Geomorphology最新文献_第3页

Evolution of deep-seated gravitational slope deformation in a deep valley of the Czech Flysch Carpathians

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-01 DOI: 10.1016/j.geomorph.2024.109545

Vladimír Chalupa , Tomáš Pánek , Michal Břežný , Francisco Gutiérrez , Alicia Medialdea

In the Czech Outer Western Carpathians (OWC), the lower limit of deep-seated gravitational slope deformations (DSGSDs) occur associated with moderate local relief and slope gradient, showing a limited degree of geomorphic development. Here, DSGSDs display a relatively high spatial frequency, despite the limited tectonic and seismic activity, often claimed as major preparatory and triggering factors. Nonetheless, favourable stratigraphic and structural features in flysch successions, together with fluvial downcutting, provide conditions prone to DSGSDs. The study area of Travný Mt. hosts the typical DSGSDs in the highest part of Czech OWC. With the aim of unravelling the controlling and triggering factors, the internal structure, and the timing and kinematics of mass-movement activity, a multidisciplinary investigation was performed. LiDAR-based and field geomorphological mapping allowed to constrain the extent of the of DSGSD, expressed by characteristic landforms such as antislope scarps and grabens. The structural analysis and geophysical surveys (ERT and GPR) provided insight into the internal structure of the DSGSD, reaching a depth of >100 m, and supported its mountain-scale spatial propagation. The instability is controlled by inherited faults, deep-penetrating joints and and the stratigraphic contact between brittle caprock overlying weaker rocks. Morphologically, the most prominent deformation is located in the upper part, which is dominated by toppling of flysch blocks with thick-bedded sandstone. The results of the trenching technique and geochronological analyses point to the episodic kinematics of this portion of the DSGSD, revealing a significant displacement event (ca. 9.9 ka) linked to a major climate change occurred after the Late Glacial/Holocene transition.

{"title":"Evolution of deep-seated gravitational slope deformation in a deep valley of the Czech Flysch Carpathians","authors":"Vladimír Chalupa , Tomáš Pánek , Michal Břežný , Francisco Gutiérrez , Alicia Medialdea","doi":"10.1016/j.geomorph.2024.109545","DOIUrl":"10.1016/j.geomorph.2024.109545","url":null,"abstract":"<div><div>In the Czech Outer Western Carpathians (OWC), the lower limit of deep-seated gravitational slope deformations (DSGSDs) occur associated with moderate local relief and slope gradient, showing a limited degree of geomorphic development. Here, DSGSDs display a relatively high spatial frequency, despite the limited tectonic and seismic activity, often claimed as major preparatory and triggering factors. Nonetheless, favourable stratigraphic and structural features in flysch successions, together with fluvial downcutting, provide conditions prone to DSGSDs. The study area of Travný Mt. hosts the typical DSGSDs in the highest part of Czech OWC. With the aim of unravelling the controlling and triggering factors, the internal structure, and the timing and kinematics of mass-movement activity, a multidisciplinary investigation was performed. LiDAR-based and field geomorphological mapping allowed to constrain the extent of the of DSGSD, expressed by characteristic landforms such as antislope scarps and grabens. The structural analysis and geophysical surveys (ERT and GPR) provided insight into the internal structure of the DSGSD, reaching a depth of >100 m, and supported its mountain-scale spatial propagation. The instability is controlled by inherited faults, deep-penetrating joints and and the stratigraphic contact between brittle caprock overlying weaker rocks. Morphologically, the most prominent deformation is located in the upper part, which is dominated by toppling of flysch blocks with thick-bedded sandstone. The results of the trenching technique and geochronological analyses point to the episodic kinematics of this portion of the DSGSD, revealing a significant displacement event (ca. 9.9 ka) linked to a major climate change occurred after the Late Glacial/Holocene transition.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"470 ","pages":"Article 109545"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160136","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}

引用次数: 0

Evolution of fluvial systems in Eurasia at different time scales

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-01 DOI: 10.1016/j.geomorph.2024.109540

David Bridgland , Tobias Lauer , Martin Stokes

引用次数: 0

Bedload response to dam removal: Results from a 6-year particle tracking survey in the Leitzaran River (Basque Country)

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-01 DOI: 10.1016/j.geomorph.2024.109542

