Journal of Marine Science and Engineering

Research

14 pages, 6642 KiB

Open AccessArticle

Shoreline Changes from Erosion and Sea Level Rise with Coastal Management in Phuket, Thailand

by Pattrakorn Nidhinarangkoon, Sompratana Ritphring, Kanon Kino and Taikan Oki

J. Mar. Sci. Eng. 2023, 11(5), 969; https://doi.org/10.3390/jmse11050969 - 1 May 2023

Cited by 3 | Viewed by 2847

Phuket, the study area of this work with 33 sandy beaches, provides about 15% of the nation’s gross domestic product from the tourism industry. Many factors cause shoreline changes affecting beach areas, such as seasonal erosion and rising sea levels. In this study, [...] Read more.

Phuket, the study area of this work with 33 sandy beaches, provides about 15% of the nation’s gross domestic product from the tourism industry. Many factors cause shoreline changes affecting beach areas, such as seasonal erosion and rising sea levels. In this study, shoreline position was the key parameter for evaluating shoreline changes. The CoastSat open-source software was selected to analyze the shoreline changes using a publicly available satellite imagery API. The future shoreline recession was projected using the Bruun rule integrated with field observation data and sea level rise scenarios from Coupled Model Intercomparison Project Phase 6 (CMIP6). The result indicated that eight of the study site’s locations were under mild erosion from 2013 to 2021. The average shoreline change varied between −4.10 and 5.47 m/year. The projection of future beach loss due to sea level rise found that 20 beaches and 32 beaches will be lost entirely under SSP1 2.6 and SSP5 8.5, respectively. Beach morphology is influenced by human-induced activities, such as coastal urbanization and the development of structures along the coast. This study discusses the effectiveness of the present coastal protection structure with data from field observations and suggests possible future management strategies. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

24 pages, 7458 KiB

Open AccessArticle

A Turbulence Survey in the Gulf of Naples, Mediterranean Sea, during the Seasonal Destratification

by Florian Kokoszka, Fabio Conversano, Daniele Iudicone, Bruno Ferron and Pascale Bouruet-Aubertot

J. Mar. Sci. Eng. 2023, 11(3), 499; https://doi.org/10.3390/jmse11030499 - 25 Feb 2023

Viewed by 1262

Abstract

The seasonality of the vertical mixing at coastal sites is not well characterized yet. Here, a time series of the dissipation rate of turbulent kinetic energy (ε) was obtained from weekly morning microstructure observations covering the destratification period (July 2015, February 2016) at [...] Read more.

The seasonality of the vertical mixing at coastal sites is not well characterized yet. Here, a time series of the dissipation rate of turbulent kinetic energy (ε) was obtained from weekly morning microstructure observations covering the destratification period (July 2015, February 2016) at a coastal site in the western Mediterranean Sea, influenced by freshwater runoffs. Estimated with bulk parameters from the public re-analyzed dataset ERA5, the Ekman layer, and the convective penetration depth scale with the mixed layer depth (MLD) with a good agreement. Below the MLD, peaks of ε are observed in the baroclinic layers that progressively overlap with the bottom layer, where repeated near-bottom turbidity peaks provide evidence of sediment resuspension, suggesting energetic processes within the bottom boundary layer. In the subsurface, moderate values (

10^{- 9}

to

10^{- 8} W {kg}^{- 1}

) are observed, following a Burr type XII distribution. Significant correlation with ε at MLD is obtained with a model combining the effects of wind, wind–wave, and convection, highlighting a calm sea bias in our data, plus a sunrise bias when morning buoyancy fluxes are stabilizing. Another correlation, obtained from a pure-wind estimation 18 h before, suggests the role of wind in generating internal waves in the stratified layers, thus, impacting mixing intensity. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

24 pages, 8778 KiB

Open AccessArticle

The Feasibility of the ERA5 Forced Numerical Wave Model in Fetch-Limited Basins

by Damjan Bujak, Goran Lončar, Dalibor Carević and Tin Kulić

J. Mar. Sci. Eng. 2023, 11(1), 59; https://doi.org/10.3390/jmse11010059 - 2 Jan 2023

Cited by 2 | Viewed by 1518

Abstract

Numerical wave models are critical in hindcasting reliable long-term time series of significant wave heights, which play a crucial role in coastal and ocean engineering activities. Although wind fields are an important input to numerical wave models, few studies have investigated the feasibility [...] Read more.

