-22-3421-2018, https://doi.org/10.5194/hess-22-3421-2018, 2018
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We analyse the control of hydroclimatic factors – erosive rainfall, ice melt, and snowmelt – on suspended sediment concentration (SSC) of Alpine catchments regulated by hydropower, and we develop a multivariate hydroclimatic–informed rating curve. We show that while erosive rainfall determines the variability of SSC, ice melt generates the highest contribution to SSC per unit of runoff. This approach allows the exploration of climate–driven changes in fine sediment dynamics in Alpine catchments.
Anna Costa, Peter Molnar, Laura Stutenbecker, Maarten Bakker, Tiago A. Silva, Fritz Schlunegger, Stuart N. Lane, Jean-Luc Loizeau, and Stéphanie Girardclos
Hydrol. Earth Syst. Sci., 22, 509–528, https://doi.org/10.5194/hess-22-509-2018, https://doi.org/10.5194/hess-22-509-2018, 2018
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We explore the signal of a warmer climate in the suspended-sediment dynamics of a regulated and human-impacted Alpine catchment. We demonstrate that temperature-driven enhanced melting of glaciers, which occurred in the mid-1980s, played a dominant role in suspended sediment concentration rise, through increased runoff from sediment-rich proglacial areas, increased contribution of sediment-rich meltwater, and increased sediment supply in proglacial areas due to glacier recession.
Anna Costa, Daniela Anghileri, and Peter Molnar
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2017-419, https://doi.org/10.5194/hess-2017-419, 2017
Manuscript not accepted for further review
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We develop a novel rating curve to simulate suspended sediment concentration (SSC) in Alpine catchments (Process-Based Rating Curve, PBRC). Instead of relating SSC to discharge, as in traditional approaches, we model SSC by differentiating the potential contributions of the main erosional and transport processes of Alpine environments: erosive rainfall, snowmelt, and icemelt. We show that PBRC significantly improves predictions of SSC, especially when analysing climate-induced changes.
Nadav Peleg, Frank Blumensaat, Peter Molnar, Simone Fatichi, and Paolo Burlando
Hydrol. Earth Syst. Sci., 21, 1559–1572, https://doi.org/10.5194/hess-21-1559-2017, https://doi.org/10.5194/hess-21-1559-2017, 2017
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We investigated the relative contribution of the spatial versus climatic rainfall variability for flow peaks by applying an advanced stochastic rainfall generator to simulate rainfall for a small urban catchment and simulate flow dynamics in the sewer system. We found that the main contribution to the total flow variability originates from the natural climate variability. The contribution of spatial rainfall variability to the total flow variability was found to increase with return periods.
Søren Thorndahl, Thomas Einfalt, Patrick Willems, Jesper Ellerbæk Nielsen, Marie-Claire ten Veldhuis, Karsten Arnbjerg-Nielsen, Michael R. Rasmussen, and Peter Molnar
Hydrol. Earth Syst. Sci., 21, 1359–1380, https://doi.org/10.5194/hess-21-1359-2017, https://doi.org/10.5194/hess-21-1359-2017, 2017
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This paper reviews how weather radar data can be used in urban hydrological applications. It focuses on three areas of research: (1) temporal and spatial resolution of rainfall data, (2) rainfall estimation, radar data adjustment and data quality, and (3) nowcasting of radar rainfall and real-time applications. Moreover, the paper provides examples of urban hydrological applications which can benefit from radar rainfall data in comparison to tradition rain gauge measurements of rainfall.
Claudio I. Meier, Jorge Sebastián Moraga, Geri Pranzini, and Peter Molnar
Hydrol. Earth Syst. Sci., 20, 4177–4190, https://doi.org/10.5194/hess-20-4177-2016, https://doi.org/10.5194/hess-20-4177-2016, 2016
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We show that the derived distribution approach is able to characterize the interannual variability of precipitation much better than fitting a probabilistic model to annual rainfall totals, as long as continuously gauged data are available. The method is a useful tool for describing temporal changes in the distribution of annual rainfall, as it works for records as short as 5 years, and therefore does not require any stationarity assumption over long periods.
Bahareh Kianfar, Simone Fatichi, Athansios Paschalis, Max Maurer, and Peter Molnar
Hydrol. Earth Syst. Sci. Discuss., https://doi.org/10.5194/hess-2016-536, https://doi.org/10.5194/hess-2016-536, 2016
Revised manuscript has not been submitted
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Raingauge observations show a large variability in extreme rainfall depths in the current climate. Climate model predictions of extreme rainfall in the future have to be compared with this natural variability. Our work shows that predictions of future extreme rainfall often lie within the range of natural variability of present-day climate, and therefore predictions of change are highly uncertain. We demonstrate this by using stochastic rainfall models and 10-min rainfall data in Switzerland.
