Статті в журналах з теми "Littoral erosion"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Littoral erosion.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 статей у журналах для дослідження на тему "Littoral erosion".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте статті в журналах для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Mohammadi, Bijan. "Uncertainty quantification in littoral erosion." Computers & Fluids 143 (January 2017): 120–33. http://dx.doi.org/10.1016/j.compfluid.2016.10.017.
2
Brunn, Per. "MEASURES AGAINST EROSION AT GROINS AND JETTIES." Coastal Engineering Proceedings 1, no. 3 (January 1, 2000): 11. http://dx.doi.org/10.9753/icce.v3.11.
Анотація:
One of the difficult problems on a littoral drift coast is the erosion on the leeside of groins and jetties. This paper will deal with the problem giving special consideration to the conditions on the Danish North Sea coast where many interesting problems of littoral drift and coastal protection are found. They are discussed as an introduction to the main part of the paper which is principally concerned with leeside erosion and measures for its prevention.
3
Ruol, Piero, Luca Martinelli, and Chiara Favaretto. "Vulnerability Analysis of the Venetian Littoral and Adopted Mitigation Strategy." Water 10, no. 8 (July 26, 2018): 984. http://dx.doi.org/10.3390/w10080984.
Анотація:
This paper discusses the key aspects of the recent Coastal Plan of the Veneto Region (IT). Its aim is to propose a single mitigation strategy for coastal erosion that is valid for the whole Veneto Region, and possibly elsewhere, as well as a method to assign a priority level to any action. The suggested mitigation action against erosion depends on urbanization level, beach width, as well as cross-shore and long-shore sediment transport. The criterion used to give a priority level to mitigation actions is based on a vulnerability index that takes into account erosive tendency, existing coastal flooding hazards, coast value, environmental relevance, tourist pressure, urbanization level, the presence of production activities, and cultural heritage. A sample case featuring the littoral of Rosolina is also provided and includes a site description, the sediment budget, critical issues and possible mitigation measures.
4
Sayao, Otavio J., and Robert B. Nairn. "PHYSICAL MODELLING OF BEACH EROSION AND LITTORAL DRIFT." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 134. http://dx.doi.org/10.9753/icce.v21.134.
Анотація:
A new procedure for physical modelling of beach sedimentary processes is presented. It is shown that the modelling requirements proposed by Dean (1985) are necessary but not sufficient for dynamic similarity. Quantification of scale effects due to slope and relative grain size scaling conditions enables extrapolation of the physical model results to prototype situations. Selected examples of the application of the proposed model design are also given.
5
Nicholls, R. J., and N. B. Webber. "Coastal erosion in the eastern half of Christchurch Bay." Geological Society, London, Engineering Geology Special Publications 4, no. 1 (1987): 549–54. http://dx.doi.org/10.1144/gsl.eng.1987.004.01.68.
Анотація:
AbstractChristchurch Bay has a long history of shoreline recession and this has given rise to some major coastal engineering problems. An area of particular concern is Hurst Beach at its eastern end, where the maximum rate of recession has increased from 1.5 m a-1 (1867 to 1968) to 3.5 m a-1 (1968 to 1982). Hurst Castle itself is now subject to wave attack on part of its frontage. The littoral sediment movement was assumed to be essentially continuous around Christchurch Bay, but, in fact, a littoral drift sub-cell boundary (i.e. a partial barrier to littoral drift) is present in the vicinity of Hordle Cliff. Therefore, the increased recession of Hurst Beach is a local problem. Milford-on-Sea is situated on a thick sequence of Pleistocene Gravels, whose erosion contributed substantially to the maintenance of Hurst Castle Spit as a major physiographic feature. However, a series of coast protection works were constructed to protect Milford-on-Sea between 1936 and 1968, removing this important source of sediment.In the long term, without any further human interference, recession rates of up to 6 m a-1 will probably occur along Hurst Beach. A breach of Hurst Beach is a major concern, as it would create an island at Hurst Castle and expose the vulnerable, low-lying, northern coast of the West Solent, including the village of Keyhaven, to increased wave attack and tidal scour. Ecologically important saltmarshes would also be destroyed.Shingle renourishment is the only environmentally acceptable engineering solution. Limited renourishment has already commenced. Any cost benefit decisions must consider the wider implications of a breach in Hurst Beach, including environmental and ecological considerations.This case study demonstrates the importance of a detailed understanding of both the littoral and offshore sediment movement for the planning of coast protection.
6
Brewer, Carol, and Michael Parker. "Distribution and Composition of Substrate in the Littoral Zone in Jackson Lake, Grand Teton National Park, Wyoming." UW National Parks Service Research Station Annual Reports 9 (January 1, 1985): 56–62. http://dx.doi.org/10.13001/uwnpsrc.1985.2483.
Анотація:
The composition of sediments varies both horizontally and vertically in a lake. The distribution of sediment types is related not only to basin geomorphology, but also to the effect of turbulent water as it moves substrate particles in the littoral zone. Definite patterns of erosion and deposition in lakes have been described by many limnologists (e.g., Hutchinson, 1957; Spence, 1982; Keddy, 1982, 1983, 1984). Sedimentation and the quality of sediments as a nutrient source affect the ability of macrophytes to colonize and persist in the littoral habitat. The ability to root in a particular area is directly related to the extent which a substrate can anchor the potentially large plants (Spence, 1982). On erosional shores, suspended sediments abrade rooted plants and may cause damage and breakage. On the other hand, the macrophyte community stabilizes bottom sediments and their presence leads to increased water clarity as particulates settle out due to reduced water currents within plant beds. Since the relationship between plants and sediments is well known, our objective was to measure the distribution and composition of the sediments in the littoral zone of the lake. Then we could relate the distribution of substrate to the distribution we had measured for macrophytes in the littoral zone.
7
Putro, Anthony Harlly Sasono, and Jung Lyul Lee. "Analysis of Longshore Drift Patterns on the Littoral System of Nusa Dua Beach in Bali, Indonesia." Journal of Marine Science and Engineering 8, no. 10 (September 26, 2020): 749. http://dx.doi.org/10.3390/jmse8100749.
Анотація:
Bali is one of the most popular tourist areas in Indonesia. With its coastline stretching 633 km, Bali has many beautiful beaches that have become world tourism attractions, thus making tourism the economic engine of Bali. The biggest priority of major tourism sites is maintaining sufficient beach width. However, based on a survey from Balai Wilayah Sungai (BWS) Bali Penida, Bali has suffered from a series of erosions along 215 km of its coastline, including Nusa Dua, in 2015. The location of the study area for this report is a 2.8 km stretch of coastline at Nusa Dua Beach. The erosion problem at Nusa Dua Beach was assessed by analyzing the longshore drift patterns. Simulations are required to assess this erosion problem, combined with the erosion rate and the simulated equilibrium shoreline for each sublittoral cell. To estimate the erosion rate, this study employed profile monitoring data of the beach obtained from 2003 to 2016. This advanced study was based on the mass conservation principle as a governing equation used to predict longshore drifts between sublittoral cells. The satellite image for every sublittoral cell was also used to check the equilibrium condition and estimate the predominant wave direction as the shoreline orientation. Nusa Dua Beach was found to suffer from the change of wave direction and the consequent generation of littoral drift after the reclamation project of Serangan Island located north of the Benoa strait. The correlation between the transportation of longshore sediments and the predominant wave direction indicates the effect of longshore drift in the system. The groin system also created a unique longshore transport pattern in the coastal area. The results obtained in this study can help manage the longshore drift system of Nusa Dua Beach and can be used to predict the beach area subject to erosion and deposition after every beach conservation project. Hence, a strategic plan for managing the shore target lines can be formulated.
