Geomorphology最新文献

Response to sea-level change in a non-deltaic coastal plain: Insights from cores chronologies

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-18 DOI: 10.1016/j.geomorph.2025.109678

Yuexin Liu , Ziyuan Wu , Gui Long , Xinqi Feng , Ping Lai , Zibin Fang , Wenwen Wu , Jiewen Xu , Guanjun Xu , Hua Tu , Hongwei Li , Wen Wang , Zhongping Lai

The North coastal South China Sea (SCS) contains densely populated deltaic and non-deltaic plains. While recent dating has advanced knowledge on land-sea interactions in deltaic areas, chronological data for non-deltaic plains remain lacking, hindering a full understanding of coastal evolution. This study establishes the first chronological framework since late-Pleistocene for Longjiang plain, a non-deltaic coastal plain shaped by wind, ocean and fluvial forces. Using quartz Optically Stimulated Luminescence (OSL) and radiocarbon (¹⁴C) dating on two cores, combined with Bayesian age-depth modeling, we identified depositional hiatuses between >123 ± 8 ka and

{7.6}_{- 0.6}^{+ 0.7}

ka and between >72 ± 4 ka and ~

{5.1}_{- 0.9}^{+ 1.2}

ka, respectively. These hiatuses were attributed to intensive erosion during last glacial sea-level fall/low stands. Below the hiatuses are strongly weathered sediments. Post-hiatus aeolian deposition during

{7.6}_{- 0.6}^{+ 0.7}

ka–

{6.5}_{- 0.5}^{+ 0.7}

ka is linked to post-glacial sea-level rise. By contrast, aeolian deposition after

{2.14}_{- 0.48}^{+ 0.69}

ka successive to tidal deposition is likely triggered by local regression caused by increased sediment supply, favored by human activity since ~2.5 ka. Erosion during last glacial sea-level fall/low stands and aeolian deposition during the latest interglacial (Holocene) sea-level high stands, support the view that aeolian dunes preserved in modern coastal areas are mainly formed at sea-level high stands, rather than low stands. They also indicate that coastal erosion-accumulation cycles, controlled by eustatic sea-level fluctuation are not limited to deltas but may prevail in non-delta coasts. Quartz OSL sensitivity variations are observed in both cores and linked to provenance change, rework/redeposition by wind or Long-term chemical weathering.

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引用次数: 0

Spatial provenance distributions in the Chinese Loess Plateau and implication for reconstruction of desert margin

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-14 DOI: 10.1016/j.geomorph.2025.109663

Hanzhi Zhang, Yang Chen, Mengying Wu, Huayu Lu, Yao Gu, Jiang Wu

Reconstructing the spatial evolution of deserts is crucial to understand the forcing mechanisms of environment change in arid region and predicting the future behavior of deserts under global warming. The eolian deposits in the Chinese Loess Plateau (CLP) provide an unrivaled archive for reconstructing the evolutionary history of deserts. While the grain size of loess is traditionally employed as an indicator of desert expansion and contraction, it primarily reflects the dust source-to-sink distance. Since the dust source of the CLP includes multiple arid regions, it remains challenging to distinguish the specific processes of an individual desert based solely on grain size. In this work, we proposed a novel provenance-based model, which can quantitatively distinguish evolutionary process of a specific desert. This model is derived from a comprehensive analysis of the Last Glacial Maximum (LGM) across transects in the CLP, which reveals that the relative contributions from the Mu Us sand fields decreased exponentially with increasing distance from the desert. We demonstrate the robustness of this model through a test on grain-size and provenance data in Luochuan, middle CLP. Finally, we apply this model to reconstruct the temporal evolution at the desert margin (Zhenbeitai, ZBT) since ca. 110 ka, which demonstrates that the boundary of the Mu Us sand fields was located approximately 20–60 km away from the ZBT site at 110–80 ka, expanded to its modern boundary at around 60–16 ka, and retreated by roughly 20 km during the Holocene. The migration of the Mu Us sand fields were primarily controlled by regional precipitation changes. This suggests that adequate regional precipitation may stabilize sand fields under future climate scenarios.

