The order Diptera(Insecta)is one of animal groups most successful in the colonization of mineralized shallow aquatic and semiaquatic environments.At the same time,the taxonomic composition of Diptera,their role in
Bioremediation of shorelines polluted by spilling oil has no secondary pollution and saves manpower and material resources, so it has a wide market. Standardizing the operation methods and materials used of the techno...Bioremediation of shorelines polluted by spilling oil has no secondary pollution and saves manpower and material resources, so it has a wide market. Standardizing the operation methods and materials used of the technology can improve its efficiency. Therefore, the research process of technical specifications for bioremediation of shorelines polluted by spilling oil at home and abroad was expounded in this study.展开更多
Puget Sound shorelines have historically provided a diversity of habitats that support a variety of aquatic resources throughout the area. These valued natural resources are iconic to the region and remain central to ...Puget Sound shorelines have historically provided a diversity of habitats that support a variety of aquatic resources throughout the area. These valued natural resources are iconic to the region and remain central to both the economic vitality and community appreciation of Puget Sound. Coastal developments over the past 30 years have placed increased pressure on aquatic resources through deterioration of upland and nearshore shoreline habitats within the region. Since a majority of Washington State upland shorelines are privately owned, regulatory authority to require future restoration on private property is not feasible. Washington States＇ Shoreline Management Act requires local jurisdictions to plan for appropriate future shoreline uses. Under the Act, future development can be regulated to protect existing ecological functions. However, lost functions cannot be retroactively restored through regulatory means, but rather require purchase or compensation of the private property to be restored. Therefore, questions remain as to the ecological resilience of the region when considering cumulative effects of existing and ongoing shoreline development and limited shoreline restoration opportunities constrained to public lands. In light of these questions, this analysis will explore opportunities to promote restoration on privately owned shorelines within Puget Sound. These efforts are intended to promote more efficient coastal management to improve ecosystem services.展开更多
Coasts are subject to multiple natural hazards,which are increasing nowadays.Coastal flooding and erosion are some of the most common hazards affecting coastlines.Being aware of the vulnerability of coasts is importan...Coasts are subject to multiple natural hazards,which are increasing nowadays.Coastal flooding and erosion are some of the most common hazards affecting coastlines.Being aware of the vulnerability of coasts is important to achieve integrated coastal management.The coastal vulnerability index(CVI)is a common index used to assess coastal vulnerability because it is easily calculated.However,given that its calculation includes numerous manual steps,it requires considerable time,which is often unavailable,to produce accurate and utilizable results.In this work,we developed a ModelBuilder model by using the tools provided by ArcGIS Pro(ESRI).Through this model,we automatized most of the steps involved in CVI calculation.We applied the ModelBuilder model in the northern Peloponnese,for which the CVI has already been calculated in three other works.We were thus able to assess the effectiveness of our ModelBuilder model.Our results demonstrated that through the ModelBuilder,most of the processes could effectively be automatized without problems,and our results are consistent with the findings of previous works in our study area.展开更多
1 A possible ancient shoreline has been found in the region of Mars explored by the Chinese rover,Zhurong,providing further evidence that an ocean may once have covered a vast area of the lowlands in the planet's ...1 A possible ancient shoreline has been found in the region of Mars explored by the Chinese rover,Zhurong,providing further evidence that an ocean may once have covered a vast area of the lowlands in the planet's northern part.2 The rover landed in southern Utopia Planitia in May 2021 and remained active for almost a year.Researchers studying data from the rover have found clues of an ancient ocean or liquid water as recently as 400,000 years ago.展开更多
The coastal zone ecological restoration project has successfully restored a cumulative shoreline length of 76 km in Fanhe Harbor and Kaozhou Bay ecological restoration shoreline (mangrove forest) located in Huidong Co...The coastal zone ecological restoration project has successfully restored a cumulative shoreline length of 76 km in Fanhe Harbor and Kaozhou Bay ecological restoration shoreline (mangrove forest) located in Huidong County, Huizhou City. Additionally, 5 619.5 m of artificial shoreline has been developed as part of the ecological restoration efforts. Various methods, including UAV remote sensing, orthophoto acquisition, and analysis using ArcGIS software, were employed to assess the length, width, coverage, and other relevant indicators of the newly established ecologically restored shoreline. The findings indicate that the average width, coverage, and ecosystem stability of mangrove forests in the restored area satisfy the criteria for the acceptance of ecological shoreline restoration. Furthermore, a relatively stable ecosystem has been established for over two years. This study offers a scientific foundation for the ecological restoration of mangrove forests and holds considerable significance for the conservation and utilization of mangrove forest resources.展开更多