A. Ibisate , H. García , D. Vázquez-Tarrío , I. Sánchez-Pinto , X. Herrero , A. Sáenz de Olazagoitia , A. Ollero

Dams, weirs and transverse barriers to rivers interrupt sediment continuity and reduce sediment supply downstream. In this regard, dam removal is an increasingly used river restoration measure to recover longitudinal connectivity of sediment, among many other river processes. In this work we present a 6-year (from 2016 to 2022) monitoring of bedload transport before, during and after the removal of the 7-meters high Olloki dam in the Leitzaran River (Basque Country). The removal process started in 2018 with the upper 3 m and was completed in 2019 with the remaining 4 m of the dam. To monitor bedload transport, we seeded RFID-tagged stones in three reaches: a control reach unaffected by the dam, a reach immediately upstream of the dam, and a reach downstream of the dam. We deployed 300 tagged stones each year (100 by reach), i.e., 1800 in total. We measured important mobilization and displacement of tracer stones (with maximum travel distances of ∼8.8 km of tracers seeded upstream the Olloki dam) during an active hydrological year following the complete removal of the dam, with some tagged particles even travelling across a downstream weir. We also reported changes in the progression of tagged stones in the dam-affected reaches (upstream and downstream) with the removal, with further and faster dispersal of sediments once the dam was removed. In addition, in these reaches we estimated larger volumes of mobilized bedload in the three years following removal than in the previous years, especially in the upstream reach. In this regard, the relationship between bedload and cumulated energy suggests that less energy was expended in the upstream reach for mobilizing bedload once the removal of the dam was completed. Conversely, in the control reach no major changes were observed before and after the removal of the dam; this reach showed only an increase in sediment mobilization during the last hydrological year, which was the most hydrologically active of the whole monitoring period. In summary, our tracer observations document that travel distances and mobilization volumes are considerably increased with dam removal, especially once the dam was completely removed.

{"title":"Bedload response to dam removal: Results from a 6-year particle tracking survey in the Leitzaran River (Basque Country)","authors":"A. Ibisate , H. García , D. Vázquez-Tarrío , I. Sánchez-Pinto , X. Herrero , A. Sáenz de Olazagoitia , A. Ollero","doi":"10.1016/j.geomorph.2024.109542","DOIUrl":"10.1016/j.geomorph.2024.109542","url":null,"abstract":"<div><div>Dams, weirs and transverse barriers to rivers interrupt sediment continuity and reduce sediment supply downstream. In this regard, dam removal is an increasingly used river restoration measure to recover longitudinal connectivity of sediment, among many other river processes. In this work we present a 6-year (from 2016 to 2022) monitoring of bedload transport before, during and after the removal of the 7-meters high Olloki dam in the Leitzaran River (Basque Country). The removal process started in 2018 with the upper 3 m and was completed in 2019 with the remaining 4 m of the dam. To monitor bedload transport, we seeded RFID-tagged stones in three reaches: a control reach unaffected by the dam, a reach immediately upstream of the dam, and a reach downstream of the dam. We deployed 300 tagged stones each year (100 by reach), i.e., 1800 in total. We measured important mobilization and displacement of tracer stones (with maximum travel distances of ∼8.8 km of tracers seeded upstream the Olloki dam) during an active hydrological year following the complete removal of the dam, with some tagged particles even travelling across a downstream weir. We also reported changes in the progression of tagged stones in the dam-affected reaches (upstream and downstream) with the removal, with further and faster dispersal of sediments once the dam was removed. In addition, in these reaches we estimated larger volumes of mobilized bedload in the three years following removal than in the previous years, especially in the upstream reach. In this regard, the relationship between bedload and cumulated energy suggests that less energy was expended in the upstream reach for mobilizing bedload once the removal of the dam was completed. Conversely, in the control reach no major changes were observed before and after the removal of the dam; this reach showed only an increase in sediment mobilization during the last hydrological year, which was the most hydrologically active of the whole monitoring period. In summary, our tracer observations document that travel distances and mobilization volumes are considerably increased with dam removal, especially once the dam was completely removed.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"470 ","pages":"Article 109542"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143160137","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}

引用次数: 0

Lithological controls on chemical weathering signatures in the semi-arid climatic regime: Study based on tropical small scale catchments

