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Bruno Castelle - One of the best experts on this subject based on the ideXlab platform.
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Longshore Drift cell development on the human impacted bight of benin sand barrier coast west africa
2014Co-Authors: Raoul Laibi, Bruno Castelle, Edward J Anthony, Rafael Almar, Nadia Senechal, Elodie KestenareAbstract:ABSTRACT Laibi, R. A., Anthony, E. J., Almar, N., Castelle, B., Senechal, Kestenare, E., 2014. Longshore Drift cell development on the human-impacted Bight of Benin sand barrier coast, West Africa. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 078–083, ISSN 0749-0208. The Bight of Benin is an open, microtidal, wave-dominated coast forming a 500 km-long mild embayment in the Gulf of Guinea, in West Africa, between the Volta River delta in Ghana, to the west, and the western confines of the Niger River delta in Nigeria to the east. The bight is exposed to energetic swells from the South Atlantic, and is characterised by Holocene sand barriers bounding lagoons. The barrier system has been sourced essentially by sand supplied through the Volta River delta, terminus of a large river catchment of 397,000 km2, although wave energy conditions and sand mineralogy also suggest inputs from the...
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High-resolution morphobathymetric analysis and evolution of Capbreton submarine canyon head (Southeast Bay of Biscay French Atlantic Coast) over the last decade using descriptive and numerical modeling
2014Co-Authors: Alaïs Mazières, Hervé Gillet, Bruno Castelle, Thierry Mulder, Corentin Guyot, Thierry Garlan, Cyrill MalletAbstract:n this study, the Capbreton canyon head, just off the coast, is investigated using high-resolution multibeam bathymetry datasets, sediment samples and numerical modeling. The HR bathymetty analysis reveals a morphological connection between the Longshore trough and the head of the canyon. The analysis of recent sediment samples shows a clear correlation between the sediment of the canyon head and that of the nearshore. Hydrodynamic modeling (a coupled wave-flow model) shows that for high-energy waves, the rotational nature of surfzone circulation reverses and wave-induced currents have the potential to transport large quantities of nearshore sands toward the canyon head. All these arguments support the assumption that the canyon head captures a part of the sand transported by Longshore Drift. Over the 15 years of observation (1998-2013), time-lapse bathymetry shows that the floor of the canyon head and one lateral gully network experienced significant morphological reworking. In terms of hazards, despite this strong activity, the position of the canyon head and the profile of its longitudinal slope remained stable and appear as a comforting factor. However, the activity of unusual lateral erosions needs to be monitored.
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Longshore Drift cell development on the human benin sand barrier coast west africa
2014Co-Authors: Raoul A La Ibi, Bruno Castelle, Edward J Anthony, Rafael Almar, Nadia SenechalAbstract:Laibi, R. A. , Anthony, E. development on the human J.A.G. (eds.), Proceedings 13 Special Issue No. 66, pp. xxx The Bight of Benin is an open, microtidal, wave of Guinea, in West Africa, between the Volta River delta in Ghana, to the west, and the western conf River delta in Nigeria to the east. The bight is exposed to energetic swells from the South Atlantic, and is characterised by Holocene sand barriers bounding lagoons. The barrier system has been sourced essentially by sand supplied throug the Volta River delta, terminus of a large river catchment of 397,000 km2, although wave energy conditions and sand mineralogy also suggest inputs from the nearshore shelf. The long Benin culminated in a mildly embayed coast wherein incident wave behaviour, beachface gradient and the Longshore sand transport system were intimately linked, generating what may be classified as an ‘equilibrium Drift with a unique and homogeneous Longshore dr coast has, however, been significantly impacted over the last 50 years by the construction of three deepwater ports in Lome (Togo), Cotonou (Benin) and Lagos (Nigeria) that have Volta River, resulting in destabilization of the former single Drift cell on this coast. The ensuing is cha racterised by long sectors of rampant coastal erosion that threate infrastructure.
