Geomorphology最新文献

{"title":"Drainage-divide migration at the Qinling and its implications for the drainage reorganization and rift evolution of the Weihe graben, Central China","authors":"Xun Zeng ,&nbsp;Xibin Tan ,&nbsp;Yiduo Liu ,&nbsp;Mingming Wang ,&nbsp;Shuang Bian ,&nbsp;Feng Shi","doi":"10.1016/j.geomorph.2025.109658","DOIUrl":"10.1016/j.geomorph.2025.109658","url":null,"abstract":"<div><div>The east-trending Qinling horst and Weihe graben system in Central China is an important tectonic transition zone between the transpressional Northeastern Tibetan Plateau and the transtensional Eastern North China Craton. However, it remains unclear how the horst-graben system and the modern drainage morphology have evolved in this region. Here we analyze the stability of the main drainage divide at the Qinling, based on χ-plot and Gilbert metrics, and estimate the divide migration rates using the catchment erosion rates from cosmogenic nuclide ¹⁰Be data. Our results show that the drainage divide in the western part of the Qinling is moving southward, while that in the eastern part is mostly stable. We suggest that the migration of the Qinling drainage divide is controlled by the subsidence of the Weihe graben, and the along-strike variation in the drainage-divide stability results from the westward expansion of the Weihe graben. Moreover, based on the wind gaps, barbed tributaries, Holocene sediment close to the wind gaps, and landscape numerical modeling results, we identify two major river capture events near the rift-bounding normal fault, likely caused by both the subsidence of the Weihe graben and the uplift of the Qinling horst in the Cenozoic. The results indicate that before the capture events, some rivers in the southern Ordos used to flow southward across the Qinling into the Sichuan Basin, which is of great significance to the evolution of the middle Yellow River.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109658"},"PeriodicalIF":3.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-term geomorphic response of a mountain stream channel to dam removal and a major flood","authors":"Piotr Cienciala,&nbsp;Alexander C. Fojtik","doi":"10.1016/j.geomorph.2025.109646","DOIUrl":"10.1016/j.geomorph.2025.109646","url":null,"abstract":"<div><div>Despite recent progress, the current understanding of the geomorphic channel responses to river restoration activities, such as dam removal, remains incomplete. Our study addressed this knowledge gap by examining the short-term (first two years) morphological response of a forested mountain channel in the inland Pacific Northwest to a dam removal-generated sediment pulse, which coincided with a considerable flood event. Even though the pulse was equivalent to decades of background sediment transport and the flood had a ≥10-year return interval, our analysis indicated generally limited changes in channel morphology and lateral activity. We attribute this stability to three factors. First, the predominantly fine pulse material was rapidly transferred through the entire length (6.5 km) of the high energy and partly confined channel with limited storage potential. The release of coarse material trapped behind the dam was restricted as part of sediment management. During the 2-year period, the limited coarse component of the pulse induced modest aggradation, extending only 1.5 km downstream of the dam. This highlights trade-offs between hazard management objectives and restoration of sediment-starved channels. Second, erosion during the flood was hindered by coarse and resistant channel boundaries, with banks reinforced by riparian root system and localized rip-rap, and, in the confined reaches, valley margin. Third, low storage of large wood contributed to the subdued morphological response. We observed that logjams, which constricted and deflected the flow, created a hot spot of erosion and deposition where upstream supply of coarse sediment was available. This sediment source was inadvertently generated where in-channel engineering works disrupted bed surface armor and stabilizing bed structures. We propose that the interactions between sediment supply from locally disturbed bed as a conditioning factor, logjam as a forcing element, and flood as a hydraulic trigger could be replicated in river restoration to improve channel complexity and dynamism.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109646"},"PeriodicalIF":3.