The complex topography of natural bedrock shorelines on islands necessitates detailed model testing to thoroughly inves-tigate wave overtopping mechanisms and their variation patterns.This understanding is vital for o...The complex topography of natural bedrock shorelines on islands necessitates detailed model testing to thoroughly inves-tigate wave overtopping mechanisms and their variation patterns.This understanding is vital for optimizing the elevation of coastal structures to meet the design requirements for wave overtopping and to ensure safety and efficacy.This paper investigates a nuclear power plant project on an island in Zhejiang Province,China.This study employs small-scale overall model tests and large-scale lo-cal model tests to examine the complex dynamics of wave interaction with the island’s shoreline.It analyzes the influences of wave parameters,shoreline geometry,and underwater topography on wave overtopping behavior.Comparisons between physical model re-sults and empirical formulae reveal substantial discrepancies in overtopping rates across different model scales.The results stress the remarkable effect of accurate underwater topography representation on wave overtopping predictions and emphasize the need for pre-cise topographic modeling.The results also show that overtopping discharges for complex terrains deviate considerably from values determined using traditional empirical formulas for breakwater overtopping.This outcome indicates that conventional methods may insufficiently address the complexities of natural coastal features.To guarantee reliable predictions of overtopping volumes at specif-ic elevations along complex coastlines,this study advocates employing physical modeling across numerous scales while accounting for detailed terrain and hydrodynamic characteristics.展开更多
Based upon the analyses of the sedimentary characteristics, the parallelism of longitudinal streams of the netty drainage system in Shanghai coastal plain to the ancient shorelines, the hydrodynamics in the northern b...Based upon the analyses of the sedimentary characteristics, the parallelism of longitudinal streams of the netty drainage system in Shanghai coastal plain to the ancient shorelines, the hydrodynamics in the northern bank of the Hangzhou Bay and the distribution of sites of ancient cultural remains, this paper indicates that during the period of 7000—4000 a B. P., the south spit of the Changjiang River mouth developed southward, and only stretched to the nearshore area of Jinshanwei. The southern end of the spit was a compoundrecurved one. In addition, the evolution of the shoreline west of Jinshanwei during the same period is discussed.展开更多
Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall(M–K)trend test,this study analyzes the linear c...Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall(M–K)trend test,this study analyzes the linear characteristics and nonlinear behavior of the medium-to long-term shoreline evolution of Jinghai Bay,eastern Guangdong Province.In particular,shoreline rotation caused by a shore-normal coastal structure is emphasized.The results show that the overall shoreline evolution over the past 30 years is characterized by erosion on the southwest beach,with an average erosion rate of 3.1 m/a,and significant accretion on the northeast beach,with an average accretion rate of 5.6 m/a.Results of the M–K trend test indicate that significant shoreline changes occurred in early 2006,which can be attributed to shore-normal engineering.Prior to that engineering construction,the shorelines are slightly eroded,where the average erosion rate is 0.7 m/a.However,after shore-normal engineering is performed,the shoreline is characterized by significant erosion(3.2 m/a)on the southwest beach and significant accretion(8.5 m/a)on the northeast beach,thus indicating that the shore-normal engineering at the updrift headland contributes to clockwise shoreline rotation.Further analysis shows that the clockwise shoreline rotation is promoted not only by longshore sediment transport processes from southwest to northeast,but also by cross-shore sediment transport processes.These findings are crucial for beach erosion risk management,coastal disaster zoning,regional sediment budget assessments,and further observations and predictions of beach morphodynamics.展开更多
The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecologic...The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecological environment changes and even global changes.Based on field measurements,combined with Linear Regression(LR)model and Inverse Distance Weighing(IDW)method,this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay.The shoreline faces a high erosion chance under the action of natural factors,while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities.The implication of change rule for ecological protection and recovery is also discussed.Measures should be taken to protect the coastal ecological environment.The models used in this paper show a high correlation coefficient between observed and modeling data,which means that this method can be used to predict the changing trend of shoreline and tidal flat.The research results of present study can provide scientific supports for future coastal protection and management.展开更多
The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified t...The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified the cultivable mycobiota associated with sand and plants collected along the coast of Gran Canaria (Spain) using culture-dependent and -independent methods. Clinically relevant species belonging to Cryptococcus spp. and related genera such as Naganishia and Papilotrema were isolated and identified from shoreline plants. Moreover, Candida tropicalis was isolated from beach sand, and Aspergillus fumigatus and Aspergillus terreus strains were associated with both types of samples (i.e., plants and beach sand). We conclude that beach sand and shoreline plants are potential reservoirs of fungi of high clinical interest. We recommend including beach sand and plants from the environment when assessing the quality of marine coastal systems. Our results open a framework for studying the natural marine environment and its role in the epidemiology of infectious diseases in order to more accurately manage public health.展开更多
Research on the laws controlling the shoreline equilibrium shape has been one important topic of studying the evolvement and stabilization of sandy coasts. After a brief review of the progress on the equilibrium shape...Research on the laws controlling the shoreline equilibrium shape has been one important topic of studying the evolvement and stabilization of sandy coasts. After a brief review of the progress on the equilibrium shape laws research, five models are introduced in detail. Advantages and disadvantages of these models are then discussed, which leads to the conclusion that the empirical formula integrating with analysis of mechanism should be the future direction of study on the headland-bay equilibrium shape laws. Finally, the importance of the study on the equilibrium shape of headland-bay in China is also discussed.展开更多
