Geomorphology最新文献

{"title":"Geomorphic development and its controlling factors of a fluvial fan in a humid region over the past 200,000 years: The case of the Kinugawa fluvial fan, Japan","authors":"Hiroaki Tateno ,&nbsp;Toshihiko Sugai","doi":"10.1016/j.geomorph.2025.109984","DOIUrl":"10.1016/j.geomorph.2025.109984","url":null,"abstract":"<div><div>We aim to elucidate the Quaternary geomorphic development of fluvial fans in a humid region, focusing on the Kinugawa fluvial fan located in the central Japanese Islands. The study area is situated within a humid temperate climatic zone, receiving 1,500–2,000 mm of annual precipitation, and is strongly influenced by the East Asian Summer Monsoon. We classified the terraces based on their elevations, outcrop observations, and borehole data. The formation ages of the terraces were estimated based on tephra analysis and aeolian deposit accumulation rates, and variations in sediment supply were evaluated through gravel lithology analysis.</div><div>The fluvial terraces in the Kinugawa fluvial fan were classified into ten terraces (T1–T10), with detailed analysis conducted for T3–T10. The findings indicate that fluctuations in precipitation were a significant factor in terrace formation, except for T4. Specifically, aggradation during periods of weakened monsoon activity and reduced precipitation likely caused river channel instability, leading to frequent avulsions and lateral expansion of active zones. Conversely, increased precipitation facilitated degradation, resulting in channel stabilization. The formation of T4 is inferred to have been influenced by an increase in sediment supply triggered by the sector collapse of Mt. Nyoho.</div><div>These findings indicate that the geomorphic development of fluvial fans in humid regions is strongly influenced by variations in precipitation, leading to avulsions and terrace formation.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109984"},"PeriodicalIF":3.1,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923023","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":"Quantifying transverse gradient effects on hydrological connectivity and optimal thresholds in the lower yellow river floodplain","authors":"Liyu Quan ,&nbsp;Gaoxu Wang ,&nbsp;Rui Shi ,&nbsp;Daiyuan Li ,&nbsp;Chaojie Niu ,&nbsp;Ming Li ,&nbsp;Caihong Hu","doi":"10.1016/j.geomorph.2025.109982","DOIUrl":"10.1016/j.geomorph.2025.109982","url":null,"abstract":"<div><div>The lower Yellow River floodplain, as a vital ecosystem supporting millions of livelihoods, faces escalating flood risks due to the formation of a “secondary suspended river”. Using cross-sectional analysis and entropy-weighted modeling (1986–2020), this study quantifies the relationship between transverse gradient and lateral hydrological connectivity in the Hedao reach. Key findings include: (1) Xiaolangdi Dam operations increased the pre-flood and post-flood transverse gradients by 51.64 % and 46.74 %, respectively; it reduced pre-flood connectivity by 15.33 %, yet increased post-flood connectivity by 19.33 %; (2) A 0.07 % transverse gradient in the study area was associated with the decline in connectivity; (3) An optimal transverse gradient threshold of 0.032 % during the pre-flood season and 0.034 % during the post-flood season is proposed to balance flood control and ecological maintenance. This threshold synergistically mitigates “secondary suspended river” risks while sustaining riparian vegetation, thus providing a regional reference for the management of sediment-rich floodplains worldwide.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109982"},"PeriodicalIF":3.1,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923022","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":"Evolution of deep-seated bedrock landslides in a deep canyon","authors":"Yao Li ,&nbsp;Zhang Wang ,&nbsp;Chenchen Qiu ,&nbsp;Ruilong Wei ,&nbsp;Jian Guo ,&nbsp;Zilong Wu ,&nbsp;Nazir Ahmed Bazai ,&nbsp;Chengming Ye","doi":"10.1016/j.geomorph.2025.109983","DOIUrl":"10.1016/j.geomorph.2025.109983","url":null,"abstract":"<div><div>Deep-seated bedrock landslides are characterized by large scales and long runout distances, frequently resulting in the formation of dammed lakes within deep canyons and causing serious damage to downstream residential areas, ecological and hydrological environment. However, deep-seated bedrock landslides are usually located in steep and inaccessible mountain area, posing a significant challenge to their effective observation and failure warnings. In this study, we utilized optical and synthetic aperture radar (SAR) satellite remote sensing, unmanned aerial vehicle (UAV) mapping, and field investigation to analyze three closely located deep-seated bedrock landslides (Baige, Xiaomojiu, and Guili) at different evolution stages along the Jinsha river in the eastern Tibetan Plateau. We analyzed the geological structures of these landslides and conducted evolution analysis to explore the potential ability of remote sensing technology in failure warning of landslide. The results indicate that the three landslides are situated within the Jinsha suture zone and are composed of broken gneiss, serpentinite, and mylonit. The complex materials and structure resulted in differential