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-01 DOI: 10.1016/j.geomorph.2024.109521

Ravi Kant Prasad , Naman Deep Singh , Sunil Kumar Singh , Vikrant Jain

Lithological controls on chemical weathering can be better constrained by studying catchments having different lithologic settings in similar climatic conditions. This study compares the weathering fluxes in two small catchments having different lithology in semi-arid region (500–800 mm year^-1 rainfall) in western India: The West Banas River (2100 km² area, 372 m relief) draining granitic/gneissic rocks and the Berach River (610 km² area; 542 m relief) flowing through shales. Sample collected in the year 2016 and 2017, were analysed for chemical composition to evaluate chemical weathering fluxes. Inverse model analysis and Soil and Water Assessment tool (SWAT) simulated runoff were combined to estimate the annual weathering fluxes. Total dissolved solids (TDS) in the West Banas ranged from 71 to 428 mgL⁻¹(avg. 227 mgL⁻¹), while the Berach River showed TDS of 190–712 mgL⁻¹(avg. 370 mgL⁻¹), with a few higher values due to anthropogenic sources. Silicate weathering rate (SilWR) is estimated as 7.7 ± 1.7 tons km⁻²y⁻¹ for the granitic West Banas catchment whereas 5.7 ± 1.2 tons km⁻²y⁻¹ for the shale lithology in the Berach River. The weathering susceptibility ratio of shale to granite is derived as 2:3. The weathering intensity is highly controlled by the susceptible minerals present in these rocks. The posteriori results of elemental ratios of the silicate endmember in shale lithology basin (Berach River) shows strong indication of incongruent weathering in the basin as a result of their constituting minerals has already gone through at least one cycle of chemical weathering during their formation. Saline-alkaline soils (SAS) contribute significantly to dissolved loads, especially in the Berach (38 ± 12 %), compared to the West Banas (26 ± 7 %). The cations derived from different lithologic sources have a dependency on the drainage basin area. However, other topographical factors showed minor control on chemical weathering.

{"title":"Lithological controls on chemical weathering signatures in the semi-arid climatic regime: Study based on tropical small scale catchments","authors":"Ravi Kant Prasad , Naman Deep Singh , Sunil Kumar Singh , Vikrant Jain","doi":"10.1016/j.geomorph.2024.109521","DOIUrl":"10.1016/j.geomorph.2024.109521","url":null,"abstract":"<div><div>Lithological controls on chemical weathering can be better constrained by studying catchments having different lithologic settings in similar climatic conditions. This study compares the weathering fluxes in two small catchments having different lithology in semi-arid region (500–800 mm year<sup>-1</sup> rainfall) in western India: The West Banas River (2100 km<sup>2</sup> area, 372 m relief) draining granitic/gneissic rocks and the Berach River (610 km<sup>2</sup> area; 542 m relief) flowing through shales. Sample collected in the year 2016 and 2017, were analysed for chemical composition to evaluate chemical weathering fluxes. Inverse model analysis and Soil and Water Assessment tool (SWAT) simulated runoff were combined to estimate the annual weathering fluxes. Total dissolved solids (TDS) in the West Banas ranged from 71 to 428 mgL<sup>−1</sup>(avg. 227 mgL<sup>−1</sup>), while the Berach River showed TDS of 190–712 mgL<sup>−1</sup>(avg. 370 mgL<sup>−1</sup>), with a few higher values due to anthropogenic sources. Silicate weathering rate (<em>Sil</em>WR) is estimated as 7.7 ± 1.7 tons km<sup>−2</sup>y<sup>−1</sup> for the granitic West Banas catchment whereas 5.7 ± 1.2 tons km<sup>−2</sup>y<sup>−1</sup> for the shale lithology in the Berach River. The weathering susceptibility ratio of shale to granite is derived as 2:3. The weathering intensity is highly controlled by the susceptible minerals present in these rocks. The posteriori results of elemental ratios of the silicate endmember in shale lithology basin (Berach River) shows strong indication of incongruent weathering in the basin as a result of their constituting minerals has already gone through at least one cycle of chemical weathering during their formation. Saline-alkaline soils (SAS) contribute significantly to dissolved loads, especially in the Berach (38 ± 12 %), compared to the West Banas (26 ± 7 %). The cations derived from different lithologic sources have a dependency on the drainage basin area. However, other topographical factors showed minor control on chemical weathering.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"470 ","pages":"Article 109521"},"PeriodicalIF":3.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159487","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}

