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Sediment Transport
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Sediment Transport

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Earth Sciences".

Deadline for manuscript submissions: closed (20 August 2023) | Viewed by 23071

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editors

Dr. Gordon Gilja

E-Mail Website
Guest Editor
Faculty of Civil Engineering, Department of Hydroscience and Engineering, University of Zagreb, Kaciceva 26, HR-10000 Zagreb, Croatia
Interests: sediment transport; bridge scour; dune morphodynamics; flood hazard; fishway hydraulics
Special Issues, Collections and Topics in MDPI journals
Dr. Manousos Valyrakis

E-Mail Website
Guest Editor
Infrastructure and Environment Research Division, School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
Interests: sediment transport dynamics; monitoring environmental flows; geomorphic processes and instrumentation
Special Issues, Collections and Topics in MDPI journals
Dr. Panagiotis Michalis

E-Mail Website
Guest Editor
Institute of Communication and Computer Systems (ICCS), 9, Iroon Politechniou Str., Zografou, GR-157 73 Athens, Greece
Interests: scour sensing; bridge monitoring; early warning; critical infrastructure; intelligent structures; structural health monitoring; climatic risks; geo-hazards; dam assessment; risk ecosystems; natural hazards
Special Issues, Collections and Topics in MDPI journals
Dr. Thomas Pahtz

E-Mail Website
Guest Editor
Ocean College, Zhejiang University, Zhoushan, China
Interests: sediment transport driven by liquids and terrestrial and extraterrestrial atmospheric winds; sediment-transport-driven bedform formation and evolution; dry and wet granular flows; landslides
Prof. Dr. Oral Yagci

E-Mail Website
Guest Editor
Department of Civil Engineering, Istanbul Technical University, 34469 Istanbul, Turkey
Interests: flow-vegetation-sediment interaction; coherent flow structures; eco-geomorphological processes; experimental hydraulics; river restoration; scour around bodies

Special Issue Information

Dear Colleagues,

Understanding the morphodynamic behavior of riverbeds is one of the most fundamental problems in fluvial geomorphology, especially in rivers suffering from extensive hydromorphological pressures. Sediment transport patterns present a continuous research challenge because of their impact on hydraulic structures, infrastructure, waterways, confluences or naturally morphologically variable zones like confluences and deltas. The significance of the physical alterations of rivers—natural or anthropogenic—is correlated with the increasing frequency, intensity and duration of natural hazards driven by climate change. The sustainable management of rivers and risk management related to them are based on the predictive tools emerging from the state-of-the-art research conducted under relevant environment-protection scenarios. Continuous advancements in the development of laboratory instruments, remote sensing techniques, numerical modelling of turbulent flows and data processing methods improve the understanding of the fluid–structure interaction underlying the sediment transport process. Such processes can vary across a wide range of scales, from the particle to the landscape, which can directly impact both the form (geomorphology) and function (ecology and biology) of natural systems and the built infrastructure surrounding them.

This Special Issue aims to publish recent advancements in sediment transport research and hydraulic engineering that contribute to filling the knowledge gap in morphodynamic processes at different scales, with an outlook towards innovative river engineering approaches, monitoring systems, available technologies, and management practices tackling rapidly changing environmental conditions. Contributions to this Special Issue can include, for example, particle-scale interactions and transport processes (sediment entrainment, momentum and energy transfer between turbulent flows and particles, interaction among grain sizes in poorly sorted mixtures, etc.), reach-scale sediment transport and geomorphic processes (bedform dynamics, derivation and solution of equations for multiphase flows, shallow water hydro-sediment-morphodynamic processes, scouring, etc.) and large-scale, highly unsteady and complex water-sediment flows (flash floods, flood defenses deterioration, dam incidents and compound disasters, reservoir operation schemes, dredging , maintenance and regulation for large rivers and navigational waterways, etc.).