deformation along the slope, manifested by varying density of tensile cracks, size of fractured zone, and cumulative displacements in different parts of the slope. In the 20 years before the 2018 Baige landslide event, the coverage area of fractured zone changes from 0.09 km² to 0.38 km², accounting for 43.6 % of the total landslide area. Deformation data from SAR images (2017–2021) reveal periodic patterns during landslide evolution, though the influence of seasonal flood level variations appears limited. The periodic deformation infers that deep-seated bedrock landslide failures may be related to precipitation infiltration and slope erosion. In conclusion, the evolution of deep-seated bedrock landslides is a prolonged surface process, and multi-source remote sensing provide effective solution for detecting surface damage and deformation at various stages of evolution.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109983"},"PeriodicalIF":3.1,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913406","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":"Unveiling tropical slow-moving landslide response to seasonality and extreme meteorological events using a combination of InSAR and optical imagery: The case study of Grand Eboulis (Réunion island)","authors":"Coline Hopquin ,&nbsp;Eric Gayer ,&nbsp;Laurent Michon ,&nbsp;Antoine Lucas ,&nbsp;Delphine Smittarello ,&nbsp;Nicolas d’Oreye ,&nbsp;Nicolas Villeneuve","doi":"10.1016/j.geomorph.2025.109965","DOIUrl":"10.1016/j.geomorph.2025.109965","url":null,"abstract":"<div><div>Slow-moving landslides can cause significant infrastructure damage and casualties, making their monitoring a critical societal challenge. In the context of climate change and the projected intensification of rainfall extremes, understanding the response of slow-moving landslides to extreme meteorological conditions is essential. However, ground-based surveys are often difficult. In this study, we associate radar interferometry and optical imagery to investigate the dynamics of a remote tropical slow-moving landslide on Réunion Island, Grand Eboulis, and its relationship with precipitation regimes. Our approach enables us to retrieve (1) the bi-monthly dynamics of the Grand Eboulis landslide from cumulative displacement maps and ground deformation time series derived from Sentinel-1B images and (2) its multi-annual dynamics from optical aerial images. Between 2016 and 2021, the landslide moved eastward and downward at rates of up to 14 cm/yr and 9 cm/yr, respectively. Displacement was punctuated by periods of accelerated motion following an exceptionally wet season in mid-2018. In contrast, two slower periods coincided with the 2018 dry season combined with an exceptionally arid 2019, and with a prolonged drought in 2020. Additionally, between 2017 and 2019, shallow failures were mapped only in 2018 at the landslide front and were attributed to Cyclone Dumazile. This study suggests that slow-moving landslides may respond to seasonal contrasts by modulating their continuous displacement and to extreme events through shallow failures. The combined use of InSAR and remote sensed optical imagery proved to be efficient for studying such a type of events and can easily be widely applicable.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109965"},"PeriodicalIF":3.1,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004856","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":"Unabated forest expansion despite increased rockfall frequency at Täschgufer slope, Switzerland","authors":"S. Gorsic ,&nbsp;C. Corona ,&nbsp;A. Bayle ,&nbsp;B. Nicoud ,&nbsp;M. Farvacque ,&nbsp;M. Stoffel","doi":"10.1016/j.geomorph.2025.109985","DOIUrl":"10.1016/j.geomorph.2025.109985","url":null,"abstract":"<div><div>Rockfall activity and forest dynamics interact closely in alpine talus environments, where climate warming is altering both geomorphic processes and vegetation patterns. This study provides a comprehensive assessment of the coupled dynamics between forest expansion and rockfall activity at the talus-forest ecotone of the Täschgufer slope (Swiss Alps). By integrating dendrogeomorphic analyses, high-resolution aerial imagery, and satellite-derived vegetation indices, we reconstruct changes in rockfall frequency and forest dynamics over the past five decades. Our results demonstrate a persistent upslope forest migration despite increasing rockfall disturbances driven by enhanced permafrost thaw. This suggests that rising temperatures and prolonged growing seasons have created favorable conditions for tree recruitment and growth and that these processes can offset increasing geomorphic disturbance. However, comparison between the mitigated and unmitigated segments of the talus slope indicates that rockfall activity alone does not control tree colonization, and that the underlying structure of the talus slope also plays a critical role in constraining the biogeomorphic balance. Our study positions the talus-forest ecotone, like the treeline, as a highly sensitive indicator of climate change, particularly given limited anthropogenic influence in these environments. The integrated methodological framework presented here provides a valuable baseline for investigating these geomorphologically disturbed ecotones and highlights the importance of multidisciplinary approaches to inform sustainable management and conservation in sensitive alpine environments.