Geomorphology最新文献_第5页

From shock to maturation: Tracing dam-impacted Jingjiang River morphodynamic adaptation using a four-stage neural SDE framework 从冲击到成熟：基于四阶段神经SDE框架的靖江大坝影响下的形态动力学适应

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-19 DOI: 10.1016/j.geomorph.2025.110138

Xiaolong Song , Hai Huang , Lei Zhang , Jianzhao Guan

In the Anthropocene, large dam construction represents one of the most profound interventions in river morphodynamics, triggering non-linear responses in hydraulic geometry that challenge traditional stationarity-based modeling approaches. This study develops a neural stochastic differential equation (SDE) framework to trace the complete morphodynamic adaptation trajectory of monthly flood season (May–October) reach-scale variables—inflow discharge (Q), reach-averaged channel width (B), depth (H), and slope (J)—in the Jingjiang reach following Three Gorges Dam operation, from initial systemic shock through progressive maturation to a new dynamic equilibrium. The framework employs a log-space ‘physical base + stochastic residual’ paradigm for morphodynamic modeling, integrated with Chronos-T5 large language models for annual driver forecasting and a comprehensive three-tier evaluation system, enabling robust analysis of non-stationary morphodynamic evolution under deep uncertainty. Using a four-stage workflow that calibrates on the post-dam ‘new normal’, retrospectively diagnoses the pre-stabilization transition, validates out-of-sample performance, and explores future scenarios, we reveal quantitative evidence of morphodynamic system maturation. Back-casting over the transitional period (2000–2008) yields coverage as low as 59.3 % (vs. 95 %), quantifying transient dam impacts; comparing a short post-dam training set (2009–2016) with an extended set (2009–2022) shows the annual-driver model shifting from variability-driven indicators to rejecting slow climatic trends as confounding noise. Future projections under Shared Socioeconomic Pathways (SSP245 and SSP585) scenarios unveil divergent morphological adaptation pathways with distinct statistical signatures—SSP245 exhibits sustained incremental adjustment (channel width Mann-Kendall trend strength τ = 0.7298) versus SSP585's shock-adaptation response (τ = 0.7747)—while Dynamic Mode Decomposition indicates identical growth rates for discharge and channel width (0.0014 and 0.0003, respectively) with slight scenario differences for depth and slope, and Convergent Cross Mapping demonstrates enhanced causal coupling under extreme forcing (causal correlation coefficient ρ = 0.986 vs. 0.993). These findings fundamentally advance our understanding of dam-impacted river morphodynamic systems and provide a transferable methodological blueprint for analyzing complex morphodynamic processes undergoing regime transitions in human-dominated landscapes.

在人类世，大型水坝建设代表了对河流形态动力学最深刻的干预之一，引发了水力几何的非线性响应，挑战了传统的基于平稳性的建模方法。本研究建立了一个神经随机微分方程（SDE）框架，以追踪三峡大坝运行后靖江河段每月汛期（5 - 10月）河段尺度变量——入流流量(Q)、河段平均河道宽度(B)、深度(H)和坡度(J)的完整形态动力学适应轨迹，从初始系统冲击到逐步成熟，再到新的动态平衡。该框架采用对数空间“物理基础+随机残差”范式进行形态动力学建模，并与用于年度驾驶员预测的Chronos-T5大型语言模型和综合三层评估系统相结合，能够对深度不确定性下的非平稳形态动力学演化进行稳健分析。使用一个四阶段的工作流程来校准大坝后的“新常态”，回顾性地诊断稳定前的过渡，验证样本外的性能，并探索未来的情景，我们揭示了形态动力学系统成熟的定量证据。在过渡时期（2000-2008年），反向浇筑的覆盖率低至59.3%（对比95%），量化了大坝的瞬态影响；将大坝后的短期训练集（2009-2016年）与扩展集（2009-2022年）进行比较，可以发现年度驱动模型从变量驱动指标转向拒绝缓慢的气候趋势作为混杂噪声。在共享社会经济路径（SSP245和SSP585）情景下的未来预测揭示了具有不同统计特征的不同形态适应途径- SSP245表现出持续的增量调整（通道宽度Mann-Kendall趋势强度τ = 0.7298）与SSP585的冲击适应响应(τ = 0.7747) -而动态模式分解表明流量和通道宽度的增长率相同（0.0014和0.0003）。在极端强迫下，收敛交叉映射显示因果耦合增强（因果相关系数ρ = 0.986比0.993）。这些发现从根本上促进了我们对水坝影响的河流形态动力学系统的理解，并为分析人类主导景观中发生政权转变的复杂形态动力学过程提供了可转移的方法蓝图。