8
Krumbein, W. C. "LITTORAL PROCESSES IN LAKES." Coastal Engineering Proceedings 1, no. 1 (May 12, 2010): 16. http://dx.doi.org/10.9753/icce.v1.16.
Анотація:
The purpose of this paper is to present the general topic of lake processes to an engineering audience from a geological point of view. It is apparent that the shores of larger lakes present many problems in common with the sea coast, but the absence of tides, and of first-rank storms, means that geological processes are less marked, and structures may in general be smaller. In contrast to many coastal areas, the Great Lakes probably have less consolidated materials in their banks and bluffs, inasmuch as the basins lie mainly in glacial deposits. Hence rates of erosion may be much greater than on harder coastal rocks. The effect of long-period changes in level also introduce problems of selecting distances above and below lake datum in structures, to allow for the more shoreward wave action during times of high levels. The much leaner shore drift along lakes as compared to the oceans also means that problems of beach development and maintenance may be more difficult to solve. Greater reliance on imported sand in closed systems seems to be the trend in some larger communities where the demand for recreational beaches is great.
9
McFall, Brian C., Honghai Li, David Arnold, Katherine E. Brutsché, David Bucaro, and Erin Maloney. "SEDIMENT TRANSPORT AND SHORELINE RESPONSE TO NEARSHORE PLACEMENT OF DREDGED SEDIMENT IN SOUTHERN LAKE MICHIGAN, USA." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 49. http://dx.doi.org/10.9753/icce.v36.sediment.49.
Анотація:
Shoreline erosion downdrift of littoral barriers, such as harbor breakwaters, is a universal concern. The beneficial use of dredged sediment through placement in the nearshore downdrift of littoral barriers is common place, but key questions about the sediment transport and shoreline response remain challenging. To that end, the shoreline at Ogden Dunes, Indiana, along the southern shores of Lake Michigan is investigated with historical aerial photographs, nearshore placement records, hydrodynamic and bathymetric field data, and numerical models.
10
Young, Adam P., Jessica H. Raymond, John Sorenson, Elizabeth A. Johnstone, Neal W. Driscoll, Reinhard E. Flick, and Robert T. Guza. "Coarse Sediment Yields from Seacliff Erosion in the Oceanside Littoral Cell." Journal of Coastal Research 263 (May 2010): 580–85. http://dx.doi.org/10.2112/08-1179.1.
11
Chapapria, Vicent J. de Esteban, J. Javier Diez Gonzalez, Miguel Arenillas Parra, and Rafael Cortes Gimeno. "COASTAL PROCESSES IN GUARDAMAR BAY (SPAIN)." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 99. http://dx.doi.org/10.9753/icce.v21.99.
Анотація:
The surrounding coastal area of the Segura's River mouth has registered in the last years many erosion problems. It is one of the biggest coastal conjunct in the Spanish mediterranean coast. A whole of studies was carried out to determine littoral and coastal processes in this area.
12
Turriza, Román Canul, Edgar Mendoza, Gregorio Posada, and Rodolfo Silva. "AN ENGINEERING BASED ANALYSIS OF THE COAST OF CAMPECHE AS THE PATH TO SUSTAINABLE MANAGEMENT DECISIONS." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 101. http://dx.doi.org/10.9753/icce.v36.papers.101.
Анотація:
Chronic coastal erosion problems have been reported in Campeche State; however, beaches and ecosystems have not yet been degraded to the point of being at high risk. A proposal for coastal segmentation is presented here, in order to rank the coastal sectors according to the urgency required for intervention; given that this approach applies a large – scale perspective; the analysis is suited to any other coastal zone. The proposed methodology hierarchically identifies littoral segments in three steps: 1) dividing the study area into littoral cells, 2) assessing coastal vulnerability and 3) identifying the immediacy of intervention needed for each coastal sector.
13
Kamphuis, J. William. "Improving shore protection design." Canadian Journal of Civil Engineering 17, no. 2 (April 1, 1990): 142–47. http://dx.doi.org/10.1139/l90-018.
Анотація:
The construction of shore protection is expensive, but the alternative of permitting erosion is also expensive. Yet any design of shore protection is based mostly on intuitive concepts. This paper presents an overview of what is lacking in our knowledge, a possible methodology for improving shore protection design and discussions about some of the most important (and often ignored) physical parameters to be considered if shore protection is to perform its task without interfering with the littoral environment. Key words: erosion, groins, seawalls, sediment transport, shore protection.
14
Dalrino and Elvi Roza Syofyan. "Kajian Terhadap Unjuk Kerja Bangunan Pengaman Pantai Dengan Penerapan Simulasi Numerik One Line Model." Jurnal Ilmiah Poli Rekayasa 10, no. 2 (April 14, 2015): 12. http://dx.doi.org/10.30630/jipr.10.2.7.
Анотація:
With the position on the west coast region of Sumatra, Padang beach facing directly to Indian Ocean that have potentially threat by the ocean waves that relatively give effect to changes in the coastline. This study was conducted to evaluating the performance of existing coastal protection structure to restrain the rate of erosion as a result of the influence of hydrodynamics process. Condition that reviewed was in form of distance shoreline as simulation results to initial reference line before. One Line Model was conducted to get shoreline change in each time step calculation. Model consists of two conditions, with the absence of coastal structures and with structure respectively. The simulation result show that potential erosion occurs at Batang Arau river mouth with no protection structure. Large erosion predicted around 59.04 meters from the shoreline position early. With coastal protection, model result obtained sedimentation of 7.33 meters coastline from its initial position. This occurs at a distance of 475 meters from the boundary domain. Modeling results also showed erosion is 18.39 meters at a distance of 250 m from the boundary domain. This is likely due to the limited modeling conditions that without reviewing of littoral transport direction that occurred in perpendicular to the coast. Result study show that the presence of a groyne in Padang coasts looks already quite effective in defense of the shoreline of the littoral transport direction, however the installation of groins seemingly did not give significant meaning in the addition of the coastline
15
Ouellet, Yvon, François Anctil, and Louis Desjardins. "Solving a harbor accretion problem: the case of Miller and, Îles-de-la-Madeleine, Quebec." Canadian Journal of Civil Engineering 16, no. 6 (December 1, 1989): 924–35. http://dx.doi.org/10.1139/l89-136.
Анотація:
This paper summarizes a group of studies regarding Millerand harbor, located on the Îles-de-la-Madeleine coast, which blocks most of the local littoral drift. The understanding and quantification of this sedimentological problem was first carried out using numerical models. Various schemes were then tested in two mobile-bed physical models. Finally, the impact of these solutions on the wave climate in the harbor and in the entrance channel was compared using a diffraction–reflection numerical model. The results show that accretion in Millerand harbor will only be controlled by the construction of a breakwater. This breakwater must close the east side of the harbor and must reach at least 2 m depth at its toe. It is also strongly recommended that two groins be built on the east-side beach to control the erosion of the cliff. The results of the diffraction–reflection model finally give some latitude to the harbor planners, as several schemes present satisfactory wave agitation maps. Key words: erosion, accretion, breakwater, diffraction–reflection, harbor, littoral drift, numerical model, physical model, wave hindcasting.
16
Mason, Martin A. "PERTINENT FACTORS IN THE PROTECTION OF THE GULF COAST." Coastal Engineering Proceedings 1, no. 2 (January 1, 2000): 19. http://dx.doi.org/10.9753/icce.v2.19.