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109985"},"PeriodicalIF":3.1,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144923024","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":"Assessing the co-occurrence of sheet and gully erosion in a wildfire-affected mountain area: A case study from Central Portugal","authors":"Bruno Martins ,&nbsp;Catarina Pinheiro ,&nbsp;Adélia Nunes","doi":"10.1016/j.geomorph.2025.109980","DOIUrl":"10.1016/j.geomorph.2025.109980","url":null,"abstract":"<div><div>Soil erosion has been recognised as a major threat to soil resources. Wildfires have contributed to the acceleration of soil loss and degradation by inducing profound hydrological and geomorphological transformations, not only through intensified erosion, but also through changes in soil properties, vegetation cover and subsequent land use. This study evaluates two primary soil erosion processes, namely sheet and gully erosion. The objectives of this research are threefold: (i) to map sheet erosion using the InVEST Sediment Delivery Ratio (SDR) model; (ii) to identify areas where both sheet and gully erosion coincide; and (iii) to determine the dominant drivers of sheet and gully erosion. A combined methodology involving InVEST-SDR and ArcGIS was employed to assess erosion rates in the Alva basin, central Portugal, affected by 2017 wildfires. The presence of gullies aggravates the soil loss and confirms a high production of sediment resulting from sheet erosion and gully erosion in the study area. The results indicate soil loss in the study area ranging from 0 to 848.89 t. ha-1.yr-1, with an average in the study area of 1.29 t/year. In general, gullies are found in areas where sediment production is greater, on a regional scale, but not locally. The results confirm the importance of some coinciding factors for sheet and gully erosion, in particular flow accumulation (FA), slope, and land use cover (LUC). However, the slope is more decisive for sheet erosion and the LUC for gully erosion. Given the quantities of sediment produced and the size of the gullies, together with the recurrence of wildfires in the study area, some erosion control practices should be implemented as a matter of urgency, particularly after wildfires.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109980"},"PeriodicalIF":3.1,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908947","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":"Anthropogenic disruption of sediment connectivity by embankment dams in the fast-eroding badland basin","authors":"Ci-Jian Yang ,&nbsp;Cheng-Hua Tsai ,&nbsp;Ying-Tong Lin","doi":"10.1016/j.geomorph.2025.109981","DOIUrl":"10.1016/j.geomorph.2025.109981","url":null,"abstract":"<div><div>Human-induced disruption of sediment connectivity is a major driver in shaping the Earth's surface. Check dams and reservoirs are common for water storage and sediment retention in rapidly eroding landscapes, which interrupt sediment transport. However, isolating the effects of anthropogenic structures on landscape evolution remains challenging. Here, we assess the effects of embankment dams in the mudstone badlands of southwestern Taiwan. Using 50 years of fluvial sediment load data, rainfall records, and airborne LiDAR DEM, we suggest that dam construction has altered sediment dynamics from source to sink. Our results indicate a 79 % decline in downstream suspended sediment loads between 1970 and 2023, despite increasing annual rainfall and the expansion of badland areas. In addition, we found that the erosion of mudstone badlands leads to the formation of flat-bottomed valleys (FBVs), which are transformed into agricultural lands and fish ponds. Yet, the difference of DEM (DoD) between 1986 and 2016 indicates that FBVs with dams have accumulated sediment volumes three times higher than FBVs without dams, and at such deposition rates, 87 % of the FBVs have silted up within 50 years. In short, our findings demonstrate that the embankment dams alter sediment loads and reshape fluvial–coast connectivity. Integrating anthropogenic structures into long-term catchment management is essential for restoring sediment connectivity and mitigating sediment-related risks.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"488 ","pages":"Article 109981"},"PeriodicalIF":3.1,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893340","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":"Reply to comment on “Surface exposure ages of middle–late pleistocene marine and fluvial terraces along the northern and southern Sanriku coasts, Northeast Japan” (Wakasa et al., 2025) by Kaneda et al. (2025)","authors":"Sachi Wakasa ,&nbsp;Tatsuya Ishiyama ,&nbsp;Daisuke Hirouchi ,&nbsp;Nobuhisa Matta ,&nbsp;Natsuko Fujita ,&nbsp;Tomoo Echigo","doi":"10.1016/j.geomorph.2025.109979","DOIUrl":"10.1016/j.geomorph.2025.109979","url":null,"abstract":"<div><div>Wakasa et al. (2025), which provided surface exposure ages of middle-to-late Pleistocene terraces in Northeast Japan, was criticized by Kaneda et al. (2025). We examine the dataset, age estimation methods, and descriptions of Wakasa et al. (2025) in light of their remarks. Even though we acknowledged that Wakasa et al. (2025) had a few errors that needed to be fixed, we came to the conclusion that the major findings and discussions did not require alteration.