Earth Surface Processes and Landforms最新文献

{"title":"Flow resistance parameterization for large wood in two-dimensional depth-averaged models: Effects of flow condition, blockage, and sediment","authors":"Fikri M. Radiyan, Xiaofeng Liu","doi":"10.1002/esp.70383","DOIUrl":"https://doi.org/10.1002/esp.70383","url":null,"abstract":"<p>Large wood (LW) significantly alters flow and bed morphology in river systems, necessitating accurate parameterization in two-dimensional (2D) hydraulic models. This study investigated the effects of LW-induced flow resistance in 2D depth-averaged models using a combination of systematic flume experiments and numerical modeling. Sixteen controlled laboratory experiments were conducted, varying flow conditions, LW blockage ratios (full-span vs half-span) and sediment presence. Rectangular porous LW structures of constant porosity (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation>$$ sim $$</annotation>\u0000 </semantics></math> 0.66) were placed in a recirculating flume, and flow data including water surface elevation and velocity were recorded. Drag coefficient (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mrow>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>d</mi>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {C}_d $$</annotation>\u0000 </semantics></math>) and Manning's roughness <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>n</mi>\u0000 </mrow>\u0000 <annotation>$$ n $$</annotation>\u0000 </semantics></math> were calibrated for each case using Gaussian Process Optimization to minimize model error based on measured water depths and flow partitioning. Results show that LW flow resistance parameterization is more complex than previously assumed. In addition to LW characteristics, it also depends on flow condition, blockage and sediment transport. Sediment presence and the resulting bed topography exert significant influence on flow resistance parameterization, followed by LW blockage configuration. Flow resistance parameters displayed wide variability even with fixed LW porosity, with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mrow>\u0000 <mi>C</mi>\u0000 </mrow>\u0000 <mrow>\u0000 <mi>d</mi>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 <annotation>$$ {C}_d $$</annotation>\u0000 </semantics></math> ranging from 14 to 65 and Manning's <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>n</mi>\u0000 </mrow>\u0000 <annotation>$$ n $$</annotation>\u0000 </semantics></math> from 1.17 to 2.6. These large <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>n</mi>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70383","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148783661","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":"Fault-controlled uplift segmentation and crust–mantle heterogeneity in the topographic evolution of the Sındırgı Segment (Western Anatolia) ruptured during the 2025 M6.1 earthquake sequence","authors":"Savaş Topal,&nbsp;Murat Nas,&nbsp;Elif Akgün,&nbsp;Mustafa Softa","doi":"10.1002/esp.70385","DOIUrl":"https://doi.org/10.1002/esp.70385","url":null,"abstract":"<p>Topographic evolution, particularly in extensional tectonic regimes, stems from fault activity and crust–mantle heterogeneity, both of which coordinate long-term rock uplift. Understanding how surface topography records the interaction between fault activity and deep lithospheric processes is essential for explaining the extension of continental regions. In this study, Moho variations were adopted as a core element to examine landscape evolution along the Sındırgı Segment in Western Anatolia through a multimodal analysis of geomorphic indices, drainage-network metrics, knickpoint distributions and the inversion of river longitudinal profiles. Morphometric parameters and normalized channel steepness showed along-strike segmentation and spatially variable uplift patterns. <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>χ</mi>\u0000 </mrow>\u0000 <annotation>$$ chi $$</annotation>\u0000 </semantics></math> and Gilbert metrics indicated uneven drainage-divide behaviour, namely, the drainage system is still adjusting. River-profile inversion showed that rock uplift got underway during the Late Pliocene and accelerated during the Early to Middle Pleistocene. This migration produced continual topographic markers preserved in the present-day relief and knickpoints. Moho depth varied along the fault and matched the cumulative uplift and landscape segmentation. So upper-crustal faulting alone is not enough to explain surface deformation and long-wavelength topography. Note that the Moho data gave a regional-scale lithospheric constraint; the observed relationship should only be interpreted as partial lithospheric modulation rather than direct causality. In conclusion, the Sındırgı Segment has not been shaped by a sole process. Instead, an intertwined system is active, in which fault-controlled surface processes interact with deeper lithospheric heterogeneity. Spatially variable tectonic forcing, coupled with ongoing drainage adjustment within an active extensional setting, drives the landscape evolution.