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scratching beneath the surface: Using Ground-Penetrating Radar to disentangle pronival ramparts, embryonic rock glaciers and moraines (Gardetta Plateau, Southwestern Alps)","authors":"Adriano Ribolini ,&nbsp;Emanuele Forte ,&nbsp;Varun Khajuria ,&nbsp;Renato R. Colucci ,&nbsp;Luca Paro ,&nbsp;Mauro Guglielmin","doi":"10.1016/j.geomorph.2025.109647","DOIUrl":"10.1016/j.geomorph.2025.109647","url":null,"abstract":"<div><div>The distinction between debris ridges/ramparts that form at the base of mountain slopes in cold environments is important to understanding the (palaeo) environmental condition that prompted their formation. Despite the definition of diagnostic criteria, the identification of the formative (nival, permafrost creep, glacial) and post-depositional mechanisms remains uncertain as it is mostly reliant on surface observations. We present the results of a Ground-Penetrating Radar (GPR) survey carried out on landforms presenting similarities from a geomorphological perspective (i.e. pronival rampart, protalus rock glacier, moraine) in the same Alpine context. The 2D radar profiles provide imaging of the internal structure of these landforms, allowing us to formulate hypotheses on the depositional processes that led to their formation. In the pronival rampart, concave upward and mound-shaped radar reflections fit with the presence of a ridge/rampart at the base of a permanent snow patch. Mound-shaped, flat or counterslope reflectors reflect the existence of stratigraphic beds mantling the sides of the ridge and infill the depression between this and the talus upslope or the retreating snow patch front. Some sequences of GPR facies sequences are consistently referable to progradational/retrogradational depositional processes. Poor articulation of facies architecture characterizes frontal moraines and embryonic protalus rock glaciers. The succession of predominantly planar radar surfaces/facies is consistent with an important aggradational component that can be explained by a stratigraphic overlap of debris layers fed by the glacial front and/or of permafrost-affected sedimentary units.</div><div>The GPR imaging of the interior of these mountain landforms frequently found at the talus foot can offer crucial data for the correct interpretation of the formative mechanisms and, thereby of the environmental conditions that promoted their formation.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"474 ","pages":"Article 109647"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry and geochronology of modern river sediments from the Heihe River on the northeastern Tibetan Plateau: Implications for weathering and sediment source-to-sink processes","authors":"Huan Kang ,&nbsp;Huiping Zhang ,&nbsp;Jiarun Tu ,&nbsp;Qinjing Shen ,&nbsp;Jiawei Zhang ,&nbsp;Xudong Zhao","doi":"10.1016/j.geomorph.2025.109657","DOIUrl":"10.1016/j.geomorph.2025.109657","url":null,"abstract":"<div><div>Deciphering the sediment source-to-sink processes in modern and dynamic fluvial systems serves as a key to understanding earth surface processes; however, the sedimentary signal preservation and propagation within sediment routing systems are complicated and heterogeneous. We conducted systematic geochemical and Sr<img>Nd isotopic analysis and zircon U<img>Pb geochronology on fluvial sediments as well as Cretaceous sandstone from the Heihe River drainage basin, located in the northeastern Tibetan Plateau. Fluctuations in geochemistry (i.e., alkali and alkaline-earth metals) close to the average unweathered bedrocks suggest that the silt-sized sediments in the drainage basin form during the early stage of chemical weathering of source rocks. The U<img>Pb ages of detrital zircons from sand-sized sediments show two significant shifts in the upper and middle reaches, i.e., the disappearance of the Tonian-Stenian age group and the dramatic increase of the Cisuralian components in mainstream sediments. Our integrated assessment of source-rock lithology, sedimentary processes, and geomorphological and climatic conditions of the drainage basin led to two important insights: (1) In arid and semiarid environments like Heihe River, chemical weathering in the drainage basin is primarily controlled by geomorphologic and climatic factors; and (2) tributary dilution and en-route storage during the sediment routing systems are key factors responsible for changes in zircon age signatures. The confluence of representative tributaries and geomorphological and climatic transformations significantly influence sediment weathering and transport processes.