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"488 ","pages":"Article 109979"},"PeriodicalIF":3.1,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144893257","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":"Coupling 2D hydro-sedimentary modelling with tracer-based flow competence estimation to determine critical bed shear stress","authors":"Guillaume Piasny ,&nbsp;Pierre-André Garambois ,&nbsp;Pascal Finaud-Guyot ,&nbsp;Laurent Schmitt","doi":"10.1016/j.geomorph.2025.109966","DOIUrl":"10.1016/j.geomorph.2025.109966","url":null,"abstract":"<div><div>The critical dimensionless shear stress for particle motion <span><math><msub><mrow><mi>θ</mi></mrow><mrow><mi>c</mi><mi>r</mi></mrow></msub></math></span> is one of the most influential parameters in estimating bedload transport rates and modelling river morphodynamics. The estimation of this parameter remains, however, challenging as particle motion depends on riverbed properties (grain size distribution, slope, flow history, etc.), which vary in space and time. This study presents a new, robust method for estimating the critical Shields parameter for two-dimensional hydro-sedimentary modelling in gravel-bed rivers, such as the “Wild Moselle” River (France). This method is based on flow competence estimated from two independent measurements of particle motion (painted bed patches and bedload tracers) and (ii) accurate computations of the maximum grain shear stress derived from a high-resolution and well-calibrated two-dimensional hydro-sedimentary model. The flow competence estimated from each approach provided complementary insights: (i) measuring the <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>95</mn></mrow></msub></math></span> mobilized out of partially eroded patches enabled us the determination <span><math><msub><mrow><mi>θ</mi></mrow><mrow><mi>c</mi><mi>r</mi><mo>,</mo><mi>D</mi><mn>95</mn></mrow></msub></math></span>, while (ii) identifying the threshold above which nearly all bedload tracers of a given size were mobilized allowed us to determine the most suitable hiding factor <span><math><mi>b</mi></math></span>. The ability of the two-dimensional hydro-sedimentary model to predict the motion of the bed surface <span><math><msub><mrow><mi>D</mi></mrow><mrow><mn>50</mn></mrow></msub></math></span> size, using the estimated values <span><math><mrow><msub><mrow><mi>θ</mi></mrow><mrow><mi>c</mi><mi>r</mi><mo>,</mo><mi>D</mi><mn>50</mn></mrow></msub><mo>=</mo><mn>0</mn><mo>.</mo><mn>035</mn></mrow></math></span> and <span><math><mrow><mi>b</mi><mo>=</mo><mo>−</mo><mn>0</mn><mo>.</mo><mn>6</mn></mrow></math></span>, was confirmed, as the computed bed shear stress exceeded the critical threshold over more than 80% of the observed eroded areas. This procedure validates both the accuracy of the estimated threshold and the effectiveness of the proposed method for determining it.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109966"},"PeriodicalIF":3.1,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144913407","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":"Contrasting long-term trends in channel width and shoreline complexity","authors":"Elizabeth R. Skaggs ,&nbsp;Jonathan M. Friedman ,&nbsp;Christopher Holmquist-Johnson","doi":"10.1016/j.geomorph.2025.109978","DOIUrl":"10.1016/j.geomorph.2025.109978","url":null,"abstract":"<div><div>Drought and reservoir management in the Colorado River Watershed have decreased peak flows, reducing the ability of rivers to erode their banks and remove encroaching vegetation. Multiple studies have documented the resulting decrease in channel width, but less attention has been paid to long-term trends in shoreline complexity, including the number and size of islands. We used a sequence of aerial photographs and satellite images collected in 13 different years to measure decadal trends in channel width and shoreline complexity for the Gray Canyon segment of the Green River, Utah. Between 1938 and 2021 peak flows decreased by 34 % and channel width decreased by 18 %, confirming observations of decreasing width in response to decreasing flows from elsewhere in the watershed. Over the same period, however, shoreline complexity increased by 5.5 % and the number of islands almost tripled, indicating that merging of islands into the encroaching floodplain was outpaced by formation and growth of new islands. The increase in shoreline complexity occurred between 1938 and 2006. No further net increase has been observed since 2006, suggesting that room for new island formation could now be limited in the narrower channel. Sequences of channel delineations already mapped to quantify long-term changes in channel width at other sites could be used to determine whether the increases in shoreline complexity we observed at Gray Canyon also occur elsewhere.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"489 ","pages":"Article 109978"},"PeriodicalIF":3.1,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144902498","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}