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753605","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":"Assessment of structural sediment connectivity using different weighting factors and field data in a mountain–piedmont catchment of the Pampean Ranges of Argentina","authors":"María Eugenia Benito,&nbsp;María Jimena Andreazzini,&nbsp;Susana Beatriz Degiovanni,&nbsp;Marco Cavalli,&nbsp;Paula Armas,&nbsp;María Santinelli","doi":"10.1002/esp.70382","DOIUrl":"https://doi.org/10.1002/esp.70382","url":null,"abstract":"<p>Sediment connectivity studies provide a holistic approach to assessing sediment fluxes in catchments, as they consider the spatial configuration of landscape components and their functional interrelationships. The index of connectivity (IC) is one of the most widely used methods to evaluate structural sediment connectivity. The IC has been adapted to different landscape contexts through various formulations of the weighting factor (W), reflecting the flexibility of the method. However, we understand that more than developing new variants, it is necessary to critically evaluate existing formulations to contribute to the standardization of the IC. This study evaluates structural sediment connectivity in the Alpa Corral-Seco catchment (Córdoba-Argentina), a mountain–piedmont system with variable vegetation cover. The aim is to compare different formulations of the W factor based on Manning's roughness coefficient (i.e., ICp, ICm and ICz) and to identify the most suitable IC for this environment. The analysis was complemented by satellite image processing and field observations to enhance the interpretation of connectivity patterns. Results indicate that ICz provides the most reliable representation, showing the highest capacity to discriminate spatial variability across different environmental contexts and the strongest agreement with field observations. ICm preserves the main geomorphological contrasts but attenuates spatial variability, making it suitable for coarse scales analyses, whereas ICp tends to smooth connectivity patterns and overestimate connectivity in vegetated areas. Spatial analysis reveals high connectivity in the mountainous sector, where the weathering and erosion of granitic outcrops and sparse vegetation favour the sediments production and transfer. Conversely, the piedmont shows low connectivity, with processes concentrated along the main channel. These findings highlight the importance of field validation and the effectiveness of Manning-based W factors in geomorphological heterogeneous catchments when using medium-resolution DEMs.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753591","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":"Flexural tectonics and lithological controls on landscape evolution in a forebulge region: Insights from Central India","authors":"Parv Kasana,&nbsp;Vimal Singh,&nbsp;Rohit Kumar,&nbsp;Arkaprabha Sarkar,&nbsp;Pavitra V. Kumar,&nbsp;Pankaj Kumar","doi":"10.1002/esp.70359","DOIUrl":"https://doi.org/10.1002/esp.70359","url":null,"abstract":"<p>Forebulge regions represent slowly deforming intraplate settings where the relative roles of flexural tectonics, lithological variability and climate in shaping landscapes remain poorly constrained. We investigate the Central Indian Forebulge (CIF), which formed in response to Himalayan loading and despite low erosion rates (2–7 m/Myr), hosts widespread transient landforms, including waterfalls, canyons and escarpments that are generally associated with tectonically active settings. To evaluate the controls on landscape evolution in CIF, we integrate morphometric analyses (normalized channel steepness index <i>k</i>_<i>sn</i>, chi profiles), catchment-averaged cosmogenic ¹⁰Be erosion rates, field-based rock strength measurements, lineament and stream orientation analysis, and flexural stress modelling. Our results show that flexural tectonics exerts a primary control on landscape organization through the generation of fracture networks that guide rivers. Modelled fibre stress magnitudes on the CIF exceed 14.2 MPa, which is sufficient to overcome the tensile strength of the lithologies present on the forebulge. These stresses are enough to generate and reactivate extensional fracture networks associated with flexural uplift. Stream orientations and lineament trends show a dominant NW–SE direction, which aligns with forebulge-parallel fracture systems. The majority of structurally controlled knickpoints also align with these NW–SE lineaments. The <i>k</i>_<i>sn</i> values are broadly similar across lithologies in spite of their different rock strengths (uniaxial compression strength range, 16–199 MPa), indicating that channel steepness does not relate directly with substrate erodibility at basin scale. Erosion rates show positive relationships with basin-averaged slope, relief and <i>k</i>_<i>sn</i> but weak relationships with precipitation and drainage area, suggesting that denudation is largely governed by the topographic gradients established under long-term tectonic forcing. These observations indicate that flexural tectonics controls the structural framework and topographic boundary conditions for river incision, whereas lithological contrasts modulate erosion efficiency and the expression of transient landforms. The weak coupling between channel steepness and lithologic erodibility demonstrates that the CIF represents a transient landscape that is not yet in steady state.