Silvan Ragettli, Tobias Bolch, and Francesca Pellicciotti
The Cryosphere, 10, 2075–2097, https://doi.org/10.5194/tc-10-2075-2016, https://doi.org/10.5194/tc-10-2075-2016, 2016
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This study presents a multi-temporal dataset of geodetically derived elevation changes on debris-free and debris-covered glaciers in the Langtang valley, Nepalese Himalaya. Overall, we observe accelerated glacier wastage, but highly heterogeneous spatial patterns and temporal trends across glaciers. Accelerations in thinning correlate with the presence of supraglacial cliffs and lakes, whereas thinning rates remained constant or declined on stagnating debris-covered glacier areas.
Matteo Saletti, Peter Molnar, Marwan A. Hassan, and Paolo Burlando
Earth Surf. Dynam., 4, 549–566, https://doi.org/10.5194/esurf-4-549-2016, https://doi.org/10.5194/esurf-4-549-2016, 2016
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This study presents a new reduced-complexity model with few parameters linked to basic physical processes, which aims to reproduce the transport of sediment as bed load and the formation and stability of channel morphology in steep mountain streams. The model is able to simulate the formation and stability of steps, bed structures commonly encountered in steep channels, by assuming that their formation is due to intense sediment transport during high flows causing jamming of particles.
J. Hall, B. Arheimer, G. T. Aronica, A. Bilibashi, M. Boháč, O. Bonacci, M. Borga, P. Burlando, A. Castellarin, G. B. Chirico, P. Claps, K. Fiala, L. Gaál, L. Gorbachova, A. Gül, J. Hannaford, A. Kiss, T. Kjeldsen, S. Kohnová, J. J. Koskela, N. Macdonald, M. Mavrova-Guirguinova, O. Ledvinka, L. Mediero, B. Merz, R. Merz, P. Molnar, A. Montanari, M. Osuch, J. Parajka, R. A. P. Perdigão, I. Radevski, B. Renard, M. Rogger, J. L. Salinas, E. Sauquet, M. Šraj, J. Szolgay, A. Viglione, E. Volpi, D. Wilson, K. Zaimi, and G. Blöschl
Proc. IAHS, 370, 89–95, https://doi.org/10.5194/piahs-370-89-2015, https://doi.org/10.5194/piahs-370-89-2015, 2015
P. Molnar, S. Fatichi, L. Gaál, J. Szolgay, and P. Burlando
Hydrol. Earth Syst. Sci., 19, 1753–1766, https://doi.org/10.5194/hess-19-1753-2015, https://doi.org/10.5194/hess-19-1753-2015, 2015
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We present an empirical study of the rates of increase in precipitation intensity with air temperature using high-resolution 10 min precipitation records in Switzerland. We estimated the scaling rates for lightning (convective) and non-lightning event subsets and show that scaling rates are between 7 and 14%/C for convective rain and that mixing of storm types exaggerates the relations to air temperature. Doubled CC rates reported by other studies are an exception in our data set.
K. Džubáková, P. Molnar, K. Schindler, and M. Trizna
Hydrol. Earth Syst. Sci., 19, 195–208, https://doi.org/10.5194/hess-19-195-2015, https://doi.org/10.5194/hess-19-195-2015, 2015
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We use a high-resolution ground-based camera system with near-infrared sensitivity to quantify the response of riparian vegetation in an Alpine river to floods with the use of vegetation indices. The vegetation showed both damage and enhancement within 1 week following floods, with a selective impact determined by pre-flood vegetation vigour, morphological setting and intensity of flood forcing. The tested vegetation indices differed in the direction of predicted change in the range 0.7-35.8%.
