Coastline Changes Research Articles

Long-term Coastline Monitoring in the Thanh Hoa Province (Vietnam) Using Landsat 5 and Landsat 8 Data

In recent years, extensive human activities have had a profound impact on the estuaries and coastal areas of Vietnam, most notably in coastal erosion and accretion. This paper used the Landsat multi-temporal data for the period 1988–2022 to assess coastline change in Thanh Hoa province (North Central Vietnam). Water indices calculated from Landsat imagery data, including NDWI, ANDWI, MNDWI, AWEInsh, AWEIsh, and BandWet, are used to extract surface water areas and then vectorize and overlay to estimate shoreline variability. The Otsu thresholding method is used to classify “water surface” and “land objects” and then evaluate the accuracy using the Kappa coefficient. The obtained results show that the ANDWI index has the highest accuracy in extracting the water body of the study area, in which the value of the Kappa coefficient reaches 0.95 compared to 0.91, 0.92, 0.93, 0.92 and 0.92 at using NDWI, MNDWI, AWEInsh, AWEIsh and BandWet indicies. Boundary vectorization and vector image overlays were performed to assess shoreline variability and map shoreline dynamics. The results obtained show that in the northern part of the coastal zone of Thanh Hoa province there is active accretion (increment) of the coastline. The average accretion rate was 150 m/year, the maximum rate was 457 m/year. In contrast, on the southern coast of Thanh Hoa province, coastline erosion predominates with a maximum rate of 38 m/year and an average rate of about 10 m/year.

Coastline Change along Pebuahan Beach in Jembrana Bali

Monitoring changes in coastlines over large areas will be more efficient using satellite imagery rather than conducting field surveys. This research aims to measure the coastline transformation that occurred over a period of time at Pebuahan Beach in Jembrana Regency. This research uses the Digital Shoreline Analysis System (DSAS) program. Ex situ data for 2004 and 2019 obtained from Landsat satellite imagery was used in this research. When compared coastline between 2004 and 2019, there was more extensive abrasion, reaching 300,577.17 m2, while the accretion that occurred only reached 159,697.67 m2. The cause of abrasion at Pebuahan Beach is sediment transport which tends to leave the beach to the west and sediment supply is trapped due to obstruction at the Pengambengan Port.

Identification and assessment of the mudflat ecological vulnerability dominated by coastline evolution in Jiangsu

Coastlines have experienced profound alterations due to human disturbances and ocean dynamics against the backdrop of climate change and intensified anthropogenic activities. Significant modifications have occurred within the muddy coastal ecosystem, rendering it extremely susceptible to heightened levels of vulnerability. However, existing studies on coastal eco-environmental vulnerability have often overlooked crucial factors such as coastline erosion and siltation, particularly concerning coastline change. In this study, we assess coastline stability utilizing Landsat remote sensing imagery to investigate the vulnerability of coastal ecology alongside 24 economic and natural parameters, serving as indices for the Coastal Vulnerability Index (CVI) of the coastal eco-environment. Subsequently, we analyze the impact factors to vulnerability and predict trends in coastline change over the next 20 years to propose recommendations for sustainable development to safeguard the coastal eco-environment. Our findings reveal a trend towards coastline stabilization in Jiangsu, with significantly higher stability observed during 2010–2020 compared to 1985–2010. The overall CVI along the Jiangsu coast shows an downward trajectory over the past 15 years, primarily influenced by tidal action and coastal topography and geomorphology. Predictive modeling suggests Jiangsu coastline is bounded by the Sheyang estuary, with the coastline to the north dominated by stabilization and to the south dominated by siltation. Climate change, coupled with intensified human activities and future coastline alterations, may exacerbate vulnerability. Effective protection strategies for coastal ecosystems necessitate a comprehensive understanding of local natural conditions, resource availability, and socioeconomic dynamics. Governmental interventions should focus on reinforcing regulatory frameworks for coastal organism management, implementing coastal protection infrastructure, and enhancing supervision and management protocols for beachfront development, thereby fostering the sustainable management of muddy coastlines.