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relationship between Longshore Drift and the head of the capbreton canyon sw france descriptive and numerical approaches
2013Co-Authors: Alaïs Mazières, Hervé Gillet, Bruno Castelle, Thierry Mulder, Corenthin Guyot, Cyril MalletAbstract:This study investigates the morphology of the head of the canyon, and confirms the presence of multi-d ecametric scars in relation with slipped sand masses. The analysis of recent sediment samplings shows a clear correlation between the canyon head sediment and nearshore sediments. The hydrodynamic modelling (coupled wave-flow model) shows that for highenergy waves, the sign of the rotational nature of surf zone circulations reverses and wave-induced cu rrents have the potential to transport large quantities of nearshore sands to wards the canyon head. These evidences support the assumption that the head of the canyon captures a part of the sand supp lied by the Longshore Drift and probably additional fine particles brought by the Adour plume. This stock is regularly destabi lized and supplies the frequent (yearly) turbidite activity in the canyon.
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dynamics of a wave dominated tidal inlet and influence on adjacent beaches currumbin creek gold coast australia
2007Co-Authors: Bruno Castelle, Darrell Strauss, Julien Bourget, Nathalie Molnar, Sophie Carole Deschamps, Rodger Benson TomlinsonAbstract:Currumbin Creek on the Australian Gold Coast is a wave-dominated tidal inlet which exhibits a particularly active morphology. The recent history of Currumbin Creek entrance has seen rapid growth of the entrance for access to the ocean by fishermen, as a world class surfing site, and as a recreational area. Before the construction of two groynes in the 70's, Currumbin Creek entrance was highly variable in terms of inlet location and sand bar characteristics due to a cyclical behaviour of spit migration. Nowadays, the entrance is stabilised. However, natural processes continue with the entrance infilling causing flood and navigation issues, resulting in a regular dredging program to maintain an open entrance and for regular beach nourishment plans. This paper investigates the behaviour of the entrance and adjacent beaches from aerial photographs and numerical modelling. Before groyne construction, sand by-passing was intense resulting in channel migration and sometimes the closure of the mouth. After training works, the Longshore Drift is diverted further north from the mouth leading to new circulation patterns behind the headland. During fair weather conditions, the sand transported by the Longshore current is trapped by Currumbin rock groyne resulting in a negative sediment budget in Palm Beach. For high energy conditions, the diverted Longshore current splits in the southern Palm Beach, resulting in a circulation cell. The sediment of the southern beaches is stirred up and transported both northward and toward the inlet.
Edward J Anthony - One of the best experts on this subject based on the ideXlab platform.
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Longshore Drift cell development on the human impacted bight of benin sand barrier coast west africa
2014Co-Authors: Raoul Laibi, Bruno Castelle, Edward J Anthony, Rafael Almar, Nadia Senechal, Elodie KestenareAbstract:ABSTRACT Laibi, R. A., Anthony, E. J., Almar, N., Castelle, B., Senechal, Kestenare, E., 2014. Longshore Drift cell development on the human-impacted Bight of Benin sand barrier coast, West Africa. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 078–083, ISSN 0749-0208. The Bight of Benin is an open, microtidal, wave-dominated coast forming a 500 km-long mild embayment in the Gulf of Guinea, in West Africa, between the Volta River delta in Ghana, to the west, and the western confines of the Niger River delta in Nigeria to the east. The bight is exposed to energetic swells from the South Atlantic, and is characterised by Holocene sand barriers bounding lagoons. The barrier system has been sourced essentially by sand supplied through the Volta River delta, terminus of a large river catchment of 397,000 km2, although wave energy conditions and sand mineralogy also suggest inputs from the...
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Longshore Drift cell development on the human benin sand barrier coast west africa
2014Co-Authors: Raoul A La Ibi, Bruno Castelle, Edward J Anthony, Rafael Almar, Nadia SenechalAbstract:Laibi, R. A. , Anthony, E. development on the human J.A.G. (eds.), Proceedings 13 Special Issue No. 66, pp. xxx The Bight of Benin is an open, microtidal, wave of Guinea, in West Africa, between the Volta River delta in Ghana, to the west, and the western conf River delta in Nigeria to the east. The bight is exposed to energetic swells from the South Atlantic, and is characterised by Holocene sand barriers bounding lagoons. The barrier system has been sourced essentially by sand supplied throug the Volta River delta, terminus of a large river catchment of 397,000 km2, although wave energy conditions and sand mineralogy also suggest inputs from the nearshore shelf. The long Benin culminated in a mildly embayed coast wherein incident wave behaviour, beachface gradient and the Longshore sand transport system were intimately linked, generating what may be classified as an ‘equilibrium Drift with a unique and homogeneous Longshore dr coast has, however, been significantly impacted over the last 50 years by the construction of three deepwater ports in Lome (Togo), Cotonou (Benin) and Lagos (Nigeria) that have Volta River, resulting in destabilization of the former single Drift cell on this coast. The ensuing is cha racterised by long sectors of rampant coastal erosion that threate infrastructure.
