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Advances in Coastal Hydrodynamic and Morphodynamic Processes under a Changing...
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Advances in Coastal Hydrodynamic and Morphodynamic Processes under a Changing Climate

A special issue of Journal of Marine Science and Engineering (ISSN 2077-1312). This special issue belongs to the section "Coastal Engineering".

Deadline for manuscript submissions: 20 December 2024 | Viewed by 3290

Special Issue Editors

Dr. Chatzipavlis Antonis

E-Mail Website
Guest Editor
School of the Environment, Marine Sciences Department, University of the Aegean, University Hill, 81100 Mytilene, Lesvos, Greece
Interests: beach morphodynamics; coastal hydrodynamics; coastal engineering
Dr. Simone Simeone

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Guest Editor
Institute for the Study for Anthropic Impact and Sustainability in the Marine Environment, National Council of Research—CNR IAS, Rome, Italy
Interests: beach morphology; coastal morphodynamics; coastal processes; climate change; coastal hydrodynamics; constrained beaches; mixed carbonatics and clastic beaches; sea level rise; coastal adaptation; wave hydrodynamics
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Currently, approximately 40% of the world’s population is located within 100 kilometers of the coast, making a significant contribution to the global economy (an estimated USD 1.5 trillion per year, which is expected to double by 2030). Beaches are one of the most dynamic environments on earth. Changes in beach morphology (morphodynamics) are based on complex process–response mechanisms operating at various spatio-temporal scales, which are not yet comprehensively understood. Simultaneously, beaches form the first line of defense against marine inundation and flooding, providing effective protection to the coastal populations, infrastructure assets, and the other coastal environments they front. Beach erosion is already threatening the livelihood and the economic activities of many coastal communities; this is a phenomenon that is expected to proliferate in the future under the anticipated changes in hydrodynamic forcing (mean and extreme sea levels). Thus, understanding beach morphodynamics and providing effective solutions for appropriate coastal protection schemes has now become an urgent issue.

This Special Issue aims to compile the latest, most fascinating research and innovative approaches in the field of beach morphodynamics, focusing on coastal resilience and sustainability. The submission of high-quality papers for publication is encouraged in order to disseminate the articles freely for research, teaching, and reference purposes.

Dr. Chatzipavlis Antonis
Dr. Simone Simeone
Guest Editors

Manuscript Submission Information

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 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

  • coastal morphodynamics
  • beach morphology
  • coastal hydrodynamics
  • climate change
  • extreme sea levels
  • mean sea level rise
  • coastal processes

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Published Papers (3 papers)

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Research

24 pages, 5700 KiB  
Article
Temporal Scales of Mass Wasting Sedimentation across the Mississippi River Delta Front Delineated by 210Pb/137Cs Geochronology
by Jeffrey Duxbury, Samuel J. Bentley, Kehui Xu and Navid H. Jafari
J. Mar. Sci. Eng. 2024, 12(9), 1644; https://doi.org/10.3390/jmse12091644 - 13 Sep 2024
Viewed by 322
Abstract
The Mississippi River Delta Front (MRDF) is a subaqueous apron of rapidly deposited and weakly consolidated sediment extending from the subaerial portions of the Birdsfoot Delta of the Mississippi River, long characterized by mass-wasting sediment transport. Four (4) depositional environments dominate regionally (an [...] Read more.
The Mississippi River Delta Front (MRDF) is a subaqueous apron of rapidly deposited and weakly consolidated sediment extending from the subaerial portions of the Birdsfoot Delta of the Mississippi River, long characterized by mass-wasting sediment transport. Four (4) depositional environments dominate regionally (an undisturbed topset apron, mudflow gully, mudflow lobe, and prodelta), centering around mudflow distribution initiated by a variety of factors (hurricanes, storms, and fluid pressure). To better understand the spatiotemporal scales of the events as well as the controlling processes, eight cores (5.8–8.0 m long) taken offshore from the South Pass (SP) and the Southwest Pass (SWP) were analyzed for gamma density, grain size, sediment fabric (X-radiography), and geochronology (210Pb/137Cs radionuclides). Previous work has focused on the deposition of individual passes and has been restricted to <3 m core penetration, limiting its geochronologic completeness. Building on other recent studies, within the mudflow gully and lobe cores, the homogeneous stepped profiles of 210Pb activities and the corresponding decreased gamma density indicate the presence of gravity-driven mass failures. 210Pb/137Cs indicates that gully sedimentary sediment accumulation since 1953 is greater than 580 cm (sediment accumulation rate [SAR] of 12.8 cm/y) in the southwest pass site, and a lower SAR of the South Pass gully sites (2.6 cm/y). This study shows that (1) recent dated mudflow deposits are identifiable in both the SWP and SP; (2) SWP mudflows have return periods of 10.7 y, six times more frequent than at the SP (66.7 y); (3) 210Pb inventories display higher levels in the SWP area, with the highest focusing factors in proximal/gully sedimentation, and (4) submarine landslides in both study areas remain important for sediment transport despite the differences in sediment delivery and discharge source proximity. Full article
(This article belongs to the Special Issue Advances in Coastal Hydrodynamic and Morphodynamic Processes under a Changing Climate)
►▼ Show Figures

