Article
Engineering, Marine
Cuiping Kuang, Xuejian Han, Jiabo Zhang, Qingping Zou, Boling Dong
Summary: The study demonstrates that introducing three offshore submerged sandbars can effectively improve the morphological changes of the beach, mainly driven by waves; the presence of sandbars has little effect on tidal current, but significantly attenuates incoming waves, facilitating the onshore transport of medium-coarse sand of the sandbars.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Civil
Nan Wang, Qin Chen, Kelin Hu, Kehui Xu, Samuel J. Bentley, Jiaze Wang
Summary: This study used a Delft3D model to explore the hydrodynamics and sediment transport in Fourleague Bay, Louisiana. The findings show that by aligning river water pulses with atmospheric conditions, the growth of surrounding wetlands can be promoted and the distance over which they benefit from sediment diversions can be extended. Multiple sediment transport processes were observed under different weather conditions.
COASTAL ENGINEERING
(2023)
Article
Geography, Physical
Victor Chavarrias, Willem Ottevanger, Kees Sloff, Erik Mosselman
Summary: Predicting the formation and break-up of immobile layers is crucial for river management, but the existing models have limitations. Through numerical modeling experiments, this paper finds that Struiksma's model cannot predict break-up and Hirano's model produces unrealistic results when sediment is immobile. To overcome these issues, two alternative models, ILSE and HANNEKE, are proposed. The HANNEKE model explicitly predicts the formation of coarse layers, but it has a more limited application range.
Article
Geography, Physical
Julianne Scamardo, Peter A. Nelson, Mary Nichols, Ellen Wohl
Summary: Compared to perennial streams, there is a lack of studies investigating the impact of large wood on sediment transport and river corridor morphology in ephemeral streams. Both large wood and vegetation effectively confine flow to the main channel, causing it to become wider and deeper. Large wood enhances channel change caused by vegetation, but vegetation has a greater influence on channel morphology due to its larger area within the stream corridor.
Article
Environmental Sciences
Jakob Siedersleben, Stefan Jocham, Markus Aufleger, Robert Klar
Summary: Different spatial resolutions of datasets have varying impacts on riverbed surveys and model predictions, with high-resolution data more accurately reflecting riverbed geometry. However, in areas with more homogeneous features, cross-profile data may provide a more accurate representation.
Article
Geosciences, Multidisciplinary
Muh Aris Marfai, Ratih Winastuti, Arief Wicaksono, Bachtiar W. Mutaqin
Summary: This study investigated the morphodynamic aspects of the Buleleng Regency by analyzing sediment transport and shoreline changes. Results showed that sediment in the study area is mainly composed of medium grain size: gravel (stone) to coarse sand, and structural mitigation is needed to counteract the accelerating impact of human activities and physical processes on the coastal landscape.
Article
Geography, Physical
Christopher J. Daly, France Floc'h, Luis P. M. Almeida, Rafael Almar, Marion Jaud
Summary: This study conducted field experiments to investigate beach cusp formation under accretive conditions at Nha Trang Beach, Vietnam. The research used measured data and XBeach simulations to analyze the variations in cusp dimensions, swash flow patterns, and sediment sorting, finding that wave period and height are key factors influencing cusp formation.
Article
Multidisciplinary Sciences
Danghan Xie, Christian Schwarz, Maarten G. Kleinhans, Karin R. Bryan, Giovanni Coco, Stephen Hunt, Barend van Maanen
Summary: Changes in upstream land-use have significant impacts on coastal environments worldwide. Mangrove removal, aimed at restoring estuarine ecosystems, paradoxically enhances sediment trapping. More comprehensive management approaches are required.
NATURE COMMUNICATIONS
(2023)
Article
Environmental Sciences
Ehab Meselhe, Kazi Sadid, Ashok Khadka
Summary: River deltas are important coastal landforms that are affected by various factors such as subsidence, storms, and sea level rise. Understanding the processes and dynamics of deltas is crucial for coastal restoration efforts. This study applied morphodynamic models to a prograding river delta, specifically the Wax Lake Delta in Louisiana, and successfully validated the models against field observations. The results provide insights into the flow and sediment distribution within interconnected delta channels, influencing the morphodynamics and growth of the delta.