Extraction and analysis of the shoreline and land reclamation patterns are important for studies on topics such as the dynamics of coastal wetland ecological environments,transportation and exchange of material energy...Extraction and analysis of the shoreline and land reclamation patterns are important for studies on topics such as the dynamics of coastal wetland ecological environments,transportation and exchange of material energy in coastal regions,and recruitment of fishery resources.Spatial-temporal variations in the shoreline and land reclamation in the Bohai Sea were analyzed based on 49 Landsat images of 7 periods from 1985 to 2015.The following conclusions were drawn.(1)The extracted shoreline data based on visual interpretation had high precision,and the shoreline extraction errors could be controlled within the theoretical range.(2)Over the past 30 years,the shoreline of the Bohai Sea has exhibited an average rate of change of 188.47 m/a and an average accretion distance of 3.55×10^3 m toward the sea.The fastest rate of shoreline change occurred in Laizhou Bay(134.78 m/a),followed by Bohai Bay(128.20 m/a)and Liaodong Bay(61.69 m/a).(3)The average rate of reclamation was 3.25×10^4 ha/a in the Bohai Sea,where the total area of aquaculture land,unused land,and salt land exceeded 60%of the total reclamation area.(4)The geometric shape of the bay became increasingly complicated from year to year,and the geometric center of gravity of the bay moved rapidly toward the sea.In addition,the area of the bay showed a significant decreasing trend.Therefore,to protect the function and structure of the ecosystem in coastal regions,we must control the scale and rate of land reclamation in the future.展开更多
Bulletins of China's National Sea Level show that the average rising rate of sea-levels in China is 3.3 mm/a over the past 40 years, with an obviously accelerated rising trend in the last decade. The rate of relat...Bulletins of China's National Sea Level show that the average rising rate of sea-levels in China is 3.3 mm/a over the past 40 years, with an obviously accelerated rising trend in the last decade. The rate of relative sea-level rise of the Yangtze River Delta reached >10 mm/a after considering the land subsidence, and Bohai Bay is even greater than 25 mm/a. The impact of the sea level rise to the coastal area will be greater in the coming years, so carrying out an assessment of this rising trend is urgent. This paper, taking the coastal area of Tianjin and Hebei as examples, comprehensively evaluates the impact of sea-level rise through multitemporal remote sensing shoreline interpretation, ground survey verification, elevation measurements for both seawall and coastal lowlands. The results show that the average elevation of the measured coastal areas of Tianjin and Hebei is about +4 m, and the total area of >100 km^2 is already below the present mean sea level. More than 270 km, ca. 31% of the total length of the seawall, cannot withstand a 1-in-100-year storm surge. Numerical simulations of the storm flooding on the west coast of Bohai Bay, for 1-in-50-years, 1-in-100-years, 1-in-200-years and 1-in-500-years, show that if there were no coastal dykes, the maximum flooding area would exceed 3000 km^2, 4000 km^2, 5300 km^2 and 7200 km^2, respectively. The rising sea has a direct and potential impact on the coastal lowlands of Tianjin and Hebei. Based on the latest development in international sea-level rise prediction research, this paper proposes 0.5 m, 1.0 m and 1.5 m as low, middle and high sea level rise scenarios by 2100 for the study area, and combines the land subsidence and other factors to the elevation of the existing seawall. Comprehensive evaluation results indicate that even in the case of a low scenario, the existing seawall will not be able to withstand a 1-in-100-years storm surge in 2030, and the potential flooding areas predicted by the model will become a reality in the near future. Therefore, the seawall design in the coastal areas of Tianjin and Hebei must consider the combined effects of land subsidence, sea level rise and the extreme storm surges caused by it.展开更多
On the basis of historical documents, this paper studies the evolutionary processes of the Jiangsu coast and re-estahhshes the positions of the shoreline in different periods. The East China Sea and the Yellow Sea mat...On the basis of historical documents, this paper studies the evolutionary processes of the Jiangsu coast and re-estahhshes the positions of the shoreline in different periods. The East China Sea and the Yellow Sea mathematical models are applied to simulate and analyze the large-scale tidal waves changes under the influence of the coastal change in Jiangsu since 1855 when the Yellow River changed its lower course into the Bohai Sea. Results from this study can be summa- rized in the following aspects： （1） the coastline change strongly affects tidal waves in the region. Generally, the tidal amphtude decreases when the coastline changes in the north coast area of the abandoned Yellow River Delta, whilst increases in the south of this region. The maximum variation of tidal amphtude takes place near the Radial Sandbank. （2） Following the erosion of the abandoned Yellow River Delta in the past century, the non-tidal points of M2 and K1 partial tides move to southwest gradually. （3） During the early 20th century, with the coastline changing, tidal range decreased 30 - 60 cm. From the abandoned Yellow River mouth to the Lvsi Port, the maximum increase of tidal range can exceed nearly 150 cm. From the early 20th century to the early 21st century, the tidal range increases by 20- 50 cm outside the Radial Sandbank. Whereas, the tidal range reduced near the abandoned Yellow River mouth by 30 ~ 50 cm.展开更多
Due to the fast development of industrialization and urbanization, shorelineextraction is necessary for the sustainable development and environment protection inmany countries. This study focused on the accurate metho...Due to the fast development of industrialization and urbanization, shorelineextraction is necessary for the sustainable development and environment protection inmany countries. This study focused on the accurate methods of extracting theinstantaneous waterline —shoreline obtained as the same instant as the satellite imageis acquired. Based on NDWI (Normalized Difference Water Index) and MNDWI(Modified Normalized Difference Water Index), the study changed the bandcombination and proposed a second modified normalized water index (SMNDWI) toextract the waterline. And, this new index is applied to three types of coast to evaluatethe performance of this method with traditional ones. Results show that SNDWI isbetter than NDWI and suitable for applying to the waterline extraction.展开更多
