Showing papers on "Shore published in 2020"
TL;DR: First evidence of MP particles are shown in marine boundary layer air samples on the French Atlantic coast during both onshore and offshore winds, indicating a potential for MPs to be released from the marine environment into the atmosphere by sea-spray giving a globally extrapolated figure of 136000 ton/yr blowing on shore.
Abstract: Global plastic litter pollution has been increasing alongside demand since plastic products gained commercial popularity in the 1930’s. Current plastic pollutant research has generally assumed that once plastics enter the ocean they are there to stay, retained permanently within the ocean currents, biota or sediment until eventual deposition on the sea floor or become washed up onto the beach. In contrast to this, we suggest it appears that some plastic particles could be leaving the sea and entering the atmosphere along with sea salt, bacteria, virus’ and algae. This occurs via the process of bubble burst ejection and wave action, for example from strong wind or sea state turbulence. In this manuscript we review evidence from the existing literature which is relevant to this theory and follow this with a pilot study which analyses microplastics (MP) in sea spray. Here we show first evidence of MP particles, analysed by μRaman, in marine boundary layer air samples on the French Atlantic coast during both onshore (average of 2.9MP/m3) and offshore (average of 9.6MP/m3) winds. Notably, during sampling, the convergence of sea breeze meant our samples were dominated by sea spray, increasing our capacity to sample MPs if they were released from the sea. Our results indicate a potential for MPs to be released from the marine environment into the atmosphere by sea-spray giving a globally extrapolated figure of 136000 ton/yr blowing on shore.
162 citations
TL;DR: In this paper, a multitemporal remote sensing and digital evaluation model with tidal correction are used to analyse the changes in shoreline and estimate the rate of erosion and accretion in Cua Dai estuary.
Abstract: Cua Dai estuary belonged to Quang Nam province is considered to be one of the localities of Vietnam having a complex erosion and accretion process. In this area, sandbars are recently observed with lots of arguments about the causes and regimes of formation. This could very likely result of not reliable source of information on shoreline evolution and a lack of historical monitoring data. Accurately identification of shoreline positions over a given period of time is a key to quantitatively and accurately assessing the beach erosion and accretion. The study is therefore to propose an innovative method of accurately shoreline positions for an analysis of coastal erosion and accretion in the Cua Dai estuary. The proposed technology of multitemporal remote sensing and digital evaluation model with tidal correction are used to analyse the changes in shoreline and estimate the rate of erosion and accretion. An empirical formula is, especially, exposed to fully interpret the shoreline evolution for multiple scales based on a limitation of satellite images during 1965 to 2018. The results show that there is a significant difference of shoreline shift between corrections and non-corrections of tidal. Erosion process tends to be recorded in the Cua Dai cape located in the Cua Dai ward, especially in the An Luong cape located in the Duy Hai commune with the length of 1050 m. Furthermore, it is observed that there is much stronger erosion in the north side compared with south side of Cua Dai estuary.
48 citations
TL;DR: This paper presents a conceptual model of alongshore and cross-shore levels of geological control, and shows how in addition to sediment supply, the basement geology influences where beaches will form by providing accommodation, and in the cross- shore, aspects of rock platform morphology such as elevation and slope are also important.
46 citations
TL;DR: The applicability of the proposed model is tested with other generic edge detection algorithms that include; Sobel, Prewitt, and Robert edge detection techniques and it was concluded that the model outperforming in accurately detecting the coastline.
Abstract: This study highlights the coastline position changes of Qingdao coastal area from 2000 to 2019, using GIS and remote sensing technologies through Digital Shoreline Analysis System and LANDSAT images. Understanding the coastline movement by suitable method is an important challenge for this extremely dynamic coast. The shoreline changes were statistically measured using three techniques, namely; Linear Regression Rate, End Point Rate and Net Shoreline Movement. For the automatic coastline extraction, different methods were applied, but among them most suitable techniques is the canny edge algorithm technique, which gives the accurate result. The result show maximum accretion reached was 266.07m/yr, 2391.85m,124.47m/yr for End point rate, net shoreline movement and linear regression rate, respectively. While, the maximum erosion was −142.55m/yr, −1234.59m, −63.22m/yr for End point rate, net shoreline movement and linear regression rate, respectively. This paper hence presents the monitoring processes of coast and analyzing the coastline change by the use of geospatial techniques that would be helpful for the coastal planning and management of the Qingdao coast. The applicability of the proposed model is tested with other generic edge detection algorithms that include; Sobel, Prewitt, and Robert edge detection techniques and it was concluded that our model outperforming in accurately detecting the coastline.