Article
Engineering, Multidisciplinary
Kazbek Kazhyken, Juha Videman, Clint Dawson
Summary: The study proposed a dispersive wave hydro-sediment-morphodynamic model by combining the SHSM equations with the dispersive term from the Green-Naghdi equations, and introduced a numerical solution algorithm based on the second-order Strang operator splitting technique. The model demonstrated the capability of accurately predicting sediment transport and bed morphodynamic processes, as well as capturing hydrodynamics and wave dispersion effects, making it suitable for simulations with prevalent dispersive wave effects.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
N. Yan, L. Colombera, N. P. Mountney
Summary: The study used time-lapse trajectories and a numerical model to simulate the evolution of rivers, finding that sediment preservation decreases predictably with time, while accretion rates do not follow the expected power-law decay. This is interpreted as reflecting the effect of geomorphic thresholds of channel transformation and cutoff.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Multidisciplinary Sciences
Stephan C. Toby, Robert A. Duller, Silvio De Angelis, Kyle M. Straub
Summary: A new quantitative tool for assessing environmental signal propagation and transfer in sediment routing systems is introduced, providing broad applicability and usefulness in the field. The study develops a framework and workflow to estimate autogenic thresholds in ancient sediment routing systems, which can be approximated using readily attainable measurements from field systems, overcoming the low temporal resolution of strata. This work demonstrates the importance of accessing short-term system dynamics from ancient sediment routing systems and setting morphodynamic limits on environmental signal propagation across ancient landscapes and into strata.
NATURE COMMUNICATIONS
(2022)
Article
Oceanography
Carter B. DuVal, Arthur C. Trembanis, Douglas C. Miller
Summary: This study introduces a novel regime-state framework to determine the dominant modifier of seabed roughness and investigates ripple decay and bioturbation. By analyzing field observations and models, the study identifies mechanisms of seabed roughness variation, providing a direction for future research.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Computer Science, Interdisciplinary Applications
Mohammad Jamous, Reza Marsooli, Mahmoud Ayyad
Summary: Predicting coastal erosion requires an accurate morphodynamic model, such as XBeach. Sensitivity analysis is conducted using a computationally cost-effective approach based on the Non-Intrusive Polynomial Chaos Expansion method. Applied to Hurricane Sandy-induced coastal erosion in New Jersey, the results demonstrate the spatial variation of model sensitivity and the reduction of parameter interaction with increasing boundary conditions, leading to a reduction in uncertainty of model output.
ENVIRONMENTAL MODELLING & SOFTWARE
(2023)
Article
Oceanography
Min Zhang, Hangxing Wu, Zhijun Dai, Jie Mi, Huayang Cai
Summary: Most tide-dominated estuaries are heavily disturbed by human interventions like embankments and reclamations, resulting in morphodynamic shrinkage. This study explores the morphological-hydrological interactions and equilibrium re-adjustment mechanism in North Branch (NB), a tide-dominated estuary in the Yangtze Estuary. The results demonstrate a mechanism of geomorphological resilience, where the estuary evolves from initial shrinking to dynamic equilibrium after reclamations. Preservation policies can ensure a long-term dynamic equilibrium for NB.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2023)
Article
Geography, Physical
Daniel J. Brogan, Lee H. MacDonald, Peter A. Nelson, Jacob A. Morgan
Article
Geography, Physical
Jacob A. Morgan, Nirnimesh Kumar, Alexander R. Horner-Devine, Shelby Ahrendt, Erkan Istanbullouglu, Christina Bandaragoda
Article
Environmental Sciences
Stephanie K. Kampf, Benjamin M. Gannon, Codie Wilson, Freddy Saavedra, Mary Ellen Miller, Aaron Heldmyer, Ben Livneh, Peter Nelson, Lee MacDonald
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2020)
Article
Geography, Physical
Jacob A. Morgan, Peter A. Nelson
Summary: Gravel-bed rivers typically have shallow riffles in wide sections and deeper pools in narrow areas. This study investigated how two different channel geometries, constant-width and variable-width, respond to changing flow and sediment supply in a flume experiment. The results showed that the variable-width channel developed bed undulations representing riffle-pools, while the straight channel had a significant increase in slope with increased sediment supply. Pool elevation changes were twice the distance of bar elevations, highlighting the importance of pool scour for riffle-pool self-maintenance in channels with width variations.