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引用次数: 0

High-density fold–cleavage structures as a controlling factor of landslides: A case study in the southern Oboke area of the Shikoku Mountains, Japan 高密度褶皱-解理构造作为滑坡的控制因素：以日本四国山小盆南地区为例

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-14 DOI: 10.1016/j.geomorph.2025.110137

Shintaro Yamasaki

Landslides frequently occur in tectonically deformed mountain areas, where folding and faulting have altered rock mass conditions. Previous research has largely focused on the impacts of large-scale folds on rock mass quality and landslide occurrence; however, even smaller folds (mesoscopic- to microscopic-scale folds, hereafter MMFs) can markedly promote landslides when dense cleavage forms in conjunction with them. To clarify how MMFs and cleavage jointly control landslide distribution and failure, this study employed (1) an inventory of landslides to determine their spatial distribution and movement directions, (2) detailed outcrop surveys along roads and landslide sites to record the geometry of fold axial surfaces and cleavage, and (3) morphological analyses of rupture surfaces and open cracks at sites with recent landslide activity. The results indicate that areas with extensive MMFs experience more frequent landslides, and that open cracks and rupture surfaces can reach greater depths if formed by the combination of steep cleavage parallel or subparallel to the MMF axial surface and schistosity already steepened by folding. Such a crack network creates expanded pathways for rainwater and groundwater, making slopes more susceptible to landslides under repeated water pressure and stress changes during heavy rainfall or seismic shaking. In addition, these two-directional discontinuities arising from folds and cleavage are likely to be important factors in landslide prediction and risk evaluation in low-grade metamorphic mountains worldwide. The study's findings thus provide a reference for slope risk assessment in mountainous regions characterized by high-density folding and cleavage development.

滑坡经常发生在构造变形的山区，那里的褶皱和断裂改变了岩体条件。以往的研究主要集中在大规模褶皱对岩体质量和滑坡发生的影响；然而，即使是较小的褶皱（介观到微观尺度的褶皱，以下简称MMFs），当密集的解理形成时，也能显著促进滑坡。为了阐明mmf和解理如何共同控制滑坡的分布和破坏，本研究采用(1)对滑坡进行清查，以确定其空间分布和运动方向；(2)沿着道路和滑坡地点进行详细的露头调查，记录褶皱轴面和解理的几何形状；(3)对近期滑坡活动地点的破裂面和开放裂缝进行形态学分析。结果表明，MMF分布广泛的地区会发生更频繁的滑坡，如果与MMF轴面平行或次平行的陡峭解理与已经被褶皱变陡的片理相结合，则开放裂缝和破裂面可以达到更大的深度。这样的裂缝网络为雨水和地下水提供了更广阔的通道，使斜坡在暴雨或地震震动期间反复出现的水压和应力变化下更容易发生滑坡。此外，这些由褶皱和解理产生的双向不连续面可能是世界范围内低变质山滑坡预测和风险评价的重要因素。研究结果可为高密度褶皱、解理发育的山区边坡风险评价提供参考。

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引用次数: 0

Rockfall susceptibility mapping from topography perspective combing slope units and physical model-based negative sample strategy in the Yangtze Three Gorges 结合边坡单元和基于物理模型的负样本策略的地形视角下长江三峡岩崩敏感性填图

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-13 DOI: 10.1016/j.geomorph.2025.110136