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753288","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":"Spatial variability of denudation rates and transient landscape adjustment in low-deforming mountains (the Strengbach catchment, Vosges Mountains, France)","authors":"Bastien Mathieux,&nbsp;Daniel S. Moreno Martin,&nbsp;Jérôme van der Woerd,&nbsp;Raphael Di Chiara Roupert,&nbsp;Gilles Rixhon,&nbsp;Anne-Sophie Mériaux,&nbsp;Silke Merchel,&nbsp;Stephanie Neuhuber,&nbsp;Alexander Wieser,&nbsp;Oscar Marchhart,&nbsp;François Chabaux","doi":"10.1002/esp.70361","DOIUrl":"https://doi.org/10.1002/esp.70361","url":null,"abstract":"<p>A set of ¹⁰Be-derived catchment-wide denudation (CWD) rates in a low mountain catchment of western Europe (Strengbach catchment, Vosges Mountains) are analysed to discuss landscape stability. Together with a morphometric study, the data highlight the heterogeneous behaviour of the main trunk and major tributaries. Overall, the rates range from 39 to 84 mm/kyr across the catchment, the main trunk shows increasing rates from 41 to 48 mm/kyr from source to outlet, and the tributaries have systematically higher rates (42 to 84 mm/kyr). To discuss the origin of these variations, we look for systematic characters related to both morphology and lithology. We apportion the landscape of each sub-catchment (upper main trunk and tributaries) among four main lithologies (granitic, metamorphic and two sandstone units) and three main morphologies (steep hillslopes near riverbeds, gentle hillslopes and steep slopes) resulting in nine landscape types defined by their combined lithological and morphological characteristics. A Monte Carlo adjustment method based on a Quantum-behaved Particle Swarm Optimization (QPSO) algorithm has been applied to retrieve the optimal denudations of each landscape type that contribute to each sub-catchment CWD rate. Our results show that some zones erode up to 10 times faster, indicating out-of-disequilibrium relief evolution. We use the inversion results to quantify the pace of landscape adjustment, including cliff retreat in tributaries and retreat of major knickpoints within a stream-power incision framework. This approach allows us to show that modest gradients of CWD at the catchment scale can coexist with an internally transient landscape with focused denudation near knickzones and cliffs. The horizontal retreat rates of knickpoints, which are up to one order of magnitude larger than sub-catchment CWD, remain slow and may explain the persistence of strong relief contrasts in a low-deformation setting. Although the ¹⁰Be CWD rates vary only slightly, large variations in denudation rates can occur because of landscape and the lithological particularities. Our methodology makes it possible to discuss CWD variations in slowly evolving environments and their role in maintaining high relief in close to steady-state mountain landscapes.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/esp.70361","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753157","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":"Fluvial Geomorphic Resilience in Alluvial Mountain Rivers to Large Floods","authors":"Riley T. Henson,&nbsp;Andrew C. Wilcox,&nbsp;W. Payton Gardner,&nbsp;Robert O. Hall Jr.","doi":"10.1002/esp.70384","DOIUrl":"https://doi.org/10.1002/esp.70384","url":null,"abstract":"&lt;p&gt;Intensification of hydroclimatic volatility increases the potential for large floods to reshape rivers and threaten infrastructure. Fluvial geomorphic resilience, defined as a river's resistance to, and recovery from, flood disturbance, offers a framework for understanding river response to extreme events and guiding management. We assessed resilience at two scales: (1) a detailed geomorphic and hydraulic analysis of the June 2022 flood on East Rosebud Creek, Montana, which was part of broader flooding in the Greater Yellowstone Ecosystem, and (2) a multiriver comparison of 13 flood-impacted alluvial mountain rivers (East Rosebud Creek plus 12 additional sites across North America and Europe). We quantified resistance using active-channel width ratios (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;W&lt;/mi&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {W}_R $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) and recovery using postflood channel evolution (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;W&lt;/mi&gt;\u0000 &lt;mi&gt;rec&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {W}_{rec} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) and recovery rate (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;R&lt;/mi&gt;\u0000 &lt;mi&gt;t&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {R}_t $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;). East Rosebud Creek showed strong spatial variability in disturbance among two defined segments, with an upstream segment shifting to new forms via widening, coarsening and/or incision, whereas a downstream segment that experienced similar flow strengths adjusted more modestly, within a dynamic geomorphic equilibrium. Slope, confinement and grain size were key influences on flood response in East Rosebud Creek. In the multiriver analysis, multilevel regression showed a