45 citations
TL;DR: The spatiotemporal trend of shoreline position of the Ganges deltaic coast of Bangladesh is revealed and that would be beneficial for the coastal management and planning of the region.
Abstract: The Ganges deltaic coast of Bangladesh experiences an incessant movement over the time. Understanding the shoreline movement of this alluvial delta and a suitable method to calculate the rate of change poses a challenge for this highly dynamic coast having erosion and accretion. Using GIS and multi temporal LANDSAT images, the study investigated the positional change of the Ganges deltaic shoreline for the period of 1977–2017. LANDSAT images were radiometrically corrected and a spectral index i.e., normalized difference water index (NDWI) was applied to differentiate water and land features. A histogram based Otsu’s Binary thresholding method along with image based visual interpretation was used to extract the shorelines. Net changes of shoreline position were statistically calculated using three different techniques, namely; End Point Rate (EPR), Linear Regression Rate (LRR) and Weighted Linear Regression (WLR). A comparison between the techniques was also made to choose and evaluate the suitable statistical technique to estimate the rate of shoreline change for this alluvial delta. Analyses showed that LRR technique had less positional uncertainty in compare to EPR and WLR, although at a particular transect the techniques were closely correlated. The EPR, WLR and LRR technique showed that the shoreline is experiencing landward movement (erosion) with an average rate of 0.62 m/yr, 0.96 m/yr and 0.27 m/yr respectively. Moreover, a high erosion rate of 5 m/yr at the mangrove forest area of the GDC is a great concern for the existence of the mangrove forest. During 1977–2017, an overall 6.29 sq. km land area has been lost although significant land depositions were observed at the river estuaries. This study revealed the spatiotemporal trend of shoreline position of the Ganges deltaic coast and that would be beneficial for the coastal management and planning of the region.
43 citations
TL;DR: This work quantifies SLR driven potential shoreline retreat and consequent coastal land loss in Europe during the twenty-first century using different combinations of geophysical datasets for (a) the location and spatial extent of sandy beaches and (b) their nearshore slopes.
Abstract: Sea level rise (SLR) will cause shoreline retreat of sandy coasts in the absence of sand supply mechanisms. These coasts have high touristic and ecological value and provide protection of valuable infrastructures and buildings to storm impacts. So far, large-scale assessments of shoreline retreat use specific datasets or assumptions for the geophysical representation of the coastal system, without any quantification of the effect that these choices might have on the assessment. Here we quantify SLR driven potential shoreline retreat and consequent coastal land loss in Europe during the twenty-first century using different combinations of geophysical datasets for (a) the location and spatial extent of sandy beaches and (b) their nearshore slopes. Using data-based spatially-varying nearshore slope data, a European averaged SLR driven median shoreline retreat of 97 m (54 m) is projected under RCP 8.5 (4.5) by year 2100, relative to the baseline year 2010. This retreat would translate to 2,500 km2 (1,400 km2) of coastal land loss (in the absence of ambient shoreline changes). A variance-based global sensitivity analysis indicates that the uncertainty associated with the choice of geophysical datasets can contribute up to 45% (26%) of the variance in coastal land loss projections for Europe by 2050 (2100). This contribution can be as high as that associated with future mitigation scenarios and SLR projections.
40 citations
TL;DR: A mixed-method approach is applied, combining expert knowledge and document analysis with the spatial visualisation of existing and future maritime spatial claims to identify potential pathways, as well as challenges and opportunities for future offshore space management with the aim of achieving the 2050 renewable energy targets.