By use of a shorehne-change numerical model （GENESIS） based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper....By use of a shorehne-change numerical model （GENESIS） based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper. Firstly, the GENESIS model is verified and model sensitivity to the major parameter changes is discussed by simulating a hydraulic model test. The beach nourishment project, after that the shoreline change is kept being monitored, is a small-scale emergency one carried out to use two bathing places on the west beach in the summer, 2008. In this paper the shoreline changes caused by the beach nourishment project are modeled by the GENESIS model, and the computed results fit well with the measured shorelines. With the same model and parameters, a long-term performance of the project is predicted, and the result shows that the bathing places only can be suitable for bathing in 2 to 3 years without subsequence nourishment project. Therefore, it is proposed to nourish the beaches in time to keep the service life of the beach in recent years and carry out the beach nourishment project for the whole west beach as soon as possible.展开更多
Beach nourishment is a common coastal management strategy used to protect beach from erosion along the sandy coastlines. This method has been successfully applied to an emergency project at the West Beach of Beidaihe ...Beach nourishment is a common coastal management strategy used to protect beach from erosion along the sandy coastlines. This method has been successfully applied to an emergency project at the West Beach of Beidaihe in the summer of 2008 and the full West Beach nourishment project in 2009-2010, which is the direct base of this study. Some basic information about the emergency engineering area at the Middle Beach is firstly described. The shoreline change of this area, including the analysis of beach width in five monitoring profiles in the bathing places of Middle Beach, is then discussed. After that a numerical modal based on one-line theory is established and the numerical results agree well with the measured shorelines, which indicates that the model is appropriate and is qualified to predict the shoreline change of the Middle Beach. With the same model and parameters, long-term performance of the project is predicted, and the result shows that without follow-up nourishment and project, the bathing places can remain suitable for bathing for about 10 a. It is suggested to nourish the beach in time and carry out the beach nourishment project for the full Middle Beach in Beidaihe.展开更多
Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization, extensively applied to forecast long-term coastal erosion evolvement and the influences o...Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization, extensively applied to forecast long-term coastal erosion evolvement and the influences of coastal engineering as well as long-term coastal management and protection. However, little concern focuses on this in China. The parabolic relationship is the most widely used empirical relationship for determining the static equilibrium shape of headland-bay beaches. This paper utilizes the relation to predict and classify 31 headland-bay beaches and concludes that these bays cannot achieve the ultimate static equilibrium planform in South China. The empirical bay equation can morphologically estimate beach stabilization state, but it is just a referential predictable means and is difficult to evaluate headland-bay shoreline movements in years and decades. By using Digital Shoreline Analysis System suggested by USGS, the rates of shoreline recession and accretion of these different headland-bay beaches are quantitatively calculated from 1990 to 2000. The conclusions of this paper include that （a） most of these 31 bays maintain relatively stable and the rates of erosion and accretion are relatively large with the impact of man-made constructions on estuarine within these bays from 1990 to 2000; （b） two bays, Haimen Bay and Hailingshan Bay, originally in the quasi-static equilibrium planform determined by the parabolic bay shape equation, have been unstable by the influence of coastal engineering; and （c） these 31 bays have different recession and accretion characters occuning in some bays and some segments. On the one hand, some bays totally exhibit accretion, but some bays show erosion on the whole. Shanwei Bay, Houmen Bay, Pinghai Bay and Yazhou Bay have the similar planforms, characterized by less accretion on the sheltering segment and bigger accretion on the transitional and tangential segments. On the other hand, different segments of some bays have two dissimilar evolvement characters. Dacheng Bay, Shenquan Bay, Hudong Bay, Wukan Bay, Fengjia Bay, Wuchang Bay, Lingshui Bay and Tufu Bay produce accretion on the tangential segment, erosion on the transitional segment and accretion on the sheltering segment. However, Guang＇ao Bay, Haimen Bay, Jinghai Bay, Sanya Bay（a）, Dajiao Bay, Hailingshan Bay, Hebei Bay, Fuhu Bay, Shuidong Bay, Wangcun Bay and Bomao Bay generate erosion on the tangential part, accretion on the transitional part and accretion on the sheltering part. It seems to imply some relations between headland-bay beach evolvement and controls on headland-bay beaches, which may possibly to classify headland-bay beach types and should be further studied.展开更多
基金supported by the Russian Foundation for Basic Research (grant no. 14-04-01139)supported by a travel grant from the Organizing Committee
文摘The order Diptera(Insecta)is one of animal groups most successful in the colonization of mineralized shallow aquatic and semiaquatic environments.At the same time,the taxonomic composition of Diptera,their role in
文摘Bioremediation of shorelines polluted by spilling oil has no secondary pollution and saves manpower and material resources, so it has a wide market. Standardizing the operation methods and materials used of the technology can improve its efficiency. Therefore, the research process of technical specifications for bioremediation of shorelines polluted by spilling oil at home and abroad was expounded in this study.
