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1 – 10 of 628Md. Jahir Uddin, Md. Nymur Rahman Niloy, Md. Nazmul Haque and Md. Atik Fayshal
This study aims to determine shoreline change statistics and net erosion and accretion, along the Kuakata Coast, a magnificent sea beach on Bangladesh’s southernmost point.
Abstract
Purpose
This study aims to determine shoreline change statistics and net erosion and accretion, along the Kuakata Coast, a magnificent sea beach on Bangladesh’s southernmost point.
Design/methodology/approach
The research follows a three stages way to achieve the target. First, this study has used the geographic information system (GIS) and remote sensing (RS) to detect the temporal observation of shoreline change from the year 1991 to 2021 through satellite data. Then, the digital shoreline analysis system (DSAS) has also been explored. What is more, a prediction has been done for 2041 on shoreline shifting scenario. The shoreline displacement measurement was primarily separated into three analytical zones. Several statistical parameters, including Net Shoreline Movement (NSM), Shoreline Change Envelope (SCE), End Point Rate (EPR) and Linear Regression Rate (LRR) were calculated in the DSAS to quantify the rates of coastline movement with regard to erosion and deposition.
Findings
EPR and LRR techniques revealed that the coastline is undergoing a shift of landward (erosion) by a median rate of 3.15 m/yr and 3.17 m/yr, respectively, from 1991 to 2021, 2.85 km2 of land was lost. Naval and climatic influences are the key reasons for this variation. This study identifies the locations of a significantly eroded zone in Kuakata from 1991 to 2021. It highlights the places that require special consideration while creating a zoning plan or other structural design.
Originality/value
This research demonstrates the spatio-temporal pattern of the shoreline location of the Kuakata beach, which would be advantageous for the region’s shore management and planning due to the impacts on the fishing industry, recreation and resource extraction. Moreover, the present research will be supportive of shoreline vulnerability. Hence, this study will suggest to the local coastal managers and decision-makers for particularizing the coastal management plans in Kuakata coast zone.
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V.R. Voller, J.B. Swenson, W. Kim and C. Paola
To present a novel moving boundary problem related to the shoreline movement in a sedimentary basin and demonstrate that numerical techniques from heat transfer, in particular…
Abstract
Purpose
To present a novel moving boundary problem related to the shoreline movement in a sedimentary basin and demonstrate that numerical techniques from heat transfer, in particular enthalpy methods, can be adapted to solve this problem.
Design/methodology/approach
The problem of interest involves tracking the movement (on a geological time scale) of the shoreline of a sedimentary ocean basin in response to sediment input, sediment transport (via diffusion), variable ocean base topography, and changing sea level. An analysis of this problem shows that it is a generalized Stefan melting problem; the distinctive feature, a latent heat term that can be a function of both space and time. In this light, the approach used in this work is to explore how previous analytical solutions and numerical tools developed for the classical Stefan melting problem (in particular fixed grid enthalpy methods) can be adapted to resolve the shoreline moving boundary problem.
Findings
For a particular one‐dimensional case, it is shown that the shoreline problem admits a similarity solution, similar to the well‐known Neumann solution of the Stefan problem. Through the definition of a compound variable (the sum of the fluvial sediment and ocean depths) a single domain‐governing equation, mimicking the enthalpy formulation of a one‐phase melting problem, is derived. This formulation is immediately suitable for numerical solution via an explicit time integration fixed grid enthalpy solution. This solution is verified by comparing with the analytical solution and a limiting geometric solution. Predictions for the shoreline movement in a constant depth ocean are compared with shoreline predictions from an ocean undergoing tectonic subsidence.
Research limitations/implications
The immediate limitation in the work presented here is that “off‐shore” sediment transport is handled in by a “first order” approach. More sophisticated models that take a better accounting of “off shore” transport (e.g. erosion by wave motion) need to be developed.
Practical implications
There is a range of rich problems involving the evolution of the earth's surface. Many of the key transport processes are closely related to heat and mass transport. This paper illustrates that this similarity can be exploited to develop predictive models for earth surface processes. Such models are essential in understanding the formation of the earth's surface and could have a significant impact on natural resource (oil reserves) and land (river restoration) management.
