Earth Surface Processes and Landforms最新文献

{"title":"Potential and constraints of uncrewed aerial vehicle orthoimagery for rivers: A direct comparison with field measurements for mapping boulders","authors":"Christopher Wård,&nbsp;Richard J. Mason,&nbsp;Ricardo Carrillo,&nbsp;Lina E. Polvi","doi":"10.1002/esp.70106","DOIUrl":"https://doi.org/10.1002/esp.70106","url":null,"abstract":"<p>Technological advances continue to improve our ability to detect landforms and landscape changes. Remote sensing can provide geomorphological information at larger scales than previously possible but interpreting this information can be more challenging than for field data. Measuring and mapping roughness elements, such as boulders and large wood, is essential for understanding geomorphic processes and restoration in many landscapes where these are abundant. Mapping roughness elements from aerial orthoimagery is common but could produce different results than field measurements due to the 2D nature of the imagery and the variable ability to detect boulders through water and vegetation. We compared measurements of river boulders from aerial imagery collected by uncrewed aerial vehicles (UAVs) to direct measurements in the field. We surveyed boulder size, density and spatial distributions using both approaches at eight river reaches in northern Sweden. We found that the density, coverage and size of boulders mapped from UAVs were strongly correlated with those from field measurements, giving confidence in UAV methods. However, the UAV approach consistently resulted in fewer boulders (30% lower density), lower boulder coverage and smaller boulders (7% smaller mean b-axis) compared to field measurements. The difference between field and UAV measurements was strongly associated with river bankfull depth. Therefore, we conclude that UAV measurements should be restricted to sites with low depth or high visibility through the water column and where bias in boulder detection with depth is not likely to influence study conclusions. In reaches with many boulders, overlap of boulders also likely reduces the suitability of aerial imagery. We conclude that aerial imagery has high potential for mapping landforms in rivers but is not directly equivalent to field studies and the implications of hiding by water, sediment and vegetation need to be considered.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144367366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cosmogenic dating of two rock avalanches in the Ama Drime Range, Central Himalayas","authors":"Mengzhen Li,&nbsp;Qinghao Ma,&nbsp;Fangheng Liu,&nbsp;Yanmin Yang,&nbsp;Jiajing Wang,&nbsp;Jiafu Zhang,&nbsp;Gengnian Liu","doi":"10.1002/esp.70102","DOIUrl":"https://doi.org/10.1002/esp.70102","url":null,"abstract":"<p>The Himalayan region, shaped by active tectonics and complex geomorphological processes, is highly susceptible to avalanches. Among various avalanche types, rock avalanches—recognized as the most prevalent failure pattern—have been extensively studied in the western Himalayan orogen, whereas research on its central segment remains limited. In this study, two newly discovered rock avalanches, located on the eastern and western sides of the Ama Drime range in the central Himalayan region, were investigated and dated using cosmogenic ¹⁰Be exposure ages. The results show that the Pengqu (PQ) rock avalanche, situated on a river terrace, was dated to 120.0 ± 13.0 ka, and the Xiaerqu (XRQ) rock avalanche, located in a glacial valley, occurred between 5.8 ± 0.5 and 4.4 ± 0.5 ka. Considering geological, climatic and seismic factors, we propose that the PQ rock avalanche was primarily caused by prolonged warm and humid conditions during the MIS 5e period, which induced internal deformation of the Kartha gneiss. In contrast, the XRQ rock avalanche was mainly driven by glacial debuttressing, which reduced the stability of the underlying rock. Ultimately, both the PQ and XRQ avalanches were triggered by fault activity, specifically the Khatar and Dinggye faults, respectively. These findings are crucial for understanding the driving mechanisms of rock avalanches in the central Himalayan region and offer valuable insights into fault activity and geomorphological evolution.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339460","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hillslope grain size variation across evolving landscapes linked to climate, tectonics and lithology","authors":"Tingan Li,&nbsp;Leonard S. Sklar,&nbsp;Nicole M. Gasparini","doi":"10.1002/esp.70111","DOIUrl":"https://doi.org/10.1002/esp.70111","url":null,"abstract":"<p>The grain size of bedload sediment regulates rates of river incision into bedrock and thus influences topographic response to temporal and spatial variations in climate, tectonics and lithology. Grain size in river networks, in turn, depends on the size distributions of rock particles produced by weathering on hillslopes, which vary with local climate, erosion rate and rock properties. Hence, understanding the evolution of erosional landscapes requires consideration of the role of grain size as both a driver and a response to topographic change. However, conventional landscape evolution models do not explicitly account for the role of grain size, in part because algorithms for predicting hillslope grain size have been lacking. Here, we couple a recently proposed model for grain size production on hillslopes with a conventional landscape evolution model, to explore the controls on grain size at the