文摘Puget Sound shorelines have historically provided a diversity of habitats that support a variety of aquatic resources throughout the area. These valued natural resources are iconic to the region and remain central to both the economic vitality and community appreciation of Puget Sound. Coastal developments over the past 30 years have placed increased pressure on aquatic resources through deterioration of upland and nearshore shoreline habitats within the region. Since a majority of Washington State upland shorelines are privately owned, regulatory authority to require future restoration on private property is not feasible. Washington States＇ Shoreline Management Act requires local jurisdictions to plan for appropriate future shoreline uses. Under the Act, future development can be regulated to protect existing ecological functions. However, lost functions cannot be retroactively restored through regulatory means, but rather require purchase or compensation of the private property to be restored. Therefore, questions remain as to the ecological resilience of the region when considering cumulative effects of existing and ongoing shoreline development and limited shoreline restoration opportunities constrained to public lands. In light of these questions, this analysis will explore opportunities to promote restoration on privately owned shorelines within Puget Sound. These efforts are intended to promote more efficient coastal management to improve ecosystem services.
文摘Coasts are subject to multiple natural hazards,which are increasing nowadays.Coastal flooding and erosion are some of the most common hazards affecting coastlines.Being aware of the vulnerability of coasts is important to achieve integrated coastal management.The coastal vulnerability index(CVI)is a common index used to assess coastal vulnerability because it is easily calculated.However,given that its calculation includes numerous manual steps,it requires considerable time,which is often unavailable,to produce accurate and utilizable results.In this work,we developed a ModelBuilder model by using the tools provided by ArcGIS Pro(ESRI).Through this model,we automatized most of the steps involved in CVI calculation.We applied the ModelBuilder model in the northern Peloponnese,for which the CVI has already been calculated in three other works.We were thus able to assess the effectiveness of our ModelBuilder model.Our results demonstrated that through the ModelBuilder,most of the processes could effectively be automatized without problems,and our results are consistent with the findings of previous works in our study area.
文摘1 A possible ancient shoreline has been found in the region of Mars explored by the Chinese rover,Zhurong,providing further evidence that an ocean may once have covered a vast area of the lowlands in the planet's northern part.2 The rover landed in southern Utopia Planitia in May 2021 and remained active for almost a year.Researchers studying data from the rover have found clues of an ancient ocean or liquid water as recently as 400,000 years ago.
文摘The coastal zone ecological restoration project has successfully restored a cumulative shoreline length of 76 km in Fanhe Harbor and Kaozhou Bay ecological restoration shoreline (mangrove forest) located in Huidong County, Huizhou City. Additionally, 5 619.5 m of artificial shoreline has been developed as part of the ecological restoration efforts. Various methods, including UAV remote sensing, orthophoto acquisition, and analysis using ArcGIS software, were employed to assess the length, width, coverage, and other relevant indicators of the newly established ecologically restored shoreline. The findings indicate that the average width, coverage, and ecosystem stability of mangrove forests in the restored area satisfy the criteria for the acceptance of ecological shoreline restoration. Furthermore, a relatively stable ecosystem has been established for over two years. This study offers a scientific foundation for the ecological restoration of mangrove forests and holds considerable significance for the conservation and utilization of mangrove forest resources.
基金funded by the National Natural Science Foundation of China(Nos.52039005,52371258,52071031)the Tianjin Science and Technology Plan Project(No.22PTZWHZ00060)the Subtopic of National Key Research and Development Program Projects(No.2022YFB2602301).
文摘The complex topography of natural bedrock shorelines on islands necessitates detailed model testing to thoroughly inves-tigate wave overtopping mechanisms and their variation patterns.This understanding is vital for optimizing the elevation of coastal structures to meet the design requirements for wave overtopping and to ensure safety and efficacy.This paper investigates a nuclear power plant project on an island in Zhejiang Province,China.This study employs small-scale overall model tests and large-scale lo-cal model tests to examine the complex dynamics of wave interaction with the island’s shoreline.It analyzes the influences of wave parameters,shoreline geometry,and underwater topography on wave overtopping behavior.Comparisons between physical model re-sults and empirical formulae reveal substantial discrepancies in overtopping rates across different model scales.The results stress the remarkable effect of accurate underwater topography representation on wave overtopping predictions and emphasize the need for pre-cise topographic modeling.The results also show that overtopping discharges for complex terrains deviate considerably from values determined using traditional empirical formulas for breakwater overtopping.This outcome indicates that conventional methods may insufficiently address the complexities of natural coastal features.To guarantee reliable predictions of overtopping volumes at specif-ic elevations along complex coastlines,this study advocates employing physical modeling across numerous scales while accounting for detailed terrain and hydrodynamic characteristics.