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the influence of amazon derived mud banks on the morphology of sandy headland bound beaches in cayenne french guiana a short to long term perspective
2004Co-Authors: Edward J Anthony, Franck DoliqueAbstract:Abstract The 1600-km-long South American coast between the Amazon and the Orinoco Deltas has a prograded muddy shoreline comprised of sandy cheniers. The 15-km-long bedrock coast of Cayenne, French Guiana, differs from the rest of this fluctuating alluvial coast in that it comprises several headland-bound fringing sandy barriers that have experienced limited progradation and do not behave as cheniers that migrate landward over a muddy base. The limited progradation of these barriers is probably due to blanketing of fluvial sand by the cover of Amazon mud on the inner shelf, which precludes shoreward reworking to supply the beach and barrier systems. Aerial photographs, satellite images and recent field observations show that alternations between ‘mud bank’ phases, when Amazon-derived mud banks migrating northwestwards attain the Cayenne area, and ‘interbank’ phases, characterised by relative scarcity of mud, result in marked spatial and temporal variations in beach dynamics and morphology. These include periodic alternations in Longshore Drift that lead to a rare form of total or partial beach rotation that does not result, as is generally reported for nonmud bank-affected beaches, from seasonal variations in deepwater wave approach directions. These beach morphological changes have been defined in terms of a simple, four-stage conceptual model comprising ‘bank’, ‘interbank’ and transitional phases. In extreme ‘bank’ phases, the mud banks responsible for muddy coastal progradation on the Amazon–Orinoco coast may directly weld onto the beaches for periods ranging from months to years, leading to a rare example at the world scale wherein the dynamics of ocean-facing beaches are completely muted under the protective cover of mud that may become rapidly colonised by mangroves. The observations also suggest that these changes do not affect the medium-term (order of tens of years) beach sand budgets. Mud welding onto the beaches may, however, sequester at short time scales (order of months to years) sand eroded from the beaches. Subsequent mud erosion leads to release of this sand and its restitution to the beach sand budget.
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short term changes in the plan shape of a sandy beach in response to sheltering by a nearshore mud bank cayenne french guiana
2002Co-Authors: Edward J Anthony, Antoine Gardel, Franck Dolique, Daniel GuiralAbstract:Montjoly is a headland-bound embayed sandy beach in Cayenne, French Guiana, that shows long-term plan shape equilibrium in spite of periodic changes in accretion and erosion that alternately affect either end of the beach. These changes are caused by mud banks that move aLongshore from the Amazon. The mechanisms involved in changes in the plan shape of the beach in response to the passage of one of these mud banks were monitored between 1997 and 2000 from airborne video imagery and field work. The beach Longshore Drift to the northwest, driven by the incident easterly to northeasterly swell usually affecting this coast, became temporarily reversed as the mud bank, migrating from east to west, initially sheltered the southeastern end of the beach. The difference in exposure to waves engendered a negative wave height gradient aLongshore towards the southeast, resulting in the setting up of a cell circulation and counter-active Longshore Drift from the exposed northwestern sector to the southeast. Sand eroded from the exposed sector accumulated first in the southeastern, and then the central sectors of the beach. The effect of increasing beach sheltering by the mudbank moving west is highlighted on the videographs by an ‘arrested’ pattern of beach shoreline development. The videographs show hardly any changes in beach plan shape since January 1999, due to sheltering of the beach from wave attack by the mud bank. It is expected that the eroded sector will recover in the future as the mud bank passes, leading to re-establishment of the northwesterly sand Drift. This temporally phased bi-directional Drift within the confines of the bounding headlands results in a rare example of mud-bank-induced beach rotation, and probably explains the long-term equilibrium plan shape of Montjoly beach. Copyright © 2002 John Wiley & Sons, Ltd.
