首页期刊导航|Geomorphology
期刊信息/Journal information
Geomorphology
Elsevier
Geomorphology

Elsevier

0169-555X

Geomorphology/Journal GeomorphologySCIAHCIISTP
正式出版
收录年代

    Landsystem models from remote and field based geomorphological mapping reveal diverse glacier dynamics on Svalbard

    McCerery, RebeccaDavies, Bethan J.Lovell, HaroldCalvo-Ryan, Rosalia...
    1.1-1.20页
    查看更多>>摘要：Glacial landsystems are geomorphological records produced by glaciers that provide important insights into past and present glacier dynamics. Here, we present a snapshot of the diversity in glacier landsystems in Svalbard. We present remote and field geomorphological mapping from 11 glaciers: seven in south Spitsbergen (Scottbreen, Renardbreen, Antoniabreen, Penckbreen, Bakaninbreen, Paulabreen and Skobreen) and four in northwest Spitsbergen (Charlesbreen, Protektorbreen, Bullbreen, and Ferdinandbreen). These examples include landform assemblages that (1) are diagnostic of recent surging in terrestrial and marine settings; (2) are characteristic of thinning polythermal glaciers that have previously been more dynamic; and (3) represent rapidly vanishing glaciers, the geomorphological endpoint for Svalbard glaciers characterised by the fragmentation and down-wasting of small cold-based glaciers. We synthesize these into four landsystem models to provide a framework for interpreting glacier dynamics in Svalbard based on geomorphological records. The hypsometries of many land-terminating glaciers in Svalbard suggests that we will increasingly observe the transition from polythermal to cold-based glacier thermal regimes as the climate continues to warm, ultimately leading to more vanishing glaciers. This has important wider implications for changing water, sediment and biogeochemical fluxes which will impact subglacial, forefield and ocean ecosystems.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Aeolian sediment transport over a granule ripple surface and its implications for geomorphological evolution

    Qian, GuangqiangYang, ZhuanlingXing, XuegangDong, Zhibao...
    1.1-1.14页
    查看更多>>摘要：Aeolian sediment transport causes a range of sand hazards and serious air pollution, but also sculpts intricate landscapes in arid and semi-arid areas. Previous studies of aeolian transport have mainly focused on the particle transport rate or flux density above various surfaces, such as sandy and gravelly beds, or have linked these factors to the dynamic processes that govern fine-grained bedforms, including dunes and sand ripples. Granule ripples have been studied less. Their sediments exhibit a bimodal size distribution, and they are armored by coarse grains at the crest. The aeolian transport characteristics above their surface are crucial for understanding their morphodynamic processes, but have been rarely studied in the field. To provide this missing data, we conducted six observations using a blowing-sediment trap on the surface of granule ripples in the northern part of China's Kumtagh Desert to elucidate the geomorphological effects of aeolian transport. The flux density decreased exponentially with increasing height, but with substantial differences in the vertical profiles of flux density for different grain-size groups. The transported particles were predominantly fine to medium sands, although coarse sands to very fine gravels also underwent saltation at high wind speeds. Wind strength significantly influenced the aeolian transport process, with particles of different sizes responding to different threshold velocities and engaging in different transport modes. We related selective, bimodal, and unimodal transport processes to the morphological evolution of granule ripples and the formation of their sedimentary structure. We suggest that the saltation of coarse particles should be fully considered to refine the theoretical framework for granule ripple evolution.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Spatio-temporal geomorphological evolution and driving factors of a transgressive dunefield, Qinghai Lake, northeastern Tibetan Plateau

    Mo, HaokunHu, GuangyinYang, LinhaiZhang, Zhi...
    1.1-1.16页
    查看更多>>摘要：This study aims to investigate the evolution and driving factors of the transgressive dunefield on the eastern shore of Qinghai Lake. Image analysis showed that the transgressive dunefield had continuously moved inland from the lakeshore and experienced three major stages between 1970 and 2020: Stage 1 (1970-1996), the dunefield moved slowly (1.40 m/yr); Stage 2 (1996-2013), the dunefield moved rapidly (15.66 m/yr); and Stage 3 (2013-2020), the movement of the dunefield slowed down (7.70 m/yr). The grain size characteristics of the surface sediments indicated that material from the lakeshore was transported inland, undergoing continuous sorting and transformation by the wind. By combining the ERA5-Land dataset and meteorological data to assess the environmental changes, it was found that the correlation between the wind and the changes in dunefield movement speed was weak, as the wind speed progressively weakened throughout the study period. However, the deceleration or acceleration of the dunefield movement often corresponded to the advance or retreat of the shoreline as the lake level rose or fell. This was because the change of the lake level and shoreline indirectly affected the movement speed by regulating the sand supply. Furthermore, the lake level and shoreline change in Qinghai Lake were still primarily controlled by climate change. In general, this study offers a valuable example of transgressive dunefield development along the lakeshore and traces its evolution over the past 50 years by multisource image data. The results suggest that transgressive dune sheets or dune fields can evolve directly from the lakeshore. It also indicates that transgressive dunefields are initiated as a response to the water level fall in cold and arid environments with abundant sand supply.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Selection of optimal factor combinations for typhoon-induced landslides susceptibility mapping using machine learning interpretability