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109657"},"PeriodicalIF":3.1,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143396221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation and evolution of grus deposits in the Çine Submassif, Southwest Türkiye: A multi-proxy approach","authors":"Murat Gül ,&nbsp;Ceren Küçükuysal ,&nbsp;Göksu Uslular ,&nbsp;Gerald Raab ,&nbsp;Markus Egli","doi":"10.1016/j.geomorph.2025.109641","DOIUrl":"10.1016/j.geomorph.2025.109641","url":null,"abstract":"<div><div>Grus deposits may be a key element in deciphering the evolution of granitic landforms due to their rapid formation, sensitivity to environmental factors, and influence on landscape morphology. This study explores the mineralogical, geochemical and structural characteristics of grus deposits developed on granitoid bedrock through subsurface weathering in a semiarid region, the Çine submassif (SW Türkiye), focusing on how topography, mineral composition and climate affect their formation and spatial variability. Two distinct grus types were identified: thinner (0–20 cm), homogenous, sand-rich deposits on upper slopes, and thicker (40–100 cm), heterogenous, gravel-rich layers in the valley and downslope near bedrock outcrops. The bimodal grain-size distributions among grus types may reflect progressive weathering along topographic gradients, where upper slopes experience limited weathering due to reduced water retention and steeper gradients, leading to the formation of thinner, sand-rich deposits. In contrast, downslopes and valleys allow for prolonged water infiltration and feldspar breakdown, resulting in thicker, gravel-rich deposits with a more advanced weathering profile. Grus consists primarily of quartz, albite, orthoclase and mica, with accessory clay minerals such as kaolinite. Geochemical data indicate a felsic grus composition with limited variations, high Chemical Index of Alteration (CIA) values (59 to 69 %), and a gradual weathering trend towards kaolinite, driven by feldspar weathering and fluctuating water infiltration along slopes.</div><div>The Principal Component Analysis (PCA) highlights chemical composition and grain size as key parameters differentiating grus types. The interplay of topography, water dynamics, and local structural and mineralogical characteristics controls both the formation and weathering intensity of grus, with variations in deposit characteristics reflecting the influence of slope position and water infiltration on weathering process. These findings provide new insights into granitoid landform evolution, while further geochronological studies are recommended to clarify the temporal evolution of grus mantles and subsurface weathering features across the region.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"474 ","pages":"Article 109641"},"PeriodicalIF":3.1,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cosmogenic dating reveals the timing of glaciers collapse in the high Dolomites valleys (Northern Italy)","authors":"Carlo Baroni ,&nbsp;Maria Cristina Salvatore ,&nbsp;Vittoria Vandelli ,&nbsp;Mauro Marchetti ,&nbsp;ASTER Team ,&nbsp;Mauro Soldati","doi":"10.1016/j.geomorph.2025.109648","DOIUrl":"10.1016/j.geomorph.2025.109648","url":null,"abstract":"<div><div>During the Last Glacial Maximum (LGM) the Italian Alps were extensively ice-covered with icefields feeding a network of interconnected valley glaciers and piedmont glaciers spilling into the foreland. The subsequent Lateglacial ice retreat occurred with different modes and timing across the region. This paper arises from the need for further investigation to better understand the glaciers' dynamics of the period and focuses on the glacial history of the Alta Badia valley (Eastern Dolomites, Italian Alps) as a key area for reconstructing the LGM glaciers' collapse and Lateglacial readvances within the region. We present a reconstruction of LGM and Lateglacial glaciers' evolution supported by cosmogenic ³⁶Cl surface exposure data - obtained for the first time in the area - and geomorphological evidence. Our findings suggest that LGM ice retreat began before 17 ka BP. Within a general trend of ice decay, we identified the Gschnitz readvance from reconstructed glacier surfaces and Equilibrium Line Altitude (ELA) estimates, supported by moraine dating (15.8–15.4 ka BP) in the southeastern sector of the valley. Similarly, a Lateglacial readvance corresponding to the traditional Daun Readvance was recognized in the southwestern sector, based on exposure ages (14.4 and 13.3 ka BP) and calculated ELA. Evidence indicates that after the Daun phase, the valley was nearly deglaciated, retaining only small glacial remnants at higher elevations. This study enhances our understanding of LGM ice retreat and Lateglacial chronology, providing insights into the Alpine glacial history and establishing a foundation for estimating paleoclimatic conditions of the region.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"474 ","pages":"Article 109648"},"PeriodicalIF":3.