Анотація:
Protection of the U. S. shores of the Gulf of Mexico against erosion or damage by waves, currents, or other littoral forces involves unique physical and economic conditions that make this area quite different from other shore regions. It is the purpose of this paper to discuss these conditions and the factors that contribute to them.
17
Valdecantos, Vicente Negro, and Manuel Quecedo Gutierrez. "BARCELONA'S LITTORAL REGENERATION LOOKING FORWARD TO THE OLIMPIC GAMES. NUMERICAL MODEL." Coastal Engineering Proceedings 1, no. 21 (January 29, 1988): 107. http://dx.doi.org/10.9753/icce.v21.107.
Анотація:
The modern technique of Coastal Engineering has enabled the succesful modification of the environment, the recuperation and the stabilization of those sandy areas which due to human action, were in a process of regression and erosion. This work developes a mathematical and numerical model to adjust and analyze the variations between the dissipative profiles and the reflectives ones. The research also emphasizes the enveloping profile to calculate the stable behaviour of the beach.
18
Bertoni, Duccio, Monica Bini, Marco Luppichini, Luigi Enrico Cipriani, Andrea Carli, and Giovanni Sarti. "Anthropogenic Impact on Beach Heterogeneity within a Littoral Cell (Northern Tuscany, Italy)." Journal of Marine Science and Engineering 9, no. 2 (February 2, 2021): 151. http://dx.doi.org/10.3390/jmse9020151.
Анотація:
In this paper the evolution of the Northern Tuscany littoral cell is documented through a detailed analysis of the increasing anthropogenic pressure since the beginning of the 20th century. This sector of the Tuscany coast has been experiencing strong erosion effects that resulted in the loss of large volumes of sandy beaches. The anthropogenic impact on natural processes have been intensified by the construction of two ports in the early decades of the 20th century. Competent authorities reacted by building hard protection structures that tried to fix the position of the shoreline but offset the erosion drive downdrift. Therefore, in the last 20 years a regional Plan was undertaken to gradually replace the hard defense schemes with a softer approach, which involved a massive use of sediment redistribution activities. Many nourishments have been done ever since, using both sand and gravel. All these hard and soft protection operations have been archived in a geodatabase, and visualized in maps that clearly show the progressive change from hard to soft defense. This database may improve the approach to any future analysis of the littoral cell both in terms of research and management, while providing a practical example that may be easily replicated elsewhere.
19
Bajorunas, L. "LITTORAL TRANSPORT IN THE GREAT LAKES." Coastal Engineering Proceedings 1, no. 7 (January 29, 2011): 20. http://dx.doi.org/10.9753/icce.v7.20.
Анотація:
The Great Lakes Superior, Michigan, Huron, Erie, and Ontario extend almost to the middle of the North American Continent. With their 95,000 square miles of water surface and their three navigable connections with the Atlantic Ocean and Gulf of Mexico, they affect the well-being of about 4.0 million people living within their vicinity in Canada and the United States. Possessing a shoreline of 6,600 miles, these waters have been called the fourth coast of the continent along with the Atlantic, Gulf, and Pacific coasts. This paper analyzes one of the many problems of the Great Lakes, the littoral transport problem.
Littoral transport has been defined as the movement of material along the shore in the littoral zone by waves and currents. The material thus transported is referred to as the littoral drift. The littoral drift originates from the beach material, being picked up by the water and transported along the shore and deposited in another location. Shore erosion, littoral transport, and deposition of drift are all factors in the littoral process.
A knowledge of the littoral process is important for many engineering projects including the construction and maintenance of shoreline harbors. The harbor breakwater extending from the shore into deep water forms a littoral barrier, and by stopping the transport action causes the depositio of drift on the updrift side. If the breakwater does not entirely stop the transport, or when the storage area on the updrift side is filled, the drift will bypass the breakwater and fill the dredged navigation channel causing frequent and expensive maintenance dredging. This problem is especially important in the small harbors on the Great Lakes planned every 25 to 30 miles as refuge for fishing and pleasure boats. These harbors have a rather small capacity for littoral drift, and the costs of maintenan dredging of so many entrance channels would be almost prohibitive.
In order to provide data required for the design and economic evaluation of the small refuge harbors on the Great .Lakes, the United States Lake Survey, Corps of Engineers, conducted a study of the best method of estimating the rate of littoral transport along the shores of the Great Lakes. Although much of the data used in this paper was taken from the above study, the views and
20
da Motta, Lucas Marchi, Elírio Ernestino Toldo, Luiz Emílio de Sá, Brito de Almeida, and José Carlos Nunes. "Sandy sediment budget of the midcoast of Rio Grande do Sul, Brazil." Journal of Marine Research 73, no. 3 (May 1, 2015): 49–69. http://dx.doi.org/10.1357/002224015815848839.
Анотація:
Calculation of the coastal sediment budget involves estimation of the timing and intensity of processes of erosion, transport, and deposition, as well as an understanding of local and regional sediment dynamics. The modern sedimentary deposits present in the coastal zone constitute the physical basis of coastal ecosystems. Knowledge of the dynamics of these sediments from the source to sink area, through regional sediment management, is critical to understanding the long-term stability of the coastal zone and the fate of these important natural resources. In this article, the littoral cell concept has been applied to the midcoast of Rio Grande do Sul, a wave-dominated and dissipative-intermediate sandy coast in southern Brazil. To analyze littoral drift variations along the 275 km long study area, the shoreline was divided into 12 cells. Littoral drift rates were estimated and compared using the energy flux method. Wave parameters were obtained from WAVEWATCH III. The sand volume of the coastal dune field (4.20 billion m3) was quantified using satellite imagery and the aeolian transport rates estimated utilizing the sediment budget residual. The net annual longshore transport rates obtained with the Coastal Engineering Research Center equation range from 0.60 to 2.63 million m3 per year. The littoral drift rates obtained with the Van Rijn (2001) and Kamphuis (1991) equations range between 0.15 and 1.00 million m3 per year. Based on the sediment budget and dune field age, the CERC formula seems more appropriate to estimate longshore transport.
21
UDA, Takaaki, Manabu YAMAMOTO, Toshiro SAN-NAMI, Kou FURUIKE, Yukiyoshi HOSHIGAMI, and Toshinori ISHIKAWA. "Beach Erosion of Hamaju Coast and Controlling Effect of Littoral Drift by Detached Breakwaters." PROCEEDINGS OF COASTAL ENGINEERING, JSCE 54 (2007): 561–65. http://dx.doi.org/10.2208/proce1989.54.561.
22
Saville, Jr., Thorndike, and Joseph M. Caldwell. "ACCURACY OF HYDROGRAPHIC SURVEYING IN AND NEAR THE SURF ZONE." Coastal Engineering Proceedings 1, no. 3 (January 1, 2000): 3. http://dx.doi.org/10.9753/icce.v3.3.
Анотація:
The analysis and solution of most beach erosion problems are based to a significant degree on the quantitative changes in the bottom hydrography as observed in successive surveys. Critical decisions as to the dominant direction of littoral drift, the average rate of this drift, and the onshore-offshore movement of material are based largely on such hydrographic surveys. As the net changes between successive surveys are usually small compared to the area being studied, the degree of accuracy or comparability of the hydrographic surveys is of considerable importance. For instance, a net change of 100,000 cubic yards over one square mile of beach represents an average change in depth of only about 0.1 feet. Thus, it can be seen that uncompensated errors in depth measurement of as little as 0.1 feet can produce indications of significant littoral sand movement which might not exist in reality.