The effects of changes in the coastline and water depth on tidal prism and water exchange of the Laizhou Bay, China

Laizhou Bay’s coastline has undergone multiple alterations due to human activities such as land reclamation and port construction. These changes in the coastline have led to modifications in the bay’s hydrodynamic conditions, which, in turn, can impact the marine environment and potentially result in a decline in biodiversity. To date, there has been no comprehensive study focusing on the coastline changes and hydrodynamic variations in Laizhou Bay. Therefore, this study utilizes coastline and water depth data from four time points—1990, 2003, 2013, and 2023—to establish a two-dimensional tidal current model of Laizhou Bay using Delft3D. Based on the good agreement between the simulated tidal current results and the observed data, this study further investigates the changes in tidal prism and water exchange in Laizhou Bay. The results indicate that tidal currents dominate the bay, with significant influences of topographic changes on the velocity and direction of tidal flows. The Eulerian residual current velocity is substantially lower than the tidal current velocity. Both tidal and residual currents play a role in controlling the distribution of materials within Laizhou Bay. Over the past three decades (1990-2023), the tidal prism in Laizhou Bay has shown a downward trend, with the tidal prism during spring, intermediate, and neap tides in 2023 reduced by 2.03%, 6.36%, and 10.19%, respectively, compared to 1990. The water exchange capacity has also weakened, with the half-exchange time being 71 days in 1990, increasing to 73 days in 2003 and 81 days in 2013, and showing a slight increase of 1 day in 2023 compared to 2013. Thus, changes in the coastline and water depth of Laizhou Bay can alter its hydrodynamic conditions, significantly impacting the tidal prism and water exchange, leading to a decrease in tidal prism and exchange rate, an increase in the water exchange period, a slower dispersion rate of pollutants, and a reduced water environmental carrying capacity. This research provides a scientific reference for protecting the marine environment and coastal management in Laizhou Bay.

Spatiotemporal dynamics and transformation of the Parana State coastline: A 34-year analysis using RS, GIS, and machine learning

The coastal zone is a critical and vibrant area within coastal cities. Analyzing the changes in the coastal zone of Parana State helps determine the spatiotemporal evolution patterns and driving forces of this region, providing guidance for resource protection and utilization. This study employs remote sensing (RS), Geographic Information System (GIS), and Machine Learning techniques, using Landsat data sets with eight distinct scenes from 1990 to 2024, to extract and analyze the coastline. Specifically, methodologies such as Shoreline Extraction, the Coastline Diversity Index (CDI), and the Coastline Utilization Index (CUI) were applied to assess the coastline's characteristics. The spatiotemporal characteristics of the coastline development in Parana are meticulously examined to ensure accuracy. The findings reveal that: 1) Over the past 34 years, the coastline of Parana State has shown a consistent increasing trend. Natural coastlines have been declining by 45% annually, while artificial coastlines have been increasing by approximately 55% annually. 2) The nature of the shoreline is transitioning from natural to sea-reclamation, engineering-enhanced, and degraded forest. 3) The coastline changes have occurred in three phases: The Built-up Land phase, the Port Petrochemical phase, and the Reducing Coastal Erosion phase. Significant shoreline extension is observed near both biological and ecological coasts. 4) The primary factors influencing the coastline alterations in Parana State include natural forces, human activities, and regional policies. These insights into the spatiotemporal dynamics of the Parana coastline can inform better coastal management and conservation strategies.

Investigating spatiotemporal coastline changes and impacts on coastal zone management: A case study in Pearl River Estuary and Hong Kong's coast

Changes in coastlines and coastal zones reflect human activities and global changes. Using Landsat imagery from 1998 to 2021, the temporal and spatial variation characteristics of coastlines and the coastal zone land-use/land-cover (LULC) in Pearl River Estuary and Hong Kong's coast were studied during this period, followed by an analysis of how human activity affects coastline changes, in an attempt to provide a basis for decision-making in coastal zone management. Our results show that the coastline expanded outward, demonstrating an obvious trend that featured increasing length. The coastal zone was observed to primarily comprise construction land and woodland, of which the construction land displayed significant growth in contrast to the woodland's decreasing trend, indicating that the coastline was changing from natural to artificial in character. Human activity in the coastal zone had a significantly positive impact on the coastline length. While the amount of coastline in all sub-regions of the study has increased overall, the coastline length in Guangzhou-Dongguan, in particular, exhibited the greatest growth. During analysis, a positive correlation emerged between coastline length and fractal dimension, in particular, the correlation between Shenzhen coastline length and fractal dimension demonstrated the highest level among the four sub-regions studied. With the exception of Hong Kong, construction land increased significantly in all coastal areas and encroached on other types of land, such as cultivated land and woodland. In addition, except for Hong Kong, human disturbance in the coastal zone increased. Among all study areas, Shenzhen revealed a significant increase in human disturbance over the period of interest, exhibiting the highest level of this factor among the sub-regions of the study. These findings could potentially facilitate effective coastal zone management to achieve sustainable development in coastal areas.