引用次数: 0

Research on the failure mode and kinematics of high-steep rock slides based on video target tracking: A case study of Bijiashan rock fall in Wu Gorge in the Three Gorges Reservoir area, China

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-01-29 DOI: 10.1016/j.geomorph.2025.109638

Xuebing Wang , Yueping Yin , Zhihua Zhang , Luqi Wang , Bolin Huang

Analyzing the failure mode and kinematics of high-steep rockslides and rockfalls is crucial for a comprehensive understanding of their instability mechanisms. Existing methods for determining the failure mode and kinematics of rockfalls either rely on large-scale outdoor experiments or involve basic video analysis. This paper proposed a flexible method for analyzing the failure mode and kinematics of high-steep rockfalls based on video target tracking, which is applicable to videos shared on online media platforms. The Bijiashan rock fall (BRF) event that occurred in the Three Gorges Reservoir area (TGRA) in China on September 28, 2021, was selected as the study case. Through video target tracking and coordinate correction, the failure mode and kinematic characteristics during the collapse process of the BRF were obtained. The rock mass in source area was segmented into three zones, top, middle, and base. The failure mode was described as that the base rock mass underwent buckling and disintegration, resulting in the middle rock mass losing balance and sliding, ultimately leading the top rock mass to fall off. During the rock slide, the largest falling rock's mass was estimated to be 37.7 kt, with an impact velocity of 51.2 m/s and an impact kinetic energy of up to 49.4 × 10⁶ kJ. This study can serve as a reference for future research on understanding the failure mode and kinematics of high-steep rock slides using video target tracking tools.

{"title":"Research on the failure mode and kinematics of high-steep rock slides based on video target tracking: A case study of Bijiashan rock fall in Wu Gorge in the Three Gorges Reservoir area, China","authors":"Xuebing Wang , Yueping Yin , Zhihua Zhang , Luqi Wang , Bolin Huang","doi":"10.1016/j.geomorph.2025.109638","DOIUrl":"10.1016/j.geomorph.2025.109638","url":null,"abstract":"<div><div>Analyzing the failure mode and kinematics of high-steep rockslides and rockfalls is crucial for a comprehensive understanding of their instability mechanisms. Existing methods for determining the failure mode and kinematics of rockfalls either rely on large-scale outdoor experiments or involve basic video analysis. This paper proposed a flexible method for analyzing the failure mode and kinematics of high-steep rockfalls based on video target tracking, which is applicable to videos shared on online media platforms. The Bijiashan rock fall (BRF) event that occurred in the Three Gorges Reservoir area (TGRA) in China on September 28, 2021, was selected as the study case. Through video target tracking and coordinate correction, the failure mode and kinematic characteristics during the collapse process of the BRF were obtained. The rock mass in source area was segmented into three zones, top, middle, and base. The failure mode was described as that the base rock mass underwent buckling and disintegration, resulting in the middle rock mass losing balance and sliding, ultimately leading the top rock mass to fall off. During the rock slide, the largest falling rock's mass was estimated to be 37.7 kt, with an impact velocity of 51.2 m/s and an impact kinetic energy of up to 49.4 × 10<sup>6</sup> kJ. This study can serve as a reference for future research on understanding the failure mode and kinematics of high-steep rock slides using video target tracking tools.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"473 ","pages":"Article 109638"},"PeriodicalIF":3.1,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137874","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}

引用次数: 0

Reconstruction of aeolian sand processes at different scales utilizing the Scale-Independent Particle Tracking Velocimetry

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-01-29 DOI: 10.1016/j.geomorph.2025.109635

Kaiyuan Guan , Yang Zhang , Xu Han , Yuanwei Lin , Xin Gao , Bin Yang

The aeolian sand process, encompassing information from dune migration to sand grain movement, requires accurate measurement through appropriate methods. Particle Tracking Velocimetry (PTV) excels in kinematic analysis of isolated objects, yet opportunities for further improvement remain. This study introduces a scale-independent PTV algorithm (SI-PTV) that tracks feature points using the Voronoi Diagram (VD). The effectiveness of SI-PTV in kinematic analysis at three scales is confirmed through comparison with existing data. Considering that the aeolian process is not limited to inland arid areas but also occurs in coastal regions and on islands, and coral sand, which differs morphologically from quartz sand, has been under-researched in terms of its dynamic behavior, this paper studies the dynamic parameters of coral sand using SI-PTV. The result shows that coral sand has a higher kinetic energy restitution coefficient than quartz sand, along with a stable impact angle distribution, leading to predominantly positive collisions.