As Guest Editors, we invite research articles, state-of-the-art reviews, applied research works, case studies and any corresponding concepts that contribute to the development of the field. The contributions for this Special Issue can include laboratory and field experimental studies, mathematical theories, the development of numerical or experimental methodologies, frameworks for the development of monitoring instruments and guidelines, numerical studies of coupled water–sediment flow, and practical case studies at various spatial and time scales. These contributions may include analyses of the sediment transport as a process (incipient motion conditions, turbulence and velocity pattern, development of empirical equations for sediment yield, bed sorting and armoring, dune migration, etc.), as well as its interaction with river structures (scour, sand bar formation, morphological development, bank undercutting, reservoir sedimentation, etc.).

Dr. Gordon Gilja
Dr. Manousos Valyrakis
Dr. Panagiotis Michalis
Dr. Thomas Pahtz
Prof. Dr. Oral Yagci
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Applied Sciences is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • bed and bank erosion
  • diversions
  • confluences
  • dam/embankment assessment
  • early warning systems
  • experimental investigation
  • field measurements
  • flow–vegetation–sediment interactions
  • fluvial hydraulics
  • geo-hazards
  • hydraulic structures
  • hydrodynamics
  • incipient motion
  • monitoring systems
  • morphodynamics
  • numerical modeling
  • reservoir sedimentation
  • remote sensing
  • river bed geomorphology
  • scour
  • scour control structures
  • sediment transport
  • waterways

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Published Papers (14 papers)

