Journal of Geophysical Research: Earth Surface最新文献_第7页

The Role of Talus Pile Mobility in Valley Widening Processes and the Development of Wide Bedrock Valleys, Buffalo River, AR 距石桩流动性在山谷拓宽过程和宽基岩山谷发育中的作用，阿肯色州布法罗河

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-08-10 DOI: 10.1029/2023JF007612

O. H. Groeber, A. L. Langston

{"title":"The Role of Talus Pile Mobility in Valley Widening Processes and the Development of Wide Bedrock Valleys, Buffalo River, AR","authors":"O. H. Groeber, A. L. Langston","doi":"10.1029/2023JF007612","DOIUrl":"10.1029/2023JF007612","url":null,"abstract":"Valley width is largely controlled by lithology and upstream drainage area, but little work has focused on identifying the processes through which valleys widen. Bedrock valleys widen by first laterally eroding bedrock valley walls, followed by the collapse of overlying bedrock material that must then be transported away from the valley wall before the valley can continue widening. We hypothesize that talus piles that cannot be transported by the river protect the valley wall and slow valley widening, while talus piles that are rapidly transported allow for uninterrupted valley widening. We used field measurements from 40 locations in both wide and narrow valleys along the Buffalo River, AR to test this hypothesis. Our data show that wide valleys tend to have fewer talus piles and smaller talus grain sizes, whereas talus in narrow valleys is larger in size and more continuous along valley walls. We calculated potential talus block entrainment at each site location and found that talus blocks in wide valleys are potentially entrained and moved away from valley walls during moderate and large flood events, whereas talus blocks in narrow valleys are very rarely moved. Our results show that the potential transport of talus piles protecting bedrock valley walls from widening is controlled by the block size of collapsed bedrock wall material relative to stream competency. Our results also suggest that persistence versus mobility of collapsed talus piles is an important process in the development of wide bedrock valleys.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JF007612","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939516","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

Rates of Evacuation of Bedload Sediment From an Alpine Glacier Control Proglacial Stream Morphodynamics 阿尔卑斯冰川床载沉积物的蒸发率控制冰川溪流形态动力学

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-08-10 DOI: 10.1029/2024JF007727

D. Mancini, M. Roncoroni, M. Dietze, M. Jenkin, T. Müller, B. Ouvry, F. Miesen, Q. Pythoud, M. Hofmann, F. Lardet, A. P. Nicholas, S. N. Lane

{"title":"Rates of Evacuation of Bedload Sediment From an Alpine Glacier Control Proglacial Stream Morphodynamics","authors":"D. Mancini, M. Roncoroni, M. Dietze, M. Jenkin, T. Müller, B. Ouvry, F. Miesen, Q. Pythoud, M. Hofmann, F. Lardet, A. P. Nicholas, S. N. Lane","doi":"10.1029/2024JF007727","DOIUrl":"10.1029/2024JF007727","url":null,"abstract":"Proglacial forefields commonly include highly dynamic fluvial systems associated with the fundamental instability between topography, flow hydraulics and sediment transport. However, there is limited knowledge of how these systems respond to changing subglacial hydrology and sediment supply. We investigated this relationship using the first continuous field-collected data sets for both suspended and bedload sediment export and proglacial river dynamics for an Alpine glacier forefield, the Glacier d’Otemma, Switzerland. The results show a strong sensitivity of fluvial morphodynamics to the balance between sediment transport capacity and supply. When subglacial bedload export rates exceeded fluvial transport capacity, we found bar construction leading to net forefield aggradation and surficial coarsening, especially on bar heads. This intensified braiding buffered the downstream transport of coarse sediment. When subglacial bedload export rates were lower than transport capacity, incision occurred, with reduced braiding intensity, net erosion and important amounts of bedload leaving the proglacial system. We found a net fining of surficial deposits except for very isolated coarsening patterns on bar heads. Thus, proglacial forefield morphodynamics are strongly conditioned by subglacial hydrology and sediment supply, but this conditioning is also influenced by the response of the forefield itself. Proglacial forefields have an important influence on the longitudinal connectivity of sediment flux in regions sensitive to climate change, such as recently deglaciated high mountain areas. The linkages we report between subglacial processes and river morphodynamics are critical for understanding the development of embryonic forefield ecosystems.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007727","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939515","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