EARTH SURFACE PROCESSES AND LANDFORMS
(2021)
Article
Engineering, Geological
Sujana Timilsina, Jeffrey D. Niemann, Sara L. Rathburn, Francis K. Rengers, Peter A. Nelson
Summary: During a seven-day extreme rainfall event in September 2013 in the Colorado Front Range, it was observed that south-facing slopes were more prone to experiencing debris flows compared to north-facing slopes. By analyzing soil moisture patterns and hydrologic processes, it was determined that differences in interception and deep drainage were the primary factors leading to the saturation of south-facing slopes. The final model predicted instability at around 72% of observed debris flow initiation sites.
Article
Geosciences, Multidisciplinary
Tingan Li, Jeremy G. Venditti, Colin D. Rennie, Peter A. Nelson
Summary: Approximating the stresses on the bed and walls of confined, narrow bedrock rivers is crucial for accurately understanding hydraulic roughness, sediment transport, bedrock erosion, and the dynamics of bedrock channels. Through the use of the ray-isovel model (RIM) and field observations, this study found that the distribution of shear stress across an idealized trapezoidal channel is influenced by the angle of the river banks and the width-to-depth ratio. The study also revealed that the complex flow structure in bedrock canyons affects the distribution of bed and wall stresses, with the bedrock walls contributing more hydraulic roughness than predicted by the RIM model.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2022)
Article
Environmental Sciences
Shelby Ahrendt, Alexander R. Horner-Devine, Brian D. Collins, Jacob A. Morgan, Erkan Istanbulluoglu
Summary: Changes in the severity and likelihood of flooding events are not only associated with changes in the intensity and frequency of streamflows, but also with adjustments in a river's conveyance capacity. The study reveals that in unregulated rivers, moderate floods have increased across the region, while in regulated rivers, this trend is suppressed or even reversed. Variations in channel conveyance are widespread, but the magnitude and timing of adjustments are not consistent. The relative importance of conveyance variability for flood risk depends on the mode of adjustment.
WATER RESOURCES RESEARCH
(2022)
Article
Geography, Physical
Julianne Scamardo, Peter A. Nelson, Mary Nichols, Ellen Wohl
Summary: Compared to perennial streams, there is a lack of studies investigating the impact of large wood on sediment transport and river corridor morphology in ephemeral streams. Both large wood and vegetation effectively confine flow to the main channel, causing it to become wider and deeper. Large wood enhances channel change caused by vegetation, but vegetation has a greater influence on channel morphology due to its larger area within the stream corridor.
Article
Environmental Sciences
Brian M. Murphy, Kathryn L. Russell, Simon Mould, Geoff Vietz, Peter A. Nelson
Summary: Urban riverscapes play a crucial role in urban planning and development, but they often suffer from degradation. To effectively manage urban riverscapes, a comprehensive assessment considering human values, hydrology, geomorphology, and ecology is necessary. This assessment can be conducted at multiple scales and provides guidance for enhancing riverscape function and urban vitality.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Wuming Ni, Jacob A. Morgan, Alexander R. Horner-Devine, Nirnimesh Kumar, Shelby Ahrendt
Summary: This research investigates the influence of sea level rise (SLR) on riverine flooding in estuaries by simulating the morphodynamic evolution of an idealized estuary under different SLR scenarios. The results show that the estuarine response to SLR is affected by both morphological changes and changes in channel hydrodynamics. Interestingly, more severe SLR scenarios lead to a decrease in flood extent in upstream areas due to tidal energy penetration and erosion, which increases the channel capacity locally.
WATER RESOURCES RESEARCH
(2022)
Article
Geosciences, Multidisciplinary
Daniel C. White, Peter A. Nelson
Summary: Meandering gravel-bed rivers exhibit sorting patterns with fine particles on bar tops and coarse particles in pools. The mechanism behind these patterns is poorly understood for gravel-bed meandering channels.
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
(2023)
Article
Geography, Physical
Daniel J. Brogan, Peter A. Nelson, Lee H. MacDonald
EARTH SURFACE DYNAMICS
(2019)