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Research

22 pages, 10942 KiB  
Article
Numerical Study of the Flow and Blockage Ratio of Cylindrical Pier Local Scour
by Mario Hurtado-Herrera, Wei Zhang, Abdelkader Hammouti, Damien Pham Van Bang and Kim Dan Nguyen
Appl. Sci. 2023, 13(20), 11501; https://doi.org/10.3390/app132011501 - 20 Oct 2023
Viewed by 659
Abstract
A three-dimensional large eddy simulation model is used to simulate the turbulent flow dynamics around a circular pier in live-bed and clear-water scour conditions. The Navier–Stokes equations are transformed into a σ-coordinate system and solved using a second-order unstructured triangular finite-volume method. [...] Read more.
A three-dimensional large eddy simulation model is used to simulate the turbulent flow dynamics around a circular pier in live-bed and clear-water scour conditions. The Navier–Stokes equations are transformed into a σ-coordinate system and solved using a second-order unstructured triangular finite-volume method. We simulate the bed evolution by solving the Exner-Polya equation assisted by a sand-slide model as a correction method. The bedload transport rate is based on the model of Engelund and Fredsœ. The model was validated for live-bed conditions in a wide channel and clear-water conditions in a narrow channel against the experimental data found in the literature. The in-house model NSMP3D can successfully produce both the live-bed and clear-water scouring throughout a stable long-term simulation. The flow model was used to study the effects of the blockage ratio in the flow near the pier in clear-water conditions, particularly the contraction effect at the zone where the scour hole starts to form. The scour depth in the clear water simulations is generally deeper than the live-bed simulations. In clear-water, the results show that the present model is able to qualitatively and quantitatively capture the hydrodynamic and morphodynamic processes near the bed. In comparison to the wide channel situation, the simulations indicate that the scour rate is faster in the narrow channel case. Full article
(This article belongs to the Special Issue Sediment Transport)
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15 pages, 26057 KiB  
Article
Torrential Hazards’ Mitigation Measures in a Typical Alpine Catchment in Slovenia
by Jošt Sodnik, Matjaž Mikoš and Nejc Bezak
Appl. Sci. 2023, 13(20), 11136; https://doi.org/10.3390/app132011136 - 10 Oct 2023
Cited by 2 | Viewed by 841
Abstract
Different sediment-related disasters due to torrential hazards, such as flash floods, debris flows, and landslides, can occur in an Alpine torrential catchment. When protecting infrastructure and human lives, different structural and non-structural protection measures can be used to mitigate permanent and future risks. [...] Read more.
Different sediment-related disasters due to torrential hazards, such as flash floods, debris flows, and landslides, can occur in an Alpine torrential catchment. When protecting infrastructure and human lives, different structural and non-structural protection measures can be used to mitigate permanent and future risks. An overview of the mitigation measures constructed near the Krvavec ski resort in northwest Slovenia (Central Europe) is presented. In May 2018, an extreme debris flood occurred in this area, causing significant economic damage. After the May 2018 event, different field investigations (i.e., geological and topographic surveys) and modeling applications (e.g., hydrological modeling, debris flow) have been conducted with the purpose of preparing the required input data for the design of protection measures against such disasters in future—due to climate change, more disasters are expected to happen in this torrential watershed. The mitigation includes the restoration of local streams, the construction of a large slit check dam for sediment retention, the construction of several smaller check dams and the construction of 16 flexible net barriers with an estimated ~8000 m3 retention volume for controlling in-channel erosion in steep torrential streams. Additionally, in order to observe and monitor potential future extreme events, an extensive monitoring system has been established in the investigated area. This monitoring system will cover measurements of flexible net corrosion, the estimation of concrete abrasion at check dams, periodical geodetic surveys using small drones (UAV), hydro-meteorological measurements using rainfall gauges and water level sensors. The recent extreme floods of August 2023 also hit this part of Slovenia, and this combination of technical countermeasures withstood the event and prevented large amounts of coarse debris from being transported to the downstream section and devastating infrastructure, as was the case in May 2018 during a less extreme event. Therefore, such mitigation measures can also be used in other torrential catchments in the Alpine environment. Full article
(This article belongs to the Special Issue Sediment Transport)
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23 pages, 5035 KiB  
Article
Coherent Flow Structures Linked to the Impulse Criterion for Incipient Motion of Coarse Sediment
by Khaldoon AlObaidi and Manousos Valyrakis
Appl. Sci. 2023, 13(19), 10656; https://doi.org/10.3390/app131910656 - 25 Sep 2023
Viewed by 675
Abstract