Simulated Slidequakes: Insights From DEM Simulations Into the High-Frequency Seismic Signal Generated by Geophysical Granular Flows 模拟滑动地震：从 DEM 模拟中洞察地球物理颗粒流产生的高频地震信号

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-08-09 DOI: 10.1029/2023JF007455

M. I. Arran, A. Mangeney, J. De Rosny, R. Toussaint

{"title":"Simulated Slidequakes: Insights From DEM Simulations Into the High-Frequency Seismic Signal Generated by Geophysical Granular Flows","authors":"M. I. Arran, A. Mangeney, J. De Rosny, R. Toussaint","doi":"10.1029/2023JF007455","DOIUrl":"https://doi.org/10.1029/2023JF007455","url":null,"abstract":"Geophysical granular flows generate seismic signals known as “slidequakes” or “landquakes”, with low-frequency components whose generation by mean forces is widely used to infer hazard-relevant flow properties. Many more such properties could be inferred by understanding the fluctuating forces that generate slidequakes' higher frequency components and, to do so, we conducted discrete-element simulations that examined the fluctuating forces exerted by steady, downslope-periodic granular flows on fixed, rough bases. Unlike our previous laboratory experiments, our simulations precluded basal slip. We show that, in its absence, simulated basal forces' power spectra have high-frequency components more accurately predicted using mean shear rates than using depth-averaged flow velocities, and can have intermediate-frequency components which we relate to chains of prolonged interparticle contacts. We develop a “minimal model”, which uses a flow's collisional properties to even more accurately predict the high-frequency components, and empirically parametrize this model in terms of mean flow properties, for practical application. Finally, we demonstrate that the bulk inertial number determines not only the magnitude ratio of rapidly fluctuating and mean forces on a unit basal area, consistent with previous experimental results, but also the relative magnitudes of the high and intermediate-frequency force components.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JF007455","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141967177","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

The Influence of Coral Reef Spur and Groove Morphology on Wave Energy Dissipation in Contrasting Reef Environments 珊瑚礁棘刺和沟槽形态对不同珊瑚礁环境中波浪能量消耗的影响

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-08-08 DOI: 10.1029/2023JF007424

Lachlan Perris, Tristan Salles, Thomas E. Fellowes, Stephanie Duce, Jody Webster, Ana Vila-Concejo

{"title":"The Influence of Coral Reef Spur and Groove Morphology on Wave Energy Dissipation in Contrasting Reef Environments","authors":"Lachlan Perris, Tristan Salles, Thomas E. Fellowes, Stephanie Duce, Jody Webster, Ana Vila-Concejo","doi":"10.1029/2023JF007424","DOIUrl":"10.1029/2023JF007424","url":null,"abstract":"Coral reefs protect coastlines from inundation and flooding and serve over 200 million people globally. Wave transformation has previously been studied on coral reef flats with limited focus on forereef zones where wave transformation is greatest during high-energy conditions. This study investigates the role of forereef spur and groove (SaG) morphology in wave energy dissipation and transmission at the reef crest. Using XBeach on LiDAR-derived bathymetry from One Tree Island in the southern Great Barrier Reef, we reproduced dissipation rates comparable to SaG field studies. We examined how wave energy dissipation differs between realistic bathymetry and those with SaG features removed, demonstrating an up to 40% decrease in dissipation when SaG features are absent. We then investigated changes to wave energy dissipation and wave transmission at the reef crest based on IPCC AR5 emission scenarios (RCP2.6 and RCP8.5) and a total disaster scenario (TD) for the year 2100. For RCP2.6, an increase in wave heights of 0.8 m and an increase in water level of 0.3 m resulted in a two-fold increase in dissipation rates. For RCP8.5 and TD, with no increase in incident wave height, dissipation rates were 29% and 395% lower than RCP2.6. This resulted in increased wave transmission at the reef crest by 1.8 and 2.7 m for the RCP8.5- and TD based models, respectively, when compared to the RCP2.6-based model. The results from our novel modeling approach of using long-shore varying accurate bathymetry on forereefs show increased wave energy dissipation rates with implications for reducing coastal flooding and island inundation on reef-lined coasts.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2023JF007424","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939517","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