    Wang, FeiZhou, LiweiZhao, JianjunLiu, Yanling...
    1.1-1.15页
    查看更多>>摘要：With the intensification of extreme climate change globally, typhoon-induced landslides have become a serious threat to people's property and lives. Although some studies have identified wind, rainfall, and vegetation as contributing factors to landslides, challenges still remain in incorporating these factors into susceptibility mapping. This study aims to establish a foundation for selecting key factors that affect the susceptibility of typhoon-induced landslides. Specifically, this study innovatively employs the interpretability of machine learning, including Partial Dependence Plots (PDP) and Shapley values, to analyze the correlation between landslides and factors, and compares this with qualitative analysis. It assesses the significance of static factors, incorporates typhoon-related factors, and examines their collective impact. The critical static factors of typhoon-induced landslides identified by Shapley values, including elevation, normalized difference vegetation index (NDVI), road, slope, land use, river, aspect of slope, and vegetation. The k-fold cross-validation was utilized for computation of average descent accuracy, and facilitated the selection of optimal combination of dynamic and static factors, the effectiveness of which was confirmed through ROC (Receiver Operating Characteristic curve). The optimal combination of dynamic factors was determined by average descent accuracy: maximum sustained wind speed, 24 h pre-rainfall, distance from the landslides to the typhoon center and wind circle radius of near gale. Through rigorous verification, it was determined that optimizing factor combinations could increase the accuracy of evaluations by 1.5 %-3.5 %, thereby enhancing both the precision and reliability of susceptibility assessments for typhoon-induced landslides.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Meandering rivers that anabranch in the upper Midwest (USA): Prevalence, morphological characteristics, and power regimes (vol 440, 108854, 2023)

    Shukla, TanyaRhoads, Bruce L.
    1.1-1.3页
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Quantifying small scale spatial variability in diffusive erosion and deposition

    Hancock, G. R.Welivitiya, W. D. Dimuth P.
    1.1-1.15页
    查看更多>>摘要：Hillslope and catchment evolution will be the cumulative product of short and long-term processes that operate and dominate over different hillslope length scales. In this study, erosion and deposition pattern rates generated over short lengths scales (0.1-3 m) are examined using erosion pins over 14 years for a field site in northern Australia. The pins consisted of two sets of nine pins located on a catchment divide. Over the 14 years, there was considerable variability in erosion and deposition with both sites being depositional (similar to 7 mm of deposition). The sites, separated by several hundred metres both had very similar erosion and deposition patterns. Annual erosion and deposition patterns were modelled using a computer-based Landscape Evolution Model (SSSPAM) that models both fluvial and diffusive erosion. Model results found that SSSPAM was unable to predict the erosion and deposition rate and patterns using a Digital Elevation Model (DEM) for the site. However, when the DEM was modified at each annual time step to capture short length scale random particle movement, SSSPAM predicted both erosion and deposition variability as well as the field measured deposition. This is the first time that a hillslope diffusion model has been evaluated for erosion produced by rainfall. The model results demonstrate that the commonly used equation for diffusion when calibrated for the site performs well.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Study on the hydrodynamic mechanics and soil mechanical characteristics under the phenomenon of river-bottom tearing scour (RBTS)

    Jiang, EnhuiLiu, YanhuiPan, LiHe, Xianfeng...
    1.1-1.15页
    查看更多>>摘要：River-bottom tearing scour (RBTS) refers to the phenomenon wherein clay layers formed by the deposition and solidification of extremely fine cohesive sediment are uplifted, and exposed to the water surface during the hyperconcentrated floods. While prior research has established the conditions for RBTS occurrence, its underlying physical mechanisms remain unclear. In this study, to investigate the hydrodynamic mechanics and soil mechanical characteristics associated with the RBTS phenomenon, a series of direct shear tests on clay blocks collected from river reaches prone to the RBTS phenomenon and flume experiments simulating the RBTS phenomenon were conducted. The former direct shear tests revealed that the clay blocks generally possess high shear strength, a characteristic strongly influenced by their water content and grain size gradation. Observations from the latter flume experiments showed pronounced turbulence around the clay blocks, with measurement data indicating that the vertical distributions of flow velocity and turbulence intensity during the RBTS phenomenon are governed by the discharge, scour pit depth and rotation angle of the clay blocks... The aforementioned turbulence was identified as the source of uplift force on the clay block, while the high shear strength of unsaturated clay blocks enables them to resist fragmentation during uplift, thereby contributing to the characteristic RBTS formation process. Moreover, empirical expressions for the vertical distribution of longitudinal flow velocity, as well as the shear strength of clay blocks during the RBTS phenomenon were proposed. The conclusions in this paper can provide new insights into the hydrodynamic mechanism and soil mechanical characteristics underlying the RBTS phenomenon.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Mineralogical investigation of modern sediments and source analysis of different grain-size fractions in the middle and lower Yellow River