{"title":"Reconstruction of aeolian sand processes at different scales utilizing the Scale-Independent Particle Tracking Velocimetry","authors":"Kaiyuan Guan , Yang Zhang , Xu Han , Yuanwei Lin , Xin Gao , Bin Yang","doi":"10.1016/j.geomorph.2025.109635","DOIUrl":"10.1016/j.geomorph.2025.109635","url":null,"abstract":"<div><div>The aeolian sand process, encompassing information from dune migration to sand grain movement, requires accurate measurement through appropriate methods. Particle Tracking Velocimetry (PTV) excels in kinematic analysis of isolated objects, yet opportunities for further improvement remain. This study introduces a scale-independent PTV algorithm (SI-PTV) that tracks feature points using the Voronoi Diagram (VD). The effectiveness of SI-PTV in kinematic analysis at three scales is confirmed through comparison with existing data. Considering that the aeolian process is not limited to inland arid areas but also occurs in coastal regions and on islands, and coral sand, which differs morphologically from quartz sand, has been under-researched in terms of its dynamic behavior, this paper studies the dynamic parameters of coral sand using SI-PTV. The result shows that coral sand has a higher kinetic energy restitution coefficient than quartz sand, along with a stable impact angle distribution, leading to predominantly positive collisions.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"473 ","pages":"Article 109635"},"PeriodicalIF":3.1,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137963","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}

引用次数: 0

The large distribution of inverted stream channel terrains in the western Qaidam Basin, North Tibetan Plateau, and implications to the fluvial ridges on Mars

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-01-27 DOI: 10.1016/j.geomorph.2025.109632

Zi-Kang Li, Sheng-Hua Li, Yi-Liang Li

The fluvial ridge, an important landform that has been documented on both Earth and Mars over different geologic times, provides critical evidence of past hydrologic activity. However, the processes of deposition and subsequent erosion of terrestrial fluvial ridges are still largely unclear, and the study of these processes is essential to a better understanding of fluvial ridges on Mars. Here, we report 16 well-preserved regions of inverted stream channels (ISCs), a type of fluvial ridge, with different morphological features and settings, widely distributed in the western Qaidam Basin (QB). Optically stimulated luminescence (OSL) dating of the ISC sediments indicates that these channels were deposited during a cold and dry climatic period (MIS 6). Based on mapping, statistical, and geometric analyses of channel length and sinuosity, we propose a classification scheme that takes into account the architecture of the individual channels and the morphology of channel networks. Our results suggest that the formation of ISCs in the Qaidam Basin occurred during the warming phase following the onset of a cooling cycle, and that the subsequent inversion of ridges is primarily the result of wind and fluvial erosion under a hyperarid climate. The ISCs can also be compared to analogous counterparts on Mars, inverted channels or sinuous ridges, due to their morphological similarities, which could potentially shed light on the hydrological environments of early Mars.