23
Lira-Pantoja, María Alejandra, Alec Torres-Freyermuth, Christian Mario Appendini, Diana Carolina Fernández, Paulo Salles, Ernesto Tonatiuh Mendoza, José López, and Adrián Pedrozo-Acuña. "CHRONIC BEACH EROSION INDUCED BY COASTAL STRUCTURES IN CHELEM, YUCATÁN." Coastal Engineering Proceedings 1, no. 33 (December 28, 2012): 125. http://dx.doi.org/10.9753/icce.v33.sediment.125.
Анотація:
The Yucatan coastline has been experiencing beach erosion during the past few decades; the erosion has reached critical points at some locations such as the Chelem beach, located near the Progreso Pier. Despite this problem, only few studies have been devoted in order to investigate the role of coastal structures on explaining the high erosion rates reported at this location. Therefore, the aim of this work is to evaluate the effects of the Progreso Pier on the wave transformation and alongshore sediment transport in the study area. Field surveys were conducted in a monthly basis in order to estimate the erosion rates and wave conditions with an ADCP installed at 8 m water depth. The field information confirmed the high erosional trends (O(1)m/year) that explain coastal infrastructure damage and property losses. The wave measurements were employed as the forcing of a wind-wave numerical model (MIKE 21 SW). The numerical model is implemented in the study area for two different scenarios, with and without the pier; this was to estimate nearshore wave conditions. Subsequently, the nearshore wave climate at 5 m water depth is employed for the calculation of alongshore sediment transport rates in 5 points that are representative of the littoral drift along the study area. The modeling results show that the pier acts as a large scale wave-sheltering structure that induces important alongshore sediment transport gradients under mean wave conditions, decreasing the capacity of the waves to recover the beach. On the other hand, during winter storms, when the direction of the waves is from the NNW, the structure does not seem to play an important role on wave transformation into the study. As a result, the Progreso Pier enhances beach erosion in the Chelem area by inducing algonshore gradients in sediment transport and decreasing the beach recovery capability
24
Mider, Gosia, James Lawrence, Philippa Mason, and Richard Ghail. "Monitoring Littoral Platform Downwearing Using Differential SAR Interferometry." Remote Sensing 12, no. 19 (October 6, 2020): 3243. http://dx.doi.org/10.3390/rs12193243.
Анотація:
A methodology for the remotely sensed monitoring, measurement and quantification of littoral zone platform downwearing has been developed and is demonstrated, using Persistent Scatterer Interferometric Synthetic Aperture Radar data and analysis. The research area is a 30 km section of coast in East Sussex, UK. This area combines a range of coastal environments and is characterised by the exposure of chalk along the cliffs and coastal platform. Persistent Scatterer Interferometry (PSI) has been employed, using 3.5 years of Sentinel-1 SAR data. The results demonstrate an average ground level change of −0.36 mm a−1 across the research area, caused by platform downwearing. Protected sections of coast are downwearing at an average of −0.33 mm a−1 compared to unprotected sections, which are downwearing more rapidly at an average rate of −1.10 mm a−1. The material properties of the chalk formations in the platform were considered, and in unprotected areas the weakest chalk types eroded at higher rates (−0.66 mm a−1) than the more resistant formations (−0.53 mm a−1). At a local scale, results were achieved in three studies to demonstrate variations between urban and rural environments. Individual persistent scatterer point values provided a near-continuous sequence of measurements, which allowed the effects of processes to be evaluated. The results of this investigation show an effective way of retrospective and ongoing monitoring of platform downwearing, erosion and other littoral zone processes, at regional, local and point-specific scales.
25
Silva, Silvanete S. da. "SOIL PHYSICAL CHARACTERISTICS NEAR THE RESERVOIR OF THE LUIZ GONZAGA HYDROELECTRIC POWER PLANT - PE." Journal of Hyperspectral Remote Sensing 8, no. 2 (October 8, 2018): 85. http://dx.doi.org/10.29150/jhrs.v8.2.p85-94.
Анотація:
The erosive processes generated at the reservoir banks affect the quantity and the water supply, causing serious environmental and economic consequences. The objective of this study was to define the erosive laminar process in the surroundings of the reservoir of the Hydroelectric Power Plant. To perform the evaluation in sixteen areas, Echanced Thematic Mapper Plus images were used from Ladsat 7 satellite, RGB color composition and 543 bands, with nine classes of use and occupation of the areas, as well as the methodology with erosion pins. The pedological survey revealed a variation in the taxonomic classes, such as: Eutrophic Regolithic Neosol (area 1); Eutrophic Littoral Neosol (areas 2, 3, 4, 12 and 13); Optical Quartzene Neosol (areas 4, 6, 7, 8, 9, 10, 11 and 16); Luvissolo Crômico Órtico (area 5); And Eutrophic Haphol Plantain (area 15); The physical characterization of the soils and the soil loss of the marginal debulking (ranging from the very low to severe level) studied were susceptible to erosive processes. Soil loss in the studied areas varied from 85.00 to 205.20 kg ha-1ano-1.
26
Lee, Sahong, and Jung Lyul Lee. "Estimation of Background Erosion Rate at Janghang Beach due to the Construction of Geum Estuary Tidal Barrier in Korea." Journal of Marine Science and Engineering 8, no. 8 (July 23, 2020): 551. http://dx.doi.org/10.3390/jmse8080551.
Анотація:
In this study, a reduction in sediment budget due to the development of a river watershed, resulting in coastal erosion, was reviewed, and the rate of background erosion was calculated through an examination of the loss of coastal sediment into the open sea. The west coast of the Korean peninsula is severely impacted by the intercept of inflowing sediments from rivers, owing to the watershed development. However, the effects have not fully propagated into the entire coastal area, and thus, the long-term coastal erosion remains insignificant. However, a serious and irrevocable disaster may occur once the coastal erosion begins. Therefore, an analysis of the coastal erosion resulting from changes in the sediment budget, due to the development of the watershed, was conducted on Janghang Songrim Beach. A littoral cell of the Geum River was selected for a quantitative analysis of the decrease in the sediment budget from the watershed development. The rate of coastal sediment loss offshore, which reflects the characteristics of the Janghang Songrim Beach, and the future rate of coastal erosion were calculated. Then, the results were verified by employing geometrically corrected satellite photographs from previous years. This will enable us to predict the time of coastal erosion in the future due to a reduction in the sediment budget and watershed development, and prepare for future disasters resulting from the coastal erosion. Based on research into the components constituting the coastal development, the present study presents theoretical formulae allowing the prediction of the sediment budget and providing a practical contribution to the prevention of coastal erosion, for which additional reliable studies need to be conducted.
27
Bitan, Menashe, Ehud Galili, Ehud Spanier, and Dov Zviely. "Beach Nourishment Alternatives for Mitigating Erosion of Ancient Coastal Sites on the Mediterranean Coast of Israel." Journal of Marine Science and Engineering 8, no. 7 (July 12, 2020): 509. http://dx.doi.org/10.3390/jmse8070509.
Анотація:
Since 2011, beach nourishment has become the preferred solution for mitigating coastal erosion along the Mediterranean coast of Israel, as it is considered “soft” and environmentally friendly. However, using fine sand for nourishment in Israel without supporting measures is problematic due to the high wave energy and strong longshore currents in the littoral zone that tend to drift the sand away. This would require ongoing, multiyear, costly, and never-ending maintenance. In the present study, we analyzed sand and pebble alternatives for nourishment of the eroded beach in front of Tel Ashkelon, an important coastal archaeological site in southern Israel that suffers from severe erosion. Based on Pranzini et al. (2018), we analyzed the alternatives, evaluated their cost and efficiency, and assessed their potential environmental impacts. The study concluded that for protecting the southern part of Tel Ashkelon beach, pebble nourishment is the optimal solution, mainly regarding durability and cost. Using this material for nourishment will better absorb the storm wave impact and protect the foot of the archaeological Tel from erosion, and require lower maintenance cost than using finer sand nourishment.