{"title":"Spatial provenance distributions in the Chinese Loess Plateau and implication for reconstruction of desert margin","authors":"Hanzhi Zhang, Yang Chen, Mengying Wu, Huayu Lu, Yao Gu, Jiang Wu","doi":"10.1016/j.geomorph.2025.109663","DOIUrl":"10.1016/j.geomorph.2025.109663","url":null,"abstract":"<div><div>Reconstructing the spatial evolution of deserts is crucial to understand the forcing mechanisms of environment change in arid region and predicting the future behavior of deserts under global warming. The eolian deposits in the Chinese Loess Plateau (CLP) provide an unrivaled archive for reconstructing the evolutionary history of deserts. While the grain size of loess is traditionally employed as an indicator of desert expansion and contraction, it primarily reflects the dust source-to-sink distance. Since the dust source of the CLP includes multiple arid regions, it remains challenging to distinguish the specific processes of an individual desert based solely on grain size. In this work, we proposed a novel provenance-based model, which can quantitatively distinguish evolutionary process of a specific desert. This model is derived from a comprehensive analysis of the Last Glacial Maximum (LGM) across transects in the CLP, which reveals that the relative contributions from the Mu Us sand fields decreased exponentially with increasing distance from the desert. We demonstrate the robustness of this model through a test on grain-size and provenance data in Luochuan, middle CLP. Finally, we apply this model to reconstruct the temporal evolution at the desert margin (Zhenbeitai, ZBT) since ca. 110 ka, which demonstrates that the boundary of the Mu Us sand fields was located approximately 20–60 km away from the ZBT site at 110–80 ka, expanded to its modern boundary at around 60–16 ka, and retreated by roughly 20 km during the Holocene. The migration of the Mu Us sand fields were primarily controlled by regional precipitation changes. This suggests that adequate regional precipitation may stabilize sand fields under future climate scenarios.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109663"},"PeriodicalIF":3.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418922","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

Analysis of the fundamental differences between dam-forming landslides and all landslides

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109665

Hang Wu , Mark A. Trigg , William Murphy , Raul Fuentes

Dam-forming landslides are of significant interest to researchers, as only about 1 % of landslides block rivers, yet these dams can cause extreme flooding when they collapse, with flood flows up to ten times larger than extreme fluvial floods. While regional studies have noted differences in the dimensional characteristics and formation indices between dam-forming and non-dam-forming landslides, a global quantitative comparison has not yet been made. Using open-access global datasets, we conducted a statistical analysis of their morphometric and spatial characteristics, including volume, height/length ratio, and geomorphological factors. Spatial clustering analysis was also performed to determine whether certain landslides are more likely to form dams. The results indicate that dam-forming landslides are a distinct subset: (i) they occur in more upstream areas with higher stream power index values; (ii) they have lower mobility, confined by steeper slopes and shorter hillslope lengths; (iii) shallower landslides with larger surface area and sufficient volume are more likely to form dams; and (iv) they exhibit different spatial clustering patterns compared to general landslides. Despite some data limitations, this global study provides a foundation for quantifying a landslide dam formation index and identifying areas prone to dam formation.

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引用次数: 0

Rapid and large-scale landscape modification caused by the draining of a glacier-dammed lake in British Columbia, Canada

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109669

John J. Clague , Brendan Miller

River terraces are ubiquitous in the formerly glaciated valleys of British Columbia, where they are commonly interpreted as products of Holocene incision of paraglacial valley fills. In this paper, we describe and interpret terrace sequences on the former floor of glacial Lake Fraser, the largest Late Pleistocene glacier-dammed lake in British Columbia. Postglacial terraces up to 120 m above the present lower Nechako and Fraser River valley floors are the dominant landforms within the former lake basin. In this paper, we focus on the Nechako River terraces between Stuart River and Prince George, a distance of about 85 km. Our reconstruction and analysis are based on high-resolution lidar imagery and field investigation of sediments exposed beneath the terraces. The highest, unpaired terraces are mainly erosional landforms developed on glacial Lake Fraser glaciolacustrine sediments, but are ornamented with low biconvex flood bars and linear erosional channels. As water drained rapidly eastward out of the lake, thin flows of fluidized lacustrine silt and sand derived from adjacent valley walls were deposited on the highest terraces and flood dunes formed below the lowest paleo-lake shorelines. At the same time, huge amounts of sediment were stripped from the emergent valley walls by landslides and gullying. This large and rapid flux of sediment provided thick gravel and sand that underlie lower Nechako Valley terraces. The lowest terraces have meandering channel forms that are markedly different from the streamlined high terrace surfaces. About 200 kettles in six clusters on mid- and low-level terraces in Nechako Valley mark locations of ice blocks that calved from the stagnating front of the remnant Cordilleran Ice Sheet to the west and became stranded on the floor of glacial Lake Fraser. The distribution of the kettles shows that Nechako and, by inference, Fraser rivers were flowing within a few metres of their present levels within years to several decades after glacial Lake Fraser drained, which challenges the common assumption implicit in the paraglacial model that the terraces developed more slowly throughout the Holocene.