文摘Based upon the analyses of the sedimentary characteristics, the parallelism of longitudinal streams of the netty drainage system in Shanghai coastal plain to the ancient shorelines, the hydrodynamics in the northern bank of the Hangzhou Bay and the distribution of sites of ancient cultural remains, this paper indicates that during the period of 7000—4000 a B. P., the south spit of the Changjiang River mouth developed southward, and only stretched to the nearshore area of Jinshanwei. The southern end of the spit was a compoundrecurved one. In addition, the evolution of the shoreline west of Jinshanwei during the same period is discussed.
基金The National Nature Science Foundation of China under contract No.42071007the Nature Science Foundation of Hainan Province under contract Nos 422RC665,421QN0883,and 423RC553。
文摘Based on high-tide shoreline data extracted from 87 Landsat satellite images from 1986 to 2019 as well as using the linear regression rate and performing a Mann-Kendall(M–K)trend test,this study analyzes the linear characteristics and nonlinear behavior of the medium-to long-term shoreline evolution of Jinghai Bay,eastern Guangdong Province.In particular,shoreline rotation caused by a shore-normal coastal structure is emphasized.The results show that the overall shoreline evolution over the past 30 years is characterized by erosion on the southwest beach,with an average erosion rate of 3.1 m/a,and significant accretion on the northeast beach,with an average accretion rate of 5.6 m/a.Results of the M–K trend test indicate that significant shoreline changes occurred in early 2006,which can be attributed to shore-normal engineering.Prior to that engineering construction,the shorelines are slightly eroded,where the average erosion rate is 0.7 m/a.However,after shore-normal engineering is performed,the shoreline is characterized by significant erosion(3.2 m/a)on the southwest beach and significant accretion(8.5 m/a)on the northeast beach,thus indicating that the shore-normal engineering at the updrift headland contributes to clockwise shoreline rotation.Further analysis shows that the clockwise shoreline rotation is promoted not only by longshore sediment transport processes from southwest to northeast,but also by cross-shore sediment transport processes.These findings are crucial for beach erosion risk management,coastal disaster zoning,regional sediment budget assessments,and further observations and predictions of beach morphodynamics.
基金supported by the National Natural Science Foundation of China (41602205, 42293261)the China Geological Survey Program (DD20189506, DD20211301)+2 种基金the Special Investigation Project on Science and Technology Basic Resources of the Ministry of Science and Technology (2021FY101003)the Central Guidance for Local Scientific and Technological Development Fund of 2023the Project of Hebei University of Environmental Engineering (GCY202301)
文摘The change processes and trends of shoreline and tidal flat forced by human activities are essential issues for the sustainability of coastal area,which is also of great significance for understanding coastal ecological environment changes and even global changes.Based on field measurements,combined with Linear Regression(LR)model and Inverse Distance Weighing(IDW)method,this paper presents detailed analysis on the change history and trend of the shoreline and tidal flat in Bohai Bay.The shoreline faces a high erosion chance under the action of natural factors,while the tidal flat faces a different erosion and deposition patterns in Bohai Bay due to the impact of human activities.The implication of change rule for ecological protection and recovery is also discussed.Measures should be taken to protect the coastal ecological environment.The models used in this paper show a high correlation coefficient between observed and modeling data,which means that this method can be used to predict the changing trend of shoreline and tidal flat.The research results of present study can provide scientific supports for future coastal protection and management.
文摘The fungal community associated with beach sand and plants located along marine coasts are an under-studied area of research despite its potential relevance to human health. In this study, we isolated and identified the cultivable mycobiota associated with sand and plants collected along the coast of Gran Canaria (Spain) using culture-dependent and -independent methods. Clinically relevant species belonging to Cryptococcus spp. and related genera such as Naganishia and Papilotrema were isolated and identified from shoreline plants. Moreover, Candida tropicalis was isolated from beach sand, and Aspergillus fumigatus and Aspergillus terreus strains were associated with both types of samples (i.e., plants and beach sand). We conclude that beach sand and shoreline plants are potential reservoirs of fungi of high clinical interest. We recommend including beach sand and plants from the environment when assessing the quality of marine coastal systems. Our results open a framework for studying the natural marine environment and its role in the epidemiology of infectious diseases in order to more accurately manage public health.
基金the National Natural Science Foundation of China under the contract No. 40576041.
文摘Research on the laws controlling the shoreline equilibrium shape has been one important topic of studying the evolvement and stabilization of sandy coasts. After a brief review of the progress on the equilibrium shape laws research, five models are introduced in detail. Advantages and disadvantages of these models are then discussed, which leads to the conclusion that the empirical formula integrating with analysis of mechanism should be the future direction of study on the headland-bay equilibrium shape laws. Finally, the importance of the study on the equilibrium shape of headland-bay in China is also discussed.