Helene Dupuis - One of the best experts on this subject based on the ideXlab platform.
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wave climate and Longshore Drift on the south aquitaine coast
2006Co-Authors: Stephane Abadie, Remi Butel, Sylvain Mauriet, Denis Morichon, Helene DupuisAbstract:Abstract The Aquitaine coast, the southern part of the French Atlantic coast, is exposed to very energetic waves, inducing large sediment transport rates and shoreline changes. Local wave characteristics are, however, not accurately defined. Neither is the Longshore Drift along the shore. In this paper, statistical parameters of directional waves are determined by using outputs over 8 years from numerical model WAVEWATCH III. Wave statistics obtained point out a very weak variability of peak directions, almost all events coming from the same 300° direction, highly energetic extreme events and a predominance of swells over wind sea states. Representative sea states are calculated using a classification process. They are set as boundary conditions for the numerical model SWAN to compute the wave parameters along the breaking line and the corresponding Longshore Drift with the Kamphuis formula. The net annual Longshore Drift is assessed by taking into account the occurrence of the wave classes. Results show a reversal of the Longshore current at the town of Capbreton. To the north, the current is directed southwards while it is northwards but very weak to the south. Locally, the pattern is reversed due to the influence of the submarine canyon of Capbreton. This new result is supported by in situ current measurements carried out along the shore. The annual average amount of sediment transported Longshore is about 40,000 m3/year to the north of Capbreton and only 1000 m3/year to the south. However, along this latter area, the Drift shows larger variations than in the north. Energetic swells account for more than two-thirds of the net annual Longshore Drift while they only occur 25% of the year. Moderately energetic swells and sea states with higher steepness, though more frequent, contribute less to the total Drift. Around the town of Capbreton, results are dependent on the frequency spectrum set at the boundary of the numerical model, highlighting the complex role played by the submarine canyon and suggesting the need for further investigations in that area.
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morphodynamics of nearshore rhythmic sandbars in a mixed energy environment sw france 2 physical forcing analysis
2005Co-Authors: Virginie Lafon, Bruno Castelle, Hélène Howa, Remi Butel, Helene Dupuis, Denis Michel, D De Melo ApolucenoAbstract:Abstract The morphology and migration of rhythmic intertidal ridge and runnel systems, and subtidal crescentic bars that border the southwest coast of France were characterized using in situ surveys and maps obtained by remote-sensing methods. The period from 1986 to 2000 was investigated. A total of 35 km of coast was mapped. This data set shows several specificities, the origin of which are examined in the present report using hydrodynamic data. A complete analysis of the influence of wave climate on both the shape and the movements of these rhythmic sedimentary patterns was performed. In addition, SWAN and MORPHODYN-coupled numerical models were used to provide quantification of both wave breaking and Longshore currents for wave parameters that were representative of the mean values and of the energetic conditions. This study demonstrated the short time response of intertidal systems to the wave forcing. When the offshore significant wave height ( H s ) was lower than 2.5 m, regular coastal ridge and runnel systems developed in the intertidal zone and migrated in the Longshore-Drift direction at a rate of 1.7–3.1 m day −1 . By contrast, the ridge and runnel system morphology abruptly changed when the H s exceeded 2.5 m, and after the storm, the typical ridge and runnel rhythmic topography was recovered within 5–9 days. The crescentic bars, which had a convex seaward shape, were affected by waves with H s values greater than 3 m (slightly less for short waves). Depending on the wave orientation, the crescentic bars moved in the Longshore-Drift direction at a rate that reached 1 m day −1 . The data suggested a slight negative correlation between the mean aLongshore length of the crescentic bar and the mean H s . Finally, it seemed that increasing the wave obliquity with respect to the coast resulted in the flattening of the crescentic bars. Thus, coupling Spot and in situ mapping to hydrodynamic records allow the characterization of coastal morphology and dynamics, with time and space samplings that are particularly well adapted to the little studied aLongshore morphodynamics. This approach should improve the difficult parameterization of morphodynamic models in high-energy environments.