{"title":"Rapid and large-scale landscape modification caused by the draining of a glacier-dammed lake in British Columbia, Canada","authors":"John J. Clague , Brendan Miller","doi":"10.1016/j.geomorph.2025.109669","DOIUrl":"10.1016/j.geomorph.2025.109669","url":null,"abstract":"<div><div>River terraces are ubiquitous in the formerly glaciated valleys of British Columbia, where they are commonly interpreted as products of Holocene incision of paraglacial valley fills. In this paper, we describe and interpret terrace sequences on the former floor of glacial Lake Fraser, the largest Late Pleistocene glacier-dammed lake in British Columbia. Postglacial terraces up to 120 m above the present lower Nechako and Fraser River valley floors are the dominant landforms within the former lake basin. In this paper, we focus on the Nechako River terraces between Stuart River and Prince George, a distance of about 85 km. Our reconstruction and analysis are based on high-resolution lidar imagery and field investigation of sediments exposed beneath the terraces. The highest, unpaired terraces are mainly erosional landforms developed on glacial Lake Fraser glaciolacustrine sediments, but are ornamented with low biconvex flood bars and linear erosional channels. As water drained rapidly eastward out of the lake, thin flows of fluidized lacustrine silt and sand derived from adjacent valley walls were deposited on the highest terraces and flood dunes formed below the lowest paleo-lake shorelines. At the same time, huge amounts of sediment were stripped from the emergent valley walls by landslides and gullying. This large and rapid flux of sediment provided thick gravel and sand that underlie lower Nechako Valley terraces. The lowest terraces have meandering channel forms that are markedly different from the streamlined high terrace surfaces. About 200 kettles in six clusters on mid- and low-level terraces in Nechako Valley mark locations of ice blocks that calved from the stagnating front of the remnant Cordilleran Ice Sheet to the west and became stranded on the floor of glacial Lake Fraser. The distribution of the kettles shows that Nechako and, by inference, Fraser rivers were flowing within a few metres of their present levels within years to several decades after glacial Lake Fraser drained, which challenges the common assumption implicit in the paraglacial model that the terraces developed more slowly throughout the Holocene.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109669"},"PeriodicalIF":3.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418805","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

Almost eroded but still there: Oldest diatreme volcanoes of pre-Quaternary age in the eastern Bohemian Massif, Czechia

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109668

Martin Kašing , Jakub Jirásek , Dalibor Matýsek , Jan Valenta , Vladislav Rapprich , Petr Tábořík , Tomáš Pek

Young volcanic forms are often well pronounced in topography and preserve valuable geological record of paleoenvironmental evolution. However, in ancient volcanic fields (Ma old), some volcanic landforms may exist only as erosional remnants that are completely transformed by long-term denudation. The identification of such structures is challenging owing to their small size and subtle geomorphic signature. Earlier magnetic surveys from the 1960s identified a minor volcanic form of unclear origin at a site within the Bruntál Volcanic Field, a Late Cenozoic intraplate volcanic province in Central Europe (Czechia). Newly conducted high-resolution magnetic, gravity, and geoelectrical surveys of the site revealed remnants of two deeply eroded diatremes and their feeder dykes. Analysis of the collected samples and excavated material from shallow trenches supports the phreatomagmatic origin of these structures. The two analogous circular diatremes, separated by a distance of 750 m, exhibit pronounced magnetic and conductive responses. Their small diameters (<100 m), coupled with minor negative gravity anomalies and the presence of excavated diatreme breccias, suggest the exposure of a deep part of the diatremes, e.g. root-zones, at the current erosional surface. The material buried in the diatremes also allows for the deduction of the previous extent of concurrently eroded Neogene sediments in the area. Despite unsuccessful attempts at Ar–Ar dating, the Neogene age assumed based on the deep erosional level of the volcanic vents makes them the oldest known maar-diatreme volcanoes in the eastern Bohemian Massif. This study provides very rare information about explosive volcanism in the area of northeastern margin of the Bohemian Massif and is the first-ever study on regional pre-Quaternary phreatomagmatism in the Bruntál Volcanic Field.