Estimating Grain Stress and Distinguishing Between Mobility and Transportability Improves Bedload Transport Estimates in Coarse-Bedded Mountain Rivers 估算颗粒应力并区分流动性和可迁移性可改进山区粗河床床面负荷迁移估算结果

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-08-07 DOI: 10.1029/2024JF007662

Jordan Gilbert, Andrew C. Wilcox

{"title":"Estimating Grain Stress and Distinguishing Between Mobility and Transportability Improves Bedload Transport Estimates in Coarse-Bedded Mountain Rivers","authors":"Jordan Gilbert, Andrew C. Wilcox","doi":"10.1029/2024JF007662","DOIUrl":"10.1029/2024JF007662","url":null,"abstract":"Estimating sediment transport in mountain rivers is challenging because of sediment supply limitation, broad grain size distributions, complex flow hydraulics, and large form drag. Consequently, sediment transport equations are lacking for application in rivers where the bed is coarse and largely immobile, but small fractions of finer, transportable sized material contribute disproportionately to bedload transport. We introduce a framework for estimating sediment transport in mountain rivers that addresses two limitations: estimating the shear stress acting on mobile grains, and accounting for the difference between mobility of size fractions, that is, whether or not a specific grain size can move at a given flow, and transportability, which we define as how much of that size present in the bed will be recruited into transport. We use two bedload data sets to develop equations for predicting incipient motion and transport rates of each grain size fraction present in the bed. We tested the new equations against incipient motion and sediment transport data we collected from streams in the Rocky Mountains, USA, and against published regional sediment yield data. Using this method results in transport estimates where the finer fractions, despite being a small fraction of the bed surface, make up a large part of the total yield. Fractions greater than the median bed grain size are mobile only during peak flood flows, consistent with the existing mountain river bedload data sets. The approach is parsimonious, requiring only data that are often readily available or obtainable: a bed grain size distribution, hydraulic geometry measurements, and discharge.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141939518","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

Traveling or Jiggling: Particle Motion Modes and Their Relative Contribution to Bed-Load Variables 行进还是抖动：粒子运动模式及其对床载荷变量的相对贡献

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-08-03 DOI: 10.1029/2024JF007637

Daniel Rebai, Alessio Radice, Francesco Ballio

{"title":"Traveling or Jiggling: Particle Motion Modes and Their Relative Contribution to Bed-Load Variables","authors":"Daniel Rebai, Alessio Radice, Francesco Ballio","doi":"10.1029/2024JF007637","DOIUrl":"10.1029/2024JF007637","url":null,"abstract":"The motion state of a particle is a crucial aspect of sediment transport problems. In this paper, we conceptualized three states: stillness, “transport”, and “non-transport”, considering that not all the particle motions contribute significantly to the mean sediment transport rate. Starting from a data set of bed-load particle tracks obtained from particle tracking velocimetry, we removed the bias from experimental uncertainty and applied one-dimensional, instantaneous, and non-parametric criteria for distinguishing the states. We described the kinematics of particles in transport and non-transport states, presenting some sample trajectories and the distributions of particle velocity and acceleration. While the transport state presents a clear distinction between stream-wise and transverse particle velocity, the non-transport state is related to isotropic particle jiggling, and does not significantly contribute to the bed-load rate. Vice-versa, the particle motions in the non-transport state are relevant for other summary indicators of the transport process, such as the mean number of moving particles and mean particle velocity. We discuss how applying the proposed non-parametric criterion for state separation is beneficial compared to parameter-dependent alternatives available in the literature. Finally, we provide an outlook on possible applications of our concept for the investigation of other sediment transport processes (incipient motion, solid-fluid interface, creeping flow).","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007637","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141886091","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