J. Hall, B. Arheimer, M. Borga, R. Brázdil, P. Claps, A. Kiss, T. R. Kjeldsen, J. Kriaučiūnienė, Z. W. Kundzewicz, M. Lang, M. C. Llasat, N. Macdonald, N. McIntyre, L. Mediero, B. Merz, R. Merz, P. Molnar, A. Montanari, C. Neuhold, J. Parajka, R. A. P. Perdigão, L. Plavcová, M. Rogger, J. L. Salinas, E. Sauquet, C. Schär, J. Szolgay, A. Viglione, and G. Blöschl
Hydrol. Earth Syst. Sci., 18, 2735–2772, https://doi.org/10.5194/hess-18-2735-2014, https://doi.org/10.5194/hess-18-2735-2014, 2014
L. Gaál, P. Molnar, and J. Szolgay
Hydrol. Earth Syst. Sci., 18, 1561–1573, https://doi.org/10.5194/hess-18-1561-2014, https://doi.org/10.5194/hess-18-1561-2014, 2014
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Cross-cutting themes: Digital Landscapes: Insights into geomorphological processes from high-resolution topography and quantitative interrogation of topographic data
Geomorphic indicators of continental-scale landscape transience in the Hengduan Mountains, SE Tibet, China
Evaluating the accuracy of binary classifiers for geomorphic applications
Massive sediment pulses triggered by a multi-stage 130 000 m3 alpine cliff fall (Hochvogel, DE–AT)
Multi-sensor monitoring and data integration reveal cyclical destabilization of the Äußeres Hochebenkar rock glacier
Size, shape and orientation matter: fast and semi-automatic measurement of grain geometries from 3D point clouds
Rockfall trajectory reconstruction: a flexible method utilizing video footage and high-resolution terrain models
Drainage reorganization induces deviations in the scaling between valley width and drainage area
Comparative analysis of the Copernicus, TanDEM-X, and UAV-SfM digital elevation models to estimate lavaka (gully) volumes and mobilization rates in the Lake Alaotra region (Madagascar)
Beyond 2D landslide inventories and their rollover: synoptic 3D inventories and volume from repeat lidar data
Coastal change patterns from time series clustering of permanent laser scan data
Measurement of rock glacier surface change over different timescales using terrestrial laser scanning point clouds
Short communication: A semiautomated method for bulk fault slip analysis from topographic scarp profiles
Short Communication: A simple workflow for robust low-cost UAV-derived change detection without ground control points
Computing water flow through complex landscapes – Part 1: Incorporating depressions in flow routing using FlowFill
Relationships between regional coastal land cover distributions and elevation reveal data uncertainty in a sea-level rise impacts model
A segmentation approach for the reproducible extraction and quantification of knickpoints from river long profiles
A method based on structure-from-motion photogrammetry to generate sub-millimetre-resolution digital elevation models for investigating rock breakdown features
A comparison of structure from motion photogrammetry and the traversing micro-erosion meter for measuring erosion on shore platforms
Measuring decadal vertical land-level changes from SRTM-C (2000) and TanDEM-X ( ∼ 2015) in the south-central Andes
Bank erosion processes measured with UAV-SfM along complex banklines of a straight mid-sized river reach
Identification of stable areas in unreferenced laser scans for automated geomorphometric monitoring
Unsupervised detection of salt marsh platforms: a topographic method
The determination of high-resolution spatio-temporal glacier motion fields from time-lapse sequences
Bumps in river profiles: uncertainty assessment and smoothing using quantile regression techniques
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Tree-root control of shallow landslides
Automated terrestrial laser scanning with near-real-time change detection – monitoring of the Séchilienne landslide
Validation of digital elevation models (DEMs) and comparison of geomorphic metrics on the southern Central Andean Plateau
3-D models and structural analysis of rock avalanches: the study of the deformation process to better understand the propagation mechanism
Frontiers in Geomorphometry and Earth Surface Dynamics: possibilities, limitations and perspectives
How does grid-resolution modulate the topographic expression of geomorphic processes?
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A nondimensional framework for exploring the relief structure of landscapes
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Katrina D. Gelwick, Sean D. Willett, and Rong Yang
Earth Surf. Dynam., 12, 783–800, https://doi.org/10.5194/esurf-12-783-2024, https://doi.org/10.5194/esurf-12-783-2024, 2024
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We evaluated the intensity and spatial extent of landscape change in the Hengduan Mountains by identifying areas where river network reorganization is occurring or expected in the future. We combine four metrics that measure topographic imbalances at different spatial and temporal scales. Our study provides a deeper understanding of the dynamic nature of the Hengduan Mountains landscape and associated drivers, such as tectonic uplift, and insights for applying similar methods elsewhere.
Matthew William Rossi
Earth Surf. Dynam., 12, 765–782, https://doi.org/10.5194/esurf-12-765-2024, https://doi.org/10.5194/esurf-12-765-2024, 2024
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Accurately identifying the presence and absence of landforms is important to inferring processes and testing numerical models of landscape evolution. Using synthetic scenarios, I show that the Matthews correlation coefficient (MCC) should be favored over the F1 score when comparing accuracy across scenes where landform abundances vary. Despite the resilience of MCC to imbalanced data, strong sensitivity to the size and shape of features can still occur when truth and model data are misaligned.