{"title":"Almost eroded but still there: Oldest diatreme volcanoes of pre-Quaternary age in the eastern Bohemian Massif, Czechia","authors":"Martin Kašing , Jakub Jirásek , Dalibor Matýsek , Jan Valenta , Vladislav Rapprich , Petr Tábořík , Tomáš Pek","doi":"10.1016/j.geomorph.2025.109668","DOIUrl":"10.1016/j.geomorph.2025.109668","url":null,"abstract":"<div><div>Young volcanic forms are often well pronounced in topography and preserve valuable geological record of paleoenvironmental evolution. However, in ancient volcanic fields (Ma old), some volcanic landforms may exist only as erosional remnants that are completely transformed by long-term denudation. The identification of such structures is challenging owing to their small size and subtle geomorphic signature. Earlier magnetic surveys from the 1960s identified a minor volcanic form of unclear origin at a site within the Bruntál Volcanic Field, a Late Cenozoic intraplate volcanic province in Central Europe (Czechia). Newly conducted high-resolution magnetic, gravity, and geoelectrical surveys of the site revealed remnants of two deeply eroded diatremes and their feeder dykes. Analysis of the collected samples and excavated material from shallow trenches supports the phreatomagmatic origin of these structures. The two analogous circular diatremes, separated by a distance of 750 m, exhibit pronounced magnetic and conductive responses. Their small diameters (<100 m), coupled with minor negative gravity anomalies and the presence of excavated diatreme breccias, suggest the exposure of a deep part of the diatremes, e.g. root-zones, at the current erosional surface. The material buried in the diatremes also allows for the deduction of the previous extent of concurrently eroded Neogene sediments in the area. Despite unsuccessful attempts at Ar–Ar dating, the Neogene age assumed based on the deep erosional level of the volcanic vents makes them the oldest known maar-diatreme volcanoes in the eastern Bohemian Massif. This study provides very rare information about explosive volcanism in the area of northeastern margin of the Bohemian Massif and is the first-ever study on regional pre-Quaternary phreatomagmatism in the Bruntál Volcanic Field.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109668"},"PeriodicalIF":3.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418919","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

Reconstructing past sea-level changes from storm-built beach ridges

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109659

Alessio Rovere , Marta Pappalardo , Sebastian Richiano , Deirdre D. Ryan , Karla Rubio-Sandoval , Patricio Martin Ruiz , Alejandro Montes , Evan J. Gowan

Storm-built beach ridges, built by waves on sedimentary coasts, can be used as geomorphological indicators of past sea level. However, quantifying the relationship between the geomorphological elements of the ridge and the paleo sea level at the time of deposition is difficult, as a beach ridge is primarily correlated to wave energy and only secondarily to the position of sea level. In this work, we propose a methodology to quantify the upper and lower limits of a storm-built beach ridge based on remote sensing data. We use the tidal model FES2022, data from the Copernicus Marine Service and beach slope gathered from satellite imagery as inputs to different wave runup models, that are used to calculate the limits of the storm-built beach ridge. We test our approach on a particularly well-preserved Pleistocene storm-built beach ridge in Patagonia, Argentina. Our results show that the paleo relative sea level reconstructed using remote sensing data coincides (82.8 % similarity) with that obtained from measured modern analog landforms at the same location.