Editorial to the Special Collection “Controls and Biasing Factors in Sediment Generation, Routing, and Provenance: Models, Methods, and Case Studies” 编辑专集 "沉积物生成、路径和来源中的控制和偏差因素：模型、方法和案例研究

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-07-30 DOI: 10.1029/2024JF007874

Laura Stutenbecker, Chris Mark, Alberto Resentini

{"title":"Editorial to the Special Collection “Controls and Biasing Factors in Sediment Generation, Routing, and Provenance: Models, Methods, and Case Studies”","authors":"Laura Stutenbecker, Chris Mark, Alberto Resentini","doi":"10.1029/2024JF007874","DOIUrl":"10.1029/2024JF007874","url":null,"abstract":"Clastic sediment composition constitutes a key archive of Earth history, controlled by allogenic and autogenic processes that impact weathering, erosion, sediment transfer, and deposition. Deciphering those processes can provide valuable insights into ancient and modern tectonic, geomorphic, climatic, and anthropogenic controls that shape sediment routing systems over a wide range of temporal and spatial scales. However, in order to clearly identify the controls on sediment composition, it is necessary to exclude sources of bias that may mask or diminish the original provenance signal. Such biases may be natural, including mineral fertility, sediment recycling, and grain size, or analytical. This special collection arises from the fifth meeting of the working group on sediment generation held at the University Milano-Bicocca in Milan, Italy, from 28 to 30 June 2022. The collation includes studies that investigate biasing factors affecting all steps of the sediment cascade and all stages of sample collection, preparation, and analysis, as well as case studies that aim to disentangle original provenance signals from geological, environmental, or analytical noise.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JF007874","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867840","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

Geochemical and Radiogenic Sr-Nd Isotope Characterization of Widespread Sandy Surface Sediments in the Great Indian Desert, Thar: Implications for Provenance Studies 塔尔印度大沙漠大范围沙质表层沉积物的地球化学和放射性 Sr-Nd 同位素特征：对产地研究的启示

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-07-30 DOI: 10.1029/2023JF007625

Rohan Bhattacharyya, Satinder Pal Singh, Abul Qasim, Azad Kashyap Chandrashekhar

{"title":"Geochemical and Radiogenic Sr-Nd Isotope Characterization of Widespread Sandy Surface Sediments in the Great Indian Desert, Thar: Implications for Provenance Studies","authors":"Rohan Bhattacharyya, Satinder Pal Singh, Abul Qasim, Azad Kashyap Chandrashekhar","doi":"10.1029/2023JF007625","DOIUrl":"10.1029/2023JF007625","url":null,"abstract":"Understanding large desert formation/evolution contributing to regional-to-global dust cycles remains a challenge. This study presents the geochemical and Sr-Nd isotope compositions of 51 surface sediment samples collected from the widespread hyper-arid Thar Desert in northwestern India. The major objective is to determine sediment provenance for a better understanding of the formation/evolution mechanism of this Great Indian Desert as well as downwind dust contributions toward the Himalayas. The compositionally immature sandy Thar sediments (CIA ∼50 ± 4, WIP ∼49 ± 12, and EuN/Eu* ∼0.80 ± 0.13) are recycled materials derived from the Himalayan orogen and later modified by quartz addition and heavy mineral depletion/sorting processes. The 87Sr/86Sr (0.7259 ± 0.0012 and εNd (−12.5 ± 2.7) in the bulk of these Thar sediments are different from the earlier published compositions of the eolian sand deposits in northwestern India. The subcategories of Thar materials collected from different dune types exposed over different lithologies (Quaternary alluvium vs. Tertiary and Mesozoic sedimentary formations) are geochemically and isotopically indistinguishable, which indicates their cogenetic sources and/or sediment reworking. Thar sediments collected in this study have a predominant Indus origin along with significant contributions from the upwind Ghaggar-Hakra paleochannels. The Indus sediments are most likely wind-eroded from the shelf region exposed during the low sea stand of LGM and afterward deglaciation. Considering the new and published data sets, the Sr-Nd isotope budget of dust deposited in the Himalayan frontal glaciers indicates that atmospheric mineral dust contribution from the upwind Indo-Gangetic Plain proximal to the Himalayas is at par with dust parcels from distant natural deserts.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 8","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867841","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