Natalie Barbosa, Johannes Leinauer, Juilson Jubanski, Michael Dietze, Ulrich Münzer, Florian Siegert, and Michael Krautblatter
Earth Surf. Dynam., 12, 249–269, https://doi.org/10.5194/esurf-12-249-2024, https://doi.org/10.5194/esurf-12-249-2024, 2024
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Massive sediment pulses in catchments are a key alpine multi-risk component. Combining high-resolution aerial imagery and seismic information, we decipher a multi-stage >130.000 m³ rockfall and subsequent sediment pulses over 4 years, reflecting sediment deposition up to 10 m, redistribution in the basin, and finally debouchure to the outlet. This study provides generic information on spatial and temporal patterns of massive sediment pulses in highly charged alpine catchments.
Lea Hartl, Thomas Zieher, Magnus Bremer, Martin Stocker-Waldhuber, Vivien Zahs, Bernhard Höfle, Christoph Klug, and Alessandro Cicoira
Earth Surf. Dynam., 11, 117–147, https://doi.org/10.5194/esurf-11-117-2023, https://doi.org/10.5194/esurf-11-117-2023, 2023
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The rock glacier in Äußeres Hochebenkar (Austria) moved faster in 2021–2022 than it has in about 70 years of monitoring. It is currently destabilizing. Using a combination of different data types and methods, we show that there have been two cycles of destabilization at Hochebenkar and provide a detailed analysis of velocity and surface changes. Because our time series are very long and show repeated destabilization, this helps us better understand the processes of rock glacier destabilization.
Philippe Steer, Laure Guerit, Dimitri Lague, Alain Crave, and Aurélie Gourdon
Earth Surf. Dynam., 10, 1211–1232, https://doi.org/10.5194/esurf-10-1211-2022, https://doi.org/10.5194/esurf-10-1211-2022, 2022
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The morphology and size of sediments influence erosion efficiency, sediment transport and the quality of aquatic ecosystem. In turn, the spatial evolution of sediment size provides information on the past dynamics of erosion and sediment transport. We have developed a new software which semi-automatically identifies and measures sediments based on 3D point clouds. This software is fast and efficient, offering a new avenue to measure the geometrical properties of large numbers of sediment grains.
François Noël, Michel Jaboyedoff, Andrin Caviezel, Clément Hibert, Franck Bourrier, and Jean-Philippe Malet
Earth Surf. Dynam., 10, 1141–1164, https://doi.org/10.5194/esurf-10-1141-2022, https://doi.org/10.5194/esurf-10-1141-2022, 2022
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Rockfall simulations are often performed to make sure infrastructure is safe. For that purpose, rockfall trajectory data are needed to calibrate the simulation models. In this paper, an affordable, flexible, and efficient trajectory reconstruction method is proposed. The method is tested by reconstructing trajectories from a full-scale rockfall experiment involving 2670 kg rocks and a flexible barrier. The results highlight improvements in precision and accuracy of the proposed method.
Elhanan Harel, Liran Goren, Onn Crouvi, Hanan Ginat, and Eitan Shelef
Earth Surf. Dynam., 10, 875–894, https://doi.org/10.5194/esurf-10-875-2022, https://doi.org/10.5194/esurf-10-875-2022, 2022
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Drainage reorganization redistributes drainage area across basins, resulting in channel and valley widths that may be unproportional to the new drainage area. We demonstrate scaling between valley width and drainage area in reorganized drainages that deviates from scaling in non-reorganized drainages. Further, deviation patterns are associated with different reorganization categories. Our findings are consequential for studies that rely on this scaling for valley width estimation.
Liesa Brosens, Benjamin Campforts, Gerard Govers, Emilien Aldana-Jague, Vao Fenotiana Razanamahandry, Tantely Razafimbelo, Tovonarivo Rafolisy, and Liesbet Jacobs
Earth Surf. Dynam., 10, 209–227, https://doi.org/10.5194/esurf-10-209-2022, https://doi.org/10.5194/esurf-10-209-2022, 2022
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Obtaining accurate information on the volume of geomorphic features typically requires high-resolution topographic data, which are often not available. Here, we show that the globally available 12 m TanDEM-X DEM can be used to accurately estimate gully volumes and establish an area–volume relationship after applying a correction. This allowed us to get a first estimate of the amount of sediment that has been mobilized by large gullies (lavaka) in central Madagascar over the past 70 years.
Thomas G. Bernard, Dimitri Lague, and Philippe Steer
Earth Surf. Dynam., 9, 1013–1044, https://doi.org/10.5194/esurf-9-1013-2021, https://doi.org/10.5194/esurf-9-1013-2021, 2021
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Both landslide mapping and volume estimation accuracies are crucial to quantify landscape evolution and manage such a natural hazard. We developed a method to robustly detect landslides and measure their volume from repeat 3D point cloud lidar data. This method detects more landslides than classical 2D inventories and resolves known issues of indirect volume measurement. Our results also suggest that the number of small landslides classically detected from 2D imagery is underestimated.