基金The National Basic Research Program(973 Program)of China,No.2015CB453303The Aoshan Scientific and Technical Innovation Program,No.2015ASKJ02-05+3 种基金The Special Fund of the Taishan Scholar Projectthe “Aoshan Talent” ProjectLaboratory for Marine Fisheries Science and Food Production ProcessesPilot National Laboratory for Marine Science and Technology(Qingdao),No.2017ASTCP-ES07
文摘Extraction and analysis of the shoreline and land reclamation patterns are important for studies on topics such as the dynamics of coastal wetland ecological environments,transportation and exchange of material energy in coastal regions,and recruitment of fishery resources.Spatial-temporal variations in the shoreline and land reclamation in the Bohai Sea were analyzed based on 49 Landsat images of 7 periods from 1985 to 2015.The following conclusions were drawn.(1)The extracted shoreline data based on visual interpretation had high precision,and the shoreline extraction errors could be controlled within the theoretical range.(2)Over the past 30 years,the shoreline of the Bohai Sea has exhibited an average rate of change of 188.47 m/a and an average accretion distance of 3.55×10^3 m toward the sea.The fastest rate of shoreline change occurred in Laizhou Bay(134.78 m/a),followed by Bohai Bay(128.20 m/a)and Liaodong Bay(61.69 m/a).(3)The average rate of reclamation was 3.25×10^4 ha/a in the Bohai Sea,where the total area of aquaculture land,unused land,and salt land exceeded 60%of the total reclamation area.(4)The geometric shape of the bay became increasingly complicated from year to year,and the geometric center of gravity of the bay moved rapidly toward the sea.In addition,the area of the bay showed a significant decreasing trend.Therefore,to protect the function and structure of the ecosystem in coastal regions,we must control the scale and rate of land reclamation in the future.
基金supported by the National Natural Science Foundation of China (41476074)China Geological Survey Program (121201006000182401).
文摘Bulletins of China's National Sea Level show that the average rising rate of sea-levels in China is 3.3 mm/a over the past 40 years, with an obviously accelerated rising trend in the last decade. The rate of relative sea-level rise of the Yangtze River Delta reached >10 mm/a after considering the land subsidence, and Bohai Bay is even greater than 25 mm/a. The impact of the sea level rise to the coastal area will be greater in the coming years, so carrying out an assessment of this rising trend is urgent. This paper, taking the coastal area of Tianjin and Hebei as examples, comprehensively evaluates the impact of sea-level rise through multitemporal remote sensing shoreline interpretation, ground survey verification, elevation measurements for both seawall and coastal lowlands. The results show that the average elevation of the measured coastal areas of Tianjin and Hebei is about +4 m, and the total area of >100 km^2 is already below the present mean sea level. More than 270 km, ca. 31% of the total length of the seawall, cannot withstand a 1-in-100-year storm surge. Numerical simulations of the storm flooding on the west coast of Bohai Bay, for 1-in-50-years, 1-in-100-years, 1-in-200-years and 1-in-500-years, show that if there were no coastal dykes, the maximum flooding area would exceed 3000 km^2, 4000 km^2, 5300 km^2 and 7200 km^2, respectively. The rising sea has a direct and potential impact on the coastal lowlands of Tianjin and Hebei. Based on the latest development in international sea-level rise prediction research, this paper proposes 0.5 m, 1.0 m and 1.5 m as low, middle and high sea level rise scenarios by 2100 for the study area, and combines the land subsidence and other factors to the elevation of the existing seawall. Comprehensive evaluation results indicate that even in the case of a low scenario, the existing seawall will not be able to withstand a 1-in-100-years storm surge in 2030, and the potential flooding areas predicted by the model will become a reality in the near future. Therefore, the seawall design in the coastal areas of Tianjin and Hebei must consider the combined effects of land subsidence, sea level rise and the extreme storm surges caused by it.
基金supproted by the National Natural Science Foundation of China(Grant No.40706034)the Special Fund of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineerirg(Grant No.2009585812)
文摘On the basis of historical documents, this paper studies the evolutionary processes of the Jiangsu coast and re-estahhshes the positions of the shoreline in different periods. The East China Sea and the Yellow Sea mathematical models are applied to simulate and analyze the large-scale tidal waves changes under the influence of the coastal change in Jiangsu since 1855 when the Yellow River changed its lower course into the Bohai Sea. Results from this study can be summa- rized in the following aspects： （1） the coastline change strongly affects tidal waves in the region. Generally, the tidal amphtude decreases when the coastline changes in the north coast area of the abandoned Yellow River Delta, whilst increases in the south of this region. The maximum variation of tidal amphtude takes place near the Radial Sandbank. （2） Following the erosion of the abandoned Yellow River Delta in the past century, the non-tidal points of M2 and K1 partial tides move to southwest gradually. （3） During the early 20th century, with the coastline changing, tidal range decreased 30 - 60 cm. From the abandoned Yellow River mouth to the Lvsi Port, the maximum increase of tidal range can exceed nearly 150 cm. From the early 20th century to the early 21st century, the tidal range increases by 20- 50 cm outside the Radial Sandbank. Whereas, the tidal range reduced near the abandoned Yellow River mouth by 30 ~ 50 cm.
基金supported by Tianjin Natural Science Foundation Project (14JCYBJC22500)
文摘Due to the fast development of industrialization and urbanization, shorelineextraction is necessary for the sustainable development and environment protection inmany countries. This study focused on the accurate methods of extracting theinstantaneous waterline —shoreline obtained as the same instant as the satellite imageis acquired. Based on NDWI (Normalized Difference Water Index) and MNDWI(Modified Normalized Difference Water Index), the study changed the bandcombination and proposed a second modified normalized water index (SMNDWI) toextract the waterline. And, this new index is applied to three types of coast to evaluatethe performance of this method with traditional ones. Results show that SNDWI isbetter than NDWI and suitable for applying to the waterline extraction.