Incipient motion has been a topic of investigation by researchers, engineers and scientists for more than a century. The main approach for studying sediment entrainment has been the static approach that uses temporal and spatial averaged flow parameters like bed shear stress and [...] Read more.
Incipient motion has been a topic of investigation by researchers, engineers and scientists for more than a century. The main approach for studying sediment entrainment has been the static approach that uses temporal and spatial averaged flow parameters like bed shear stress and stream power to link them indirectly to sediment entrainment. Recent research outputs have shed light on the important role of turbulent fluctuations in the sediment transport process. It is suggested that the approach of using temporal and spatial averaged parameters fails to account for the dynamic and probabilistic nature of the entrainment process, as inherited by flow turbulence. This has led to the introduction of the only dynamic criteria in the literature for studying sediment entrainment, namely the impulse and energy criteria. These criteria take into account both the magnitude and duration of the turbulent flow event used for assessing the conditions that can result in sediment entrainment. In light of this, this work aims to assess whether there is a trend in terms of the type of flow structures that occur in sequence before and after the occurrences of the flow impulses that have resulted in the coarse particle’s entrainment. To achieve this, we conducted a well-controlled laboratory experiment to investigate the incipient motion of a 7 cm diameter instrumented particle. Five runs of the experiment were performed at flowrates close to the threshold of motion. The instrumented particle was equipped with micro-electro-mechanical sensors (MEMS) to accurately measure its inertial dynamics and detect motion. The sensors recorded entrainment events, and these events were stochastically linked to the impulses occurring for the tested flow conditions. Quadrant analysis was used to investigate the type of flow structures that occurred before, during and after the occurrence of quadrant events with an impulse above the critical impulse. The findings herein associate coarse particle entrainments with energetic impulses linked primarily to sweep events (Q4) and secondarily, sequence of sweeps (Q4) and ejections (Q1). Full article
(This article belongs to the Special Issue Sediment Transport)
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18 pages, 4511 KiB  
Article
Estimation of Changes in Sediment Transport along the Free-Flowing Middle Danube River Reach
by Dejana Đorđević, Enikő Anna Tamás, Ljubiša Mihajlović, Csaba Abonyi, Aleksandar Vujanović and Béla Kalocsa
Appl. Sci. 2023, 13(18), 10513; https://doi.org/10.3390/app131810513 - 21 Sep 2023
Cited by 1 | Viewed by 657
Abstract
The subject of this study is an approximately 300 km long Middle Danube River reach that spans from river kilometer (rkm) 1581 in Hungary to (rkm) 1255 in Serbia. The observed drying of floodplains in Hungary some thirty years ago initiated the hydrological [...] Read more.
The subject of this study is an approximately 300 km long Middle Danube River reach that spans from river kilometer (rkm) 1581 in Hungary to (rkm) 1255 in Serbia. The observed drying of floodplains in Hungary some thirty years ago initiated the hydrological studies. However, problems related to the navigation route maintenance of the Danube River and those in the water supply of irrigation and drainage canal networks are now present in the whole free-flowing middle Danube region. The study aims at investigating the correlation between the observed water level decrease and recorded incision of the river bed at gauging stations and the indirect estimation of the long-term sediment transport along the sand-bed reach based on the surveillance cross-sections’ data collected during regular monitoring surveys on the navigable Danube. It starts with hydrological analyses of the 70-year-long time series of water level and discharge yearly data and continues with morphological and correlation studies. It ends with the estimation of sediment transport. The decreasing trend in water levels and the increasing trend in cross-sectional areas are persistent. There is a linear correlation between the two. Longitudinal changes in sediment transport indicate the existence of both degrading and aggrading riverbed reaches. Full article
(This article belongs to the Special Issue Sediment Transport)
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17 pages, 4618 KiB  
Article
Advances in Monitoring and Understanding the Dynamics of Suspended-Sediment Transport in the River Drava, Slovenia: An Analysis More than a Decade-Long
by Janja Kramer Stajnko, Renata Jecl and Matjaž Nekrep Perc
Appl. Sci. 2023, 13(15), 9036; https://doi.org/10.3390/app13159036 - 07 Aug 2023
Cited by 1 | Viewed by 718
Abstract
Managing sediment transport in streams is crucial to the surface water resource development strategy and has several implications for flood risk and water management, hydropower use, and balancing river morphology. This paper summarises the movement and behaviour of suspended sediment within the Slovenian [...] Read more.