Abstract: Over the last decade, the accelerated transition towards cleaner means of producing energy has been clearly prioritised by the European Union through large-scale planned deployment of wind farms in the North Sea. From a spatial planning perspective, this has not been a straight-forward process, due to substantial spatial conflicts with the traditional users of the sea, especially with fisheries and protected areas. In this article, we examine the availability of offshore space for wind farm deployment, from a transnational perspective, while taking into account different options for the management of the maritime area through four scenarios. We applied a mixed-method approach, combining expert knowledge and document analysis with the spatial visualisation of existing and future maritime spatial claims. Our calculations clearly indicate a low availability of suitable locations for offshore wind in the proximity of the shore and in shallow waters, even when considering its multi-use with fisheries and protected areas. However, the areas within 100 km from shore and with a water depth above –120 m attract greater opportunities for both single use (only offshore wind farms) and multi-use (mainly with fisheries), from an integrated planning perspective. On the other hand, the decrease of energy targets combined with sectoral planning result in clear limitations to suitable areas for offshore wind farms, indicating the necessity to consider areas with a water depth below –120 m and further than 100 km from shore. Therefore, despite the increased costs of maintenance and design adaptation, the multi-use of space can be a solution for more sustainable, stakeholder-engaged and cost-effective options in the energy deployment process. This paper identifies potential pathways, as well as challenges and opportunities for future offshore space management with the aim of achieving the 2050 renewable energy targets.
33 citations
TL;DR: In this paper, the authors provide a comprehensive assessment of the Irrawaddy Delta's evolution and identify its influencing factors using remote sensing images from 1974 to 2018, published literature and available datasets on the river, and human impacts in its drainage basin.
32 citations
TL;DR: This work shows an integrated approach for coastal environmental monitoring, which aimed to understand the relation between beach-dune morphodynamics, marine litter abundance and environmental forcing, and set the ground for marine litter dynamic modelling on the shore.
32 citations
TL;DR: For example, the authors found that most of the particles were found within the smallest size classification (0.355-0.999mm; 73%), with fragments (63%) and pellets (26%) forming the dominant morphologies.
31 citations
TL;DR: The present 16-year dataset captures daily beach response at the scale of a storm to three large cycles of interannual variability, through the impact of the most energetic winter since at least 75 years and prominent seasonal erosion/recovery cycles.
Abstract: Sandy beaches are highly dynamic environments buffering shores from storm waves and providing outstanding recreational services. Long-term beach monitoring programs are critical to test and improve shoreline, beach morphodynamics and storm impact models. However, these programs are relatively rare and mostly restricted to microtidal alongshore-uniform beaches. The present 16-year dataset contains 326 digital elevation models and their over 1.635 × 106 individual sand level measurements at the high-energy meso-macrotidal rip-channelled Truc Vert beach, southwest France. Monthly to bimonthly topographic surveys, which coverage progressively extended from 300 m to over 2000 m to describe the alongshore-variable changes, are completed by daily topographic surveys acquired during a 5-week field campaign. The dataset captures daily beach response at the scale of a storm to three large cycles of interannual variability, through the impact of the most energetic winter since at least 75 years and prominent seasonal erosion/recovery cycles. The data set is supplemented with high-frequency time series of offshore wave and astronomical tide data to facilitate its future use in beach research. Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.13070153
TL;DR: It is shown that local land subsidence can increase the flood vulnerability caused by sea level rise by 2100 projections, and can represent an increase of 25% in the flood area in the central area of Singapore for the RCP4.5 scenario.
Abstract: Global mean sea level rise associated with global warming has a major impact on coastal areas and represents one of the significant natural hazards. The Asia-Pacific region, which has the highest concentration of human population in the world, represents one of the larger areas on Earth being threatened by the rise of sea level. Recent studies indicate a global sea level of 3.2 mm/yr as measured from 20 years of satellite altimetry. The combined effect of sea level rise and local land subsidence, can be overwhelming for coastal areas. The Synthetic Aperture Radar (SAR) interferometry technique is used to process a time series of TerraSAR-X images and estimate the land subsidence in the urban area of Singapore. Interferometric SAR (InSAR) measurements are merged to the Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 sea-level rise scenarios to identify projected inundated areas and provide a map of flood vulnerability. Subsiding rates larger than 5 mm/year are found near the shore on the low flat land, associated to areas recently reclaimed or built. The projected flooded map of Singapore are provided for different sea-level rise scenarios. In this study, we show that local land subsidence can increase the flood vulnerability caused by sea level rise by 2100 projections. This can represent an increase of 25% in the flood area in the central area of Singapore for the RCP4.5 scenario.