28
Ietto, Fabio, Nicola Cantasano, and Gaetano Pellicone. "A New Coastal Erosion Risk Assessment Indicator: Application to the Calabria Tyrrhenian Littoral (Southern Italy)." Environmental Processes 5, no. 2 (April 11, 2018): 201–23. http://dx.doi.org/10.1007/s40710-018-0295-6.
29
Cappucci, Sergio, Duccio Bertoni, Luigi Enrico Cipriani, Gianfranco Boninsegni, and Giovanni Sarti. "Assessment of the Anthropogenic Sediment Budget of a Littoral Cell System (Northern Tuscany, Italy)." Water 12, no. 11 (November 19, 2020): 3240. http://dx.doi.org/10.3390/w12113240.
Анотація:
In the present study we describe a straightforward and highly replicable methodology to assess the anthropogenic sediment budget within a coastal system (the Northern Tuscany littoral cell, Italy), specifically selected in a partially natural and partially highly urbanized coastal area, characterized by erosion and accretion processes. The anthropogenic sediment budget has been here calculated as an algebraic sum of sediment inputs, outputs and transfer (m3) within a 40 year time interval (1980–2020). Sediment management strongly influences the sediment budget and, even if its evaluation is crucial to assess the efficiency of a coastal management policy, it is often difficult to quantify the anthropogenic contribution to sedimentary processes. Different types of intervention are carried out by a variety of competent authorities over time (Municipalities, Marinas, Port Authorities), and the correct accountability of sediment budget is no longer known, or possible, for the scientific community. In the Northern Tuscany littoral cell, sedimentation is concentrated in a convergent zone and updrift of port structures, which have determined a series of actions, from offshore dumping and disposal into confined facilities (sediment output), to bypassing and redistribution interventions (sediment transfer); conversely, river mouths and coastal areas protected by groins and barriers are subjected to severe erosion and coastline retreat, resulting in many beach nourishments (sediment input). The majority of coastal protection interventions were carried out to redistribute sand from one site to another within the study area (2,949,800 m3), while the sediment input (1,011,000 m3) almost matched the sediment output (1,254,900 m3) in the considered time interval. A negative anthropogenic sediment budget (−243,900 m3) is here documented.
30
Jiang, Angela Wenping, Michael Hughes, Peter Cowell, Angus Gordon, Juan Carlos Savioli, and Roshanka Ranasinghe. "A HYBRID MODEL OF SWASH-ZONE LONGSHORE SEDIMENT TRANSPORT ON REFLECTIVE BEACHES." Coastal Engineering Proceedings 1, no. 32 (January 30, 2011): 29. http://dx.doi.org/10.9753/icce.v32.sediment.29.
Анотація:
The hydrodynamics and sediment transport in the swash zone is currently outside the domain of coastal-area models, which is a significant limitation in obtaining littoral sediment-transport estimates, especially on steep reflective beaches where the waves practically break on the beachface. In this study, an existing process-based coastal model (MIKE 21) is combined with a theoretical derivation of swash processes, resulting in an innovative hybrid modelling approach that is capable of estimating longshore sediment transport in the swash zone. The method relies upon estimation of swash hydrodynamics from an extended ballistic swash model with friction included. The terminal bore and other incident wave properties were computed from the output of a spectral-wave model (MIKE 21 SW). The Bagnold-type equation was applied to estimate gross transport volumes and the longshore component was computed for the sand volume displaced during the up-rush. The newly developed hybrid modelling approach was applied to Jimmys beach, a steep reflective beach (D50 = 0.3 mm, gradient=0.1) along the northern shoreline of Port Stephens, Australia. The model results yield the alongshore swash transport pathways and the indicative transport volumes. A point of divergence is identified at the beach erosion area, which is of critical importance in terms of shoreline erosion and management. The preliminary results suggest that swash-zone transport can account for a large percentage of the total littoral drift for such beaches. However, further field or laboratory data are required to test model utility, as well as to tune calibration parameters based on the site-specific conditions.
31
Lin, Lihwa, Honghai Li, Frank Wu, and Lisa Andes. "LITTORAL TRANSPORT MODELING FOR OCEAN BEACH AND SAN FRANCISCO BIGHT, CALIFORNIA." Coastal Engineering Proceedings 1, no. 33 (October 25, 2012): 59. http://dx.doi.org/10.9753/icce.v33.sediment.59.
Анотація:
This paper presents the littoral sediment transport numerical modeling effort of simulating physical processes of high energy coastline, including inlet and coastal zone, at Ocean Beach and San Francisco Bight, California. The study site is dominated by strong tidal current and breaking wave-induced longshore current. The numerical models for waves, currents, water levels, and sediment transport are provided by the Coastal Modeling System developed at the US Army Engineer Research and Development Center. The water level, current, wave, sediment, and bathymetric data collected by the US Army Engineer District, San Francisco, and USGS in recent years are assembled and utilized for model calibration and validation. One main effort of the study is to demonstrate the beneficial use of dredged clean material from the ship channel maintenance for onshore beach nourishment and nearshore berm placement at Ocean Beach to remediate the chronicle erosion threatening the structural integrity of the adjacent Great Highway. The modeling effort is intended to guide future dredging activities, dredged material placement site selection and evaluation, beneficial use of dredged material for nearshore and onshore beach nourishment for shore and beach protection. The model result can support and improve decision making for regional and local sediment management, enhance cross-mission benefit, and ultimately reduce the dredging project life-cycle costs.
32
Caldwell, Joseph M. "BY-PASSING SAND AT SOUTH LAKE WORTH INLET, FLORIDA." Coastal Engineering Proceedings 1, no. 1 (May 12, 2010): 34. http://dx.doi.org/10.9753/icce.v1.34.
Анотація:
This paper describes the installation of and results obtained with the sand pumping plant located on the north jetty of South Lake Worth Inlet, Florida. This pumping plant was installed in order to pump drifting beach sand past the littoral drift barrier formed by the creation of South Lake Worth Inlet with its protecting jetties. It was anticipated that the pumping of the sand would relieve the erosion of the shore south of the inlet and cut down on the rate of shoaling in Lake Worth at the inner end of the inlet channel. A discussion of the results obtained with the installation is also included in the paper.
33
Carrión, BenjamÃn, and Rolando GarcÃa. "COMPREHENSIVE STUDY AND MONITORING PROGRAM FOR BEACHES AT VIÑA DEL MAR CHILE." Coastal Engineering Proceedings, no. 36 (December 30, 2018): 43. http://dx.doi.org/10.9753/icce.v36.risk.43.
Анотація:
On August 8th 2015, an extreme storm event affected central Chile. Significant wave heights up to 5.0 m at a depth of 20m were estimated in front of Viña del Mar. Beaches suffered massive erosion and relevant damage to coastal infrastructure occur (Figure 1), jeopardizing the touristic industry of the city. These episodes motivated the execution of the largest comprehensive study and monitoring plan ever done on the littoral system of Viña del Mar. The study considered reviewing historical records, hydrological analysis of the related river basins, several bathymetric and topographic surveys, sediment samples, measurements of waves and currents, monitoring cameras for field recording and extensive numerical modelling.
34
Leth, Jørgen O., Birger Larsen, and Dennis Anthony. "Sediment distribution and transport in the shallow coastal waters along the west coast of Denmark." Geological Survey of Denmark and Greenland (GEUS) Bulletin 4 (July 20, 2004): 41–44. http://dx.doi.org/10.34194/geusb.v4.4779.