{"title":"Reconstructing past sea-level changes from storm-built beach ridges","authors":"Alessio Rovere , Marta Pappalardo , Sebastian Richiano , Deirdre D. Ryan , Karla Rubio-Sandoval , Patricio Martin Ruiz , Alejandro Montes , Evan J. Gowan","doi":"10.1016/j.geomorph.2025.109659","DOIUrl":"10.1016/j.geomorph.2025.109659","url":null,"abstract":"<div><div>Storm-built beach ridges, built by waves on sedimentary coasts, can be used as geomorphological indicators of past sea level. However, quantifying the relationship between the geomorphological elements of the ridge and the paleo sea level at the time of deposition is difficult, as a beach ridge is primarily correlated to wave energy and only secondarily to the position of sea level. In this work, we propose a methodology to quantify the upper and lower limits of a storm-built beach ridge based on remote sensing data. We use the tidal model FES2022, data from the Copernicus Marine Service and beach slope gathered from satellite imagery as inputs to different wave runup models, that are used to calculate the limits of the storm-built beach ridge. We test our approach on a particularly well-preserved Pleistocene storm-built beach ridge in Patagonia, Argentina. Our results show that the paleo relative sea level reconstructed using remote sensing data coincides (82.8 % similarity) with that obtained from measured modern analog landforms at the same location.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"476 ","pages":"Article 109659"},"PeriodicalIF":3.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438095","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

Spatial Clustering and distribution characteristics of large landslides in the Yalong River Basin, China 中国雅砻江流域大型滑坡的空间集聚与分布特征

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109667

Chengqiu Li, Jing Zhang, Lichan Gao, Xiaoli Chen, Siyuan Ma, Renmao Yuan

The Yalong River Basin (YRB), situated on the eastern margin of the Tibetan Plateau, is characterized by high vertical erosion rates, rugged terrain, narrow gorges, and steep hill slopes, which host many large landslides. Analyze the distribution characteristics of landslides in this region is significant for understanding geomorphic evolution and assessing potential landslide risks. In the current study, a landslide database for the Yalong River was initially established based on remote sensing interpretation and field investigation. A total of 729 landslides were mapped, including 191 medium-scale and 538 large-scale landslides. According to the updated Varnes classification, 538 large landslides (73.8 %) were recognized and divided into four major types: slides (344 cases), flows (109 cases), topples (56 cases), and slope deformations (29 cases). The total area of these landslides was 886.2 km², and they were predominantly concentrated in the alpine canyon areas along the middle segment of the Yalong River. Based on integrated kernel density estimation and spatial autocorrelation, three landslide cluster zones (A, B, and C) were identified, with zone B showing the highest concentration of large landslides. Statistical results indicate that large landslides are concentrated in areas with elevations of 1500–3500 m, slopes of 20°–40°, topographic reliefs of 400–600 m, and dominant aspects being E, SE and SW. Active faults in the YRB play a crucial role in the formation and spatial distribution of landslides, showing a notable correlation with fault geometry, arrangement, and movement types.

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引用次数: 0

Investigating changes in proglacial stream suspended sediment concentration and their drivers using large scale remote sensing

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109664

Lily K. Vowels , William H. Armstrong , Irina Overeem , Daniel McGrath , Brianna Rick , Adrian Dye , Derek Martin

Glaciers are prolific sediment producers, and quantifying trends in proglacial suspended sediment concentration (SSC) is critical for understanding the evolution of sediment dynamics in glacierized systems, a task impeded by sparse in situ observations in these often-remote environments. In this study, we use Landsat-derived spectral reflectance to quantify how SSC changed between 1984 and 2023 across a range of proglacial river systems (n = 54) in Alaska and northwestern Canada. We investigated how observed SSC changes were related to upstream proglacial lakes, as well as glaciological factors. We found that 54 % of all study sites underwent statistically significant SSC changes (median rate of statistically significant change = −1.8 mg L⁻¹ yr⁻¹ or − 0.7 % yr⁻¹; IQR = −8.4 to 0.5 mg L⁻¹ yr⁻¹). Streams below proglacial lakes are more likely to have significant changes than systems without lakes (60 % of sites with upstream lakes vs 42 % of sites without upstream lakes). SSC declines dominate statistically significant trends for sites with upstream lakes, while increasing SSC is dominant for rivers with no upstream proglacial lake. We perform statistical analyses to investigate potential physical drivers of SSC change and find a direct association between glacier area and a site's median SSC as one of the few significant correlations. Proglacial lake area and its change are poor predictors for both downstream median SSC and SSC change. Together, these findings show clear changes in sediment dynamics in glacierized watersheds over ~40 years, with proglacial lakes playing a notable but complicated role in downstream sedimentary processes.