Mapping of morphological coastline changes based on aerial photographs and Discrete Fourier Transform, Hel Peninsula, Poland

The coast is a dynamic zone where constantly occurring hydrodynamic and morphodynamic processes affect the shape of the shore. The paper presents a method based on spatial and spectral analysis of changes in the coastline position based on data obtained from aerial photographs interpretation and Fourier analysis, on the example of the Hel Peninsula. The Hel Peninsula is one of the most interesting accumulation forms of the Polish Baltic coast, where dynamic changes of the seashore cause the occurrence of time-varying sections of accumulation-abrasion of the coastline. For the purpose of detecting the coastline changes, historical aerial photographs from the years 1947, 1957, 1963, 1991 were used. It was assumed that the over-40-year research period, which includes the obtained series of aerial photographs, would allow for a sufficient study of the long-term shoreline changes, which allow for distinguishing the length of characteristic coastline undulations. The quasi-wave signal of the shoreline changes obtained from the aerial photographs interpretation, after using Fourier analysis, enabled an effective and precise identification of the coastline undulation. The spatial analyses, showed that the Hel Peninsula is clearly divided into a part subjected to accumulation processes and an abraded one. Furthermore, the dynamics of coastline changes was determined, showing that the abrasive processes were intensifying. Moreover, spectral Fourier analysis allowed for the precise identification of coastline undulations with dominant lengths. The obtained results of spatial and spectral analysis indicate that abrasive-accumulation sections with a length of about 0.3–4.5 km dominate on the Hel Peninsula shoreline.

Forecasting future scenarios of coastline changes in Türkiye's Seyhan Basin: a comparative analysis of statistical methods and Kalman Filtering (2033–2043)

Forecasting future scenarios of coastline changes in Türkiye's Seyhan Basin: a comparative analysis of statistical methods and Kalman Filtering (2033–2043)

Extraction of lanceolate imagery for analysis of mangrove extent and shoreline changes

This study aims to determine the area of Topang Island's mangrove forest, an area experiencing extreme line changes and the magnitude of the coastline change rate from 1991 to 2021 on Topang Island, Kepulauan Meranti Regency, Riau Province. The method used in this research is remote sensing and field survey. The data obtained were discussed descriptively. The results found that the calculation of wave height prediction on the coast of Topang Island was included in the low category with an average height of 0.12 meters. The research area is dominated by abrasion, based on visual observations, Topang Island has a type of peat and muddy beach. The area of mangroves on Topang Island from 2001 to 2021 saw a big change, either adding or reducing the area of mangroves. Topang Island experienced the worst abrasion in the eastern part with an average abrasion rate of 6.13 m/year, and accretion in the western part with an average accretion rate of 0.62 m/year.

Impact evaluation of development plans in the Egyptian harbors on morphological changes using numerical simulation (case study: Damietta harbor, northeastern coast of Egypt)