    Chen, DianbaoLiu, WeiPang, HongliFu, Xiangnan...
    1.1-1.17页
    查看更多>>摘要：The Yellow River has the highest suspended sediment load among the Earth's big rivers. High sediment supply and rapid sediment accumulation caused numerous flood disasters such as channel breaches and diversions through history. Understanding sediment characteristics and relative contributions from potential source areas is important for recognizing the formation of hyperconcentrated flows and implementing water and sediment regulation projects. We here combine mineral analyses (clay minerals and heavy minerals) of 52 samples of modern riverbed sediments from the middle and lower reaches of the Yellow River and its tributaries, the Haihe River Basin, and the Huaihe River Basin to explore sediment-transport processes in the Huang-Huai-Hai Plain. Frequency models are used to calculate the relative contributions of each potential source area to the sediments of different grain-size in the lower Yellow River. Our results show that clay-sized sediments originate mainly from the Weihe Basin and the southern Loess Plateau, whereas coarser sediments (> 30 mu m) are primarily supplied by the Jinshaan Gorge (the mainstream) and its western tributaries. This study underscores the heterogeneity of sediment sources of sediments with different grain-size in the lower Yellow River. It will shed new light on further research on the mechanisms of the formation of hyperconcentrated flows. Our findings contribute to the formulation of strategies for water and soil conservation and water-sediment regulation in the middle Yellow River; and they provide fundamental provenance analysis data for future studies of the connectivity of the Yuxi Gorge, and sedimentary and geomorphological research related to the diversion of the Yellow River to the Huaihe River Basin.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Transition of predominant regional tectonics to global climate forcing for Asian summer monsoons at ∼7.2 Ma

    Gao, PengWang, XiaoxueChen, HaoqiChen, Yixin...
    1.1-1.9页
    查看更多>>摘要：Much has been known regarding late Neogene East Asian summer monsoon (EASM) history and potential forcing mechanisms due to the existence of late Neogene loess deposits on the Chinese Loess Plateau. No continuous loess deposits exist in South Asian monsoon region, and many studies infer South Asian summer monsoon (SASM) variations mainly from low-elevation marine or fluvio-lacustrine sediments. However, inconsistent viewpoints emerge regarding the evolution of the SASM from the late Miocene to the Pleistocene and the potential forcing mechanisms based on these sediments. Here we present an SASM record derived from environmental magnetic parameter in late Neogene fluvio-lacustrine strata from the high-elevation Zhada Basin in southern Tibet. The results show the SASM experienced four stages of variations over the late Miocene to the early Pleistocene, with stronger monsoon precipitation corresponding to warmer climate after similar to 7.2 Ma. However, SASM intensification prior to similar to 7.2 Ma was contrary to effects of global climate variations, which we attributed to thermal and mechanical effects of the northeastward growth of the Tibetan Plateau on the SASM. A comparison with the EASM records suggests that the EASM also experienced a transition of dominant driving forcing from the Tibetan Plateau uplift to global climate at similar to 7.2 Ma, with the exception of the interval 4.5-2.7 Ma when the EASM intensification was controlled by regional tectonics (possibly closure of the Panama Seaway). This study clarifies evolution history of the Asian summer monsoons and recognizes their main forcing mechanisms since 10 Ma.
      原文链接:
    • NETL
    • NSTL
    • Elsevier

    Comment on De Ritis, R., Cocchi, L., Passaro, S, Chiappini, M., 2024. Giant slide, hidden caldera structure, magnetic anomalies, and tectonics in southern Tyrrhenian Sea (Italy)

    Torrente, Maurizio M.Milia, Alfonsa
    1.1-1.5页
    查看更多>>摘要：De Ritis et al. (2024, hereinafter DER24) compiled new detailed magnetic anomaly maps of the sea floor along the Campania Margin encompassing the southern Gaeta Bay and the offshore of Ischia and Campi Flegrei, one of the highest-risk volcanic areas in the world. Due to the area's importance, we maintain that some interpretations should be discussed in more depth because their original magnetic data can furnish new insights into the reconstruction of the volcano-tectonic evolution of the highly populated Campi Flegrei. In their abstract, DER24 wrote: "The study results provide valuable insights into the relationship between volcanic, magmatic, and tectonic activity", and this comment addresses these specific questions.
      原文链接:
    • NETL
    • NSTL
    • Elsevier