Managing sediment transport in streams is crucial to the surface water resource development strategy and has several implications for flood risk and water management, hydropower use, and balancing river morphology. This paper summarises the movement and behaviour of suspended sediment within the Slovenian portion of the River Drava, covering a span of thirteen years from 2005 to 2018. An analysis of relevant data collected during this period is also presented. Suspended-sediment dynamics strongly depend on flow velocity, seasonal variations in sediment sources, and human interventions in the riverbed. The transportation of material in the River Drava results in the accumulation of sediments in reservoirs and riverbeds, consequently impeding the natural hydrological cycle by reducing the outflow into aquifers. The 2018 high-water event is analysed in terms of the dependence of concentration of suspended sediments on discharge, where counterclockwise hysteresis was observed, providing an essential clue to the origin of sediment. Sediments from the River Drava in Slovenia are managed with some conventional processes and are mainly deposited or reintegrated into rivers and aquatic ecosystems. Some additional sediment management strategies with long-term solutions for efficient and comprehensive water management, hydropower, and ecological problems are proposed. Full article
(This article belongs to the Special Issue Sediment Transport)
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16 pages, 3211 KiB  
Article
A Novel Suspended-Sediment Sampling Method: Depth-Integrated Grab (DIG)
by Joel T. Groten, Sara B. Levin, Erin N. Coenen, J. William Lund and Gregory D. Johnson
Appl. Sci. 2023, 13(13), 7844; https://doi.org/10.3390/app13137844 - 04 Jul 2023
Viewed by 2879
Abstract
Measuring suspended sediment in fluvial systems is critical to understanding and managing water resources. Sampling suspended sediment has been the primary means of understanding fluvial suspended sediment. Specialized samplers, sampling methods, and laboratory methods developed by select U.S. Federal Agencies are more representative [...] Read more.
Measuring suspended sediment in fluvial systems is critical to understanding and managing water resources. Sampling suspended sediment has been the primary means of understanding fluvial suspended sediment. Specialized samplers, sampling methods, and laboratory methods developed by select U.S. Federal Agencies are more representative of river and stream conditions than commonly used grab sampling and total suspended solids (TSS) laboratory methods but are not widely used because they are expensive, time consuming, and not required as part of water quality standards in the United States. A new suspended-sediment sampling method called a depth-integrated grab (DIG) was developed by combining certain elements from both grab and depth-integrating sampling methods and suspended-sediment concentration (SSC) laboratory methods. The goal of the DIG method was to provide more accurate results than Grab-TSS while being easier and cheaper to sample than specialized samplers and methods. Approximately 50 paired comparison samples were collected at 9 sites in Minnesota from 2018 through 2019. Results showed no significant difference between the DIG and specialized sampling methods and a significant difference between both methods and the Grab-TSS method. The DIG-SSC provided an improved alternative to the Grab-TSS method, but additional research and testing is important to evaluate if this method is appropriate in different conditions than were observed in this study. Full article
(This article belongs to the Special Issue Sediment Transport)
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35 pages, 14091 KiB  
Article
Upstream and Downstream Changes in the Channel Width and Sinuosity Due to Dam Construction in Tropical Rivers: The Case of Colombia
by Diana C. Alvarado, Andrés Vargas-Luna and Juan Diego Giraldo-Osorio
Appl. Sci. 2023, 13(12), 7109; https://doi.org/10.3390/app13127109 - 14 Jun 2023
Viewed by 2686
Abstract
In Colombia, most of the energy is produced by using water resources. However, the morphological impact of damming has not been thoroughly studied yet. Therefore, upstream and downstream changes in the channel width and sinuosity along the river due to the Betania, Prado, [...] Read more.
In Colombia, most of the energy is produced by using water resources. However, the morphological impact of damming has not been thoroughly studied yet. Therefore, upstream and downstream changes in the channel width and sinuosity along the river due to the Betania, Prado, Salvajina, and Urrá I Dams, four of the oldest hydroelectric projects, were estimated. These changes were reported by using aerial photographs and satellite images to compare the river before and after dam construction. The analysis was complemented by including hydrological trends and geological characteristics of the areas to evaluate their relevance on the impacts on channel morphology. It was shown that factors such as valley confinement and the bank’s composition are key to determining the magnitude of the impact downstream of the dam. Upstream of the dam, contrastingly, the influence of the reservoir geometry controls the magnitude of the morphological changes, marking the boundaries of affected areas. The impacts of dam construction on river morphology vary notably, but including the geological characteristics of the river reach can be useful to improve predictions of the channel morphology response. The proposed methodology can be used to identify biotic compensation measures for new projects, a task that is not well defined in several countries. Full article