{"title":"The large distribution of inverted stream channel terrains in the western Qaidam Basin, North Tibetan Plateau, and implications to the fluvial ridges on Mars","authors":"Zi-Kang Li, Sheng-Hua Li, Yi-Liang Li","doi":"10.1016/j.geomorph.2025.109632","DOIUrl":"10.1016/j.geomorph.2025.109632","url":null,"abstract":"<div><div>The fluvial ridge, an important landform that has been documented on both Earth and Mars over different geologic times, provides critical evidence of past hydrologic activity. However, the processes of deposition and subsequent erosion of terrestrial fluvial ridges are still largely unclear, and the study of these processes is essential to a better understanding of fluvial ridges on Mars. Here, we report 16 well-preserved regions of inverted stream channels (ISCs), a type of fluvial ridge, with different morphological features and settings, widely distributed in the western Qaidam Basin (QB). Optically stimulated luminescence (OSL) dating of the ISC sediments indicates that these channels were deposited during a cold and dry climatic period (MIS 6). Based on mapping, statistical, and geometric analyses of channel length and sinuosity, we propose a classification scheme that takes into account the architecture of the individual channels and the morphology of channel networks. Our results suggest that the formation of ISCs in the Qaidam Basin occurred during the warming phase following the onset of a cooling cycle, and that the subsequent inversion of ridges is primarily the result of wind and fluvial erosion under a hyperarid climate. The ISCs can also be compared to analogous counterparts on Mars, inverted channels or sinuous ridges, due to their morphological similarities, which could potentially shed light on the hydrological environments of early Mars.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"473 ","pages":"Article 109632"},"PeriodicalIF":3.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137964","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}

引用次数: 0

Alongshore runup variability across contrasting beach states: Insights from field observations

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-01-27 DOI: 10.1016/j.geomorph.2025.109640

Ashley David Gracia-Barrera , Amaia Ruiz de Alegría-Arzaburu , Giovanni Coco , Gonzalo Simarro , Daniel Calvete

Most beaches exhibit alongshore morphological variability, which is often overlooked in predictive empirical parameterizations of the runup. This study examines alongshore runup variations in relation to intertidal and subtidal morphology on an intermediate beach in the NW Pacific of Baja California. UAV imagery, combined with topographic and bathymetric measurements, was used to determine the runup elevation along a 500-m stretch of beach with diverse morphological characteristics: Terraces and Cross-shore Channels (TCC), Transverse Bar and Rip (TBR), Reflective conditions (R), and Reflective beaches with Multiple Channels (RMC). The largest runup variations were observed under intermediate conditions (TBR), where rip channels and transverse bars significantly influenced the runup. Distinct signatures associated with different morphologies were evident in the spectral shape of the swash, with well-developed rip channels promoting more incident swash unless wave breaking occurred at bars at the head of the rip. Swash showed alongshore variability ranging by a factor between 1.4 and 2.7, depending on the beach state. This factor can be much larger when evaluated over the incident and infragravity swash components. Such variability could not be explained by changes in beach slope alone. The setup, as the lower component of the runup, exhibited minimal alongshore change, with a coefficient of variation of <23 %. Wave runup, setup and swash observations were compared against various existing parameterizations. The results showed that the variability of incident swash is well captured by parameterizations based on foreshore slope and deep-water wave parameters. While predictions of infragravity swash improve when accounting for beach morphology, most of the alongshore variability remains unrepresented, particularly for milder slopes. This research highlights the influence of alongshore morphological variations on runup and underscores the necessity of incorporating these variations into parameterizations to enhance accuracy.

{"title":"Alongshore runup variability across contrasting beach states: Insights from field observations","authors":"Ashley David Gracia-Barrera , Amaia Ruiz de Alegría-Arzaburu , Giovanni Coco , Gonzalo Simarro , Daniel Calvete","doi":"10.1016/j.geomorph.2025.109640","DOIUrl":"10.1016/j.geomorph.2025.109640","url":null,"abstract":"<div><div>Most beaches exhibit alongshore morphological variability, which is often overlooked in predictive empirical parameterizations of the runup. This study examines alongshore runup variations in relation to intertidal and subtidal morphology on an intermediate beach in the NW Pacific of Baja California. UAV imagery, combined with topographic and bathymetric measurements, was used to determine the runup elevation along a 500-m stretch of beach with diverse morphological characteristics: Terraces and Cross-shore Channels (TCC), Transverse Bar and Rip (TBR), Reflective conditions (R), and Reflective beaches with Multiple Channels (RMC). The largest runup variations were observed under intermediate conditions (TBR), where rip channels and transverse bars significantly influenced the runup. Distinct signatures associated with different morphologies were evident in the spectral shape of the swash, with well-developed rip channels promoting more incident swash unless wave breaking occurred at bars at the head of the rip. Swash showed alongshore variability ranging by a factor between 1.4 and 2.7, depending on the beach state. This factor can be much larger when evaluated over the incident and infragravity swash components. Such variability could not be explained by changes in beach slope alone. The setup, as the lower component of the runup, exhibited minimal alongshore change, with a coefficient of variation of <23 %. Wave runup, setup and swash observations were compared against various existing parameterizations. The results showed that the variability of incident swash is well captured by parameterizations based on foreshore slope and deep-water wave parameters. While predictions of infragravity swash improve when accounting for beach morphology, most of the alongshore variability remains unrepresented, particularly for milder slopes. This research highlights the influence of alongshore morphological variations on runup and underscores the necessity of incorporating these variations into parameterizations to enhance accuracy.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"473 ","pages":"Article 109640"},"PeriodicalIF":3.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137873","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}