TL;DR: In this article, all morpho-topographic data available for the Gulf of Taranto, in combination with Vertical Land Movements and sea-level rise trends, were considered by assessing the local evolution of the coastal trend as well as the future marine submersion.
Abstract: The dynamics of the sandy coast between Castellaneta and Taranto (Southern Italy) has been influenced by many natural and anthropogenic factors, resulting in significant changes in the coastal system over the last century. The interactions between vertical components of sea-level changes and horizontal components of the sedimentary budget, in combination with anthropogenic impact, have resulted in different erosion and accretion phases in the past years. Local isostatic, eustatic, and vertical tectonic movements, together with sedimentary budget changes, must be considered in order to predict the shoreline evolution and future marine submersion. In this study, all morpho-topographic data available for the Gulf of Taranto, in combination with Vertical Land Movements and sea-level rise trends, were considered by assessing the local evolution of the coastal trend as well as the future marine submersion. Based on the predicted spatial and temporal coastal changes, a new predictive model of submersion was developed to support coastal management in sea-level rise conditions over the next decades. After that, a multi-temporal mathematical model of coastal submersion was implemented in a Matlab environment. Finally, the effects of the relative sea-level rise on the coastal surface prone to submersion, according to the Intergovernmental Panel on Climate Change Assessment Reports (AR) 5 Representative Concentration Pathways (RCP) 2.6 and RCP 8.5 scenarios, were evaluated up to 2100.
TL;DR: Satellite-derived shorelines and corresponding eroded and accreted areas of coastal zones have been calculated and assessed for 15 km along the coasts of Ezbet Elborg, Nile Delta, Egypt and a developed approach is designed based on Landsat satellite images combined with GIS to estimate an accurate shoreline changes and study the effect of seawalls on it.
Abstract: Monitoring the dynamic behavior of shorelines is an essential factor for integrated coastal management (ICM). In this study, satellite-derived shorelines and corresponding eroded and accreted areas of coastal zones have been calculated and assessed for 15 km along the coasts of Ezbet Elborg, Nile Delta, Egypt. A developed approach is designed based on Landsat satellite images combined with GIS to estimate an accurate shoreline changes and study the effect of seawalls on it. Landsat images for the period from 1985 to 2018 are rectified and classified using Supported Vector Machines (SVMs) and then processed using ArcGIS to estimate the effectiveness of the seawall that was constructed in year 2000. Accuracy assessment results show that the SVMs improve images accuracy up to 92.62% and the detected shoreline by the proposed method is highly correlated (0.87) with RTK-GPS measurements. In addition, the shoreline change analysis presents that a dramatic erosion of 2.1 km2 east of Ezbet Elborg seawall has occurred. Also, the total accretion areas are equal to 4.40 km2 and 10.50 km2 in between 1985-and-2000 and 2000-and-2018, respectively, along the southeast side of the study area.
TL;DR: In this paper, the authors employed Digital Shoreline Analysis System (DSAS) extension tool in ArcGIS platform to study and analyse the shoreline dynamics of Sagar Island by utilizing satellite images extending 40 years (1975-2015).
Abstract: Sagar Island is a very popular pilgrimage destination located in the western part of Indian Sundarbans. This study employs Digital Shoreline Analysis System (DSAS) extension tool in ArcGIS platform to study and analyse the shoreline dynamics of Sagar Island by utilizing satellite images extending 40 years (1975–2015). 44 transects with 100 m spacing were laid and divided into six littoral cells (LCs). End Point Rate (EPR) and Linear Regression (LR) models were utilized to analyze the shoreline change patterns and also for predicting the future shoreline positions. It was observed that almost the entire southern portion of Sagar Island is susceptible to high rate of shoreline erosion. Most of the erosion occurred in Dhablat (LC 4 (a)) in the south eastern part at a rate of 11.695 ± 2.1 m/year. The mean shoreline change rate was also high in LC5 (±23.525 m/year). However, the overall shoreline change rate for the island was 4.94 m/year and uncertainty of total shoreline change rate was ±4.4 m/year. The study shows the usefulness of DSAS as a scientific tool for shoreline change studies and highlights state of erosion in the study area.