The Egyptian government is grappling with the challenge of sedimentation in Damietta Harbor (DH), leading to expensive and recurring dredging operations for safe vessel navigation. This research examined the changes in the region's coastline, both before and after the port was established between 1977 and 1995. The impact of the government's policy to halt backfilling in the navigation lane on adjacent beaches until 2023 was also assessed using remote sensing (RS) and the Digital Shoreline Analysis System (DSAS) program, revealing varying yearly accretion and erosion rates. Following a shoreline movement tracking procedure, in the period from 1985 to 2023, the total areas undergoing erosion and accretion amounted to −1.36 km2 and +2.21 km2, respectively.To address the issue, the research team developed scenarios reflecting regional realities and conducted a numerical simulation using the Coastal Modeling System (CMS). Morphological alterations in the approach channel and pre- and post-port regions were monitored to assess the scenarios. The study also explored how deepening the navigation channel affected the annual sediment volume. Results showed that Scenario 5, involving breakwaters extension and the new western breakwater (NWBW), effectively controlled sediment. However, sedimentation increased with the deepening of the navigation channel. Scenario 7, with a 19 m deepening, exhibited slightly higher sediment volume by 21.75% but stood out for its capacity to handle large vessels. Additionally, the sedimentation in the navigation channel experienced a notable 72.1% decrease in Scenario 8, which portrays the anticipated final state of DH compared to the benchmark case.The study noted morphological changes from planned coastal constructions on the eastern side, including detached breakwaters (DBW) and Y-groins (Y-gs). Despite significant development costs, these structures were deemed insufficient to stabilize the shoreline. In summary, the research highlights the complexity of addressing sedimentation in DH, emphasizing the need for nuanced approaches in coastal management, and considering the consequences of deepening navigation channels.

The impact mechanism of human activities on the evolution of coastal wetlands in the Liaohe River Delta

IntroductionThis study aims to investigate the impact of human activities on the evolution of coastal wetlands in the Liaohe River Delta. Understanding these impacts is crucial for the management, protection, and sustainable development of the ecological environment in the region.MethodsQuantitative analysis of the evolution of coastal wetlands along the Liaohe River from 1995 to 2020 using Landsat series remote sensing images. This study examines the changes in different landscapes and explores the impact of human activities on wetlands through methods such as land transfer matrix, landscape pattern index, and human activity hotspots.ResultsThe results show that the area of coastal wetlands in the Liaohe River Delta exhibited a fluctuating downward trend from 1995 to 2020. The eastern and western parts of the delta experienced greater disturbance to wetland landscapes due to human activities, while the northern and southern parts were mostly waters and reed lands with a smaller degree of human disturbance. Human activities have led to significant changes in farmland, ponds, rice paddies, construction land, and reed fields, thereby promoting the evolution of coastal wetlands.DiscussionThis article discusses the characteristics of landscape pattern evolution in the study area, as well as the impact of human interference, economy, policies, and other factors on it, and compares it with the evolution patterns of other coastal wetlands in China. The changes in the landscape pattern of the study area are mainly reflected in the reduction and fragmentation of natural wetland areas, which are closely related to human activities, especially the development of construction and agriculture. The main economic manifestation is that the increase in land demand due to economic and urban development has led to the transformation of natural wetlands into construction land and other artificial landscapes. The implementation of regulations such as the Wetland Protection Law has contributed to the rational use and ecological restoration of wetlands, and also reflects the influence of policy factors. Compared with other studies, coastal wetlands in China generally face issues of degradation and loss, mainly caused by human activities, but also affected by natural factors such as rising sea levels, changes in coastlines, and climate change.

Citizen perceptions of Great Lakes coastline change and management efforts

Fluctuating water levels, nearshore flooding and associated coastal erosion present management challenges for coastal communities around the world. Along the Great Lakes, integrated coastal zone management efforts involve a complex array of people and institutions, which include citizens of coastal communities. At this point in time, there are few studies focused on community members' perceptions of and views on current management efforts on the Great Lakes. To address this need, the present study analyzes survey data from the public and six Great Lake communities with three objectives in mind. One, to understand perceptions of the causes of coastline change and the hazards associated with these changes. Two, to understand the consequences of coastline change for people and the greater community. Three, to understand citizens’ viewpoints about different strategies for managing coastline changes and the parties responsible for managing the coastline. Study results indicate conflicting perceptions between community members about common coastline management efforts (e.g. armoring, beach nourishment, and setbacks). They also indicate a general lack of knowledge about the complexities and responsible parties for coastline management, which in some cases, may be individual property owners themselves. The results of this study suggest efforts to educate citizens may be critical for future stewardship of the Great Lakes, which requires community partnerships and buy in to be successful.