基金supported by two funds from the Department of Land and Resources of Hebei Province,China(Grant Nos.HEBEIGT2006ZT and HEBEIGT2008-2903)two grants from the Ministry of Science and Technology,China(Grant Nos.2008BAJ08B14 and 2007FY110300-03)
文摘By use of a shorehne-change numerical model （GENESIS） based on one-line theory, a preliminary modeling study on shoreline changes caused by a beach nourishment project in Beidaihe, China, is presented in this paper. Firstly, the GENESIS model is verified and model sensitivity to the major parameter changes is discussed by simulating a hydraulic model test. The beach nourishment project, after that the shoreline change is kept being monitored, is a small-scale emergency one carried out to use two bathing places on the west beach in the summer, 2008. In this paper the shoreline changes caused by the beach nourishment project are modeled by the GENESIS model, and the computed results fit well with the measured shorelines. With the same model and parameters, a long-term performance of the project is predicted, and the result shows that the bathing places only can be suitable for bathing in 2 to 3 years without subsequence nourishment project. Therefore, it is proposed to nourish the beaches in time to keep the service life of the beach in recent years and carry out the beach nourishment project for the whole west beach as soon as possible.
基金The Department of Land and Resources of Hebei Province,China under contract Nos HEBEIGT2006ZT and HEBEIGT2008–2903the State Oceanic Administration of China under contract No.2009008-05Kwang-Hua Fund for College ofCivil Engineering,Tongji University of China
文摘Beach nourishment is a common coastal management strategy used to protect beach from erosion along the sandy coastlines. This method has been successfully applied to an emergency project at the West Beach of Beidaihe in the summer of 2008 and the full West Beach nourishment project in 2009-2010, which is the direct base of this study. Some basic information about the emergency engineering area at the Middle Beach is firstly described. The shoreline change of this area, including the analysis of beach width in five monitoring profiles in the bathing places of Middle Beach, is then discussed. After that a numerical modal based on one-line theory is established and the numerical results agree well with the measured shorelines, which indicates that the model is appropriate and is qualified to predict the shoreline change of the Middle Beach. With the same model and parameters, long-term performance of the project is predicted, and the result shows that without follow-up nourishment and project, the bathing places can remain suitable for bathing for about 10 a. It is suggested to nourish the beach in time and carry out the beach nourishment project for the full Middle Beach in Beidaihe.
基金supported by the National Nature Science Foundation of China(Grant No. 40576041)
文摘Headland-bay beach equilibrium planform has been a crucial problem abroad to long-term sandy beach evolution and stabilization, extensively applied to forecast long-term coastal erosion evolvement and the influences of coastal engineering as well as long-term coastal management and protection. However, little concern focuses on this in China. The parabolic relationship is the most widely used empirical relationship for determining the static equilibrium shape of headland-bay beaches. This paper utilizes the relation to predict and classify 31 headland-bay beaches and concludes that these bays cannot achieve the ultimate static equilibrium planform in South China. The empirical bay equation can morphologically estimate beach stabilization state, but it is just a referential predictable means and is difficult to evaluate headland-bay shoreline movements in years and decades. By using Digital Shoreline Analysis System suggested by USGS, the rates of shoreline recession and accretion of these different headland-bay beaches are quantitatively calculated from 1990 to 2000. The conclusions of this paper include that （a） most of these 31 bays maintain relatively stable and the rates of erosion and accretion are relatively large with the impact of man-made constructions on estuarine within these bays from 1990 to 2000; （b） two bays, Haimen Bay and Hailingshan Bay, originally in the quasi-static equilibrium planform determined by the parabolic bay shape equation, have been unstable by the influence of coastal engineering; and （c） these 31 bays have different recession and accretion characters occuning in some bays and some segments. On the one hand, some bays totally exhibit accretion, but some bays show erosion on the whole. Shanwei Bay, Houmen Bay, Pinghai Bay and Yazhou Bay have the similar planforms, characterized by less accretion on the sheltering segment and bigger accretion on the transitional and tangential segments. On the other hand, different segments of some bays have two dissimilar evolvement characters. Dacheng Bay, Shenquan Bay, Hudong Bay, Wukan Bay, Fengjia Bay, Wuchang Bay, Lingshui Bay and Tufu Bay produce accretion on the tangential segment, erosion on the transitional segment and accretion on the sheltering segment. However, Guang＇ao Bay, Haimen Bay, Jinghai Bay, Sanya Bay（a）, Dajiao Bay, Hailingshan Bay, Hebei Bay, Fuhu Bay, Shuidong Bay, Wangcun Bay and Bomao Bay generate erosion on the tangential part, accretion on the transitional part and accretion on the sheltering part. It seems to imply some relations between headland-bay beach evolvement and controls on headland-bay beaches, which may possibly to classify headland-bay beach types and should be further studied.