Анотація:
Until recently, studies of the regional distribution of seabed sediments off the littoral zone of the Danish North Sea coast had been concentrated on the Jutland Bank area (Fig. 1; Leth 1996, 1998). Knowledge on the sedimentary conditions and processes along the entire west coast of Jutland has, however, significantly increased as a result of 2000 km of newly acquired high-resolution seismic and side-scan sonar data, supplemented by about 100 vibrocores. These data were collected by the Geological Survey of Denmark and Greenland (GEUS) during joint projects with the Danish Coastal Authority between 1998 and 2001 (Leth et al. 1999; Larsen & Leth 2001). The coastal zone off west Jutland displays a highly dynamic environment, where sediment transport is governed by strong tidal and wave-induced currents. The net wavegenerated current is south going, while the coastal current has a net direction towards the north (Knudsen et al. 2002). The direction of the net littoral drift is southward from the outlet of Limfjorden to Blåvands Huk, with net erosion north of Nymindegab and aggregation to the south; the offshore part of this depositional system has recently been studied (Larsen & Leth 2001).
35
Bui, Vinh Trong, Tin Trung Huynh, Trinh Nguyen Doan Le, Hoang Minh Ly, Phong Thanh Le, and Dien Le The Tran. "Monitoring and predicting the shoreline change in Can Gio area in condition of the sea level rise." Science and Technology Development Journal 17, no. 3 (September 30, 2014): 45–53. http://dx.doi.org/10.32508/stdj.v17i3.1475.
Анотація:
Locating on the domestic and international navigation routes (Long Tau-Tac Dinh Cau route, Soai Rap route) the Can Gio area is impacted by waterway traffic activities. The seasonal movement of sand bars on the Can Gio is significantly impacted by hydrodynamic of the river mouth. With the important roles of the area, the authors consider the coastal morphology processes under the hydrodynamic. In this paper, the authors has inherited previous studies combined the satellite image analysis to detect the shoreline changes from 1973 to 2013. Besides, numerical modeling was also applied to predict the shoreline changes under impacts of the sea level rise. Results show that, the Can Gio shoreline prolonging from Can Thanh to Dong Hoa is seriously eroded, with average of 7-10 m/year, maximum to 15 m/year. It is found that, beach erosion at Can Gio is a kind of surface erosion impacted by human trigger (shrimp ponds, beach encroachment…). In addition, natural factors (wave, long-shore current, littoral materials) also contribute to increase the erosion rate. Predicted results with sea level rise scenarios show that, the Dong Hoa and Can Thanh will be seriously eroded while the 30-4 beach will be annually deposited.
36
Romagnoli, Claudia, Flavia Sistilli, Luigi Cantelli, Margherita Aguzzi, Nunzio De Nigris, Maurizio Morelli, Maria Gabriella Gaeta, and Renata Archetti. "Beach Monitoring and Morphological Response in the Presence of Coastal Defense Strategies at Riccione (Italy)." Journal of Marine Science and Engineering 9, no. 8 (August 7, 2021): 851. http://dx.doi.org/10.3390/jmse9080851.
Анотація:
The coastal area at Riccione, in the southern Emilia-Romagna littoral region, is exposed to erosive processes, which are expected to be enhanced by climate change. The beach, mostly composed of fine sand, is maintained through various defense strategies, including frequent nourishment interventions for balancing the sediment deficit and other experimental solutions for reducing coastal erosion. Artificial reshaping of the beach and “common practices” in the sediment management redefine the beach morphology and the sediment redistribution almost continuously. These activities overlap each other and with the coastal dynamics, and this makes it very difficult to evaluate their effectiveness, as well as the role of natural processes on the beach morphological evolution. Topo-bathymetric and sedimentological monitoring of the beach has been carried out on a regular basis since 2000 by the Regional Agency for Prevention, Environment and Energy of Emilia-Romagna (Arpae). Further monitoring of the emerged and submerged beach has been carried out in 2019–2021 in the framework of the research project STIMARE, focusing on innovative strategies for coastal monitoring in relation with erosion risk. The aim of this study is to assess the coastal behavior at the interannual/seasonal scale in the southern coastal stretch of Riccione, where the adopted coastal defense strategies and management actions mostly control the morphological variations in the emerged and submerged beach besides the wave and current regime. The topo-bathymetric variations and erosion/accretion patterns provided by multitemporal monitoring have been related to natural processes and to anthropogenic activities. The morphological variations have been also assessed in volumetric terms in the different subzones of the beach, with the aim of better understanding the onshore/offshore sediment exchange in relation with nourishments and in the presence of protection structures. The effectiveness of the adopted interventions to combat erosion, and to cope with future climate change-related impacts, appears not fully successful in the presence of an overall sediment deficit at the coast. This demonstrates the need for repeated monitoring of the emerged and submerged beach in such a critical setting.
37
TABOSA, WERNER FARKATT, ZULEIDE LIMA, HELENICE VITAL, and INGRED MARIA GUIMARÃES GUEDES. "Monitoramento Costeiro das Praias de São Bento do Norte e Caiçara do Norte - NE/Brasil." Pesquisas em Geociências 28, no. 2 (December 31, 2001): 383. http://dx.doi.org/10.22456/1807-9806.20312.
Анотація:
Sedimentary dynamic studies were conducted on the North littoral of Rio Grande do Norte State, comprising the São Bento do Norte and Caiçara do Norte cities, based on coastal processes data (wind, currents, waves and tides), beach profiles (monitoring six beach profiles, between June of 2000 and august of 2001), and elements in the morphologic and structural features. The coastline changes due to erosion and deposition are the major concern for the coastal zone management of this area. This work is setting the necessity to understand the causes of erosion before construction of protective structure on erosional beaches. Some items can be observed: 1) The destruction effects in the coastline were not eliminated by the construction of a groyne-field; 2) The increase of the erosion process in the area after the last groyn. The main modifications happened on the months of November 2000 and March 2001, probably conditioned mainly by the change of the medium direction of the winds, that varied from 225ºAz to 320ºAz in this period of 14 months of monitoring. In the month of November 2000, the registered average was of the order of 72ºAz (profile P1) and 90ºAz (profile P6), in the same sequence we obtained a variation of the order of 95ºAz and 85ºAz, for the month of March of 2001. In this context, it was observed that the period of repetition of the waves reached averages of the order of 2’03”Seg (mar/01, profile P1) and 6’07”Seg (mar/01, profile P6). The height of the waves was also registered in this period as being the highest, with values of 0,44m (mar/01, profile P1) and 0,50m (mar/01, profile P6). The beaches in the studied area can be classified as reflective to intermediate.
38
Anfuso, G., E. Pranzini, and G. Vitale. "An integrated approach to coastal erosion problems in northern Tuscany (Italy): Littoral morphological evolution and cell distribution." Geomorphology 129, no. 3-4 (June 2011): 204–14. http://dx.doi.org/10.1016/j.geomorph.2011.01.023.
39
Gerhardt, Simone, and Bernhard Schink. "Redox Changes of Iron Caused by Erosion, Resuspension and Sedimentation in Littoral Sediment of a Freshwater Lake." Biogeochemistry 74, no. 3 (June 2005): 341–56. http://dx.doi.org/10.1007/s10533-004-4725-3.
40
Schofield, Clive, and Suzanne Lalonde. "Rising Seas and Retreating Coasts: Implications for the Arctic." International Journal of Marine and Coastal Law 35, no. 3 (August 3, 2020): 468–97. http://dx.doi.org/10.1163/15718085-bja10016.