(This article belongs to the Special Issue Sediment Transport)
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17 pages, 4269 KiB  
Article
Surrogate Method for Suspended Sediment Concentration Monitoring on the Alluvial Reach of the River Danube (Baja, Hungary)
by László Vas and Enikő Anna Tamás
Appl. Sci. 2023, 13(10), 5826; https://doi.org/10.3390/app13105826 - 09 May 2023
Cited by 2 | Viewed by 1066
Abstract
Sediment balance is essential for understanding changes in river morphology and ecosystems and related services depending on them. However, the currently used methods to quantify riverine sediment processes are not adequate enough. We have examined the sediment regime of the Danube River, particularly [...] Read more.
Sediment balance is essential for understanding changes in river morphology and ecosystems and related services depending on them. However, the currently used methods to quantify riverine sediment processes are not adequate enough. We have examined the sediment regime of the Danube River, particularly the suspended sediment yield. This parameter can be calculated based on stage or discharge using a suspended sediment yield rating curve; however, the uncertainty of this method can reach even 150%. The suspended sediment yield of a section does not only depend on processes that take place in the riverbed; thus, it cannot be described by only one easily measurable parameter. An integrated surrogate method based on turbidity registration is tested in order to determine suspended sediment yield on the lower Hungarian (sand-bed alluvial) reach of the Danube River. The near-bank turbidity is converted into suspended sediment concentration and then into suspended sediment yield. The turbidity is measured with a built-in turbidity probe, while the suspended sediment yield is determined with traditional methods (discharge measurement, suspended sediment sampling, laboratory processing, and calculation). The traditional and integrated surrogate methods are compared based on the results of the measurements, and different aspect correlations are established between flow parameters, turbidity, and suspended load. The results achieved with the integrated method are promising, but more measurements are required in order to refine the relationships in a broader interval. Full article
(This article belongs to the Special Issue Sediment Transport)
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19 pages, 2513 KiB  
Article
Analysis of Variables Influencing Scour on Large Sand-Bed Rivers Conducted Using Field Data
by Antonija Harasti, Gordon Gilja, Nikola Adžaga and Mark Žic
Appl. Sci. 2023, 13(9), 5365; https://doi.org/10.3390/app13095365 - 25 Apr 2023
Cited by 1 | Viewed by 1157
Abstract
Throughout the lifespan of a bridge, morphological changes in the riverbed affect the variable action-imposed loads on the structure. This emphasizes the need for accurate and reliable data that can be used in model-based projections targeted for the identification of risk associated with [...] Read more.
Throughout the lifespan of a bridge, morphological changes in the riverbed affect the variable action-imposed loads on the structure. This emphasizes the need for accurate and reliable data that can be used in model-based projections targeted for the identification of risk associated with bridge failure induced by scour. The aim of this paper is to provide an analysis of scour depth estimation on large sand-bed rivers under the clear water regime, detect the most influential (i.e., explanatory) variables, and examine the relationship between them and scour depth as a response variable. A dataset used for the analysis was obtained from the United States Geological Survey’s extensive field database of local scour at bridge piers, i.e., the Pier-Scour Database (PSDB-2014). The original database was filtered to exclude the data that did not reflect large sand-bed rivers, and several influential variables were omitted by using the principal component analysis. This reduction process resulted in 10 influential variables that were used in multiple non-linear regression scour modeling (MNLR). Two MNLR models (i.e., non-dimensional and dimensional models) were prepared for scour estimation; however, the dimensional model slightly overperformed the other one. According to the Pearson correlation coefficients (r), the most influential variables for estimating scour depth were as follows: Effective pier width (r = 0.625), flow depth (r = 0.492), and critical and local velocity (r = 0.474 and r = 0.436), respectively. In the compounded hydraulic-sediment category, critical velocity had the greatest impact (i.e., the highest correlation coefficient) on scour depth in comparison to densimetric Froude and critical Froude numbers that were characterized by correlation coefficients of r = 0.427 and r = 0.323, respectively. The remaining four variables (local and critical bed shear stress, Froude number, and particle Reynolds number) exhibited a very weak correlation with scour depth, with r < 0.3. Full article
(This article belongs to the Special Issue Sediment Transport)
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25 pages, 8805 KiB  
Article
Development of a Two-Dimensional Hybrid Sediment-Transport Model
by Yaoxin Zhang, Mohammad Al-Hamdan and Daniel Wren
Appl. Sci. 2023, 13(8), 4940; https://doi.org/10.3390/app13084940 - 14 Apr 2023
Viewed by 1153
Abstract
This paper presents the development of a two-dimensional hydrodynamic sediment transport model using the finite volume method based on a collocated unstructured hybrid-mesh system consisting of triangular and quadrilateral cells. The model is a single-phase nonequilibrium sediment-transport model for nonuniform and noncohesive sediments [...] Read more.
This paper presents the development of a two-dimensional hydrodynamic sediment transport model using the finite volume method based on a collocated unstructured hybrid-mesh system consisting of triangular and quadrilateral cells. The model is a single-phase nonequilibrium sediment-transport model for nonuniform and noncohesive sediments in unsteady turbulent flows that considers multiple sediment-transport processes such as deposition, erosion, transport, and bed sorting. This model features a hybrid unstructured mesh system for easy mesh generation in complex domains. To avoid interpolation from vertices in conventional unstructured models, this model adopted a second-order accurate edge-gradient evaluation method to consider the mesh irregularities based on Taylor’s series expansion. In addition, the multipoint momentum interpolation corrections were integrated to avoid possible nonphysical oscillations during the wetting-and-drying process, common in unsteady sediment transport problems, to ensure both numerical stability and numerical accuracy. The developed sediment transport model was validated by a benchmark degradation case for the erosion process with armoring effects, a benchmark aggradation case for the deposition process, and a naturally meandering river for long-term unsteady sediment-transport processes. Finally, the model was successfully applied to simulate sediment transport in a reservoir that was significantly affected by typhoon events. Full article
(This article belongs to the Special Issue Sediment Transport)
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28 pages, 135573 KiB  
Article
Nature-Based Solutions for Flood Mitigation and Soil Conservation in a Steep-Slope Olive-Orchard Catchment (Arquillos, SE Spain)
by Patricio Bohorquez, Francisco José Pérez-Latorre, Inmaculada González-Planet, Raquel Jiménez-Melero and Gema Parra
Appl. Sci. 2023, 13(5), 2882; https://doi.org/10.3390/app13052882 - 23 Feb 2023
Cited by 2 | Viewed by 1819
Abstract
The frequency and magnitude of flash floods in the olive orchards of southern Spain have increased because of climate change and unsustainable olive-growing techniques. Affected surfaces occupy >85% of the rural regions of the Upper Guadalquivir Basin. Dangerous geomorphic processes record [...] Read more.
The frequency and magnitude of flash floods in the olive orchards of southern Spain have increased because of climate change and unsustainable olive-growing techniques. Affected surfaces occupy >85% of the rural regions of the Upper Guadalquivir Basin. Dangerous geomorphic processes record the increase of runoff, soil loss and streamflow through time. We report on ripple/dune growth over a plane bed on overland flows, deep incision of ephemeral gullies in olive groves and rock-bed erosion in streams, showing an extraordinary sediment transport capacity of sub-daily pluvial floods. We develop a novel method to design optimal solutions for natural flood management and erosion risk mitigation. We adopt physical-based equations and build a whole-system model that accurately reproduces the named processes. The approach yields the optimal targeted locations of nature-based solutions (NbSs) for active flow-control by choosing the physical-model parameters that minimise the peak discharge and the erosion-prone area, maximising the soil infiltration capacity. The sub-metric spatial resolution used to resolve microtopographic features of terrains/NbS yields a computational mesh with millions of cells, requiring a Graphics Processing Unit (GPU) to run massive numerical simulations. Our study could contribute to developing principles and standards for agricultural-management initiatives using NbSs in Mediterranean olive and vineyard orchards. Full article
(This article belongs to the Special Issue Sediment Transport)
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23 pages, 8418 KiB  
Article
Bedload Sediment Transport Estimation in Sand-Bed Rivers Comparing Traditional Methods and Surrogate Technologies
by Philipe Ratton, Tobias Bernward Bleninger, Rodrigo Bahia Pereira and Fábio Veríssimo Gonçalves
Appl. Sci. 2023, 13(1), 5; https://doi.org/10.3390/app13010005 - 20 Dec 2022
Viewed by 1540
Abstract
Bedload sediment transport in rivers can cause impacts, such as bed erosion/deposition, sandbank formation and changes in flow capacity. Bedload sampling techniques have limitations related to spatial and temporal resolution. These constraints are more relevant in rivers with dunes and high sediment transport. [...] Read more.