A dataset of remote sensing coastline changes of Guangxi, China, during 1990–2020

As an important gateway at the intersection of the 'Belt and Road' initiative, Guangxi is situated along the Beibu Gulf to the south endowed with abundant coastal port infrastructure and marine biological resources. The remote sensing monitoring of the location change and type transformation along its coastline provides valuable scientific data support for the sustainable development and management of the coastal zone. The study uses Landsat TM/OLI data spanningz five time periods from 1990 to 2020 to delineate the coastline of Guangxi. We use ArcGIS 10.2 to visually interpret the coastline location, dividing the coastline into two primary types: artificial and natural, with six secondary categories. This dataset is characterized by long time series, high accuracy, comprehensive coastline types and a focus on coastline trends before and after 2015 (the first year of sustainable development goals). The dataset can be applied to the study of spatial-temporal distribution characteristics of coastlines and the evolution of land-sea patterns.

GIS-BASED ESTIMATION OF SHORELINE CHANGE AT THE OLIE PIER HARBOR HERITAGE SITE, MANGGAR, EAST BELITUNG, INDONESIA

The coastal area is a dynamic region influenced by continuous interactions between land and the sea. Changes in coastal compositions are closely related to shoreline instability. This study analyzes coastline changes at the Olie Pier Heritage Site, Manggar, East Belitung, Indonesia, using statistical-based techniques EPR (End Point Rate) and NSM (Net Shoreline Movement) 2015 to 2023. The DSAS (Digital Shoreline Analysis System) was employed to calculate the shoreline alterations in every transect with a distance of about 100 m. The study area is generally predominated by a moderate abrasion. The EPR and NSM values indicate a potential for future shoreline changes, considering the present status and future estimations of oceanographic parameters (currents, wind, waves, tides). The highest erosion is identified in the Lalang Village with a shoreline retreat (NSM) of -65.38 m and a retreat rate (EPR) of 8.78 m/year. On the other hand, the highest accretion is observed in the Baru Village with a NSM of -56.68 m and EPR of 7.61 m/year. The implications of these shoreline changes on the heritage site and the coastal environment contribute to the management of coastal areas amidst global environmental challenges. This study provides valuable insights into conservation and sustainable development efforts in the coastal region of East Belitung.

Post-Tsunami Shoreline Changes in Parts of Palu Bay

This research was conducted in part of Palu Bay which is included in the administrative area of Palu City. The problems in this study are: (1) How is the change of coastline in some parts of Palu Bay? (2) How much area was affected by the Tsunami in parts of Palu Bay? This study aims to: (1) To know the changes of coastline in some parts of Palu Bay. (2) Know the area affected by the Tsunami in part of Palu Bay. This type of research is quantitative descriptive research. The method used to obtain data is by using Geographic Information System (GIS) analysis with overlay techniques. The results showed that there were changes in the coastline in the form of abrasion or loss of land with a total area of 61.53 hectares and additional land (accretion) with a total area of 5.1 hectares. The total area affected by the tsunami in parts of Palu Bay amounted to 622.83 hectares. The sub-districts that experienced the largest tsunami impact were the Tawaeli district with an area of 169.96 hectares, Mantikulore sub-district with an area of 145.55 hectares, the North Palu sub-district with an area of 116.25 hectares, the Ulujadi sub-district with an area of 104.66 hectares, the West Palu sub-district with an area of 58.39 hectares, while East Palu sub-district was the smallest tsunami impacted area with an area of 28.02 hectares.

Monitoring of coastline change using Sentinel-2 MSI data. A case study in Thanh Hoa Province, Vietnam

Vietnam is a coastal country with a coastline of more than 3,260 km, stretching from north to south. Coastal change in Vietnam is complicated further by the effects of climate change, including erosion and accretion, causing great impacts on infrastructure and the environment. This article presents the results of assessing coastline changes in Thanh Hoa Province (North Central region of Vietnam) from Sentinel-2 MSI satellite image data for the period 2015–23. Three Sentinel-2 MSI images taken in December 2015, December 2020 and December 2023 were used to calculate the water indices, including Normalised Difference Water Index (NDWI), Modified Normalised Difference Water Index (MNDWI) Argumented Normalised Difference Water Index (ANDWI) and Automated Water Extraction Index (AWEIsh), then extract the shoreline using the thresholding method and select the water index with the highest accuracy through comparing the overall accuracy and Kappa coefficient. The coastlines of 2015, 2020 and 2023 years are overlaid to evaluate the coastal changes in the study area. The results received in the study provide objective and timely information, helping managers effectively monitor and respond to coastline changes.