Анотація:
Abstract This article addresses both the physical impacts and international legal issues arising from two interlinked stressors on Arctic coastlines: sea level rise and coastal erosion. Key aspects of the legal regime governing the baselines from which coastal States calculate the outer limits of their maritime zones are reviewed and a synopsis of the practice among the Arctic littoral States is provided. The article then turns to a discussion of the practical and international legal responses available to deal with the present and future challenge of rising seas and retreating coasts. The concluding section offers with some reflections on the way forward for a region experiencing some of the most devastating impacts of climate change.
41
Lamgharbaj, Mustapha, Rachid El Ansari, Hajar El Talibi, Said El Moussaoui, Hinde Cherkaoui Dekkaki, and Issam Etebaai. "Geochemical and mineralogical characterization of coastal sediments in Al-Hoceima Bay (Central Rif, Morocco)." E3S Web of Conferences 298 (2021): 04003. http://dx.doi.org/10.1051/e3sconf/202129804003.
Анотація:
This work aims to characterize the morphosedimentaty dynamics of the shores of Al-Hoceima Bay through geochemical and mineralogical analysis of surface sediments. The results reveal a direct relationship between marine hydrodynamic forcing on the one hand and detrital inputs from land on the other. Calcimetric analysis makes it possible to highlight the transport and deposition processes at the beaches of Al-Hoceima bay. The difference in the reasonably high carbonate contents in the western beaches (Isli, Cala Bonita and Quemado) (> 60%) and low in the beaches of the central and eastern zone (Sfiha, Souani, Salina and Lharch) (≈ 15%) are mainly due to the influence of coastal currents, littoral drift, and fluvial action. The higher levels of heavy minerals in Lharch beach (18%) are expressed by volcanic outcrops of Cap Quelates and Jbel Tamsamen. The low values at the Souani and Tayth beaches (7% on average) are due to erosion by the two types of coastal drift, NW-SE and NNE-SSW, which carry the sediments of schist origin brought by the Oueds Ghiss and Nekôr. In contrast, the reasonably high contents in the Sfiha beach (12%) are attributed to the accumulation of allochthonous sediments by NW-SE littoral drift which carries sediments of volcanometamorphic origin from Rass Quelates.
42
Coelho, Carlos, Raquel Silva, Fernando Veloso-Gomes, and Francisco Taveira-Pinto. "Potential effects of climate change on northwest Portuguese coastal zones." ICES Journal of Marine Science 66, no. 7 (May 14, 2009): 1497–507. http://dx.doi.org/10.1093/icesjms/fsp132.
Анотація:
Abstract Coelho, C., Silva, R., Veloso-Gomes, F., and Taveira-Pinto, F. 2009. Potential effects of climate change on northwest Portuguese coastal zones. – ICES Journal of Marine Science, 66: 1497–1507. Coastal erosion is a common problem in Europe; a result of the dynamic nature of its coastal zones, of anthropogenic influences, such as coastal interventions and littoral occupation, and of the effects of climate change. The increase in the occurrence of extreme events, the weakening of river-sediment supplies, and the general acceleration of sea level rise (SLR) probably tends to aggravate coastal erosion on decadal time-scales. Describing vulnerability and risk patterns for energetic environmental actions is important for coastal planning and management to rationalize the decision-making process. To minimize negative effects, the various processes causing erosion must be understood to assess the possible prediction scenarios for coastal evolution in the medium to long term. This paper describes the application of a coastal (shoreline evolution) numerical model to a stretch of the Portuguese coast to determine the effects of various scenarios of wave action and SLR that might result from climate change over the next 25 years. We conclude that the effects of SLR are less important than changes in wave action. The numerical model was also applied in a generic situation to compare shoreline evolution with and without anthropogenic intervention.
43
Mamadou, Touré, Ané Niamien Jean N., Tiémélé Jacques André, Kassi A. Jean-Baptiste, and Djagoua Eric M. Valère. "Etude De L’évolution Du Trait De Côte À L’aide De L’outil Mobitc : Cas Du Littoral De Grand-Bassam." European Scientific Journal, ESJ 14, no. 18 (June 30, 2018): 79. http://dx.doi.org/10.19044/esj.2018.v14n18p79.
Анотація:
This study proposes an assessment of the historical coastline (TDC) mobility of the Ivorian coastline, specifically the Grand-Bassam coastline (Côte d'Ivoire), and suggests reflections on the sustainable management of the coastal environment in Côte d'Ivoire, taking into account coastal erosion. The objective is to evaluate, using the MobiTC software, the spatio-temporal and statistical evolution of the morphology of the Grand-Bassam coastal zone in order to plan appropriate coastal developments. Specifically, it is to extract images on google earth, to treat them under MobiTC and to analyze the rate of spatio-temporary and statistical evolution of coastlines. To do this, data from QuickBird images provided by Google Earth from 1984, 1988, 1992, 1996, 2000, 2004, 2008, 2012 and 2016 in the study area were used. Different software was used for image processing. The ENVI 5.1 software allowed georeferencing and thresholding to make the images superimposable and highlight the baseline. The digitization of the images was done with ArcGis software. The QGIS 2.18 software was used to convert the .shp files to the mid / mif format of the MobiTC software. The latter makes it possible to understand the statistical evolution of the coastline dynamics from the creation of a baseline, the skeleton of envelopes and traces. The variations observed between 1984 and 2016 show a fattening of 0.23 m / year in some sectors and an erosion rate of 0.34 m / year in other sectors. It is noted that 62.79% of the coastline is accretion and 37.21% is eroding.
44
Ostendorp, Wolfgang, Frank Peeters, Hilmar Hofmann, Helmut Schlichtherle, and Hansjörg Brem. "Erosion Hazards and Efficient Preservation Measures in Prehistoric Cultural Layers in the Littoral of Lake Constance (Germany, Switzerland)." Conservation and Management of Archaeological Sites 18, no. 1-3 (July 2, 2016): 217–29. http://dx.doi.org/10.1080/13505033.2016.1182757.
45
Peynador, Carlos, and Federico Méndez-Sánchez. "Managing coastal erosion: A management proposal for a littoral cell in Todos Santos Bay, Ensenada, Baja California, Mexico." Ocean & Coastal Management 53, no. 7 (July 2010): 350–57. http://dx.doi.org/10.1016/j.ocecoaman.2010.04.016.
46
Punzo, Michele, Chiara Lanciano, Daniela Tarallo, Francesco Bianco, Giuseppe Cavuoto, Rosanna De Rosa, Vincenzo Di Fiore, et al. "Application of X-Band Wave Radar for Coastal Dynamic Analysis: Case Test of Bagnara Calabra (South Tyrrhenian Sea, Italy)." Journal of Sensors 2016 (2016): 1–9. http://dx.doi.org/10.1155/2016/6236925.
Анотація:
Sea state knowledge has a key role in evaluation of coastal erosion, the assessment of vulnerability and potential in coastal zone utilization, and development of numerical models to predict its evolution. X-band radar measurements were conducted to observe the spatial and temporal variation of the sea-state parameters along a 3 km long sandy-gravelly pocket beaches forming a littoral cell on Bagnara Calabra. We produced a sequence of 1000 images of the sea state extending offshore up to 1 mile. The survey has allowed monitoring the coastline, the directional wave spectra, the sea surface current fields, and the significant wave heights and detecting strong rip currents which cause scours around the open inlets and affect the stability of the submerged reef-type breakwaters. The possibility to validate the data acquired with other datasets (e.g., LaMMA Consortium) demonstrates the potential of the X-band radar technology as a monitoring tool to advance the understanding of the linkages between sea conditions, nearshore sediment dynamics, and coastal change. This work proves the possibility to obtain relevant information (e.g., wave number, period, and direction) for evaluation of local erosion phenomena and of morphological changes in the nearshore and surf zone.