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引用次数: 0

How is the occurrence of rainfall-triggered landslides related to extreme rainfall?

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-13 DOI: 10.1016/j.geomorph.2025.109666

Binru Zhao , Lulu Zhang , Xia Gu , Wen Luo , Zhaoyuan Yu , Linwang Yuan

In a warming climate, more frequent occurrences of extreme rainfall may increase the risk of landslides due to the triggering and preconditioning effects of rainfall conditions on landslides. However, the relationship between rainfall-triggered landslides and extreme rainfall has rarely been quantified. Here, by making full use of rich landslide records and dense rainfall measurements in the Liguria region, Bayesian analysis was applied to calculate the conditional probability of landslide occurrences under extreme and non-extreme rainfall. By considering the impact of the antecedent cumulative rainfall responsible for landslide occurrences and the threshold for determining extreme rainfall, it is found that extreme rainfall has a higher probability of triggering landslides than non-extreme rainfall, up to 33 times in the Liguria region, but this is still an underestimate when the impact of missing landslide records is taken into account. This indicates that extreme rainfall plays a much more significant role in triggering landslides than non-extreme rainfall. The satellite-based and reanalysis rainfall datasets are great alternatives to rain gauge data for areas with insufficient rainfall measurements for this analysis, although both underestimate the ratio of landslide probability under extreme rainfall to non-extreme rainfall.

{"title":"How is the occurrence of rainfall-triggered landslides related to extreme rainfall?","authors":"Binru Zhao , Lulu Zhang , Xia Gu , Wen Luo , Zhaoyuan Yu , Linwang Yuan","doi":"10.1016/j.geomorph.2025.109666","DOIUrl":"10.1016/j.geomorph.2025.109666","url":null,"abstract":"<div><div>In a warming climate, more frequent occurrences of extreme rainfall may increase the risk of landslides due to the triggering and preconditioning effects of rainfall conditions on landslides. However, the relationship between rainfall-triggered landslides and extreme rainfall has rarely been quantified. Here, by making full use of rich landslide records and dense rainfall measurements in the Liguria region, Bayesian analysis was applied to calculate the conditional probability of landslide occurrences under extreme and non-extreme rainfall. By considering the impact of the antecedent cumulative rainfall responsible for landslide occurrences and the threshold for determining extreme rainfall, it is found that extreme rainfall has a higher probability of triggering landslides than non-extreme rainfall, up to 33 times in the Liguria region, but this is still an underestimate when the impact of missing landslide records is taken into account. This indicates that extreme rainfall plays a much more significant role in triggering landslides than non-extreme rainfall. The satellite-based and reanalysis rainfall datasets are great alternatives to rain gauge data for areas with insufficient rainfall measurements for this analysis, although both underestimate the ratio of landslide probability under extreme rainfall to non-extreme rainfall.</div></div>","PeriodicalId":55115,"journal":{"name":"Geomorphology","volume":"475 ","pages":"Article 109666"},"PeriodicalIF":3.1,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418921","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

Nonlinear modeling of river dunes: Insights in long-term evolution of dune dimensions and form roughness

IF 3.1 2区地球科学 Q2 GEOGRAPHY, PHYSICAL

Geomorphology

Pub Date : 2025-02-12 DOI: 10.1016/j.geomorph.2025.109649

W.M. van der Sande , P.C. Roos , T. Gerkema , S.J.M.H. Hulscher

River dunes are large-scale (primary) bed patterns commonly occurring worldwide. Capturing these features in process-based morphodynamic models is challenging, partly because of steep gradients at the lee side of the bedform. Here, we present a new morphodynamic model with a hydrodynamic module (solved within OpenFOAM) that is capable of capturing lee side effects such as flow separation, and with a sediment transport formulation that suppresses steep lee slopes. Model results suggest that river dunes develop as free instabilities of the flat bed, characterized by initial exponential growth. After the initial phase, dunes reach a quasi-equilibrium, with the wavenumber of the dominant topographic mode decreasing over time; this holds for a range of parameter settings. Furthermore, we show that the spatially averaged water depth – a proxy for roughness – increases with about 3–5 %; the effective roughness length increases with about 50–100 %.

引用次数: 0