Figure 1

Figure 1
<p>Map outlining the Mississippi River Delta Front (MRDF) study site in vicinity of the “birds’ foot”, (<b>a</b>) displaying the subaerial and subaqueous bathymetry with study sites outlined in red. (<b>b</b>) The Southwest Pass and (<b>c</b>) the South Pass display piston core locations, with black dots and dotted lines outlining a select gully–lobe complex within each. Bathymetry is from Baldwin et al. (2018) [<a href="#B3-jmse-12-01644" class="html-bibr">3</a>], imagery is open source “world imagery” from ESRI.</p> Full article ">Figure 2
<p>Delta front seafloor diagram (adapted from Coleman et al. 1980 [<a href="#B1-jmse-12-01644" class="html-bibr">1</a>]) outlining major morphological features of the study sites. Upper, intermediate, and lower zones of the environment range from 20 to 300 m in depth and feature incising gullies coalescing into mudflow lobes downslope overlying earlier, Holocene-aged deposits [<a href="#B14-jmse-12-01644" class="html-bibr">14</a>].</p> Full article ">Figure 3
<p>Downcore physical property profiles for piston cores. Gamma density (solid), porosity (dashed), and mean grain size (phi units in black dots with error bars showing standard deviation) are laid out for the Southwest Pass (<b>top</b>) and South Pass (<b>bottom</b>), ordered by depositional environment.</p> Full article ">Figure 4
<p>Diagnostic X-radiography for each of the depositional environments showing common fabrics present within cores. Red lines indicate possible unconformity locations. By core, (<b>a</b>) PS17-03 undisturbed topset apron with laminated bedding present throughout; (<b>b</b>) PS17-06, a mudflow gully core with large amounts of biogenic gas expansion exacerbated by desiccation with no visible bedding beside an unconformity separating two homogenous layers; (<b>c</b>) mudflow lobe core PS17-07, showing biogenic gas voids below an unconformity; (<b>d</b>) prodelta core PS17-09, with cm-scale sandy layers and abundant burrowing throughout; (<b>e</b>) PS17-24, a mudflow gully core from the South Pass showing a possible unconformity with angled bedding below and homogenous above.</p> Full article ">Figure 5
<p>Depositional mechanism interpretation displayed over stratigraphic profile, gamma density, and <sup>210</sup>Pb/<sup>137</sup>Cs profiles by pass.</p> Full article ">Figure 6
<p>CHIRP seismic profiles parallel to shore, progressing distally (<b>A</b>–<b>C</b>) and perpendicular (<b>D</b>), outlined as tracts with corresponding A’–D’ in <a href="#jmse-12-01644-f001" class="html-fig">Figure 1</a>. Identified depositional environments are listed on each transect down to observable seismic basement.</p> Full article ">Figure 7
<p>Depositional environment analysis. (<b>a</b>) Relative composition of cores by sedimentation mechanism, (<b>b</b>) accumulation rates by depositional environments, (<b>c</b>) calculated mudflow return period (years) by depositional environment.</p> Full article ">Figure 8