Mieke Kuschnerus, Roderik Lindenbergh, and Sander Vos
Earth Surf. Dynam., 9, 89–103, https://doi.org/10.5194/esurf-9-89-2021, https://doi.org/10.5194/esurf-9-89-2021, 2021
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Sandy coasts are areas that undergo a lot of changes, which are caused by different influences, such as tides, wind or human activity. Permanent laser scanning is used to generate a three-dimensional representation of a part of the coast continuously over an extended period. By comparing three unsupervised learning algorithms, we develop a methodology to analyse the resulting data set and derive which processes are dominating changes in the beach and dunes.
Veit Ulrich, Jack G. Williams, Vivien Zahs, Katharina Anders, Stefan Hecht, and Bernhard Höfle
Earth Surf. Dynam., 9, 19–28, https://doi.org/10.5194/esurf-9-19-2021, https://doi.org/10.5194/esurf-9-19-2021, 2021
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In this work, we use 3D point clouds to detect topographic changes across the surface of a rock glacier. These changes are presented as the relative contribution of surface change during a 3-week period to the annual surface change. By comparing these different time periods and looking at change in different directions, we provide estimates showing that different directions of surface change are dominant at different times of the year. This demonstrates the benefit of frequent monitoring.
Franklin D. Wolfe, Timothy A. Stahl, Pilar Villamor, and Biljana Lukovic
Earth Surf. Dynam., 8, 211–219, https://doi.org/10.5194/esurf-8-211-2020, https://doi.org/10.5194/esurf-8-211-2020, 2020
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This short communication presents an efficient method for analyzing large fault scarp data sets. The programs and workflow required are open-source and the methodology is easy to use; thus the barrier to entry is low. This tool can be applied to a broad range of active tectonic studies. A case study in the Taupo Volcanic Zone, New Zealand, exemplifies the novelty of this tool by generating results that are consistent with extensive field campaigns in only a few hours at a work station.
Kristen L. Cook and Michael Dietze
Earth Surf. Dynam., 7, 1009–1017, https://doi.org/10.5194/esurf-7-1009-2019, https://doi.org/10.5194/esurf-7-1009-2019, 2019
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UAVs have become popular tools for detecting topographic changes. Traditionally, detecting small amounts of change between two UAV surveys requires each survey to be highly accurate. We take an alternative approach and present a simple processing workflow that produces survey pairs or sets that are highly consistent with each other, even when the overall accuracy is relatively low. This greatly increases our ability to detect changes in settings where ground control is not possible.
Kerry L. Callaghan and Andrew D. Wickert
Earth Surf. Dynam., 7, 737–753, https://doi.org/10.5194/esurf-7-737-2019, https://doi.org/10.5194/esurf-7-737-2019, 2019
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Lakes and swales are real landscape features but are generally treated as data errors when calculating water flow across a surface. This is a problem because depressions can store water and fragment drainage networks. Until now, there has been no good generalized approach to calculate which depressions fill and overflow and which do not. We addressed this problem by simulating runoff flow across a landscape, selectively flooding depressions and more realistically connecting lakes and rivers.
Erika E. Lentz, Nathaniel G. Plant, and E. Robert Thieler
Earth Surf. Dynam., 7, 429–438, https://doi.org/10.5194/esurf-7-429-2019, https://doi.org/10.5194/esurf-7-429-2019, 2019
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Our findings examine several data inputs for probabilistic regional sea-level rise (SLR) impact predictions. To predict coastal response to SLR, detailed information on the landscape, including elevation, vegetation, and/or level of development, is needed. However, we find that the inherent relationship between elevation and land cover datasets (e.g., beaches tend to be low lying) is used to reduce error in a coastal response to SLR model, suggesting new applications for areas of limited data.
Boris Gailleton, Simon M. Mudd, Fiona J. Clubb, Daniel Peifer, and Martin D. Hurst
Earth Surf. Dynam., 7, 211–230, https://doi.org/10.5194/esurf-7-211-2019, https://doi.org/10.5194/esurf-7-211-2019, 2019
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The shape of landscapes is influenced by climate changes, faulting or the nature of the rocks under the surface. One of the most sensitive parts of the landscape to these changes is the river system that eventually adapts to such changes by adapting its slope, the most extreme example being a waterfall. We here present an algorithm that extracts changes in river slope over large areas from satellite data with the aim of investigating climatic, tectonic or geologic changes in the landscape.