Numerical wave models are critical in hindcasting reliable long-term time series of significant wave heights, which play a crucial role in coastal and ocean engineering activities. Although wind fields are an important input to numerical wave models, few studies have investigated the feasibility of the widely used ERA5 wind reanalysis dataset in fetch-limited basins. In this work, we investigated the feasibility of the ERA5 forced numerical wave model (SWAN) in fetch-limited basins. ERA5 wind velocities were first compared to ground-based meteorological stations, showing poorer accuracy compared to finer gridded ALADIN wind data. Subsequently, the white-capping coefficient C_ds in the Janssen white-capping formulation was calibrated separately using a surrogate model when establishing the ERA5 and ALADIN forced wave models. The calibrated ERA5 forced model showed a similar agreement to wave buoy data as the calibrated ALADIN forced wave model during the calibration period and even superior accuracy in the validation period. Overall, these results show that the wave model calibration procedure mitigates the effect of the poorer accuracy of the ERA5 wind data on the significant wave height results. Nevertheless, both ERA5 and ALADIN forced wave models showed an alarming overprediction for high simulated significant wave heights. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

28 pages, 12579 KiB

Open AccessArticle

Hydrology and Dynamics in the Gulf of Naples during Spring of 2016: In Situ and Model Data

by Luigi Gifuni, Paola de Ruggiero, Daniela Cianelli, Enrico Zambianchi and Stefano Pierini

J. Mar. Sci. Eng. 2022, 10(11), 1776; https://doi.org/10.3390/jmse10111776 - 18 Nov 2022

Cited by 1 | Viewed by 1757

Abstract

The hydrology and circulation in the northwestern part of the Gulf of Naples are analyzed during the transition period from spring to summer (April–June) 2016 through numerical simulations and in situ observations. The simulations were performed with the high-resolution sigma-coordinate Campania Regional Ocean [...] Read more.

The hydrology and circulation in the northwestern part of the Gulf of Naples are analyzed during the transition period from spring to summer (April–June) 2016 through numerical simulations and in situ observations. The simulations were performed with the high-resolution sigma-coordinate Campania Regional Ocean Model (CROM) encompassing the wider Campania coastal system. Temperature, salinity and density were measured at the Long Term Ecological Research Program Mare-Chiara sampling site located two miles from the coast, while current intensity and direction were measured in situ by an acoustic Doppler current profiler connected to an elastic beacon anchored at a short distance from the city of Naples. The modeled circulation scenarios and the marine hydrology provided by the model on a regular grid allow interpreting the observational data during the selected period. In turn, the model-data comparison clarifies the model performance in reproducing the nearshore marine dynamics, which goes beyond the actual model resolution. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

20 pages, 6105 KiB

Open AccessArticle

Gulf of Naples Advanced Model (GNAM): A Multiannual Comparison with Coastal HF Radar Data and Hydrological Measurements in a Coastal Tyrrhenian Basin

by Florian Kokoszka, Simona Saviano, Vincenzo Botte, Daniele Iudicone, Enrico Zambianchi and Daniela Cianelli

J. Mar. Sci. Eng. 2022, 10(8), 1044; https://doi.org/10.3390/jmse10081044 - 29 Jul 2022

Cited by 2 | Viewed by 1495

Abstract

High-resolution modelling systems have increasingly become an essential requirement to investigate ocean dynamics over a wide range of spatial and temporal scales, and to integrate the punctual ocean observations. When applied in coastal areas, they also have the potential to provide a detailed [...] Read more.