TL;DR: In this article, the authors present the methodology for carrying out measurements of the tombolo oceanographic phenomenon using Unmanned Aerial Vehicles (UAVs) and UAVs on the example of a waterbody adjacent to the Sopot pier.
Abstract: The human impact on the ecosystem has been particularly evident in the last century; it transforms the Earth’s surface on an unprecedented scale and brings about irreversible changes. One example is an oceanographic phenomenon known as a tombolo, i.e., a narrow belt connecting the mainland with an island lying near the shore formed as a result of sand and gravel being deposited by sea currents. The phenomenon contributes to an increase in the biogenic substance content in the littoral zone, which leads to increased cyanobacteria blooming in the summer period. Moreover, the debris accumulation in the littoral zone results in the mud formation, which makes the beach landscape less attractive. One of the main features of the tombolo phenomenon is its variability of shape, which includes the form of both the shore and the seabed adjacent to it. Therefore, to describe its size and spatio-temporal variability, it is necessary to apply methods for geodetic (the land) and hydrographic (the sea) measurements that can be carried out in different ways. The aim of the paper is to present the methodology for carrying out measurements of the tombolo oceanographic phenomenon using Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicles (USV) on the example of a waterbody adjacent to the Sopot pier. It also presents the results of surveys carried out in November 2019 within this area. The study demonstrated that the integration of two measuring devices whose development began in the second decade of the 20th century, i.e., UAVs and USVs, enables accurate (even up to several centimeters) and reliable determination of the scale and variability of the phenomena occurring in the littoral zone.
TL;DR: Investigating rates and susceptibility to shoreline change using a 76-year multi-temporal dataset (1942 to 2018) through the Digital Shoreline Analysis System (DSAS) revealed that the eastern zone faced rapid shoreline progression, with the highest rates due to the development of coastal areas for urban settlement.
Abstract: According to the Intergovernmental Panel on Climate Change (IPCC), global mean sea levels may rise from 0.43 m to 0.84 m by the end of the 21st century. This poses a significant threat to coastal cities around the world. The shoreline of Karachi (a coastal mega city located in Southern Pakistan) is vulnerable mainly due to anthropogenic activities near the coast. Therefore, the present study investigates rates and susceptibility to shoreline change using a 76-year multi-temporal dataset (1942 to 2018) through the Digital Shoreline Analysis System (DSAS). Historical shoreline positions were extracted from the topographic sheets (1:250,000) of 1942 and 1966, the medium spatial resolution (30 m) multi-sensor Landsat images of 1976, 1990, 2002, 2011, and a high spatial resolution (3 m) Planet Scope image from 2018, along the 100 km coast of Karachi. The shoreline was divided into two zones, namely eastern (25 km) and western (29 km) zones, to track changes in development, movement, and dynamics of the shoreline position. The analysis revealed that 95% of transects drawn for the eastern zone underwent accretion (i.e., land reclamation) with a mean rate of 14 m/year indicating that the eastern zone faced rapid shoreline progression, with the highest rates due to the development of coastal areas for urban settlement. Similarly, 74% of transects drawn for the western zone experienced erosion (i.e., land loss) with a mean rate of −1.15 m/year indicating the weathering and erosion of rocky and sandy beaches by marine erosion. Among the 25 km length of the eastern zone, 94% (23.5 km) of the shoreline was found to be highly vulnerable, while the western zone showed much more stable conditions due to anthropogenic inactivity. Seasonal hydrodynamic analysis revealed approximately a 3% increase in the average wave height during the summer monsoon season and a 1% increase for the winter monsoon season during the post-land reclamation era. Coastal protection and management along the Sindh coastal zone should be adopted to defend against natural wave erosion and the government must take measures to stop illegal sea encroachments.
TL;DR: This article presents the results of extensive and integrated geodetic and hydrographic measurements, the purpose of which was to make a 3D model of the phenomena developing in Sopot, to determine the size and speed of the geospatial changes.