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143379392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Shoreline responses to rapid water level increases in Lake Michigan","authors":"Hazem U. Abdelhady ,&nbsp;Cary D. Troy ,&nbsp;Longhuan Zhu ,&nbsp;Pengfei Xue ,&nbsp;Guy Meadows ,&nbsp;Chin H. Wu","doi":"10.1016/j.geomorph.2025.109639","DOIUrl":"10.1016/j.geomorph.2025.109639","url":null,"abstract":"<div><div>High-resolution multispectral satellite imagery was utilized to quantify shoreline recession at eleven beaches around Lake Michigan during a record-setting water level increase between 2013 and 2020. Shoreline changes during this period ranged from 20 m to 62 m, corresponding to 52–95 % of the initial beach widths. Average estimated shoreline erosion across all beaches varied from 1 % to 75 % of the observed changes, with the remainder attributed to inundation. Significant correlations were found between shoreline erosion and wave-related factors, including offshore wave power, offshore bathymetric slope, storm energy, and potential alongshore sediment transport divergence. In contrast, parameters related to cross-shore transport, such as dimensionless fall velocity, exhibited weak correlations. Additionally, the results underscore the importance of distinguishing between immediately reversible changes (inundation) and morphological changes that could be reversible over longer timescales, when assessing the impact of rising water levels. The findings also suggest that in addition to waves playing a key role in regulating shoreline changes, alongshore sediment transport processes may play a more crucial role in beach erosion during significant water level increases than cross-shore processes, challenging traditional models of beach adjustment to rising waters.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109639"},"PeriodicalIF":3.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143402954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flow dynamics and bed morphology in a narrow channels: A comparative study of experimental and numerical approaches to velocity distribution","authors":"Pritam Kumar,&nbsp;Vangapandu Deepak,&nbsp;Anurag Sharma","doi":"10.1016/j.geomorph.2025.109645","DOIUrl":"10.1016/j.geomorph.2025.109645","url":null,"abstract":"<div><div>The effects of narrow channels on flow structure and hydrodynamics have been widely studied. However, due to the complexity of flow dynamics in narrow channels, three-dimensional flow properties have rarely been explored. This paper presents a novel experiment investigating the influence of narrow channels with an aspect ratio of 4.615 on three-dimensional turbulent properties and bed morphology. The findings contribute to a deeper understanding of how narrow channels impact turbulent properties and bed feature dynamics in mobile bed flows. The results showed that longitudinal velocity is higher towards the centre and free surface, while vertical velocity shows upward flow near the bed and downward flow towards the free water surface, with intensities varying across the channel. Experimental longitudinal velocity was compared numerically using the Realizable k-ε model by Ansys Fluent software and an analytical model. Both models performed well in predicting values, with the analytical model showing slightly higher accuracy as indicated by statistical indices. Turbulent kinetic energy and Reynolds shear stress are higher close to the bed and banks of the channel. Bed features generates ripple bedforms, which are dynamic and complex, influenced by flow dynamics, sediment transport, and channel geometry, creating a rich and intricate flow environment. The three dimensional skewness and kurtosis are also explored in this paper. This information is valuable for river or canal design engineers, with implications for stability and navigation, and it can guide maintenance strategies for narrow rivers and canals.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"474 ","pages":"Article 109645"},"PeriodicalIF":3.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatio-temporal interpolation of ~530 Ma paleo-DEM to quantify denudation of a terrestrial impact crater","authors":"J. Aswathi ,&nbsp;S. James ,&nbsp;S. Keerthy ,&nbsp;A. Rajaneesh ,&nbsp;V.R. Rani ,&nbsp;K.S. Sajinkumar ,&nbsp;Thomas Oommen ,&nbsp;R.B. Binoj Kumar","doi":"10.1016/j.geomorph.2025.109644","DOIUrl":"10.1016/j.geomorph.2025.109644","url":null,"abstract":"<div><div>Erosion and weathering are two of the several exogenic processes that control the intensity and patterns of landform evolution. Based on previous studies, the varied erosion rates observed in the geological past depends on factors like mean relief (morphology), climate, lithology, and time. Meteorite impact craters have unique geomorphic features, being