High-resolution modelling systems have increasingly become an essential requirement to investigate ocean dynamics over a wide range of spatial and temporal scales, and to integrate the punctual ocean observations. When applied in coastal areas, they also have the potential to provide a detailed representation of transport and exchange processes at the sub-basin scale. This paper presents a validation exercise between the surface fields generated by the regional ocean modeling system (ROMS), developed for the Tyrrhenian Sea and downscaled for the Gulf of Naples (GNAM Gulf of Naples advanced model), and a 4 year-long (2009–2012) record of high-frequency radar (HFR) data. The comparison between hourly and seasonal model results and HFR surface fields is focused on the Gulf of Naples (GoN), where an observational network of three HFR sites has been operational since 2004, and on a specific subdomain characterized by the presence of the Sarno river, a long-term ecological research station (LTER-MC) and one important canyon area. An evaluation on a transect delimiting inshore–offshore zones in the GoN is also presented. The GNAM model was also compared with in situ hydrological parameters of temperatures and salinities retrieved at the LTER-MC fixed monitoring station. According to the skill metrics, basic circulation features are accurately reproduced by the circulation model, despite some model drawbacks in terms of increment of energy content in the surface current field occurring during specific seasonal events. The results allow us to identify potential model errors and to suggest useful improvements, the outcome also confirms the unique capability of HF radar systems to provide fine-scale measurements for the validation of numerical models and to counterbalance the lack of high-resolution measurements in coastal areas. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

32 pages, 14096 KiB

Open AccessArticle

Water Circulation and Transport Time Scales in the Beagle Channel, Southernmost Tip of South America

by Andrea Cucco, Jacobo Martín, Giovanni Quattrocchi, Harold Fenco, Georg Umgiesser and Daniel Alfredo Fernández

J. Mar. Sci. Eng. 2022, 10(7), 941; https://doi.org/10.3390/jmse10070941 - 8 Jul 2022

Cited by 13 | Viewed by 2155

Abstract

The Beagle Channel is a long and narrow interoceanic passage within the Tierra del Fuego archipelago in the southernmost tip of South America. A high-resolution 3D hydrodynamic model based on the finite elements method was applied to investigate the residual circulation, water fluxes [...] Read more.

The Beagle Channel is a long and narrow interoceanic passage within the Tierra del Fuego archipelago in the southernmost tip of South America. A high-resolution 3D hydrodynamic model based on the finite elements method was applied to investigate the residual circulation, water fluxes and transport time scales inside this channel. Numerical solutions were analyzed at seasonal time scale and the model results compared with observed ocean data. The circulation pattern is characterized by a west-to-east residual flow with low intensity and low seasonal variability. The water fluxes through the channel were estimated to be, on average, around 12,700 m³/s, with inflow through its western entrance and eastwards outflow mainly through the Mackinlay Strait. The water residence times vary seasonally with basin averages between 36 and 43 days and maximum values between 53 and 95 days. The results provide an overview of the hydrodynamics and water residence times in the Beagle Channel, a unique ecosystem threatened by recent anthropogenic pressures and climate change. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

20 pages, 7145 KiB

Open AccessArticle

Human Intervention–Induced Changes in the Characteristics of the Turbidity Maximum Zone and Associated Mouth Bars in the Yangtze Estuary

by Weihua Li, Chenjuan Jiang, Shuhua Zuo and Jiufa Li

J. Mar. Sci. Eng. 2022, 10(5), 584; https://doi.org/10.3390/jmse10050584 - 26 Apr 2022

Cited by 1 | Viewed by 1689

Abstract

In the past two decades, the dynamic sedimentation process of the Yangtze Estuary has been seriously disturbed by coupled human interventions from the river basin to the estuary, especially the impoundment of the Three Gorges Dam in 2003 and the large-scale Deep-water Navigational [...] Read more.

In the past two decades, the dynamic sedimentation process of the Yangtze Estuary has been seriously disturbed by coupled human interventions from the river basin to the estuary, especially the impoundment of the Three Gorges Dam in 2003 and the large-scale Deep-water Navigational Channel (DNC) regulation project in 1998–2010. This study investigated the changes in sedimentary dynamic and geomorphological processes in the turbidity maximum zone (TMZ) by analyzing the historical and present data for current, salinity, suspended sediment, and bathymetry. The results show that the decreased riverine sediment input caused a lagging decrease in suspended sediment concentration in the TMZ during the flood seasons. The DNC caused changes in the flow structure, sediment transport, and geometry of the TMZ in the North Passage (NP) and the South Passage (SP). In the NP, decreased ebb transport in the upper reaches led to landward migration of the TMZ during low discharges, while increased ebb transport in the middle and lower reaches caused the seaward migration of the TMZ during high discharges. As the associated topography of the TMZ, the mouth bar in the NP was mostly removed by channel dredging. However, rapid deposition at the location of the previous mouth bar indicates the formation of an incipient bar. In the SP, increased ebb transport after the DNC-induced disappearance of the TMZ and the mouth bar in the upper reaches and the seaward migration of the TMZ in the middle and lower reaches. Therefore, we found that the construction of dams and large-scale estuarine projects changed the sediment dynamics and geomorphological processes of the TMZ and even affected the long-term evolution of the estuary. Construction regulation projects in the TMZ, intended to narrow the cross-section and enhance seaward sediment transport, may produce the opposite effect. Before and after engineering projects, their impacts on estuarine processes need to be carefully estimated. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