Abstract: A tombolo is a narrow belt connecting a mainland with an island lying near to the shore, formed as a result of sand and gravel being deposited by sea currents, most often created as a result of natural phenomena. However, it can also be caused by human activity, as is the case with the Sopot pier—a town located on the southern coast of the Baltic Sea in northern Poland (φ = 54°26’N, λ = 018°33’E). As a result, the seafloor rises constantly and the shoreline moves towards the sea. Moreover, there is the additional disturbing phenomenon consisting of the rising seafloor sand covering over the waterbody’s vegetation and threatening the city's spa character. Removal of the sand to another place has already been undertaken several times. There is a lack of precise geospatial data about the tombolo’s seafloor course, its size and spatial shape caused by only lowering the seafloor in random places, and the ongoing environmental degradation process. This article presents the results of extensive and integrated geodetic and hydrographic measurements, the purpose of which was to make a 3D model of the phenomena developing in Sopot. The measurements will help determine the size and speed of the geospatial changes. Most of the modern geodetic and hydrographic methods were used in the study of these phenomena. For the construction of the land part of geospatial model, the following were used: photos from the photogrammetric flight pass (unmanned aerial vehicle—UAV), laser scanning of the beach and piers, and satellite orthophotomaps for analysis of the coastline changes. In the sea part, bathymetric measurements were carried out with an unmanned surface vehicle (USV).
TL;DR: In this paper, the authors apply the one-line change model LX-Shore, which couples longshore and cross-shore processes and can handle complex shoreline planforms, non-erodible emerged headlands and submerged rocky features.
TL;DR: The authors find that a North Yorkshire rocky cliff has been eroding at a similar rate over the last 7 kyr, and they do not observe an increase in erosion rates in response to modern sea level rise.
Abstract: Predicted sea-level rise and increased storminess are anticipated to lead to increases in coastal erosion. However, assessing if and how rocky coasts will respond to changes in marine conditions is difficult due to current limitations of monitoring and modelling. Here, we measured cosmogenic 10Be concentrations across a sandstone shore platform in North Yorkshire, UK, to model the changes in coastal erosion within the last 7 kyr and for the first time quantify the relative long-term erosive contribution of landward cliff retreat, and down-wearing and stripping of rock from the shore platform. The results suggest that the cliff has been retreating at a steady rate of 4.5 ± 0.63 cm yr−1, whilst maintaining a similar profile form. Our results imply a lack of a direct relationship between relative sea level over centennial to millennial timescales and the erosion response of the coast, highlighting a need to more fully characterise the spatial variability in, and controls on, rocky coast erosion under changing conditions. Predicted sea-level rise is widely anticipated to lead to increased coastal erosion, however, assessing how rocky coasts will respond to changes in marine conditions is difficult to constrain. Here, the authors find that a North Yorkshire rocky cliff has been eroding at a similar rate over the last 7 kyr, and they do not observe an increase in erosion rates in response to modern sea level rise.
TL;DR: In this article, the authors used remote sensing and GIS (Geographic Information System) techniques to observe the dynamics of the shoreline in the coastal region of Sayung, Indonesia, from 1988 up to 2017.
TL;DR: Examination of the accuracy of intertidal topographic data derived from a video camera system compared to data acquired with unmanned aerial vehicle (UAV) surveys of a reflective beach suggests that a low-cost shore-based camera can produce profile data for effective coastal management in West Africa and elsewhere.
Abstract: Video camera systems have been used over nearly three decades to monitor coastal dynamics. They facilitate a high-frequency analysis of spatiotemporal shoreline mobility. Video camera usage to measure beach intertidal profile evolution has not been standardized globally and the capacity to obtain accurate results requires authentication using various techniques. Applications are mostly site specific due to differences in installation. The present study examines the accuracy of intertidal topographic data derived from a video camera system compared to data acquired with unmanned aerial vehicle (UAV, or drone) surveys of a reflective beach. Using one year of 15-min video data and one year of monthly UAV observations, the intertidal profile shows a good agreement. Underestimations of intertidal profile elevations by the camera-based method are possibly linked to the camera view angle, rectification and gaps in data. The resolution of the video-derived intertidal topographic profiles confirmed, however, the suitability of the method in providing beach mobility surveys matching those required for a quantitative analysis of nearshore changes. Beach slopes were found to vary between 0.1 and 0.7, with a steep slope in May to July 2018 and a gentle slope in December 2018. Large but short-scale beach variations occurred between August 2018 and October 2018 and corresponded to relatively high wave events. In one year, this dynamic beach lost 7 m. At this rate, and as also observed at other beaches nearby, important coastal facilities and infrastructure will be prone to erosion. The data suggest that a low-cost shore-based camera, particularly when used in a network along the coast, can produce profile data for effective coastal management in West Africa and elsewhere.