47
George, Douglas A., John L. Largier, Gregory Brian Pasternack, Patrick L. Barnard, Curt D. Storlazzi, and Li H. Erikson. "Modeling Sediment Bypassing around Idealized Rocky Headlands." Journal of Marine Science and Engineering 7, no. 2 (February 7, 2019): 40. http://dx.doi.org/10.3390/jmse7020040.
Анотація:
Alongshore sediment bypassing rocky headlands remains understudied despite the importance of characterizing littoral processes for erosion abatement, beach management, and climate change adaptation. To address this gap, a numerical model sediment transport study was developed to identify controlling factors and mechanisms for sediment headland bypassing potential. Four idealized headlands were designed to investigate sediment flux around the headlands using the process-based hydrodynamic model Delft-3D and spectral wave model SWAN. The 120 simulations explored morphologies, substrate compositions, sediment grain sizes, and physical forcings (i.e., tides, currents, and waves) commonly observed in natural settings. A generalized analytical framework based on flow disruption and sediment volume was used to refine which factors and conditions were more useful to address sediment bypassing. A bypassing parameter was developed for alongshore sediment flux between upstream and downstream cross-shore transects to determine the degree of blockage by a headland. The shape of the headland heavily influenced the fate of the sediment by changing the local angle between the shore and the incident waves, with oblique large waves generating the most flux. All headlands may allow sediment flux, although larger ones blocked sediment more effectively, promoting their ability to be littoral cell boundaries. The controlling factors on sediment bypassing were determined to be wave angle, size, and shape of the headland, and sediment grain size.
48
ABO ZED, ABO BAKER I. "Effects of waves and currents on the siltation problem of Damietta harbour, Nile Delta coast, Egypt." Mediterranean Marine Science 8, no. 2 (December 3, 2007): 33. http://dx.doi.org/10.12681/mms.152.
Анотація:
This study evaluates the effect of prevailing dynamic factors on the sedimentation process in Damietta Harbour along the Nile delta coast of Egypt. The monitoring program spanned the period between 1978 and 1999 and included measurements of waves, currents and bathymetric profiles. The evaluation was based on determination of erosion and accretion rates, current regime, sediment transport, wave characteristics and wave refraction. Results revealed that the predominant wave direction from N-NW sector (86 %) throughout the year is responsible for generation of a longshore eastward current. Less frequent waves from the N-NE sector generate an opposing longshore westward current. The refraction pattern for the prevailing wave direction indicates that the harbour and its navigation channel are located within a divergence of wave orthogonal and in an accretion sediment sink area. The annual net rate of littoral drift on the western side of the harbour is about 1.43 * 105 m3 (accretion), while the annual net rate of littoral drift on the eastern side is about 2.54 * 105 m3 (erosion). Currents fluctuate tremendously in speed and direction, especially during the winter months. Hence, sediment transport takes place in offshore, eastward, and onshore directions. Progressive vector diagrams show that the largest near bottom offshore, onshore and easterly net drift occurs during summer, spring and winter respectively. The onshore sediment transport generated during spring and summer plays an important role in the redistribution of eroded sediments during the winter. The overall study of dynamic factors indicated that the harbour site is characterized by eastern, western, offshore and onshore sediment movements. Therefore, the north-south orientation of the navigation channel, with its depth greater than the surrounding area, interrupts sediment drift from different directions and reduces the current speed. Consequently, the sediments sink within the navigation channel from different directions. The sources of sediments contributing to the siltation process of the harbour and its navigation channels are mainly derived from the Rosetta promontory, Burullus beaches, Damietta promontory and from offshore and the dumping area.
49
Jarocki, Walenty. "WAVE EFFECT ON THE COAST FORMATION AND EROSION." Coastal Engineering Proceedings 1, no. 7 (January 29, 2011): 12. http://dx.doi.org/10.9753/icce.v7.12.
Анотація:
Various authors explain differently the mechanism of action of waves on the_ sediment movement. Some authors consider that the waves are raising the soil fractions from the bottom and water currents transfer them along the seaboard. The other authors suppose that each wave shears some soil in the bottom in littoral zone of the waves and wind is oblique to the shoreline. Beach currents catch and transport the sediment particles along the seaboard. These authors suppose when the wind is in the direction of seaboard /from sea/ then the bottom currents move in the opposite direction. These currents transport the ground particles in the direction of sea and thus the seaboard erosion arises. When the wind direction is opposite, the botto currents arise in the direction of seaboard and they cause the transportation of ground and the accumulation of seaboards. These reasons show that the action of waves would cause only the separation of ground particles and their asoeading. Our last investigations and observations of the sediment movement have led the conclusion that the waves may cause the raise of the sediment partciles and also their transport. The character of this transport depends on the wave kind and on the height and length of waves. General quantity of the lifted particles by means of waves increases as the power of waves or height and length of waves increases. If the power of waves decreases these particles fall. The waves are able to transport the bed load and detritus load without cooperation of the water current in spite of horizontal or inclined bottom. Under the action of waves the sediment moves the oscillatory movement. The waves move the bed load in the shallow exterior zones with the horizontal bottom only, towards the wave propagation. This material may be moved perpendicular the slope, according to the wave direction or in the opposite on< If the approaching wave creates the acute angle to the shoreline then the bed load moves near the seaboard. The transport of the bed load and of detritus loai change if the water current and waves appear simultaneously. The water current acts generally on the detritus load because the water moves this material easier than the bed load which rolls on the bottom.
50
ESTEVES, LUCIANA SLOMP, and ISAAC RODRIGUES DOS SANTOS. "Impacto Econômico da erosão na praia do Hermenegildo (RS), Brasil." Pesquisas em Geociências 28, no. 2 (December 31, 2001): 393. http://dx.doi.org/10.22456/1807-9806.20313.
Анотація:
Although there is still a discussion about the extent of erosion along the Rio Grande do Sul shoreline, some places are recognized as intensely eroded, such as Jardim do Éden beach, Conceição Lighthouse, and Hermenegildo. This study evaluates the economic impacts of erosion in Hermenegildo based on the costs of coastal protection, destruction of structures during storms, and depreciation of beachfront property values. The study area consists in the 2-km long urbanized shore of Hermenegildo, a beach village located in the southernmost littoral of Brazil, 12 km north of the Uruguayan border. Erosion has threatened beachfront development during storms, resulting in a heavily armored shoreline. Quarrystone revetments (rip rap) and/or seawalls are the most common structures. A strong storm struck this coast in 16 April 1999 destructing 22 houses, all concrete structures, half of the quarrystone revetments, and 80% of the timber seawalls. After that storm, similar structures were built to protect beachfront properties. According to interviews conducted with property owners, average protection costs were estimated in U$ 2,203/property or U$79,308/km. Extrapolating the average costs for the 72 protected properties, total expenses in coastal defense is estimated in U$ 158,616. Considering a storm with same intensity and destruction power reaching the coast of Hermenegildo, the expected damage in land loss, destruction of houses and structures would be in the order of U$ 394,000. Analysis of the real estate sales in the last three years indicates a depreciation of 50-80% in beachfront property values while properties located further inland had a depreciation of 10%. Beach erosion has impacted the local economy and will continue to do so until the problem is effectively addressed. As the values at risk in Hermenegildo are relatively lower than usual coastal protection measures, probably relocation of structures or alternative techniques might be the best management option.