landscape scale. We conducted a series of numerical experiments, varying rock uplift rate, temperature, precipitation and rock properties, to evolve a suite of steady-state and transient landscapes. Model simulations suggest that rock uplift rate, through its effect on erosion rate and hillslope residence time, is more influential than climate in controlling the variation in hillslope grain size distributions in tectonically active landscapes. Overall, coarser size distributions result from faster rates of uplift, as well as from colder and drier conditions, and lithologies with lower erodibility and weathering susceptibility. These results are broadly consistent with patterns of hillslope grain size variation reported in field studies but likely underpredict the potential magnitude of variation because of the limitations of the model linking grain size and hillslope weathering. This work is a first step toward incorporating grain-sized explicit algorithms for bedrock incision into landscape evolution models to capture the potential for feedback among grain size, climate, tectonics and lithology in evolving landscapes.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70111","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal rotation of California pocket beaches","authors":"Jonathan A. Warrick,&nbsp;Daniel Buscombe,&nbsp;Kilian Vos,&nbsp;Andrew C. Ritchie,&nbsp;Bob Battalio","doi":"10.1002/esp.70115","DOIUrl":"https://doi.org/10.1002/esp.70115","url":null,"abstract":"<p>Pocket beaches are short, headland-bound coastal landforms that may exhibit shoreline rotation in response to time-varying wave conditions. Here we examine the presence, location and style of pocket beach rotation along the 1700 km coast of California using a comprehensive 22-year satellite-derived shoreline dataset. These analyses identify 23 pocket beaches that exhibit annual cycles of rotation, and these beaches have two general types. In southern California, pocket beaches rotate clockwise, or towards the south, in the winter season (‘winter southward’ transport of sand). These beaches have symmetric rotation patterns and strong seasonality in wave direction (winter west swell and summer south swell), which is indicative of rotation from seasonal oscillations in longshore sediment transport. In northern California, pocket beaches rotate counterclockwise, or towards the north, in the winter (‘winter northward’ transport of sand), and they are characterized by strong asymmetry (winter beach is overall narrower than the summer beach) and strong seasonality in wave power. Rotation of these northern California beaches is related to both cross-shore and longshore sediment transport, caused by large west-to-northwest swell of the winter and smaller northwest wind waves of the summer. We acknowledge that many more rotating pocket beaches likely exist in California owing to the undersampling of the smallest beaches in the source data. In the end, we conclude that seasonally rotating pocket beaches are a fundamental coastal landform type of the California coast, owing to its wave seasonality and rocky and cliff-backed morphology.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70115","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracking landslide sediment: 10Be dilution of detrital quartz in multiple grain sizes following the 2016 Mw 7.8 Kaikōura earthquake, New Zealand","authors":"Dina M. Fieman,&nbsp;Jamie Howarth,&nbsp;Kevin Norton,&nbsp;Allison Duvall,&nbsp;Claire E. Lukens,&nbsp;Katie Jones,&nbsp;Klaus Wilcken,&nbsp;Seth Williams,&nbsp;John Stone","doi":"10.1002/esp.70050","DOIUrl":"https://doi.org/10.1002/esp.70050","url":null,"abstract":"<p>Cosmogenic radionuclides (CRNs) have been proposed as a tool for tracking landslide sediment, yet interpreting the <i>in-situ</i> ¹⁰Be signal through time with respect to the post-seismic sediment cascade has proved challenging in the few examples where it has been applied. To determine how useful the ¹⁰Be concentration is in providing insights into the fluvial response of co-seismic sediment delivery, we measured the ¹⁰Be concentration in multiple grain sizes in two catchments in New Zealand affected by the 2016 Kaikōura earthquake. A 6-year post earthquake time series of ¹⁰Be measurements was compared to a sediment budget produced by differencing lidar surveys over the same study period. Results showed that the ¹⁰Be concentrations in the sand fraction are controlled by the post-seismic hillslope delivery, whereas the ¹⁰Be concentrations in the coarser grains respond to the total volume of landslide material in the active channel. Faster ¹⁰Be dilution and recovery of the sand fraction indicates that the transport rate of the sediment pulse is highly dependent on grain size. The residence of the fine-grained sediment is estimated to be within a decade of the earthquake, although it may take several centuries to evacuate the entirety of the landslide pulse. We observe different magnitudes of ¹⁰Be dilution between two study catchments, which is attributable to a difference in connected landslide volume from hillslopes. We also demonstrate that the dilution factor has little relationship to conventional landslide metrics on a global scale. Our analysis suggests that the magnitude of dilution is controlled through a complex relationship between the connected landslide volume, the degree of sediment mixing and the delivery and evacuation time of landslide sediment. Additionally, if coarse sediment is primarily sourced through mass-wasting events, measuring just the sand ¹⁰Be concentration will bias the catchment-averaged erosion rate.