<p>Site-wide radioisotope analysis with (<b>a</b>) <sup>210</sup>Pb radioisotope inventories (<b>top</b>) and (<b>b</b>) <sup>210</sup>Pb index analysis by depositional environment. Concentrations of <sup>210</sup>Pb show preferential deposition in the undisturbed and gully cores of the Southwest Pass.</p> Full article ">Figure 9
<p>Timeseries of major forcing events (floods/hurricanes/dams) plotted along estimated mudflow occurrence dates by core. Major hurricane occurrences were referenced from the NOAA Historical Hurricane Tracker as category 3+ hurricanes with tracks within 70 miles of the Head of Passes. High-risk hurricanes are those described by Guidroz (2009) [<a href="#B12-jmse-12-01644" class="html-bibr">12</a>], and other focused river discharge (Talbert’s Landing) are referenced from the River Gauges Database (USACE). The first occurrence of <sup>137</sup>Cs (1953) forms a backstop for cores PS17-09, PS17-24, and PS17-30 and a forestop in PS17-03. The arrows indicate the South Pass depositional hiatus of hypopycnal deposition at much lower rates to the base of the core (listed in <a href="#jmse-12-01644-t001" class="html-table">Table 1</a>). Asterix (*) indicates calculation based off of <sup>137</sup>Cs due to the full penetration.</p> Full article ">
26 pages, 34475 KiB  
Article
Hydrodynamic Modeling of Water Renewal Time and Potential Dissolved Matter Using TELEMAC: Applications to Shediac Bay (New Brunswick, Canada)
by Chinh Lieou, Serge Jolicoeur, Thomas Guyondet, Stéphane O’Carroll and Tri Nguyen-Quang
J. Mar. Sci. Eng. 2024, 12(3), 461; https://doi.org/10.3390/jmse12030461 - 7 Mar 2024
Viewed by 917
Abstract
This study examines the hydrodynamic regimes in Shediac Bay, located in New Brunswick, Canada, with a focus on the breach in the Grande-Digue sand spit. The breach, which was developed in the mid-1980s, has raised concerns about its potential impacts on water renewal [...] Read more.
This study examines the hydrodynamic regimes in Shediac Bay, located in New Brunswick, Canada, with a focus on the breach in the Grande-Digue sand spit. The breach, which was developed in the mid-1980s, has raised concerns about its potential impacts on water renewal time and water quality in the inner bay. The aims of this study, using mathematical modeling approaches, were to evaluate the flow regimes passing through the breach and influences on the distribution of dissolved matter, providing insights into whether the breach should be allowed to naturally evolve or be artificially infilled to prevent contaminant stagnancy in the bay. The study considered three simulation scenarios to comprehend the water renewal time and the role of the breach in the environmental management of Shediac Bay. Results indicated that completely closing the breach would significantly increase the water renewal time in the inner bay, although the spatial extent of this increase is limited. However, the study identified some limitations, including the need to better define the concentration limit for considering water as renewed and the lack of consideration of dynamic factors such as wind and wave effects. Full article
(This article belongs to the Special Issue Advances in Coastal Hydrodynamic and Morphodynamic Processes under a Changing Climate)
►▼ Show Figures

Figure 1

Figure 1
<p>Delineation of the study limits (Grande-Digue–Northumberland Strait), modeled area and its bathymetry (the color scale, in meters).</p> Full article ">Figure 2
<p>Observation stations and observed parameters (water level, current velocity, temperature, and salinity).</p> Full article ">Figure 3
<p>Calculation mesh for the entire domain and the finer mesh at the main study area.</p> Full article ">Figure 4
<p>Applied initial conditions in the model: (<b>Left</b>) Type A and (<b>Right</b>) Type B.</p> Full article ">Figure 5
<p>Model calibration: comparison between the computed and observed water level.</p> Full article ">Figure 6
<p>Model calibration: comparison between the computed and observed current speed.</p> Full article ">Figure 7
<p>Model calibration: comparison between the computed and observed salinity.</p> Full article ">Figure 8
<p>Model validation: comparison between the computed and observed water level.</p> Full article ">Figure 9
<p>Model validation: comparison between the computed and observed current velocity.</p> Full article ">Figure 10
<p>Model validation: comparison between the computed and observed salinity.</p> Full article ">Figure 11
<p>Velocity distribution and streamlines in the flood tide and ebb tide periods (scenario 1).</p> Full article ">Figure 12
<p>(<b>a</b>) Location of the present breach; (<b>b</b>) dimension of a modeled enlarged breach (scenario 3).</p> Full article ">Figure 13
<p>Comparison of flow distribution in the three scenarios.</p> Full article ">Figure 14
<p>(<b>a</b>) Entire view of the renewal time for the three scenarios (initial condition type A); (<b>b</b>) closer view of the renewal time at the main study area for the three scenarios (initial condition type A).</p> Full article ">Figure 15
<p>(<b>a</b>) Entire view of the renewal time for the three scenarios (initial condition type B); (<b>b</b>) closer view of the renewal time at the main study area for the three scenarios (initial condition type B).</p> Full article ">Figure 16
<p>(<b>a</b>) Location of the random cross-section A-A’ to analyze the spatial changes of renewal time for the three scenarios; (<b>b</b>) location of the point used (blue dot) to analyze the evolution of tracer concentration for the three scenarios.</p> Full article ">Figure 17
<p>Comparison of renewal time at the random cross section A-A’ for the two types of initial conditions A and B.</p> Full article ">Figure 18
<p>Temporal evolution of tracer concentration and its difference in the three scenarios: (<b>a</b>) using type A initial condition; (<b>b</b>) using type B initial condition.</p> Full article ">Figure 18 Cont.
<p>Temporal evolution of tracer concentration and its difference in the three scenarios: (<b>a</b>) using type A initial condition; (<b>b</b>) using type B initial condition.</p> Full article ">
21 pages, 58703 KiB  
Article
A Four-Year Video Monitoring Analysis of the Posidonia oceanica Banquette Dynamic: A Case Study from an Urban Microtidal Mediterranean Beach (Poetto Beach, Southern Sardinia, Italy)
by Daniele Trogu, Simone Simeone, Andrea Ruju, Marco Porta, Angelo Ibba and Sandro DeMuro
J. Mar. Sci. Eng. 2023, 11(12), 2376; https://doi.org/10.3390/jmse11122376 - 16 Dec 2023
Cited by 1 | Viewed by 1293
Abstract
This paper investigates the dynamics of the cross-shore extensions of banquettes, a sedimentary structure mostly made by rests of Posidonia oceanica (L.) Delile, in a sandy urban beach located in the Gulf of Cagliari, Italy, western Mediterranean. A video monitoring station was installed [...] Read more.
This paper investigates the dynamics of the cross-shore extensions of banquettes, a sedimentary structure mostly made by rests of Posidonia oceanica (L.) Delile, in a sandy urban beach located in the Gulf of Cagliari, Italy, western Mediterranean. A video monitoring station was installed above the promontory south of the beach. We analysed a four-year image database and related these dynamics to wave and wind parameters (obtained from the Copernicus and ERA5 databases) from September 2016 to September 2020. Our results showed that banquette deposition occurred in concomitance with the presence of leaf litter in the surf zone associated with mild storm events. Erosion of the banquettes occurred during more intense storms. When leaf litter was not present in the surf zone, banquettes were not deposited even with mild storms. Wind can influence the banquette dynamics: under certain conditions of speed intensity, the banquettes may be removed offshore, supplying litter in the surf zone, or they may be covered by sediment. The permanence of the banquettes on the beaches also depended on their composition: when the banquettes were intertwined with reeds, their removal by the waves did not occur even during intense storms, and this sedimentary structure can protect the beach from flooding. Full article
(This article belongs to the Special Issue Advances in Coastal Hydrodynamic and Morphodynamic Processes under a Changing Climate)
►▼ Show Figures