positive log-transformed relationship between normalized flood peak exceedance above the &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;Q&lt;/mi&gt;\u0000 &lt;mn&gt;1.5&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {Q}_{1.5} $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msubsup&gt;\u0000 &lt;mi&gt;Q&lt;/mi&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;mo&gt;*&lt;/mo&gt;\u0000 &lt;/msubsup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt;$$ {Q}_p^{ast } $$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) and mean &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 ","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753015","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":"Enhancing wind-induced erosion resistance of Indian Thar Desert sand using enzyme-induced carbonate precipitation","authors":"Monika Dagliya,&nbsp;Neelima Satyam,&nbsp;Ankit Garg","doi":"10.1002/esp.70377","DOIUrl":"https://doi.org/10.1002/esp.70377","url":null,"abstract":"<p>Soil reinforcement is a potential solution to mitigate wind-induced sand erosion. Previously, microbiologically induced calcite precipitation (MICP) has been used to control sand erosion and enhance the strength of soil particles. However, it has limitations. The present study explores the effectiveness of an alternative biologically inspired method, enzyme-induced carbonate precipitation (EICP), in enhancing the stability and strength of aeolian sand. The novelty of this study lies in the identification of an optimal dosage through a multiscale evaluation of EICP performance, specifically targeting high-velocity erosion resistance (up to 30 m/s), surface strength uniformity, penetration depth, mechanical reinforcement and the explicit characterization of calcite thermal stability. Plant-based Jack bean urease was used at varying concentrations with a 1-M cementation solution. To mitigate wind-induced sand erosion, surface treatment was performed using the spray method. The treated specimens were subjected to a wind tunnel test, a surface strength test, a calcite test, scanning electron microscopy (SEM) analysis and energy-dispersive X-ray spectroscopy (EDX) analysis. To evaluate the strength of soil particles, unconfined compressive strength (UCS) and split tensile strength (STS) samples were treated using the stopped and gravity flow methods and were tested for UCS, STS, ultrasonic pulse velocity (UPV) and calcite formation. Additionally, to assess the thermal behaviour of the formed calcite, thermogravimetric analysis (TGA) was performed. The study demonstrated that the EICP method effectively mitigates erosion up to a wind speed of 30 m/s and achieves optimal soil strength, with a maximum UCS value of 756 kPa and 5% calcite formation. However, practical implementation considerations, including extended treatment duration and long-term durability under field conditions, require further investigation before large-scale application.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753270","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":"A sediment record of floods ca. 1820–1950 for the River Isla, eastern Scotland","authors":"Richard Tipping,&nbsp;Emily Stratton,&nbsp;Richard Bates","doi":"10.1002/esp.70381","DOIUrl":"https://doi.org/10.1002/esp.70381","url":null,"abstract":"<p>A 2.4 m long highly stratified sediment stratigraphy was recovered from an abandoned meander in the lowland reach of the River Isla in Perthshire, in eastern Scotland, 200 m from the river, closely connected to it through having no flood embankment. The meander was isolated from the active channel around 1820. Sediments were sampled by Eijelkamp peat gouge and Wink vibro-corer, described from photographs in great detail in the laboratory, then subsampled at contiguous 1.0 cm intervals for particle size distributions and dated by ²¹⁰Pb and ¹³⁷Cs. Flood units were defined visually as mineral sediment bands ≥3 mm thick with sharp boundaries usually capped post-flood by fine-grained and often organic-rich laminae and bands. Changes in flood regimes were defined from particle size distributions and occurred in the late 1820s, the mid-1830s, the late 1830s, the mid-1850s, the late 1860s, the late 1880s and the mid-1900s. Large magnitude floods occurred in the late 1840s and early 1850s and from the 1880s to ca. 1910. Stratification was lost in sediments formed after 1950. The chronology of floods ca. 1820–1950 corresponds in part to that from a new documentary record of flood frequency derived from local and regional newspapers 1820–1960. There are more sediment flood bands (<i>n</i> = 146) than reported floods (<i>n</i> = 99); newspapers probably underrepresent the numbers of floods. Flood frequency is best calculated from precisely dated documentary data, but the sediment record provides more and better estimates of flood magnitude than newspaper accounts.