Originality/value
For the most part the solution methods developed in this work are extensions of the standard numerical techniques used in heat transfer. The novelty of the work presented rests in the nature of the problems solved, not the method used. The particular novel feature is the time and space dependence of the latent heat function; a feature that leads to interesting analytical and numerical results.
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Abstract
Purpose
Coastal zone ecological restoration project is of great significance to alleviate marine ecological degradation. Evaluating the effect of coastal ecological restoration projects and identifying the obstacle factors affecting their restoration level can provide an empirical basis for future Marine ecological restoration projects.
Design/methodology/approach
However, due to the initial stage of coastal zone ecological restoration projects, the actual monitoring data of coastal zone ecological restoration is relatively lacking. Based on the CRITIC-TOPSIS (combination of CRITIC method and TOPSIS method) method, combined with the subjective perception of the public and the actual data of the restoration project, this paper proposes an evaluation method of the coastal zone ecological restoration effect to obtain the specific implementation effect of the coastal zone ecological restoration project. The main obstacle factors affecting the evaluation of coastal ecological restoration effect are identified by using the obstacle degree model.
Findings
This paper conducted an empirical study on the restoration of sandy shoreline and coastal wetland in Qinhuangdao city. Based on the data of restoration projects and the subjective perception of ecological restoration by the public in Qinhuangdao city, the research results showed that the coastal zone ecological restoration effect of Qinhuangdao city was general. The quality of the restoration project and the public perception have an important influence on the evaluation of the restoration effect. Improving the quality of the restoration project, strengthening the public's participation in ecological restoration and allowing the public to better participate in the ecological restoration of the coastal zone can improve the effect of ecological restoration of the coastal zone in an all-round way.
Originality/value
The research results of this paper have a guiding role in the ecological restoration of coastal cities in the future, and also have a demonstration and reference role for the assessment of the effect of ecological restoration of coastal zones.
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Using oceanographer Rachel Carson's study The Edge of the Sea (1955) to contextualise tidal spaces, this chapter discusses how constantly shifting and eroding coastlines act as a…
Abstract
Using oceanographer Rachel Carson's study The Edge of the Sea (1955) to contextualise tidal spaces, this chapter discusses how constantly shifting and eroding coastlines act as a site for writing, re-writing and performing acts of cultural and personal memory. It also considers the ecological impact of human activity on tidal spaces and their more-than-human inhabitants.
14-18 NOW's Pages of the Sea, directed by Danny Boyle, invited communities around the United Kingdom to meet on their local beach to commemorate those who were lost in World War I by marking portraits in the tidal sands. Choreographer Chloë Smith's Tidal, performed in Berwick-upon-Tweed in 2015, was commissioned as a commemorative work but became an act of personal memorialising when Smith's brother drowned prior to the event. Performance company Curious's Out of Water (2012–2014), invites participants on a dawn-walk to the shoreline exploring memory, time, genealogy and water through song and movement. My own collaborative site-responsive work, Tide Times (2018), created with electroacoustic composer Tim Cooper for the tidal island of Cramond, explores the multiple identities of place over time. Tide Times encouraged audiences to create their own tidal poems and artworks through a series of invitations in treasure chests hidden around the island.
In explicating these aforementioned artworks, which explore ideas of remembrance using tidal spaces, this chapter will also acknowledge the forgetting that is implicit in performing these actions. What can the legacy of commemorations traced in such a transient and precarious space as a tidal zone be? This chapter argues that while shorelines provide sites for large and small scale acts of public remembering, they are simultaneously acts of forgetting as the twice daily tides cause inevitable erasure.
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Understanding the factors that contribute to the growth of sediment delta lobes in river systems has significant benefit towards protecting civil and social infrastructure from…
Abstract
Purpose
Understanding the factors that contribute to the growth of sediment delta lobes in river systems has significant benefit towards protecting civil and social infrastructure from severe weather events. To develop this understanding, this paper aims to construct a three‐dimensional numerical model of a sediment delta depositing on to a two‐dimensional bedrock basement entering an ocean at a constant sea‐level.