Figure 1

Figure 1
<p>In panel (<b>A</b>), the red rectangle highlights the framing area of the camera, while the red circle indicates where the camera was installed. The dashed green line represents the upper limit of <span class="html-italic">P. oceanica</span> meadows. Panels (<b>B</b>,<b>C</b>), on the other hand, show examples of banquettes settling within the study area highlighted by the yellow dashed square in panel (<b>A</b>).</p> Full article ">Figure 2
<p>Geographical setting of the study area (western Mediterranean Sea) with: (<b>A</b>) red dashed lined: wave exposure angles (referred to the N = 0°) and fetch for the study area within Poetto beach; (<b>B</b>) location of video monitoring system and limits of Poetto beach; (<b>C</b>) detail of study area and the three transects (red lines T1, T2, and T3); (<b>D</b>) wind speed and direction for the four years of monitoring from the ERA5 reanalysis dataset (green star in panel (<b>A</b>) represents the grid node where the data were downloaded); (<b>E</b>) significant wave height and direction for the four years of monitoring at the Copernicus Marine Environment Monitoring Service virtual buoy (orange star in panel (<b>B</b>) represents the grid node where the data were downloaded). The yellow dotted line indicates that figure (<b>C</b>) is a zoom of the area within the yellow rectangle of panel (<b>B</b>).</p> Full article ">Figure 3
<p>Panel (<b>A</b>): oblique image from video monitoring system: the dots named with letters highlight the fixed ground control points in study area. Panel (<b>B</b>): orthorectified image with an example of measurement of the banquette cross-shore extension: the crosses represent the start and end points for each measurement.</p> Full article ">Figure 4
<p>Time series of the banquette extensions along the three transects (panels T1, T2, and T3) for the four years of acquisitions, with the related significant wave height (Hs) and peak wave period (Tp). I (red rectangle), II (violet rectangle), and III (blue rectangle) represent the periods that were split, respectively, in <a href="#sec3dot1-jmse-11-02376" class="html-sec">Section 3.1</a>, <a href="#sec3dot2-jmse-11-02376" class="html-sec">Section 3.2</a> and <a href="#sec3dot3-jmse-11-02376" class="html-sec">Section 3.3</a>.</p> Full article ">Figure 5
<p>Time series of the banquette extensions along the three transects (panels T1, T2, and T3) for the period from the 20th of October 2016 to 20th of June 2017.</p> Full article ">Figure 6
<p>Exemplified images of the first interval period: large accumulation of <span class="html-italic">P. oceanica</span> floating leaf litter was detected (brown patches in the shallow water fronting the beach).</p> Full article ">Figure 7
<p>Time series of the banquette extensions along the three transects (panels T1, T2, and T3) for the period from the 18th of October 2018 to the 22nd of January 2019.</p> Full article ">Figure 8
<p>Exemplified images of the second interval period: floating leaf litter was only detected in October 2018 at the same time as the presence of banquettes. In the following months, neither banquettes nor floating leaf litter were detected. Panel (<b>A</b>): during october 2018 banquette and floating leaf litter were present in the study area. Panel (<b>B</b>–<b>D</b>): during other months of the second period neither floating leaf litter nor any banquette was detected.</p> Full article ">Figure 9
<p>Time series of the banquette extensions along the three transects (panels T1, T2, and T3) for the period from the 30th of November 2019 to the 20th of June 2020. The seagrass berm in this period was largely mixed with <span class="html-italic">Arundo donax</span> reeds (deposited during the event highlighted by green line) that seemed to make the structure more resistant to erosion during storm events, such as the example shown by vertical blue line.</p> Full article ">Figure 10
<p>Images acquired on the 19th of January 2020, two days before the storm peak, next to area T2. <span class="html-italic">A. donax</span> and <span class="html-italic">P. oceanica</span> rests were well intertwined. The fences, not being particularly hard structures, were broken down by the swell without significantly restricting the movement of the reeds towards the emerged beach.</p> Full article ">Figure 11
<p>Deposition of banquettes at the end of a storm. In panel (<b>A</b>), an extended floating leaf litter in the surf zone is highlighted (dark area between the dashed red lines). During the storm (panel (<b>B</b>)), this vegetal biomass was transported and sedimented on the shore, building the banquette, as visible from panel (<b>C</b>,<b>D</b>) (dark area within the red lines in panel (<b>D</b>)). Moreover, in panel (<b>D</b>), another huge floating leaf litter deposition is visible in the surf zone.</p> Full article ">Figure 12
<p>Some examples of banquettes (within the red circles) partly removed and partly covered with sand during offshore wind events. Panel (<b>A</b>,<b>B</b>): mean wind speed between the two days was 62.9 Km h<sup>−1</sup>. Panel (<b>C</b>,<b>D</b>): mean wind speed between the two days was 49.8 Km h<sup>−1</sup>. Panel (<b>E</b>,<b>F</b>): mean wind speed between the two days was 61.2 Km h<sup>−1</sup>.</p> Full article ">
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Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title1: Monitoring of bar migration and its impact on swash dynamics on a dissipative beach with video imagery and field measurements
Abstract: In this contribution, the hydro-morphological behavior during energetic storm events of a microtidal dissipative beach that experiences erosional phenomena and is of high economic importance (Marmari beach, Kos island, Greece) is presented. The study focuses on the deposition and formation of the longshore sandbar under different recorded wind and wave conditions, while the evolution of the shoreline and the wave run-up maxima line is also investigated. To achieve that, a beach optical monitoring system (comprising of a video camera and a meteorological station) and a high frequency wave logger were deployed at the study area during the energetic winter-spring period. Pre and post-storm positions of the longshore sandbar and the shoreline are compared to investigate the storm impact on beach morphology, while swash maxima is examined in conjunction with the recorded waves approaching from offshore. Results suggest that the beach system showed significant spatio-temporal variability during the monitoring period. The position of the sandbar and the shoreline is controlled by the coastal hydrodynamic action (littoral drift), while a strong correlation is found when checking the distance between the shoreline and the sandbar.