Ankit Kumar Verma and Mary Carol Bourke
Earth Surf. Dynam., 7, 45–66, https://doi.org/10.5194/esurf-7-45-2019, https://doi.org/10.5194/esurf-7-45-2019, 2019
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The article describes the development of a portable triangle control target to register structure-from-motion-derived topographic data. We were able to generate sub-millimetre-resolution 3-D models with sub-millimetre accuracy. We verified the accuracy of our models in an experiment and demonstrated the potential of our method by collecting microtopographic data on weathered Moenkopi sandstone in Arizona. The results from our study confirm the efficacy of our method at sub-millimetre scale.
Niamh Danielle Cullen, Ankit Kumar Verma, and Mary Clare Bourke
Earth Surf. Dynam., 6, 1023–1039, https://doi.org/10.5194/esurf-6-1023-2018, https://doi.org/10.5194/esurf-6-1023-2018, 2018
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This research article provides a comparison between the traditional method of measuring erosion on rock shore platforms using a traversing micro-erosion meter (TMEM) and a new approach using structure from motion (SfM) photogrammetry. Our results indicate that SfM photogrammetry offers several advantages over the TMEM, allowing for erosion measurement at different scales on rock surfaces with low roughness while also providing a means to identify different processes and styles of erosion.
Benjamin Purinton and Bodo Bookhagen
Earth Surf. Dynam., 6, 971–987, https://doi.org/10.5194/esurf-6-971-2018, https://doi.org/10.5194/esurf-6-971-2018, 2018
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We show a new use for the SRTM-C digital elevation model from February 2000 and the newer TanDEM-X dataset from ~ 2015. We difference the datasets over hillslopes and gravel-bed channels to extract vertical land-level changes. These signals are associated with incision, aggradation, and landsliding. This requires careful correction of the SRTM-C biases using the TanDEM-X and propagation of significant uncertainties. The method can be applied to moderate relief areas with SRTM-C coverage.
Gonzalo Duró, Alessandra Crosato, Maarten G. Kleinhans, and Wim S. J. Uijttewaal
Earth Surf. Dynam., 6, 933–953, https://doi.org/10.5194/esurf-6-933-2018, https://doi.org/10.5194/esurf-6-933-2018, 2018
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The challenge to measure three-dimensional bank irregularities in a mid-sized river reach can be quickly solved in the field flying a drone with ground-control points and later applying structure from motion photogrammetry. We tested a simple approach that achieved sufficient resolution and accuracy to identify the full bank erosion cycle, including undermining. This is an easy-to-use and quickly deployed survey alternative to measure bank erosion processes along extended distances.
Daniel Wujanz, Michael Avian, Daniel Krueger, and Frank Neitzel
Earth Surf. Dynam., 6, 303–317, https://doi.org/10.5194/esurf-6-303-2018, https://doi.org/10.5194/esurf-6-303-2018, 2018
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The importance of increasing the degree of automation in the context of monitoring natural hazards or geological phenomena is apparent. A vital step in the processing chain of monitoring deformations is the transformation of captured epochs into a common reference systems. This led to the motivation to develop an algorithm that realistically carries out this task. The algorithm was tested on three different geomorphic events while the results were quite satisfactory.
Guillaume C. H. Goodwin, Simon M. Mudd, and Fiona J. Clubb
Earth Surf. Dynam., 6, 239–255, https://doi.org/10.5194/esurf-6-239-2018, https://doi.org/10.5194/esurf-6-239-2018, 2018
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Salt marshes are valuable environments that provide multiple services to coastal communities. However, their fast-paced evolution poses a challenge to monitoring campaigns due to time-consuming processing. The Topographic Identification of Platforms (TIP) method uses high-resolution topographic data to automatically detect the limits of salt marsh platforms within a landscape. The TIP method provides sufficient accuracy to monitor salt marsh change over time, facilitating coastal management.
Ellen Schwalbe and Hans-Gerd Maas
Earth Surf. Dynam., 5, 861–879, https://doi.org/10.5194/esurf-5-861-2017, https://doi.org/10.5194/esurf-5-861-2017, 2017
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The simple use of time-lapse cameras as a visual observation tool may already be a great help for environmental investigations. However, beyond that, they have the potential to also deliver precise measurements with high temporal and spatial resolution when applying appropriate processing techniques. In this paper we introduce a method for the determination of glacier motion fields from time-lapse images, but it might also be adapted for other environmental motion analysis tasks.
Wolfgang Schwanghart and Dirk Scherler
Earth Surf. Dynam., 5, 821–839, https://doi.org/10.5194/esurf-5-821-2017, https://doi.org/10.5194/esurf-5-821-2017, 2017
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River profiles derived from digital elevation models are affected by errors. Here we present two new algorithms – quantile carving and the CRS algorithm – to hydrologically correct river profiles. Both algorithms preserve the downstream decreasing shape of river profiles, while CRS additionally smooths profiles to avoid artificial steps. Our algorithms are able to cope with the problems of overestimation and asymmetric error distributions.