Design/methodology/approach
The approach used adapts and applies techniques and schemes previously used in building numerical heat transfer models of melting systems. Particular emphasis is placed on modifying fixed grid enthalpy like schemes.
Findings
The resulting model provides important insight on the features that control the partition of sediment delta deposition between the land and ocean domains. The model also illustrates how tectonic subsidence may control the rate of delta growth.
Originality/value
This is the first numerical heat transfer inspired model of a three‐dimensional sediment delta deposit over both land and ocean domains. The problem has scientific merit in that it represents a melting‐like moving boundary problem with two distinct moving boundaries and a space/time dependent latent heat. Further, this work is a necessary first step towards building a comprehensive understanding of how to restore delta systems to protect civil and social infrastructure.
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Md Mahdi Hj Abd Latif and Gabriel Y.V. Yong
The coast at Berakas in the Brunei-Muara district of Brunei Darussalam suffers from erosion caused by a combination of fluvial and marine processes. This paper investigates the…
Abstract
The coast at Berakas in the Brunei-Muara district of Brunei Darussalam suffers from erosion caused by a combination of fluvial and marine processes. This paper investigates the rate and pattern of erosion along a 1.8-km stretch of coast to compare the difference between the unprotected and protected sections. We used (i) image and spatial analysis and (ii) field geomorphology. The Digital Shoreline Analysis System (DSAS) in ArcGIS was used to compare the study area using two Google Earth images. The study found that the unprotected section had receded by 4.6 m between 2009 and 2019, while the protected section had advanced by 8.0 m over the same period; intense gullying and slumping of cliff continued at both sections. The detached headland breakwaters in the protected section were effective in stabilizing the coast. A concrete drain installed parallel to the cliff edge appears to be capable of intercepting storm runoff, but its effectiveness was undermined by lack of maintenance. We conclude that terrestrial-fluvial processes continue to erode coastal land and cause slumping of the cliff face at Berakas. However, coastal protection structures that curb the marine process could stabilize the coastline, even where sediment transport is active.
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Achilleas G. Samaras and Christopher G. Koutitas
To study the impact of River Nestos (North Greece) dams construction on coastal morphology.
Abstract
Purpose
To study the impact of River Nestos (North Greece) dams construction on coastal morphology.
Design/methodology/approach
In order to study the evolution of the coastal morphology in the area, an “one‐line shoreline change model” was developed (PELNCON). The model's input comprises the field characteristics, the wave characteristics at the breaker line and a “source” term for the sediment supply rate by River Nestos. The model calculates the shoreline change over a given period of time. The annually transported sediment quantity by the river is estimated using filed measurements and other models' results for various sites along the Greek part of the hydrologic basin of Nestos (Nestos is a transboundary river extending along Greece and Bulgaria).
Findings
The “PELNCON” results demonstrate a serious erosion threat for the coastal area due to the sediment budget deficit of about 1.8 × 106 m3/year.
Research limitations/implications
The developed model is subject to common structural weaknesses of computational modelling based on the one‐line shoreline change theory.
Practical implications
The developed model is user‐friendly and can be applied to any coastal area of known characteristics, providing realistic results.
Originality/value
This paper is an attempt to model the correlation between two large‐scale phenomena, namely coastal erosion and water/sediment management in river basins, setting at the same time the basis for further study on this particular scientific field.
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Russell Jones and Elizabeth Strange
Over the past century, the rate of sea level rise (SLR) has increased more than twice the average historical rate and the US Environmental Protection Agency estimates that by 2100…
Abstract
Purpose
Over the past century, the rate of sea level rise (SLR) has increased more than twice the average historical rate and the US Environmental Protection Agency estimates that by 2100 the sea level will increase nearly two feet in many coastal areas. Property owners and municipalities typically respond to SLR by constructing seawalls and similar structures to protect shoreline property (a practice known as “armoring”). The degree to which SLR and armoring threaten key coastal habitats has not been well studied, however. This study, aims to develop an inundation model on behalf of Stratus Consulting to examine anticipated habitat changes in coastal Ocean County, New Jersey.