Title2: Temporal scales of mass wasting sedimentation across the Mississippi River Delta Front delineated by 210Pb/137Cs Geochronology
Abstract: The Mississippi River Delta Front (MRDF) is a subaqueous apron of rapidly deposited and weakly consolidated sediment extending from the subaerial portions of the Birdsfoot Delta of the Mississippi River, long known to be characterized by mass-wasting sediment transport. Four (4) depositional environments dominate regionally (undisturbed topset apron, mudflow gully, mudflow lobe, and prodelta) centering around mudflow distribution initiated by a variety of factors (hurricanes, storms, Fluid pressure). In order to better understand spatial-temporal scales of events as well as controlling processes, eight 5.8 to 8.0 m cores taken from the South (SP) and Southwest Passes (SWP) were analyzed for gamma density, grain size, sediment fabric (X-radiography), and geochronology (210Pb/137Cs radionuclides). Building on other recent stud-ies, within the mudflow gully and lobe core, homogeneous, stepped profiles of 210Pb activities and corresponding decreased gamma density indicate the presence of gravity driven mass-failures. 210Pb/137Cs indicates gully sedimentary sediment accumulation since 1953 is greater than 580 cm (sediment accumulation rate [SAR] of 12.8 cm/y) in the Southwest Pass site, and lower SAR of S Pass gully sites (2.6 cm/y). This study shows that (1) recent dated mudflow deposits are identifiable in both the SWP and SP; (2) a SWP mudflows have return periods of 10.7 y, six times the return period at SP (66.7 y); (3) 210Pb inventories display higher levels overall in the SWP area with highest focusing factors in proximal/gully sedimentation, and (4) submarine landslides in both study areas remain important for sediment transfer despite differences is sediment delivery and discharge source proximity.

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