15 pages, 2657 KiB

Open AccessArticle

Shoreline Detection Accuracy from Video Monitoring Systems

by Jaime Arriaga, Gabriela Medellin, Elena Ojeda and Paulo Salles

J. Mar. Sci. Eng. 2022, 10(1), 95; https://doi.org/10.3390/jmse10010095 - 11 Jan 2022

Cited by 4 | Viewed by 1948

Abstract

Video monitoring has become an indispensable tool to understand beach processes. However, the measurement accuracy derived from the images has been taken for granted despite its dependence on the calibration process and camera movements. An easy to implement self-fed image stabilization algorithm is [...] Read more.

Video monitoring has become an indispensable tool to understand beach processes. However, the measurement accuracy derived from the images has been taken for granted despite its dependence on the calibration process and camera movements. An easy to implement self-fed image stabilization algorithm is proposed to solve the camera movements. Georeferenced images were generated from the stabilized images using only one calibration. To assess the performance of the stabilization algorithm, a second set of georeferenced images was created from unstabilized images following the accepted practice of using several calibrations. Shorelines were extracted from the images and corrected with the measured water level and the computed run-up to the 0 m contour. Image-derived corrected shorelines were validated with one hundred beach profile surveys measured during a period of four years along a 1.1 km beach stretch. The simultaneous high-frequency field data available of images and beach surveys are uncommon and allow assessing seasonal changes and long-term trends accuracy. Errors in shoreline position do not increase in time suggesting that the proposed stabilization algorithm does not propagate errors, despite the ever-evolving vegetation in the images. The image stabilization reduces the error in shoreline position by 40 percent, having a larger impact with increasing distance from the camera. Furthermore, the algorithm improves the accuracy on long-term trends by one degree of magnitude (0.01 m/year vs. 0.25 m/year). Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

22 pages, 8142 KiB

Open AccessArticle

Water and Salt Transports in the Hengsha Channel of Changjiang Estuary

by Rui Ma and Jianrong Zhu

J. Mar. Sci. Eng. 2022, 10(1), 72; https://doi.org/10.3390/jmse10010072 - 6 Jan 2022

Viewed by 1666

Abstract

In a multilevel bifurcated estuary, the channels between the bifurcated branches play important roles in the exchanges of water and salt. In the Changjiang Estuary, the Hengsha Channel (HC) connects the North Channel (NC) and the North Passage (NP). In this paper, based [...] Read more.

In a multilevel bifurcated estuary, the channels between the bifurcated branches play important roles in the exchanges of water and salt. In the Changjiang Estuary, the Hengsha Channel (HC) connects the North Channel (NC) and the North Passage (NP). In this paper, based on a two-way nesting unstructured quadrilateral grid, finite-differencing, three-dimensional estuarine and coastal ocean model, the tidal and seasonal variations in the water and salt transports in the HC were simulated, and their dynamic mechanism was analyzed. The residual water and salt transports in the HC both flow southward from the NC to the NP. In wet season, the residual water transport in the HC is 677 m³/s during neap tide and 245 m³/s during spring tide, and the residual salt transport is 0. In dry season, the residual water and salt transports in the HC are 1278 m³/s and 0.38 t/s during neap tide, respectively, and 1328 m³/s and 12.61 t/s during spring tide. Affected by the northerly wind and the southeastward baroclinic gradient force, the water and salt fluxes in dry season are much larger than those in wet season. The dynamic mechanism responsible for the water transport in the HC was numerically simulated and analyzed. Full article

(This article belongs to the Special Issue Dynamics in Coastal Areas)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Dynamics in Coastal Areas

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI