Journal of Coastal Conservation最新文献

Abstract

The study analyzes satellite imagery, beach morphology, grain size, river discharge and bathymetry, and tidal water level along the central Ganges-Brahmaputra-Meghna (GBM) delta coast and examines the processes of coastal development. Integrated remote sensing and geographic information system (GIS) techniques were used to monitor coastal dynamics in the GBM delta from 1978 to 2023. The analysis shows that the west and central coasts eroded about 0.03–2.40 km and lost 14.54 km² of land during the study period. In contrast, the east coast advanced 0.09–1.42 km and gained 2.80 km². Beach slopes varied with the west coast having slope between 1° and 2°, and consisting of bimodal, poorly sorted, very fine-grained sand. The central and eastern coastline have slopes between 1° and 4°, and 3° and 5°, respectively, with unimodal, well-sorted to moderately well-sorted fine-grained sand. Statistical analysis of tidal water levels shows an increasing trend (8–12 mm yr⁻¹), while river discharge decreased by 22.57–55.94% during the period November to May due to the upstream dams, and channels were silted. On the east coast, characterized by weak longshore currents, there is minimal transfer of sediment to the sea, and the coastline advanced. Conversely, the current gets stronger when it moves to the west, and the coastlines experience the erosion. The coastal development of the area was influenced by unequal sediment supply and accommodation created at the river mouth due to the sea level rise (SLR). In addition to the natural factors, anthropogenic activities have also influenced the coastal sustainability in the study area.

Coastlines are tectonically active places with an impact on physical as well as social and economic restructuring of cities. They play an essential role in the development of urban areas. Furthermore, coastal environments may offer important health benefits. They may also present numerous threats to human health and well-being time to time. With the rapid urbanization in coastal cities, the lack of urban green space and transportation problems have emerged recently, and the cities have grown towards the sea by coastal filling areas as a solution. Especially the construction of highway on the coastline in the Black Sea region of Turkey has adversely impacted relationship between the people and the sea in the city of Trabzon. In this study, initially a literature review was conducted and parameters were specified for coastline usages. A survey study was conducted with 140 individuals who actively use the coastline in the city of Trabzon, in order to specify the past and current coastline usages. The evaluation of the past and current usage shows that people want to meet the sea but feel uncomfortable with the landscape with the fillings. According to the Anova test, the unmodified form of area was chosen to ‘have a more natural landscape (5.77)’ while the modified form of area was preferred ‘to be renovated (4.12)’. This highlights the users’ longing for the past. Therefore, authorities need to address the impact of differences between parameters in depth on the usage of the area on the coastal landscape. Coastal ecology solutions should also be produced with the ecological design approaches.

Statistical evaluation of sea’s state is essential for the design and managements of marine structures, operations, shipping and navigation security. For the purpose of coastal navigation, little to no research has been done on the state of the sea along the Nigerian coast. Understanding the local sea’s state can help to lessen the frequency of incidents brought on by ships capsizing. In order to notify users of probable areas where vessel overturning may occur, this study therefore employs the warning and prediction services system created and developed by the Indian National Centre for Ocean Information Services (INCOIS). The system bases its warning advisory on the Boat Safety Index (BSI), a newly developed index with a sufficient threshold. Furthermore, this study investigates the statistical properties of the sea’s state along the Nigerian coast, using daily significant wave height (SWH) and 10 m wind speed (u) data spanning 37 years (1980–2016). The Douglas smooth (wavelet) sea’s state classification prevailed in both cases in the sea. It occurred more in the dry season than in the rainy season. The Douglas smooth (wavelets) sea also prevailed in all months of the year except in August, when the Douglas slight sea had higher occurrences. A spatial analysis using SWH showed that Douglas calm seas are predominant in the eastern waters of the study region. The majority of the study area's waters are dominated by the Douglas smooth (wavelets) sea, which is especially prevalent in the area around Lagos Lagoon. In the western coast of the study area, the Douglas slight sea had the highest frequencies. Very low occurrences of the Douglas moderate and rough seas were observed over the research area. Additionally, a spatial analysis using u revealed that the Douglas smooth (wavelets) sea prevailed in the eastern coast of the study area. The Douglas light and moderate seas increased offshore. In the far western coast of the study location, the Douglas rough to high seas showed very rare occurrences. In all, very little or no occurrence of the Douglas rough to phenomenal seas was observed. Insignificant trends exist for the Douglas smooth (wavelets) sea over the study area. The Boat Safety Index used to evaluate the research location showed that it is considered safe for coastal sailing.

Mangrove forests protect the coastal environment and reduce shoreline shift, deforestation, and flood inundation. Global sea-level rise (SLR) and Bay of Bengal (BoB) cyclonic effects in the Bay of Bengal (BOB) is gradually trigger environmental degradation, flood inundation, and mangrove deforestation. Bangladesh Sundarbans are also affected by SLR and flood inundation every year. Sundarban Biosphere Reserve (SBR) is vulnerable because of extreme climatic conditions and anthropogenic activities. Those environmental effects are measurable through remote sensing (RS) and GIS approaches. Three types of satellite data, like Landsat 8 OLI/TIRS, Sentinel-1 GRD and Sentinel-2 MSI datasets, were applied with the Google Earth Engine (GEE) cloud computing platform. Around 11.57 km² of mangrove forest will be lost from 2017 to 2022. The cyclone effects are located twice, like Mora (2017) and Sitrang (2022), while affected landforms are 77.15 km² (1.38%) and 218.75 km² (3.93%), respectively. Vegetation monitoring indices are also good outcomes for forest land change assessment over the examined area. Forest degradation index (FDI) values were observed in 1950 (2017) and 2620 (2022), which mentioned that north, middle, and near-shore areas are affected lands. Some adaptation planning implemented by the local government includes future disaster management, early warning system, reduction of river bank erosion, restricted forest area, and mangrove plantation. Putney Island, Bangabandhu Island, and Dimer Island are the most deforested lands. These investigation outcomes are helpful for future disaster planning, coastal environment management, awareness, mangrove forest restoration, and novel approaches to protect the coastal environment with healthier improvement policies.

The Little Andaman Island face exploitation masked as development through the implementation of policies and schemes, which ultimately deplete and degrade its natural resources. Additionally, the island is also susceptible to frequent natural disasters and the adverse effects of climate change, compounding environmental challenges. The main aim of this study was to assess the dynamic changes in the landscape of Little Andaman during the years 1976, 1989, 2010, 2014, and 2022 using satellite data. Thematic maps of the area were generated using visual interpretation techniques. The study revealed that the dominant land cover in Little Andaman was forests, which gradually decreased from 622.79 km² in 1976 to 579.6 km² in 2022, resulting in an overall loss of 43.1 km² over 47 years. On the other hand, settlements, including built-up areas and agriculture, nearly doubled in size from 18.9 km² in 1976 to 36.60 km² in 2022. Mangroves, in contrast, exhibited stable coverage, with an area of approximately 31 km² in 1976, showing minor fluctuations until 2022. Plantations experienced an increase from 19.37 km² in 1989 to 22.28 km² in 2022. Water bodies also expanded gradually, reaching 10.4 km² in 2010 and maintaining a consistent size until 2022. In the meantime, degraded forests and degraded mangroves showed minimal changes over the years. The study identified a range of factors contributing to these changes, with a particular focus on tsunamis, climate change, and government policies and schemes.

Abstract

This work seeks to demonstrate how light pollution impacts fishing activities, including catch rates and the profits of fishermen. Our goal is to examine how light pollution affects the fishing dynamics of sardines and anchovies in the Casablanca-Rabat region of Morocco, within a bioeconomic framework involving these two marine populations. In this article, we show that our model is well posed by studying the positivity and the boundedness of our system, and then we show the local stability of the interior equilibrium point. Then, we move on to calculating the fishing effort that maximizes fishermen’s profits and catches under two main constraints: The influence of light pollution on the sustained viability of the sardine and anchovy populations. Using data reported by the National Fisheries Research Institute (INRH), we obtain detailed results in numerical simulations.

Shoreline change analysis is crucial for identifying coastal issues and understanding their underlying causes. This study focuses on investigating the coastal impacts of the Derekoy Fishing Port in Samsun, a city located on the Black Sea coast of Turkey. Temporal changes between 1984 and 2021 were analyzed using Landsat-5 TM/Landsat-8 OLI satellite images in conjunction with image processing and geographic information systems (GIS). Net shoreline movement (NSM), shoreline change envelope (SCE), end point rate (EPR), and linear regression rate (LRR) methods were used to investigate the changes in the shoreline. Polygon overlay analysis was utilized to determine the areas of erosion and accretion. The results indicate that prior to the port's construction, the coast remained relatively stable during the period of 1984–1995. However, sediment accretion occurred on the updrift side of the port, while erosion intensified on the downdrift side during the port's construction from 1995 to 2004. Despite the implementation of coastal protection structures to combat erosion, complete prevention was not achieved, and erosion shifted further eastward. Throughout 1984–2021, approximately 15.62 hectares of beaches were lost due to erosion, with a maximum value of -56.2 m recorded. The coastal erosion and the construction of coastal protection structures have disturbed coastal morphology and resulted in various environmental and socio-economic issues along the 19 Mayis and Atakum beaches. This study reveals the significant consequences of a small fishing port built without proper planning and adequate precautions, drawing attention to the problems.

Topography and vegetation have a significant role in soil development in different ecosystems. Interactions between soil and landforms help to understand the pedogenic processes and soil variability. The present study assessed the impact of various landforms and vegetation on pedological variability along the toposequence of the eastern coastal plain. We characterized 46 soil profiles from five landforms, viz., foothills, upland, alluvial plains, coastal plains, and sandbars and performed factor analysis. The frequency distribution of the soil properties was significantly skewed with each other’s. Soils are classified into three orders: Alfisols, Inceptisols, and Entisols from hills to sandbars. The soils were characterized by clay (2.50–65.8%), AWC (4.0–28.0%), pH (5.40–9.40), EC (0.03–5.60 dSm⁻¹), OC (0.01–1.13%), CEC (1.0-31.60 cmol (p⁺) kg⁻¹), BS (57–95%) and ESP (0.54–27.8%). Whereas alluvial plain soils are rich in clay and organic carbon, foothill and upland soils experience severe to moderate soil erosion, leading to the leaching of basic cations. Coastal plains face regular seawater intrusion and flooding, causing excess deposition of salts, which alter the soil pedogenic process under different landforms and land use. Soil pH, EC, clay, CEC and ESP significantly influenced the paddy yield in alluvial and coastal plains landforms. Development of landform and soil relationships concerning land uses in coastal regions helps to identify factors involved in soil development, pedogenic processes and crop productivity.