TL;DR: In this paper, the authors assess Pleistocene shoreline migrations on the south coast of South Africa in relation to fluctuating sea-levels and changes in sediment supply, and demonstrate a prevalence of dissipative beaches and mixed coasts on the coast of the Palaeo-Agulhas Plain.
TL;DR: The results indicate that there is a decrease in area of the lake and integrated use of multi-temporal satellite images and statistical parameters are very effective and useful for shoreline change analysis.
Abstract: This study was performed along the shorelines of Lake Salda in Turkey during the elapsed period from 1975 to 2019 in order to detect shoreline changes. Within this framework, geographic information system, digital shoreline analysis system, Modified Normalized Difference Water Index, and multi-temporal satellite images were utilized. The measurement of shoreline displacement was mainly divided into six analysis regions. In digital shoreline analysis system, several statistical parameters such as end point rate, linear regression rate, shoreline change envelope, and net shoreline movement were computed to measure the rates of shoreline displacement in terms of erosion and accretion. The maximum shoreline change between 1975 and 2019 was determined as 556.45 m by shoreline change envelope parameter. The maximum shoreline change was 16.35 m/year by end point rate parameter and 12.91 m/year by linear regression rate parameter. While erosion has been observed in 3rd, 4th and 6th segments, accretion has been observed in other segments. When all the transects were taken into consideration, an accretion observed. The results indicate that there is a decrease in area of the lake. Experiment results show that integrated use of multi-temporal satellite images and statistical parameters are very effective and useful for shoreline change analysis. It is thought that the structures such as irrigation pond and dam that are built on the streams that recharge the lake and average rainfall and average temperature conditions are the main reasons of the fluctuations and changes in the shorelines.
TL;DR: In this paper, the authors collected aerial photography using an unmanned aerial vehicle to produce structure-from-motion-derived digital elevation models and orthophotos to characterise and quantify the erosion of two actively eroding stratigraphic layers on a shore platform in Glamorgan, south Wales, UK, over 78 years.
Abstract: The majority of shore platforms form in rocks that are characterised by layered stratigraphy and pervasive jointing. Plucking of weathered, joint and bed bounded blocks is an important erosion process that existing models of platform development do not represent. Globally, measuring platform erosion rates have focused on microscale (< 1 mm) surface lowering rather than mesoscale (0.1‐1 m) block detachment, yet the latter appears to dominate the morphological development of discontinuity rich platforms. Given the sporadic nature of block detachment on platforms, observations of erosion from storm event to multi‐decadal timescales (and beyond) are required to quantify shore platform erosion rates. To this end, we collected aerial photography using an unmanned aerial vehicle to produce structure‐from‐motion‐derived digital elevation models and orthophotos. These were combined with historical aerial photographs to characterise and quantify the erosion of two actively eroding stratigraphic layers on a shore platform in Glamorgan, south Wales, UK, over 78‐years. We find that volumetric erosion rates vary over two orders of magnitude (0.1‐10 m3 yr‐1) and do not scale with the length of the record. Average rates over the full 78‐year record are 2‐5 m3 yr‐1. These rates are equivalent to 1.2‐5.3 mm yr‐1 surface lowering rates, an order of magnitude faster than previously published, both at our site and around the world in similar rock types. We show that meso‐scale platform erosion via block detachment processes is a dominant erosion process on shore platforms across seasonal to multi‐decadal timescales that have been hitherto under‐investigated.
Esso1
TL;DR: In this paper, the authors provided the primary requirement of shoreline change rate for the past 26 years using geo-spatial technology and field investigation for proper management of the coast.