Fangyi Yan , Haijia Wen , Yujie Li , Jiwei Hu , Peng Xie

Rockfalls occurring along the Yangtze River's reservoir banks pose a considerable threat to shipping safety, necessitating extensive spatial identification. Numerical analysis methods are often employed to assess rockfall stability, yet the inherent complexity of rock structures and the uncertainty of related parameters pose significant challenges in providing accurate inputs for numerical simulation models. Fortunately, the advent of high-precision DEM (Digital Elevation Model) models and advancements in artificial intelligence techniques now enable preliminary identification of potential rockfall locations based on topographic factors. In this study, the r.slopeunits method was employed to delineate slope units along the Yangtze River's reservoir banks, while the Scoops3D model was used to screen stable slope units. These stable units, together with known potential rockfall units, formed the dataset for machine learning. Unlike previous susceptibility assessment methods, this study focused on constructing the dataset using seven refined topographic factors, all derived exclusively from DEM data. The LightGBM algorithm was adopted for rockfall susceptibility prediction, with model validation conducted via 5-fold cross-validation and 100 random splits of the training and test sets (at a 7:3 ratio). The results indicated that slope standard deviation had the greatest impact on slope stability, with 87.6 % of rockfalls occurring in extremely high-risk areas. These findings underscore the importance of topographic factors in assessing rockfall susceptibility along the reservoir banks. Furthermore, the model achieves rockfall risk assessment using only DEM data, demonstrating strong generalization capability and providing extensive support for disaster prevention efforts.

长江水库两岸发生的岩崩对航运安全构成了相当大的威胁，需要进行广泛的空间识别。岩崩稳定性评估通常采用数值分析方法，但岩石结构固有的复杂性和相关参数的不确定性给数值模拟模型提供准确的输入带来了重大挑战。幸运的是，高精度DEM（数字高程模型）模型的出现和人工智能技术的进步，现在可以根据地形因素初步确定潜在的落石位置。本文采用r.s ropeunits方法对长江库区岸线边坡单元进行圈定，采用Scoops3D模型对稳定边坡单元进行筛选。这些稳定的单元，连同已知的潜在岩崩单元，形成了机器学习的数据集。与以往的敏感性评估方法不同，该研究侧重于使用七个精细的地形因子构建数据集，这些因子均来自DEM数据。岩崩敏感性预测采用LightGBM算法，模型验证采用5倍交叉验证，训练集和测试集随机分割100次（比例为7:3）。结果表明，边坡标准差对边坡稳定性的影响最大，87.6%的落石发生在极高危地区。这些发现强调了地形因素在水库岸线岩崩易感性评估中的重要性。此外，该模型仅使用DEM数据即可实现岩崩风险评估，具有较强的泛化能力，为防灾工作提供了广泛的支持。

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引用次数: 0

Late-Quaternary activity of parallel normal faults along the southern margin of the Yuguang Basin in the Shanxi Rift, China and its seismogeological implications 山西裂谷玉光盆地南缘平行正断层晚第四纪活动及其地震地质意义

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-12 DOI: 10.1016/j.geomorph.2025.110135

Junjie Zou , Feng Shi , Honglin He , Zhigang Shao , Wenqiao Li , Yoshiki Shirahama , Zhanyu Wei , Jianhua Huang

The geometric structure of faults, especially normal faults in extensional regions, is often complex. In faulted depression basins, normal faults typically exhibit branching in both bedrock and sedimentary areas. While paleoearthquake history in sedimentary regions can be studied through the trenching method, this method is not applicable to bedrock faults. For bedrock faults, terrestrial Light Detection and Ranging (t-LiDAR) has become an effective tool for analyzing fault scarps. To fully evaluate fault activity, traditional methods should be combined with new techniques. In this study, we focus on the Yu-Guang Basin southern marginal fault (YBSM Fault) in the Shanxi Rift, China. Although previous studies have investigated the fault, the co-seismic slip history and seismogenic potential remain unclear. We analyzed the Nanmazhuang (NMZ) bedrock fault surface using quantitative morphological analysis, aerial, and field surveys, identifying two seismic events with co-seismic dip slips of 3.1 m and 3.4 m. Empirical formulas suggest the bedrock branch fault can produce earthquakes with magnitudes greater than 7.5. At the Xizhuangtou (XZT) site, a Holocene fault was found with a cumulative displacement of 7 m and a throw rate of 0.7–0.85 mm/yr. A paleoearthquake with a co-seismic slip of 0.4–0.5 m occurred after 23.4–22.5 ka in sediments. The complete paleoearthquake sequence indicates an average recurrence interval of ~6.8 ka and an average elapsed time of ~8.5 ka for the sedimentary fault branch. The study integrates data from both fault branches, demonstrating that both are potential seismic risk sources. Considering the bedrock fault's large coseismic slip and capacity for M > 7.5 earthquakes, as well as the longer elapsed time, attention to seismic hazards on the YBSM Fault is critical.