Analisis Perubahan Garis Pantai Pada Wilayah Pesisir Kecamatan Amurang Kabupaten Minahasa Selatan Sulawesi Selatan

Chandra, 2023 this study is to determine the extent of coastline changes in the coastal area of Amurang District, South Minahasa Regency and the causes of coastline changes that occur in the Coastal Area of Amurang District, South Minahasa Regency. Changes in coastline are determined by the amount of sediment that goes in and out of each section of the coast. If the incoming sediment is higher than the outgoing, then the beach will experience sedimentation on the contrary, if the incoming sediment is smaller than the outgoing, then the beach will experience erosion. This research was conducted in several stages, namely collecting data and information and analyzing data. Initial image processing consists of image provisioning, image recovery, image cropping, and image sharpening. Field surveys and supporting data collection, as well as advanced image processing which includes classification, supporting data processing, image overlay and interpretation of research results. Changes in the coastline in the coastal area of Amurang District in 5 years average -1.81 Ha, abrasion with a toal of -7.23 Ha and an average accretion of 1.47 Ha with a total of 5.8 Ha, and changes in the coastline in the coastal area of Amurang district are caused by two factors, namely hydro-oceanographic factors that cause abrasion while anthrophogenic factors cause accretion.

Analysis of Vegetation Density Changes on Coastline Changes in the Glagah Coastal Area, Kulon Progo Regency 2018 and 2023

Abstract The construction of Yogyakarta International Airport, which is only 400 meters from Glagah Beach, means that the Kulon Progo Regency Government must pay more attention to guarding the coastline, so that abrasion does not reach Yogyakarta International Airport and the surrounding settlements. The objectives of this research are (1) to identify changes in vegetation density, (2) to identify changes in coastlines, (3) to analyze the relationship between the two in the Glagah Coastal Area, Kulon Progo Regency in 2018 and 2023. The method used in this research is integration between remote sensing and geographic information systems. Remote sensing is used to obtain the Normalized Difference Vegetation Index (NDVI), while the geographic information system is used to analyze shoreline changes using Digital Shoreline Analysis System (DSAS) tools. Based on the 2018 NDVI values, it is known that the area of non-vegetation is 28.2 Ha, low vegetation is 35.2 Ha, medium vegetation is 22.2 Ha, and high vegetation is 26 Ha. The area of each ndvi class in 2023, namely non-vegetation 20.3 Ha, low vegetation 38.2 Ha, medium vegetation 37.9 Ha, and high vegetation 17.7 Ha. The largest amount of abrasion along the Glagah coastline occurred in Sindutan Urban Village, reaching - 56.43 meters and the largest accretion occurred in Jangkaran Urban Village, reaching 65.64 meters. The results of linear regression (0.256) and F test (0.172) show that there is no influence between changes in vegetation density on changes in coastlines in the Glagah coastal area. Even though the results show there is no correlation between vegetation density and changes in coastlines, the role of vegetation is very important in preventing abrasion.

Simulation Model of Lembasada Coastline Changes in Supporting Post Tsunami 2018 Tourism Beaches

Simulation Model of Lembasada Coastline Changes in Supporting Post Tsunami 2018 Tourism Beaches

Landmark Base Point Approach to Positional and Coastal Accuracy Analysis for Historical Map Before WWI: A Case Study 1836 Moltke and 1914 German Blue about in Historical Peninsula of İstanbul

AbstractCartography, unquestionably one of the world’s oldest disciplines of scientific study, is among the fields that have been most influenced by technological improvements. These improvements have enhanced interest in historical maps while also paving the way for modern mapping. All of this process has created new topics of study for cartographers. It is possible to examine old maps using software such as MapAnalyst which can enable the investigation of time-dependent changes. In this study, two historical maps, namely, Moltke and German Blue, were analyzed in the study area including the Historical Peninsula, Golden Horn, some part of Bosphorus, and the Marmara Sea in İstanbul, Türkiye, employing Helmert, Affine, and Huber loss robust estimation methods. It was revealed that the region with the highest deterioration on both maps is between Beşiktaş and Üsküdar. The coastline change analysis was also performed. According to the results, it was observed that the regions with the most coastal change are located on the southern and eastern coasts of the Historical Peninsula.