Design/methodology/approach
The model used a geographical information system to map predicted changes in coastal habitats under two alternative SLR scenarios and six different shoreline armoring scenarios. The paper then used information from local experts and the scientific literature to predict changes in the relative abundances of fish and bird species under the different scenarios.
Findings
Under all scenarios, the model predicted substantial declines in the areal extent of Spartina marshes and in the annual production of finfish and shrimp. Declines in these marsh‐dependent species would have significant impacts on commercial and recreational fisheries. The study also predicted substantial declines in bird species such as songbirds and dabbling ducks.
Originality/value
The results of the study can help local stakeholders and decision‐makers plan responses to SLR. Conventional armoring responses could result in substantial and irreversible losses of coastal habitats and the species dependent on these habitats.
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The use of geotextile sand containers (GSCs) in shoreline protection systems has moderately grown since the first applications in the 1970s and increasingly used as an alternative…
Abstract
The use of geotextile sand containers (GSCs) in shoreline protection systems has moderately grown since the first applications in the 1970s and increasingly used as an alternative to natural stone, slag, and concrete. Due to their economical, technical and ecological advantages, the use of geotextiles and geocomposites for filter and drainage functions is increasing worldwide and has a 40 year history already. For coastal protection measures, nonwovens are proven to have long-term resistance against ultraviolet radiation and saltwater. High elongation behavior provides superior properties during loading in coastal protection means, which is determined as being the biggest risk for damaging geotextiles. Such applications require certain functional characteristics in the geotextiles, besides their basic properties, which are required to be engineered by the judicious optimization of the needlepunching process. In this study, the effect of the process parameters including punch density and depth of needle penetration has been investigated on the mechanical (tensile strengths in the machine and cross-machine directions) properties of needlepunched nonwoven geotextiles. These process parameters are then empirically related to the fabric properties by using a multiple regression technique.
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Serafeim Polyzos and Dionissios Minetos
Non‐marketable natural coastal resources such as beaches, sand‐dune systems and cliff sides have an economic value deriving not least from the various services which they provide…
Abstract
Purpose
Non‐marketable natural coastal resources such as beaches, sand‐dune systems and cliff sides have an economic value deriving not least from the various services which they provide as well as the human demand for consuming some of these services. Coastal defence projects designed to protect the coast against erosion and flooding by the sea have often caused irreversible degradation to coastal natural resources. The main aim of this article is to investigate whether the joint use of cost‐benefit analysis and environmental resource valuation techniques can give any insights toward the sustainable use of the coast. Design/methodology/approach – This paper employs cost‐benefit analysis (CBA) in order to assess the justifiability of carrying out coast protection works in a particular location. This paper also uses contingent valuation methodology (CVM) to estimate the economic values of non‐marketable coastal environmental services. In particular, this paper employs willingness to pay (WTP) technique and try to elicit satisfaction values from beach users by conducting an on‐site questionnaire survey. Findings – his paper argues that there are many advantages in approaching shoreline protection project appraisal both from an environmental as well as an economics point of view. However, when conducting a cost‐benefit analysis the monetary value of environment elicited by contingent valuation techniques has very limited use in it self. It can set the financial budget within which likely coast protection options should be considered but it cannot determine which option is more sustainable. What the decision‐maker needs is to give real meaning to this value by translating it into people's specific preferences and behavioural characteristics. The next step should be setting out pragmatic project characteristics to accommodate the above preferences. Practical implications – Knowledge‐based planning and scheduling as well as informed coastal protection decisions is central to achieving sustainability in the coastal zone. Prior to managing a coastal area, the baseline information needed is the economic value of services that the coastal location in question provides. Originality/value – Generally speaking, the economic value of non‐marketable natural coastal resources such as beaches is closely associated with the way in which society perceives the environment. Both use and non‐use values that are placed upon the environment by individuals have an anthropocentric basis. In this respect, it could be argued that these values often reflect multiple coastal zone uses, conflicts of human interests, levels of environmental education, environmental awareness and environmental appreciation.
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