断层的几何结构，特别是伸展地区的正断层，往往是复杂的。在断陷盆地中，正断层在基岩区和沉积区均表现出分支。虽然可以通过沟槽法研究沉积区的古地震史，但这种方法不适用于基岩断层。对于基岩断层，地面光探测与测距（t-LiDAR）已成为分析断层陡坡的有效工具。要充分评价断层活动性，必须将传统方法与新技术相结合。本文以山西裂谷中的玉光盆地南缘断裂（YBSM）为研究对象。虽然已有研究对该断层进行了调查，但同震滑动史和发震潜力仍不清楚。利用定量形态学分析、航空和野外调查等方法对南马庄基岩断裂面进行了分析，确定了同震倾角分别为3.1 m和3.4 m的两次地震事件。经验公式表明基岩分支断层可产生7.5级以上的地震。在西庄头（XZT）遗址发现了一条全新世断层，累计位移为7 m，抛出速率为0.7 ~ 0.85 mm/yr。23.4 ~ 22.5 ka后发生同震滑动0.4 ~ 0.5 m的古地震。完整的古地震序列表明，沉积断裂分支的平均重现间隔为~6.8 ka，平均经过时间为~8.5 ka。该研究整合了两个断层分支的数据，表明两者都是潜在的地震危险源。考虑到基岩断层同震滑动量大，承受7.5级地震的能力，以及经过的时间较长，对YBSM断层地震危险性的关注是至关重要的。

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引用次数: 0

The curious case of a short fault scarp in the podhale basin: Implications for late pleistocene geodynamics of the central western carpathians 洼洼盆地短断崖的奇特案例：喀尔巴阡山脉中西部晚更新世地球动力学的启示

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-12 DOI: 10.1016/j.geomorph.2025.110134

Jacek Szczygieł , Jerzy Zasadni , Piotr Kłapyta , Marta Woszczycka , Krzysztof Gaidzik , Maciej Mendecki , Artur Sobczyk , Christoph Grützner

Areas with low deformation rates, such as continental interiors or mature orogens, may represent significant seismic hazard zones, albeit still insufficiently recognized. Relatively low-magnitude earthquakes occurring in such regions pose challenges for paleoseismology, despite occasional documented surface fault ruptures. This study focuses on a scarp located in the Podhale Basin (Central Western Carpathians) that deviates from empirical displacement-length scaling relationships. Despite its relatively short length of only 3 km, the scarp, measuring 4 m in height, presents several indications of its tectonic origin, yet to some extent scarp height could have been exaggerated by creep of weathered clays. Geophysical GPR and ERT surveys revealed a vertical discontinuity directly beneath the scarp. Moreover, we identified distinct features interpreted as a fault zone in a trench across the scarp. Lacking material suitable for dating, we estimated the age of the fault scarp at 10–50 ka using simple linear diffusion modeling. However, this result requires caution due to assumptions like scarp formation from a single event. Yet, the consistency of the estimated age with the superposition of the scarp relative to the morphology and weathered covers from the last glaciation is noteworthy. Furthermore, morphological and geological mapping suggests dextral oblique kinematics of the studied fault. The prevailing trend of NE (NNE) compression across the Podhale and Orava basins and the Tatra Mountains aligns the dextral Brzegi fault with the broader Alpine-Carpathian geodynamic framework. The Brzegi fault, as part of the broader Białka fault zone, provides evidence of far-field effects, serving as an NNW-striking dextral antithetic fault to major sinistral NE-SW striking faults. The recognized pattern indicates the continued post-Miocene Alpine extrusion towards the Carpathians.

变形率低的地区，如大陆内部或成熟造山带，可能是重要的地震危险区，尽管尚未得到充分认识。在这些地区发生的相对低震级的地震给古地震学带来了挑战，尽管偶尔有地表断层破裂的记录。本研究的重点是位于Podhale盆地（喀尔巴阡山脉中西部）的一个断崖，该断崖偏离了经验位移-长度缩放关系。尽管它的长度相对较短，只有3公里，但它的高度为4米，显示了它的构造起源的几个迹象，但在某种程度上，悬崖的高度可能被风化粘土的蠕变所夸大。地球物理探地雷达（GPR）和ERT调查显示，陡坡正下方有一个垂直不连续面。此外，我们确定了明显的特征，解释为断裂带在一个沟槽横跨悬崖。由于缺乏适合定年的材料，我们使用简单的线性扩散模型估计断崖的年龄为10-50 ka。然而，这个结果需要谨慎，因为假设像陡坡形成的单一事件。然而，值得注意的是，估计年龄与陡崖相对于末次冰期的形态和风化盖层的叠加相一致。此外，形态和地质填图表明研究断层的右向斜运动学。整个Podhale和Orava盆地以及Tatra山脉的NE向（NNE）压缩趋势使Brzegi断裂的右侧与更广泛的阿尔卑斯-喀尔巴阡地球动力学框架对齐。Brzegi断层，作为更广泛的Białka断裂带的一部分，提供了远场效应的证据，作为北北西向的右向断层与北东-西南向的主要左向断层的对偶断层。该模式表明中新世以后阿尔卑斯山脉继续向喀尔巴阡山脉挤压。

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引用次数: 0

Deep-seated cave inception and shallow sulfuric acid maze cave genesis in Southern Irecê Basin, São Francisco Craton (Brazil) 巴西<e:1>圣弗朗西斯科克拉通Irecê盆地南部深层溶洞形成与浅层硫酸迷宫溶洞成因

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-10 DOI: 10.1016/j.geomorph.2025.110126

Philippe Audra , Luca Pisani , Marco Antonellini , Francisco Hilario R. Bezerra , Augusto S. Auler , Vincenzo La Bruna , Giovanni Bertotti , Fabrizio Balsamo , Cayo C.C. Pontes , Rebeca S. Lima , Marjan Temovski , Xianfeng Wang , Jo De Waele

Ioiô Cave is a 4.7 km long maze cave in the southern tip of the Irecê Basin (Bahìa, Brazil), and although still actively forming today, it hosts signs of a long speleogenetic history. Deep rising hydrothermal fluids weathered the carbonates, creating dark ghost-rocks and quartz and dolomite veins, mainly in the anticlinal hinges and below the siliciclastic seals. This silicification, although not directly dated, is probably associated with the end of the Brasiliano-age tectono-thermal activity (Lower Cambrian) based on isotopic and trace element data and regional tectonic correlations. Since the Plio-Quaternary, the progressive exhumation of the carbonate reservoir increasingly favored the introduction of meteoric oxygen-rich water from the surface, causing sulfide oxidation at shallow aquifer depth. The CO₂ produced by Sulfuric Acid Speleogenesis (SAS) rose along fractures and degassed at shallow depth, producing carbonic speleogenesis close to the water table. This carbonic speleogenesis, probably still active, produced a maze network, by horizontal diffusion of aggressive fluids from the feeders. Surface breaching increased air flow activating degassing and supersaturation of the basins, with deposition of subaqueous calcite shelves, carved with bubble trails resulting from CO₂ degassing related to still-ongoing pyrite oxidation (localized SAS).

Ioiô洞穴是位于Irecê盆地（Bahìa，巴西）南端的一个长4.7公里的迷宫洞穴，尽管今天仍在活跃地形成，但它拥有悠久的洞穴形成历史的迹象。深层上升的热液流体风化了碳酸盐，形成了黑色的鬼岩和石英白云岩脉，主要在背斜铰链和硅质密封下面。这种硅化作用虽然不能直接确定年代，但根据同位素和微量元素数据以及区域构造对比，可能与brasiliano时代构造-热活动（下寒武统）的结束有关。上第四纪以来，随着碳酸盐岩储层的不断发掘，地表大气富氧水的引入日益有利于浅层含水层的硫化物氧化。硫酸造井（SAS）产生的CO2沿裂缝上升，并在浅层脱气，在靠近地下水位处产生碳酸盐岩造井。这种可能仍然活跃的碳洞穴形成作用，通过从喂食器流出的侵蚀性液体的水平扩散，形成了一个迷宫网络。表面破裂增加了空气流动，激活了盆地的脱气和过饱和，水下方解石架沉积，留下了与仍在进行的黄铁矿氧化（局部SAS）有关的二氧化碳脱气所造成的气泡痕迹。

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引用次数: 0

Provenance changes of Quaternary fillings and geomorphic processes of modern aeolian sand formation in the Hailar Basin, NE China 海拉尔盆地第四纪充填物的物源变化及现代风成砂的地貌过程

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-08 DOI: 10.1016/j.geomorph.2025.110127

Yehui Wang , Yuanyun Xie , Lei Sun , Zhenyu Wei , Haodong Qi , Haijin Liu , Peng Wu

Terrestrial sedimentary systems, as faithful records of the coupling between tectonic and climatic processes, not only reflect the evolutionary history of surface processes but also profoundly influence regional and even global environmental changes through complex feedback mechanisms. The Hailar Basin in Northeast China, as a Quaternary terrestrial basin in an arid-semi-arid region, holds significant importance for understanding the East Asian dust system and response mechanisms to the tectonic and climate through clarifying its geomorphic evolution and aeolian surface processes. The Quaternary fillings in the Hailar Basin, NE China, consist mainly of the Early Pleistocene Baitushan Formation, the Late Pleistocene Hailar Formation, and the Holocene aeolian sand covers. In this study, we present the first detrital zircon UPb geochronological data for the infilling and major river sediments in the Hailar Basin. This study aims to reveal changes in the provenance and surface processes of the Hailar Basin since the Early Pleistocene through zircon age comparison, quantitative results of inverse Monte Carlo, and multidimensional scaling (MDS). By integrating the evolution of sedimentary facies and the depositional ages of various strata, the research further explores the dominant driving mechanisms behind these changes, providing an important reference for sedimentary research on terrestrial basins in Northeast Asia. The results indicate that tectonics and climate jointly influenced the changes in surface processes, including provenance shifts and the formation of the modern Hulunbuir Sandy Land (HLSL). With the uplift of the Great Xing'an Range during the Early Pleistocene (∼1.4 Ma), a significant amount of coarse-grained clastics, such as gravels and sands, were transported by major rivers into the basin, resulting in the formation of the Baitushan Formation sediments (with ∼98 % of the material derived from the Great Xing'an Range). At this stage, climate may exert a slight potential influence on the intensity of source erosion and the rate of sedimentation. In the Late Pleistocene, the uplift of the Great Xing'an Range ceased, leading to the accumulation of fine-grained sediments of the Hailar Formation within the basin and the concurrent development of fluvial-lacustrine landscapes. Meanwhile, the uplift of the Central Mongolia Block (C. MG) and the intensification of the East Asian Winter Monsoon (EAWM) resulted in the deposition of a substantial amount of sandy material (25.19–48.5 %) from the C. MG into the basin. Subsequently, the warmer and wetter regional climate increased precipitation and fluvial erosion, leading to the continuous reworking of detrital materials from the C. MG, the basin basement, and the Hailar Formation through the interplay of northwesterly winds and fluvial processes. Ultimately, this process drove the formation of the modern aeolian sands in the HLSL.

陆相沉积体系作为构造过程与气候过程耦合的忠实记录，不仅反映了地表过程的演化历史，而且通过复杂的反馈机制深刻影响着区域乃至全球的环境变化。海拉尔盆地是位于干旱-半干旱区的第四纪陆相盆地，通过阐明其地貌演化和风成过程，对了解东亚沙尘系统及其对构造和气候的响应机制具有重要意义。海拉尔盆地第四纪充填物主要包括早更新世白头山组、晚更新世海拉尔组和全新世风成砂盖层。本文首次获得了海拉尔盆地充填体和主要河流沉积物的碎屑锆石UPb年代学资料。通过锆石年龄对比、逆蒙特卡罗定量结果和多维标度（MDS）等方法，揭示海拉尔盆地早更新世以来物源和地表过程的变化。结合沉积相演化和各地层沉积时代，进一步探索这些变化背后的主导驱动机制，为东北亚陆相盆地沉积研究提供重要参考。结果表明，构造和气候共同影响了地表过程的变化，包括物源转移和现代呼伦贝尔沙地的形成。早更新世（~ 1.4 Ma）随着大兴安岭的隆升，大量砾石、砂石等粗粒碎屑被主要河流带入盆地，形成了白头山组沉积物（其中~ 98%的物质来自大兴安岭）。在这个阶段，气候可能对源侵蚀的强度和沉积速率产生轻微的潜在影响。晚更新世，大兴安岭隆升停止，盆地内形成海拉尔组细粒沉积，河湖景观同步发育。与此同时，中蒙古地块（C. MG）的隆升和东亚冬季风（EAWM）的增强导致中蒙古地块向盆地沉积了大量的砂质物质（25.19 ~ 48.5%）。随后，温暖湿润的区域气候增加了降水和河流侵蚀，导致西北风和河流作用的相互作用使c - MG、盆地基底和海拉尔组的碎屑物质不断再加工。最终，这一过程推动了HLSL现代风成沙的形成。

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引用次数: 0

Drainage basin reorganisation in Trivandrum block, Southern Western Ghats, India 印度西高止山脉南部Trivandrum地块的流域重组

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-08 DOI: 10.1016/j.geomorph.2025.110132

M. Vandana, J. Amal Dev, J.K. Tomson, Srikumar Chattopadhyay

Drainage basin reorganisation is a fundamental earth surface process with significant implications for landscape evolution, sediment routing, and hydrological regimes. In this study, we investigate the Kallada and Ithikkara rivers in the southern Western Ghats to constrain the timing, mechanisms, and geomorphic consequences of river capture in their upper catchments. Morphometric and sedimentary provenance analyses indicate that the upper Kallada and Ithikkara basins were once part of a single, integrated drainage network. Chi (χ) analysis further reveals that following the river capture event, the Ithikkara basin experienced a substantial reduction in upper catchment area. The chi map geometry suggests that the upper Kallada basin, presently located upstream of a pronounced channel elbow, may originally have drained through the present Ithikkara channel before being captured by the Kallada river. Detrital zircon UPb geochronology from sediments of both rivers exhibits remarkably similar age spectra, with prominent peaks at ~2500 Ma, ~1900 Ma, ~1000 Ma, ~750 Ma, and ~550 Ma, indicating derivation from a shared sediment source. Integration of geomorphic metrics with provenance data supports a scenario in which tectonic or geomorphic processes separated the upper Kallada basin from the main Ithikkara drainage system, resulting in reorganisation of the regional river network. These findings demonstrate the value of combining quantitative geomorphic approaches with sedimentary geochronology to reconstruct past drainage evolution, even in tectonically stable regions, and provide new insights into the links between river capture, sediment provenance, and landscape dynamics in the southern Western Ghats.

流域重组是一个基本的地表过程，对景观演变、沉积物路径和水文制度具有重要意义。在这项研究中，我们调查了西高止山脉南部的Kallada和Ithikkara河，以限制河流在其上游集水区捕获的时间、机制和地貌后果。形态计量学和沉积物源分析表明，上卡拉达盆地和伊蒂卡拉盆地曾经是一个单一的、完整的水系网络的一部分。Chi （χ）分析进一步表明，在河流捕获事件发生后，Ithikkara流域上游集水区面积大幅减少。chi地图的几何形状表明，目前位于一个明显的河道弯头上游的上卡拉达盆地，在被卡拉达河捕获之前，可能最初通过现在的伊蒂卡拉河道排干。两河沉积物的碎屑锆石UPb年代学显示出非常相似的年龄谱，在~2500 Ma、~1900 Ma、~1000 Ma、~750 Ma和~550 Ma有明显的峰值，表明它们来自共同的沉积物源。地貌指标与物源数据的整合支持了这样一种假设，即构造或地貌过程将卡拉达上游盆地与主要的伊蒂卡拉流域系统分离开来，从而导致了区域河流网络的重组。这些发现证明了定量地貌学方法与沉积地质年代学相结合的价值，即使在构造稳定的地区，也可以重建过去的排水演化，并为西高止山脉南部河流捕获、沉积物来源和景观动态之间的联系提供了新的见解。

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引用次数: 0

Effects of sediment connectivity changes on channel evolutionary trajectory: the case study of the Taro and Ceno rivers in the Northern Apennines (Italy) 沉积物连通性变化对河道演化轨迹的影响——以意大利亚平宁北部塔罗河和奇诺河为例

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-08 DOI: 10.1016/j.geomorph.2025.110131

Sharon Pittau , Vittoria Scorpio

The post-1950s evolutionary trajectories of the Taro and Ceno rivers (Northern Apennines, Italy) were investigated, focusing on the correlation between channel adjustments and sediment alterations. The specific aims were to: i) highlight similarities and dissimilarities between the evolutionary trajectories of the two rivers; ii) assess the role of sediment connectivity decrease caused by land use changes along the hillslopes, and iii) evaluate the impact of gravel mining.