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detailed numerical simulation of landslide dam failure considering non-uniform and multi-layered sediments: A case study of the second Baige landslide dam in the Jinsha River, China","authors":"Jiangtao Yang,&nbsp;Danyi Shen,&nbsp;Zhenming Shi,&nbsp;Sandra Soares-Frazão","doi":"10.1002/esp.70097","DOIUrl":"https://doi.org/10.1002/esp.70097","url":null,"abstract":"<p>Prediction of the dam failure process and downstream flooding is crucial for hazard management and understanding the local morphological changes associated with landslide dam events. Indeed, numerous models exist to simulate landslide dam failures, but the characteristics of these dams, especially their very specific material composition, are often oversimplified or neglected. This paper presents a 2D numerical model that accounts for non-uniform and multi-layered sediments. It is applied to the failure of the second Baige landslide dam and the results are validated through comparisons with field observations. The effects of the upstream inflow rate and dam material composition on the failure process are investigated. Additionally, the numerical results are compared to those obtained from five other detailed, less detailed or empirical models. The results show that the proposed model accurately reproduces the dam failure process and captures the evolution of surface grain size distribution during the event. Increased upstream inflow rates significantly increase the peak discharge but have a limited effect on the final breach while lower inflow rates significantly extend the time to failure, allowing for emergency interventions and evacuation. Due to the high inflow discharge in the case of the Baige event and relatively fine dam material, all sediment sizes are mobilized, resulting in negligible differences in failure evolution between uniform and non-uniform sediment scenarios. Furthermore, unlike empirical and simplified numerical models, the proposed model does not rely on limited case studies or predefined breach evolution assumptions, providing a more reliable simulation framework. It therefore offers a practical and flexible framework for hazard assessment and mitigation planning in mountainous regions worldwide.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144256275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distributed estimation of surface sediment size in paraglacial and periglacial environments using drone photogrammetry","authors":"Gerardo Zegers,&nbsp;Masaki Hayashi,&nbsp;Alex Garcés","doi":"10.1002/esp.70093","DOIUrl":"https://doi.org/10.1002/esp.70093","url":null,"abstract":"<p>Grain-size analysis offers insights into geological processes and landform dynamics. Traditional grain-size sampling methods are labour intensive and offer limited spatial coverage, posing challenges in paraglacial and periglacial environments characterized by large spatial variability in sediment sizes. This study introduces a new workflow that combines structure-from-motion, image segmentation and texture-based optical granulometry techniques to estimate surface grain size in paraglacial and periglacial environments efficiently. Utilizing high-resolution orthomosaics (ground sampling distance <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation>$$ sim $$</annotation>\u0000 </semantics></math>8 mm) and Cellpose, a deep-learning image segmentation model, the new workflow achieves high-accuracy grain-size distributions (GSDs) with low errors. These GSDs, along with lower resolution orthomosaics (ground sampling distance <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation>$$ sim $$</annotation>\u0000 </semantics></math>30 mm), are used to train SediNet—a machine-learning framework—to predict GSDs accurately from <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mn>340</mn>\u0000 <mo>×</mo>\u0000 <mn>340</mn>\u0000 </mrow>\u0000 <annotation>$$ 340times 340 $$</annotation>\u0000 </semantics></math> pixel tiles. Tested across six alpine basins in the Canadian Rockies and a rock glacier in Italy, the model demonstrates effectiveness and accuracy, promising advancements in geoscientific research and the understanding of paraglacial and periglacial dynamics.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70093","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144244412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observing the mass balance and emergence velocity of a temperate glacier on Mt. Yulong, southeastern Tibetan Plateau","authors":"Xingguo Yan,&nbsp;Shijin Wang,&nbsp;Zhenqi Sun,&nbsp;Xinggang Ma,&nbsp;Tao Pu,&nbsp;Yuanqing He","doi":"10.1002/esp.70100","DOIUrl":"https://doi.org/10.1002/esp.70100","url":null,"abstract":"<p>Temperate glaciers in the southeastern Tibetan Plateau are shrinking rapidly in response to ongoing climate change. This study focuses on the Baishui River Glacier No. 1, a typical temperate glacier in the Yulong Snow Mountain. Through field observations over four years, we have obtained records and valuable data on the mass balance, ice flow velocity and emergence velocity. The results show that it has been in a state of negative mass balance in recent 4-years. The mass loss ranges from 1.17 ± 0.18 to 1.46 ± 0.25 m w.e., with an average annual mass loss of 1.29 ± 0.17 m w.e. The average ice flow velocity is ~29.24 ± 3.51 m yr⁻¹, with spatial differences related to glacier morphology and mass turnover. These differences can be attributed to the glacier's morphological characteristics (such as width, slope, thickness and crevasse) and the large mass turnover conditions. In its low-latitude wet climate, BRG1 has a fast emergence velocity of ~4.07 ± 1.03 m yr⁻¹. The emergent ice flow is insufficient cannot offset melting. Slope change uncertainties hamper calculating surface mass balance from emergence velocity. Our data reveals a significant correlation (r² = 0.69) between ice flow velocity and emergence velocity, and a very significant negative one (r² = 0.78) between ice flow velocity and mass balance. Faster ice flow transports more ice to lower, warmer areas, accelerating melting. The data presented in this article offers valuable and useful insights into the physical ice flow model of such low-latitude temperate glaciers.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Landscape evolution and aquifer building processes in a carbonate fold-and-thrust belt, Italian Southern Alps: Insights from 3D geo-modelling","authors":"Paola Bellotti,&nbsp;Riccardo Bersezio,&nbsp;Chiara Zuffetti","doi":"10.1002/esp.70109","DOIUrl":"https://doi.org/10.1002/esp.70109","url":null,"abstract":"<p>Carbonate aquifers of fold-and-thrust mountain belts supply a large amount of human water demand all over the world. Aiming to improve carbonate aquifer modelling, we investigated the relationships between landscape evolution and aquifer building processes in the Southalpine thrust belt of Lombardy Region. The rationale was to learn about the coevolution of tectono-stratigraphic, karstic and landscape genetic processes that led to the present-day carbonate aquifer configuration. Morpho-structural analyses and 3D geo-modelling permitted to relate the assemblage of aquifer heterogeneities to the geomorphological evolution of the Gaverina springs setting. Mesozoic pre- and syn-rift stratigraphy predisposed the future different limestone aquifer types (extensive cave vs. phreatic systems). The inherited Mesozoic extensional structures controlled alpine thrusting, shaping, sizing and deploying the different carbonate aquifers and shale aquitards. Coevolution of different karst systems and landscape started since the Neogene emersion above sea level. Three Miocene increments of slip and uplift rates, erosional unroofing of tectonic units, epi- and endokarst genesis and exhumation are recorded by landforms and sediments that witness the stabilization and raising steps of the relative base levels before the Pliocene marine transgression. The present-day elevation (350 m above sea level) of the late Pliocene coastal sediments onlapping the local relief, constrains the minimum estimates of Neogene and Quaternary uplift amounts, during which the karst systems developed downwards chasing the lowering of the reference base levels. Pleistocene glacial advances mainly acted on the valley floor, eroding and lowering the local base level. On the slopes, ablation tills and ice-contact deposits dammed some low-elevation springs, plausibly contributing to expand the phreatic zone upwards. The geo-morphological controls on hydrostratigraphy and the landscape–aquifer coevolution described at the Gaverina site are comparable to those of many settings of the Mediterranean peri-Tethyan fold-and-thrust belts, suggesting that this approach might find a broad application.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144244379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gravel bar shielding: A mechanism responsible for bar stability in gravel- and cobble-bedded streams","authors":"Ariel do Prado,&nbsp;Cristiano Padalino Galeazzi,&nbsp;David Mair,&nbsp;Philippos Garefalakis,&nbsp;Renato Paes de Almeida,&nbsp;Alexander C. Whittaker,&nbsp;Fritz Schlunegger","doi":"10.1002/esp.70107","DOIUrl":"https://doi.org/10.1002/esp.70107","url":null,"abstract":"<p>The stability of gravel bars and riverbanks is often attributed to the presence of vegetation, yet the conditions controlling the stability of such bars without of a vegetation cover have remained unclear. Here, we propose that such controls are exerted by what we refer to as ‘lateral lag deposits’, which result from the winnowing of gravel bar edges during periods when channels widen. We base this interpretation on an example from the Sense River, Switzerland, a natural wandering-braided stream with gravel-cobble bars devoid of vegetation. Through a survey where we measured the size of several thousands of grains along two up to 50 m-long reaches, we found that the 84th percentile values (D₈₄) of the grain size distributions (GSD) are consistently larger on the eroded bar edges compared to the bar top or the channel between bars. At these bar edges, the coarse grains appear to shield the gravel bar from lateral erosion, thus forming a lag deposit. Orthoimages taken along the studied reaches between 2017 and 2023 reveal that the target lateral lag deposits outlasted several lower-discharge floods, during which the sedimentological architecture of the investigated reach changed multiple times. We therefore suggest that lateral lag deposits are among the sedimentological structures of braided streams with the highest preservation potential and that they exert the largest threshold to the complete reworking of gravel bars without vegetation.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"50 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70107","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144219951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}