Abstract: Coastal zone is a central attraction for coastal engineers, scientists and coastal community due to economic and developmental activities of the coast. Kerala has 593 km of coastline. More than 50% of the coast is occupied with artificial structures such as ripraps, groins, seawall, ports and fishing harbours. These coastal protection structures and developmental activities played a major role in altering the shoreline position significantly. Therefore, periodical analysis and monitoring of shoreline change is the primary requirement for effective planning and management of the coast. This paper provides the primary requirement of shoreline change rate for the past 26 years using geo-spatial technology and field investigation for proper management of the coast. Landsat 5 and 7, Resourcesat 1 and 2 and Cartosat-1 data set were used as primary data source. Long-term shoreline change rate (1990–2016) was calculated using weighted linear regression statistical method. The morphological study was carried out to substantiate the shoreline change pattern. For detailed investigation, the study area was divided into five sediment sub-cells. The analysis revealed that the maximum erosion of 54% was noticed in sediment sub-cells II, followed by IV (52%) and III (43%) respectively. The result also indicated that the accretion/erosion pattern of shoreline change on either side of breakwaters was varying from place to place. The effectiveness of the coastal protective seawall was very minimal. This indicates that proper planning of any artificial structures is the basic requirement for effective management of the coast. The overall shoreline change status of Kerala coast indicates that 45% of the coast is eroding and 34% of the coast is in stable condition. Only 21% of the coast is of accreting nature. The field survey was carried out to validate the analysed results for entire coast, specifically along the coastal structures. The study demonstrates that the combined effect of satellite data and field investigation can be a reliable approach for shoreline change analysis for these complex environments.
TL;DR: In this article, the authors assess the shoreline shifting and erosion-accretion measurement of Hatiya island and make an attempt to understand the impact of water level, temperature and rainfall on shoreline movement and erosionaccretion using GIS and remote sensing technique.
TL;DR: Litter loads peaked in autumn when seasonal rains washed litter into False Bay, suggesting that most litter comes from local land-based sources, but 60% of plastic items floated in water.
TL;DR: In this paper, a large-scale satellite-derived dataset was used to investigate statistically robust trends in shoreline position over a 31-year period from 1987 to 2017, at a regional scale.
Abstract: This study demonstrates how a large-scale satellite-derived dataset can be used to investigate statistically robust trends in shoreline position over a 31-year period from 1987 to 2017, at a regional scale. Regional patterns of shoreline behaviour are important for resolving consistent or, alternatively, dissimilar patterns of past shoreline change. Such patterns are best explored using temporally frequent and spatially extensive datasets. Here we analyse satellite-derived shorelines to identify spatial patterns of hotspots of coastline change on the wave-exposed coast of Victoria in south-east Australia where rates of change exceed 0.5 m yr−1. Analysis of shoreline position changes at a 50 m alongshore interval along 900 km of the 1230 km coastline reveals a number of distinct behaviours related to coastal type (rock vs sand coast), landform, shoreline orientation and/or anthropogenic drivers of change. Overall the results show that statistically significant change in shoreline position has affected only a relatively small proportion of the study region over the last 31 years; that the proportion and rate of progradational and recessional change is similar; and that change is localised but dispersed widely along the Victorian coast. Coasts located at the entrances to large tidal inlets have shown the greatest change. The association of hotspots with embayed sandy beaches and adjacent to headlands points to the importance of geological control on shoreline behaviour. Consistent with other regional scale studies of shoreline change, this study found little regional coherence in shoreline behaviour. Instead change is predominately attributed to local factors such as the geological framework of the coast, localised hydrodynamic conditions and anthropogenic influences. Collectively, these results indicate that there is strong geologic control on shoreline erosion in Victoria due to the high diversity of landforms along the coastline; and that further analysis is required to tease out the seasonal to interannual sensitivities to changes in the historical wave climate and the secondary interaction of sediment supply for headlands and hydrodynamics for tidal inlets.
TL;DR: In this paper, the authors analyzed the shoreline changes in Sayung coast during 24 years period from 1994 to 2018 by extracting multi-temporal satellite imagery of Landsat 5, 7, and Sentinel 2A.