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148753057","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":"Temporal evolution of nearshore tidal currents field in the Yellow River Delta over the past four decades","authors":"Li Zilu,&nbsp;Li Yan,&nbsp;Wang Qing,&nbsp;Zhan Chao,&nbsp;Su Teng","doi":"10.1002/esp.70363","DOIUrl":"https://doi.org/10.1002/esp.70363","url":null,"abstract":"<p>Over the past four decades, the water and sediment fluxes of the Yellow River to the sea and the deltaic coastal morphology have changed markedly under the combined influence of human activities and natural processes. There is an urgent need to quantitatively investigate how shoreline adjustments driven by outlet migration and the embayment north of the river mouth affect the nearshore tidal-current field. In this study, Landsat imagery and multi-year bathymetric data were used to resolve shoreline changes, subaqueous topographic evolution, and outlet shifts of the Yellow River Delta in 1987, 2000, and 2023. A numerical hydrodynamic model was established to quantitatively evaluate the influence of different outlet and shoreline configurations on the nearshore tidal regime and to reveal the response mechanisms of the tidal-current field to shoreline evolution, river-mouth deflection and changes in runoff intensity. The results indicate the following: (1) Nearshore tidal currents are predominantly rectilinear, and an elliptical high-velocity zone (&gt;0.8 m/s) that migrates with the river mouth has persisted. Northward deflection of the river mouth has created an embayment between the Gudong seawall and the mouth, where current speed has decreased significantly, with a maximum reduction of 0.46 m/s, corresponding to a change rate of 78.23%. (2) Runoff intensity strongly modulates water levels and tidal currents near the river mouth. The runoff-dominated area expands with increasing discharge, and under extreme runoff (4000 m³/s), the influence can extend up to approximately 10 km offshore beyond the mouth. (3) The distribution and strength of the tidal-current field are significantly affected by the outlet course and shoreline configuration. Corresponding adjustments of the tidal-current field are observed in regions of intense erosion and accretion, such as the Gudong nearshore area and the active and abandoned river mouths. These findings are of considerable engineering value for understanding delta morphodynamics and informing nearshore environmental management.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752817","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":"Early post-fire debris-flow initiation following the March 2024 Yajiang Fire, Sichuan, China","authors":"Yong-hao Zhou,&nbsp;Kun He,&nbsp;Xie-wen Hu,&nbsp;Xue-qiang Gong","doi":"10.1002/esp.70380","DOIUrl":"https://doi.org/10.1002/esp.70380","url":null,"abstract":"<p>Burned slopes, with reduced vegetation cover, enhanced soil water repellency and decreased infiltration capacity, are highly susceptible to post-fire debris flows and can pose immediate threats to infrastructure and communities in steep mountain regions. However, the initiation mechanisms of the first set of debris flows after a fire remain poorly understood, hindering effective hazard management. Following the 15 March 2024 Yajiang Fire in Sichuan, China, which burned approximately 278.8 km², 506 post-fire debris-flow events occurred during the same year and caused severe damage. Within this broader context, this study focuses on the early post-fire stage and uses the Baima catchment as a detailed study site to investigate how ash-rich hillslope sediment was redistributed, stored in channels and subsequently involved in debris-flow initiation. By combining rainfall and wind records, soil water repellency tests, repeated measurements of ash thickness on hillslopes, surveys of dry-ravel storage within channels, unmanned aerial vehicle (UAV) mapping, repeated field investigations and sediment analyses, we show that wind and gravity rapidly transferred ash from slopes to channels. Within 11 days after the fire, approximately 93.8% of the ash in the Baima catchment had accumulated in channels as dry-ravel deposits, which became the dominant source material for the earliest debris flows. Field evidence indicates that these early debris flows were initiated when rainfall mixed with channel-stored dry-ravel deposits to form a high-viscosity, ‘concrete-like’ mixture, which was then driven downslope by continued inflow and gravity. At the regional scale, early post-fire debris flows were concentrated in small, steep catchments, most of them smaller than 1 km². In the Baima catchment, about 86.6% of the solid material in the debris flow was derived from loose ash-rich sediment. Coarse particles were preferentially deposited at catchment outlets as a granular phase, whereas finer ash-rich material extended farther downstream as a muddy phase. These findings provide direct field evidence for the initiation of early post-fire debris flows in the Hengduan Mountains, showing that rapid hillslope-to-channel sediment transfer can preload small, steep burned catchments and strongly influence their earliest debris-flow response. This study therefore provides a process-based basis for early hazard recognition and emergency response to post-fire debris-flow hazards in the Hengduan Mountains and other similar steep mountain regions.</p>","PeriodicalId":11408,"journal":{"name":"Earth Surface Processes and Landforms","volume":"51 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2026-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148752971","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}