François Clapuyt, Veerle Vanacker, Fritz Schlunegger, and Kristof Van Oost
Earth Surf. Dynam., 5, 791–806, https://doi.org/10.5194/esurf-5-791-2017, https://doi.org/10.5194/esurf-5-791-2017, 2017
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This work aims at understanding the behaviour of an earth flow located in the Swiss Alps by reconstructing very accurately its topography over a 2-year period. Aerial photos taken from a drone, which are then processed using a computer vision algorithm, were used to derive the topographic datasets. Combination and careful interpretation of high-resolution topographic analyses reveal the internal mechanisms of the earthflow and its complex rotational structure, which is evolving over time.
Denis Cohen and Massimiliano Schwarz
Earth Surf. Dynam., 5, 451–477, https://doi.org/10.5194/esurf-5-451-2017, https://doi.org/10.5194/esurf-5-451-2017, 2017
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Tree roots reinforce soils on slopes. A new slope stability model is presented that computes root reinforcement including the effects of root heterogeneities and dependence of root strength on tensile and compressive strain. Our results show that roots stabilize slopes that would otherwise fail under a rainfall event. Tension in roots is more effective than compression. Redistribution of forces in roots across the hillslope plays a key role in the stability of the slope during rainfall events.
Ryan A. Kromer, Antonio Abellán, D. Jean Hutchinson, Matt Lato, Marie-Aurelie Chanut, Laurent Dubois, and Michel Jaboyedoff
Earth Surf. Dynam., 5, 293–310, https://doi.org/10.5194/esurf-5-293-2017, https://doi.org/10.5194/esurf-5-293-2017, 2017
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We developed and tested an automated terrestrial laser scanning (ATLS) system with near-real-time change detection at the Séchilienne landslide. We monitored the landslide for a 6-week period collecting a point cloud every 30 min. We detected various slope processes including movement of scree material, pre-failure deformation of discrete rockfall events and deformation of the main landslide body. This system allows the study of slope processes a high level of temporal detail.
Benjamin Purinton and Bodo Bookhagen
Earth Surf. Dynam., 5, 211–237, https://doi.org/10.5194/esurf-5-211-2017, https://doi.org/10.5194/esurf-5-211-2017, 2017
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We evaluate the 12 m TanDEM-X DEM for geomorphometry and compare elevation accuracy (using over 300 000 dGPS measurements) and geomorphic metrics (e.g., slope and curvature) to other modern satellite-derived DEMs. The optically generated 5 m ALOS World 3D is less useful due to high-frequency noise. Despite improvements in radar-derived satellite DEMs, which are useful for elevation differencing and catchment analysis, lidar data are still necessary for fine-scale analysis of hillslope processes.
Céline Longchamp, Antonio Abellan, Michel Jaboyedoff, and Irene Manzella
Earth Surf. Dynam., 4, 743–755, https://doi.org/10.5194/esurf-4-743-2016, https://doi.org/10.5194/esurf-4-743-2016, 2016
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The main objective of this research is to analyze rock avalanche dynamics by means of a detailed structural analysis of the deposits coming from data of 3-D measurements. The studied deposits are of different magnitude: (1) decimeter level scale laboratory experiments and (2) well-studied rock avalanches.
Filtering techniques were developed and applied to a 3-D dataset in order to detect fault structures present in the deposits and to propose kinematic mechanisms for the propagation.
Giulia Sofia, John K. Hillier, and Susan J. Conway
Earth Surf. Dynam., 4, 721–725, https://doi.org/10.5194/esurf-4-721-2016, https://doi.org/10.5194/esurf-4-721-2016, 2016
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The interdisciplinarity of geomorphometry is its greatest strength and one of its major challenges. This special issue showcases exciting developments that are the building blocks for the next step-change in the field. In reading and compiling the contributions we hope that the scientific community will be inspired to seek out collaborations and share ideas across subject-boundaries, between technique-developers and users, enabling us as a community to gather knowledge from our digital landscape
Stuart W. D. Grieve, Simon M. Mudd, David T. Milodowski, Fiona J. Clubb, and David J. Furbish
Earth Surf. Dynam., 4, 627–653, https://doi.org/10.5194/esurf-4-627-2016, https://doi.org/10.5194/esurf-4-627-2016, 2016
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High-resolution topographic data are becoming more prevalent, yet many areas of geomorphic interest do not have such data available. We produce topographic data at a range of resolutions to explore the influence of decreasing resolution of data on geomorphic analysis. We test the accuracy of the calculation of curvature, a hillslope sediment transport coefficient, and the identification of channel networks, providing guidelines for future use of these methods on low-resolution topographic data.