引用次数: 0

Terrain-driven circulation around megadune–lake system in China's Badain Jaran Sand Sea

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-01-27 DOI: 10.1016/j.geomorph.2025.109633

Ping Lü, Zhibao Dong, Tianjie Shao, Zhengcai Zhang, Fang Ma

China's Badain Jaran Sand Sea has the world's largest megadunes. However, hypothesized explanations of their formation are based on weak evidence. To clarify the formation and maintenance mechanisms for these dunes, it's necessary to describe this landform's circulation. In this study, we measured the wind regime around a magadune–lake system from 2019 to 2021 to comprehensively characterize the terrain - driven circulation primarily induced by the roughness - disturbance impact exerted by the megadunes. The circulation generally disperses outward from the lake's center, and wind speed gradually increased from the megadune's bottom to its top. During the daytime, strong winds rise along the megadune's slope; at night, the megadune produces mountain winds and land winds, with downward airflow from the top of the megadune towards the center of the lake, but with low frequency and low wind speed. This creates a resultant drift direction (RDD) that is consistent between day and night, with both RDD pointing towards the megadune's top. RDD changes little between seasons, and is consistent with the annual RDD (from the megadune's bottom to its top). Two factors drive the circulation: First, the dune's height represents a roughness element that creates a deep convective boundary layer that triggers a strong ascending flow. Second, the flow is driven by differences in the thermal properties between the lake and the sand particles. Our results suggest that the terrain-driven circulation around megadune–lake systems flows from the dune's bottom to its top and explains the characteristics of the world's largest megadunes. Our work provides an empirical basis for a more comprehensive understanding of the formation and maintenance of the megadune–lake system.

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引用次数: 0

Speleogenesis of Valdemino Cave (Borgio Verezzi, Liguria, Northern Italy) shows very slow uplift of this coast since Middle Pleistocene

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-01-27 DOI: 10.1016/j.geomorph.2025.109636

Jo De Waele , Chuan-Chou Shen , Bartolomeo Vigna , Adriano Fiorucci , Paola Marini , Chun-Yuan Huang , Hsun-Ming Hu

Valdemino show cave (Borgio Verezzi, Northern Italy) is located 600 m from the Ligurian coast. The cave, hosted in Triassic dolostones, is characterised by mixing corrosion morphologies and large collapses, some of which covered with thick speleothems, and lacks typical morphologies and sediments related to turbulent water flow. U/Th dating of speleothems allowed bracketing the timing of collapses, coastal mixing, and speleogenesis. The oldest speleothems indicate the first phases of speleogenesis to have occurred prior to ca. 600 thousand years ago (ka, before 1950 CE), whereas important calcite deposition occurred during both warmer and colder periods. Collapses repeatedly took place during cold stages, since at least 600 ka. Present drip waters are highly mineralised, causing speleothem growth and testifying to a long water-rock contact, despite the poor thickness (<10 m) of the rock above the cave. Speleogenesis is mainly related to coastal mixing corrosion which dissolved portions of the rock mass during various periods of the Middle- to Upper Pleistocene, and occurs still today in deeper parts of the cave. During cold stages, when the sea retreated and the water table lowered, loss of buoyancy caused cave rooms to collapse, creating the voids accessible today. The Valdemino cave system was positioned several times in the fresh-salt water mixing zone during different sea level highstands over the last 600 ka, the highest of which occurred during MIS 5e. This demonstrates that this coastal sector must have been subjected to a slow uplift since 600 ka, with rates of ca. 0.05 m/ka. Six-hundred thousand year old corroded speleothems, that were in the mixing zone during MIS 5e, are now found at +6 m above present mean sea level.

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引用次数: 0