characterized by both negative relief features (the bowl-shaped depression) and positive features (such as elevated rims; additionally, central elevated areas for complex craters). This makes them a suitable morphologic feature to study both erosion and deposition. This study estimates the long-term erosion of Ramgarh crater in western India, a crater debated on its morphology and erosion rates. This study uses a paleo-digital elevation model (paleo-DEM), a reconstruction of the crater morphology at ⁓528 Ma- the potential upper age of formation of Ramgarh, along with previously established models with suitable modifications to quantify erosion from the final stage to the present day. The type of projectile and its physical characteristics such as diameter and volume were also estimated. Reconstruction of the crater's paleo-position was achieved through GPlates (a GIS-based paleo-reconstruction model), followed by recreating the transient and final crater morphology (including parameters such as crater diameter and true depth, rim height, and thickness of proximal ejecta) for two age limits (528 Ma and 395 Ma). The intermittent morphology of the crater was generated using mathematical equations to depict the sequence of changes through time. The erosion of the crater, quantified in terms of cumulative volume, is between 0.41 and 0.58 km³. This range is based on four conditions pertaining to two different final crater rim heights (mathematically derived) as well as two age limits. Overall, this study provides valuable insights into the long-term morphological evolution of Ramgarh crater and contributes to the understanding of impact crater's erosion processes.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"474 ","pages":"Article 109644"},"PeriodicalIF":3.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The fluvio-deltaic interaction on river channel morphodynamical equilibrium in the lower Yellow River","authors":"Dangwei Wang ,&nbsp;Yuanxu Ma ,&nbsp;Xiaofang Liu ,&nbsp;Zuwen Ji ,&nbsp;Anjun Deng ,&nbsp;Jianguo Chen ,&nbsp;Yuhai Wang","doi":"10.1016/j.geomorph.2025.109643","DOIUrl":"10.1016/j.geomorph.2025.109643","url":null,"abstract":"<div><div>Upstream river channel adjustments exhibit complex responses to changes in base level, particularly those induced by delta river channel avulsions. While this phenomenon has been studied, the equilibrium of river channels under the influence of base level changes and fluvial transport remains unclear. The Yellow River delta, known for frequent channel avulsions, exerts a time-varying impact on upstream river channel dynamics. In this study, we employed multi-source data to quantify the overall effect of delta evolution on upstream river channel changes in the lower Yellow River. We analyzed water level fluctuations at a discharge of 3000 m³/s (a representative near-bankfull discharge) from five hydrological stations over the period from 1951 to 1990. The water levels at all five cross-sections showed an overall rising trend with fluctuations. However, the trends at different stations during the same period were not synchronous, indicating that the river channel bed elevation did not rise or fall uniformly across the entire lower Yellow River. To explore this further, we conducted lagged linear regression to determine how river channel changes responded to delta propagation both downstream and upstream. The regression results showed no lag in water level changes at the five hydrological stations in the downstream direction. However, in the upstream direction, the water levels at Huayuankou, Gaocun, Aishan, and Luokou demonstrated a maximum delayed response of up to 8 years to changes at the Lijin station. This suggests that river channel adjustments can experience up to an 8-year delay in response to flow-sediment regimes at Lijin, likely due to the backwater effects of deltaic evolution. The point of transition where lagged regression coefficients in both the downstream and upstream directions converge near Aishan was identified as the upper boundary of the delta backwater effect. At this location, the downstream influence of fluvial processes and the upstream influence of delta backwater equilibrate. This point is situated approximately 500 km from the Xiaolangdi Dam and 250 km from Lijin. Our findings offer new insights into the ongoing debate regarding river channel adjustments in the lower Yellow River, under the dual influence of fluvial sediment transport and delta backwater effects.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"474 ","pages":"Article 109643"},"PeriodicalIF":3.1,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143372607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}