A Sediment Budget for a Sand Bed River Partitioned by Sand Fractions 按沙粒分区计算的沙床河流沉积物预算

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-07-22 DOI: 10.1029/2023JF007384

Christina M. Leonard, John C. Schmidt

{"title":"A Sediment Budget for a Sand Bed River Partitioned by Sand Fractions","authors":"Christina M. Leonard, John C. Schmidt","doi":"10.1029/2023JF007384","DOIUrl":"10.1029/2023JF007384","url":null,"abstract":"Sediment budgets are widely used to measure reach-scale sediment accumulation and evacuation. Such measurements, however, cannot determine when the disturbance is major and the measured sediment mass imbalance is reflective of a river adjusting to a new equilibrium state, as opposed to situations when the disturbance is minor, and the mass imbalance is reflective of a river adjusting within its existing behavioral regime. Sediment sorting among channels and floodplains can have a large effect on how a river responds to a disturbance. Fine sediment may accumulate in the floodplains while coarser sediment erodes from the channel bed. We demonstrate that if a sediment budget does not account for the different behavior and destination of grain sizes, the budget cannot reveal important channel adjustments. In this study, we evaluated how a sand bed river responded to increases in sediment supply by partitioning a sediment budget among silt/clay and five sand fractions. On average, 12 metric tons/meter (downstream)/year of sand was evacuated from the system, but sorting caused channel margins to behave differently from vegetated islands, revealing how a river can slightly narrow while in deficit. Floodplain shaving and bed coarsening evacuated sediment while channel geometry barely changed, consistent with a river adjusting to a minor disturbance within its behavioral regime. This study is an important reminder that sediment mass imbalance does not always lead to channel change. Mechanisms such as floodplain shaving and bed textural change help rivers absorb minor disturbances and resist channel change.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141754207","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

Modeling Riverbed Elevation and Bedload Tracer Transport Resting Times Using Fractional Laplace Motion 利用分数拉普拉斯运动模拟河床高程和床面负荷示踪迁移静止时间

IF 3.5 2区地球科学

Journal of Geophysical Research: Earth Surface Pub Date : 2024-07-22 DOI: 10.1029/2024JF007771

Zi Wu, Arvind Singh

{"title":"Modeling Riverbed Elevation and Bedload Tracer Transport Resting Times Using Fractional Laplace Motion","authors":"Zi Wu, Arvind Singh","doi":"10.1029/2024JF007771","DOIUrl":"10.1029/2024JF007771","url":null,"abstract":"Riverbed elevations play a crucial role in sediment transport and flow resistance, making it essential to understand and quantify their effects. This knowledge is vital for various fields, including river engineering and stream ecology. Previous observations have revealed that fluctuations in the bed surface can exhibit both multifractal and monofractal behaviors. Specifically, the probability distribution function (PDF) of elevation increments may transition from Laplace (two-sided exponential) to Gaussian with increasing scales or consistently remain Gaussian, respectively. These differences at the finest timescale lead to distinct patterns of bedload particle exchange with the bed surface, thereby influencing particle resting times and streamwise transport. In this paper, we utilize the fractional Laplace motion (FLM) model to analyze riverbed elevation series, demonstrating its capability to capture both mono- and multi-fractal behaviors. Our focus is on studying the resting time distribution of bedload particles during downstream transport, with the FLM model primarily parameterized based on the Laplace distribution of increments PDF at the finest timescale. Resting times are extracted from the bed elevation series by identifying pairs of adjacent deposition and entrainment events at the same elevation. We demonstrate that in cases of insufficient data series length, the FLM model robustly estimates the tail exponent of the resting time distribution. Notably, the tail of the exceedance probability distribution of resting times is much heavier for experimental measurements displaying Laplace increments PDF at the finest scale, compared to previous studies observing Gaussian PDF for bed elevation.","PeriodicalId":15887,"journal":{"name":"Journal of Geophysical Research: Earth Surface","volume":"129 7","pages":""},"PeriodicalIF":3.5,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141754212","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