Bedload sediment transport in rivers can cause impacts, such as bed erosion/deposition, sandbank formation and changes in flow capacity. Bedload sampling techniques have limitations related to spatial and temporal resolution. These constraints are more relevant in rivers with dunes and high sediment transport. This paper presents a comparison between bedload transport rates estimated with direct and indirect methods in a river with sand dunes. The case study area is a stretch of the Taquari River, in Brazil. Surveys were carried out on three consecutive days, during a flood season. A SonTek M9-ADCP with HydroSurveyor capabilities activated was used to simultaneously measure bathymetry and water velocities throughout a river reach, and also to perform moving-bed tests at six verticals along a predefined cross-section. A mechanical trap (Helley–Smith) was used to collect bedload samples at the same time and positions where the moving-bed tests were performed. Sediment transport was calculated and compared following different approaches: (1) ADCP-BT (Bottom Tracking); (2) modified ISSDOTv2 method (dune tracking); (3) HelleySmith mechanical trap; (4) and five empirical equations. The results showed good agreement between the methodologies, indicating the potential of using ADCPs for hydro sedimentological studies due to the advantages of integrating bathymetry, flow velocity and bedload data. Full article
(This article belongs to the Special Issue Sediment Transport)
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15 pages, 13216 KiB  
Article
Sedimentological Analysis of the Turbidite Sequence in the Northern Part of the West Crocker Formation, Northwest Sabah
by Nurul Afifah Mohd Radzir, Che Aziz Ali and Kamal Roslan Mohamed
Appl. Sci. 2022, 12(23), 12149; https://doi.org/10.3390/app122312149 - 28 Nov 2022
Cited by 1 | Viewed by 1804
Abstract
Gravity-flow deposits form the northern part of the Crocker Formation (Oligocene–Early Miocene), with the most significant interpretation as a sand-rich system in the proximal and a mud-rich system in the distal area of the deep-water turbidite depositional setting. Seven outcrop localities in the [...] Read more.
Gravity-flow deposits form the northern part of the Crocker Formation (Oligocene–Early Miocene), with the most significant interpretation as a sand-rich system in the proximal and a mud-rich system in the distal area of the deep-water turbidite depositional setting. Seven outcrop localities in the northern-part area were selected for mapping and sampling, starting from Kota Kinabalu up to the Telipok area to evaluate the sedimentary sequence. This study used mapping, field observation, and log sketches in the field, as well as extensive analysis and interpretation of sedimentological methods to investigate the sequence of sediment outcrops in the Crocker Formation area of northwest Sabah. During the fieldwork, five main facies were found, namely, massive sandstone facies (f1), graded sandstone facies (f2), laminated sandstone facies (f3), interbedded sandstone and mudstone facies (f4), and mudstone facies (f5). These northern-part outcrops are interpreted as being deposited from the highest to the lowest turbidity currents and the actuality of pelagic mudstone deposition, based on their fining-coarsening-upward pattern. The five geometrical bodies were proposed as laterally contiguous depositional environments, namely, (1) inner fan channel, (2) inner fan channel–levee complex, (3) mid-fan channelized lobes, (4) non-channelized lobes/distal lobes, and (5) basin plains. The facies interpretation shows that the study area consists of lobes, channel–levee complexes, and levees formed in a fan of a deep-water basin setting, with the basinal plain enveloped by thick mudstone deposits. This northern part of the Crocker Formation is interpreted as a multiple-sourced sediment, shelf-fed, Type II, low-efficiency, and sand-rich turbidite depositional system. Full article
(This article belongs to the Special Issue Sediment Transport)
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Article
Migration and Diffusion of Surface Sediments in Bohai Bay: Evidence from Grain Size and Elements
by Bo Zhao, Lianjie Zhang, Jishun Yan, Xia Lin, Peng Wang, Pan Zhang, Yonghai Yu and Shuai Yu
Appl. Sci. 2022, 12(21), 10738; https://doi.org/10.3390/app122110738 - 23 Oct 2022
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Abstract
Grain size and element content of surface sediment from Bohai Bay were analyzed to study the sediment migration and diffusion based on grain size trend analysis (GSTA) and discriminant function (DF). The sediment in the southern, central and western part of Bohai Bay [...] Read more.
Grain size and element content of surface sediment from Bohai Bay were analyzed to study the sediment migration and diffusion based on grain size trend analysis (GSTA) and discriminant function (DF). The sediment in the southern, central and western part of Bohai Bay mainly originates from the Yellow River, while that in the northern part of Bohai Bay mainly originates from the Luanhe River. The influence boundary between the Yellow River and the Luanhe River is estimated to be at 38°50′ N. In both the southern and northern parts of Bohai Bay, sediment is transported into the bay under the influence of prevailing waves, strongest waves and tidal remnants, resulting in sediment accumulation in western Bohai Bay. The coastal sediment of Bohai Bay is generally in a state of offshore movement, which is consistent with the large-scale coastline retreat in past decades found by previous studies. Full article
(This article belongs to the Special Issue Sediment Transport)
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