Changes in active channel width and bed level were quantified using multi-temporal orthophotos (1954–2020) and topographical cross-sections. Land use dynamics were reconstructed through multi-temporal land cover maps, and changes in structural sediment connectivity were assessed by applying the Index of Connectivity (IC). Evolution of landslide-prone areas was analysed to estimate changes in sediment supply, and the influence of anthropogenic activities was also considered through mapping gravel mining areas and in-channel works.

Results showed progressive afforestation, after the 1950s in the Ceno and after the 1970s in the Taro basin, with decreases in landslide-prone areas and IC. Hillslope stabilization caused a decrease in sediment supply to both channels, with subsequent channel narrowing and bed incision (−50 % and −3.3 m in the Taro and −38 % and −2.5 m in the Ceno, respectively). More intense morphological changes in the Taro, especially between 1954 and 1976, were linked to the intense gravel mining activity, completely absent along the Ceno. The combined effects of catchment-scale afforestation and reach-scale gravel extraction therefore played a key role in shaping the dissimilarities in the evolutionary trajectories between the two rivers.

研究了意大利亚平宁北部塔罗河和奇诺河在20世纪50年代后的演变轨迹，重点研究了河道调整与沉积物变化之间的相关性。具体目的是：1)强调两条河流演化轨迹的异同；Ii)评估沿坡土地利用变化导致的沉积物连通性下降的作用；iii)评估砾石开采的影响。利用多时相正射影像（1954-2020）和地形剖面量化了活跃水道宽度和河床水平的变化。通过多时相土地覆被图重构土地利用动态，应用连通性指数（IC）评价结构沉积物连通性变化。通过分析滑坡易发区的演变来估计泥沙供应的变化，并通过绘制砾石矿区和河道内工程来考虑人为活动的影响。结果表明，20世纪50年代和70年代后，在切诺流域和塔罗流域，渐进式造林减少了滑坡易发区和IC。山坡稳定导致两个河道的泥沙供应减少，随后河道变窄和河床切割（分别为- 50%和- 3.3 m，分别为- 38%和- 2.5 m）。特别是在1954年至1976年之间，塔罗河更剧烈的形态变化与激烈的砾石开采活动有关，而在Ceno河沿岸则完全没有。因此，流域尺度的造林和河段尺度的砾石开采的综合效应在形成两条河流进化轨迹的差异中发挥了关键作用。

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引用次数: 0

Northeastern Tibetan Plateau paleo-Yellow River drainage expansion at ~3 Ma linked to the East Asian summer monsoon intensification

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-12-08 DOI: 10.1016/j.geomorph.2025.110133

Benhong Guo , Jiechang Gao , Zhenghao Qin , Fuhang Niu , Yindi Wang , Tingjiang Peng , Shanpin Liu , Chengying Liu , Junsheng Nie

The fluvial terrace sequences in the northeastern Tibetan Plateau indicate that the modern Yellow River primarily originated in the Lanzhou Basin around 1.8 Ma and subsequently extended into the interior of the Tibetan Plateau through headward erosion. However, the evolutionary history and driving mechanisms of the paleo-Yellow River during the Pliocene-Pleistocene, prior to the formation of the modern Yellow River system, remain unclear despite its establishment by ~3.6 Ma. In this study, we present the new results of magnetic susceptibility and combined with previous sedimentological analyses and detrital zircon UPb ages of fluvial sequences spanning the interval of ~3.6–2.2 Ma in the Lanzhou Basin, in the northeastern Tibetan Plateau. Our results reveal a rapid increase in the sediment supply into the Lanzhou Basin from the northeastern Tibetan Plateau at ~3 Ma, signaling an expansion of the paleo-Yellow River drainage system at this time. This Late Pliocene drainage system expansion coincides with the intensification of the East Asian summer monsoon, which may reflect interactions between the evolution of the paleo-Yellow River and climate change.

然而，在现代黄河体系形成之前的上新世-更新世古黄河的演化历史和驱动机制，尽管在约3.6 Ma时就已形成，但仍不清楚。本文结合前人的沉积学分析和碎屑锆石UPb年龄，对~3.6 ~ 2段的河流层序进行了磁化率测定。这种晚上新世水系扩张与东亚夏季风的强化相吻合，可能反映了古黄河演化与气候变化的相互作用。

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引用次数: 0