Livia Piermattei, Luca Carturan, Fabrizio de Blasi, Paolo Tarolli, Giancarlo Dalla Fontana, Antonio Vettore, and Norbert Pfeifer
Earth Surf. Dynam., 4, 425–443, https://doi.org/10.5194/esurf-4-425-2016, https://doi.org/10.5194/esurf-4-425-2016, 2016
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We investigated the applicability of the SfM–MVS approach for calculating the geodetic mass balance of a glacier and for the detection of the surface displacement rate of an active rock glacier located in the eastern Italian Alps. The results demonstrate that it is possible to reliably quantify the investigated glacial and periglacial processes by means of a quick ground-based photogrammetric survey that was conducted using a consumer grade SRL camera and natural targets as ground control points.
Anette Eltner, Andreas Kaiser, Carlos Castillo, Gilles Rock, Fabian Neugirg, and Antonio Abellán
Earth Surf. Dynam., 4, 359–389, https://doi.org/10.5194/esurf-4-359-2016, https://doi.org/10.5194/esurf-4-359-2016, 2016
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Three-dimensional reconstruction of earth surfaces from overlapping images is a promising tool for geoscientists. The method is very flexible, cost-efficient and easy to use, leading to a high variability in applications at different scales. Performance evaluation reveals that good accuracies are achievable but depend on the requirements of the individual case study. Future applications and developments (i.e. big data) will consolidate this essential tool for digital surface mapping.
Sebastiano Trevisani and Marco Cavalli
Earth Surf. Dynam., 4, 343–358, https://doi.org/10.5194/esurf-4-343-2016, https://doi.org/10.5194/esurf-4-343-2016, 2016
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The generalization of the concept of roughness implies the need to refer to a family of roughness indices capturing specific aspects of surface morphology. We test the application of a flow-oriented directional measure of roughness based on the geostatistical index MAD (median of absolute directional differences), computed considering gravity-driven flow direction. The use of flow-directional roughness improves geomorphometric modeling and the interpretation of landscape morphology.
Stuart W. D. Grieve, Simon M. Mudd, Martin D. Hurst, and David T. Milodowski
Earth Surf. Dynam., 4, 309–325, https://doi.org/10.5194/esurf-4-309-2016, https://doi.org/10.5194/esurf-4-309-2016, 2016
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Relationships between the erosion rate and topographic relief of hillslopes have been demonstrated in a number of diverse settings and such patterns can be used to identify the impact of tectonic plate motion on the Earth's surface. Here we present an open-source software tool which can be used to explore these relationships in any landscape where high-resolution topographic data have been collected.
D. T. Milodowski, S. M. Mudd, and E. T. A. Mitchard
Earth Surf. Dynam., 3, 483–499, https://doi.org/10.5194/esurf-3-483-2015, https://doi.org/10.5194/esurf-3-483-2015, 2015
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Rock is exposed at the Earth surface when erosion rates locally exceed rates of soil production. This transition is marked by a diagnostic increase in topographic roughness, which we demonstrate can be a powerful indicator of the location of rock outcrop in a landscape. Using this to explore how hillslopes in two landscapes respond to increasing erosion rates, we find that the transition from soil-mantled to bedrock hillslopes is patchy and spatially heterogeneous.
M. T. Melis, F. Mundula, F. DessÌ, R. Cioni, and A. Funedda
Earth Surf. Dynam., 2, 481–492, https://doi.org/10.5194/esurf-2-481-2014, https://doi.org/10.5194/esurf-2-481-2014, 2014
S. Zhao and W. Cheng
Earth Surf. Dynam., 2, 433–441, https://doi.org/10.5194/esurf-2-433-2014, https://doi.org/10.5194/esurf-2-433-2014, 2014
S. Hergarten, J. Robl, and K. Stüwe
Earth Surf. Dynam., 2, 97–104, https://doi.org/10.5194/esurf-2-97-2014, https://doi.org/10.5194/esurf-2-97-2014, 2014
W. Schwanghart and D. Scherler
Earth Surf. Dynam., 2, 1–7, https://doi.org/10.5194/esurf-2-1-2014, https://doi.org/10.5194/esurf-2-1-2014, 2014
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Short summary
This paper presents a novel methodology to identify and quantitatively analyze deposition and erosion patterns in ephemeral ponds or in perennial lakes with strong water level fluctuations. We apply this method to unravel the water and sediment balance of Lac Wégnia, a designated Ramsar site in Mali. The study can be a showcase for monitoring Sahelian lakes using remote sensing data, as it sheds light on the actual drivers of change in Sahelian lakes.
This paper presents a novel methodology to identify and quantitatively analyze deposition and...