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morphodynamics of nearshore rhythmic sandbars in a mixed energy environment sw france i mapping beach changes using visible satellite imagery
2004Co-Authors: Virginie Lafon, Hélène Howa, Helene Dupuis, Denis Michel, D De Melo Apoluceno, Jeanmarie FroidefondAbstract:Abstract This paper presents a new method to analyze the morphology and migration of shallow water sandbanks based on the retrieval of maps from high-resolution Spot satellite imagery. This approach was applied to the study of intertidal ridge and runnel systems and subtidal crescents that border the southwest coast of France. Maps were obtained from 16 Spot images recorded between 1986 and 2000. Ridge and runnel shapes, with regard to a reference level, were delineated using a watercolor reflectance code parameterized and validated with field data. Crescent plan shapes, which appear on the images due to water transparency or breaking-induced foam, were directly extracted. The spatial maps show that, in conformity with field surveys, the mean aLongshore spacing of intertidal systems and crescents range from 370 ± 146 m (variability is indicated by standard deviation) to 462 ± 188 m, and from 579 ± 200 to 818 ± 214 m, respectively. Several couples of images also show that ridge and runnel systems and crescents move in the Longshore Drift direction (southward) by about 2.4–3.1 and 1 m day−1, respectively. ALongshore migration rates of intertidal systems are confirmed by field surveys, whilst crescent dynamics cannot be validated because there is no in situ data available. To complete these measurements, an analysis of the influence of wave climate on both the shape and movements of these rhythmic sedimentary patterns is proposed in a companion paper.
D De Melo Apoluceno - One of the best experts on this subject based on the ideXlab platform.
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morphodynamics of nearshore rhythmic sandbars in a mixed energy environment sw france 2 physical forcing analysis
2005Co-Authors: Virginie Lafon, Bruno Castelle, Hélène Howa, Remi Butel, Helene Dupuis, Denis Michel, D De Melo ApolucenoAbstract:Abstract The morphology and migration of rhythmic intertidal ridge and runnel systems, and subtidal crescentic bars that border the southwest coast of France were characterized using in situ surveys and maps obtained by remote-sensing methods. The period from 1986 to 2000 was investigated. A total of 35 km of coast was mapped. This data set shows several specificities, the origin of which are examined in the present report using hydrodynamic data. A complete analysis of the influence of wave climate on both the shape and the movements of these rhythmic sedimentary patterns was performed. In addition, SWAN and MORPHODYN-coupled numerical models were used to provide quantification of both wave breaking and Longshore currents for wave parameters that were representative of the mean values and of the energetic conditions. This study demonstrated the short time response of intertidal systems to the wave forcing. When the offshore significant wave height ( H s ) was lower than 2.5 m, regular coastal ridge and runnel systems developed in the intertidal zone and migrated in the Longshore-Drift direction at a rate of 1.7–3.1 m day −1 . By contrast, the ridge and runnel system morphology abruptly changed when the H s exceeded 2.5 m, and after the storm, the typical ridge and runnel rhythmic topography was recovered within 5–9 days. The crescentic bars, which had a convex seaward shape, were affected by waves with H s values greater than 3 m (slightly less for short waves). Depending on the wave orientation, the crescentic bars moved in the Longshore-Drift direction at a rate that reached 1 m day −1 . The data suggested a slight negative correlation between the mean aLongshore length of the crescentic bar and the mean H s . Finally, it seemed that increasing the wave obliquity with respect to the coast resulted in the flattening of the crescentic bars. Thus, coupling Spot and in situ mapping to hydrodynamic records allow the characterization of coastal morphology and dynamics, with time and space samplings that are particularly well adapted to the little studied aLongshore morphodynamics. This approach should improve the difficult parameterization of morphodynamic models in high-energy environments.
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morphodynamics of nearshore rhythmic sandbars in a mixed energy environment sw france i mapping beach changes using visible satellite imagery
2004Co-Authors: Virginie Lafon, Hélène Howa, Helene Dupuis, Denis Michel, D De Melo Apoluceno, Jeanmarie FroidefondAbstract:Abstract This paper presents a new method to analyze the morphology and migration of shallow water sandbanks based on the retrieval of maps from high-resolution Spot satellite imagery. This approach was applied to the study of intertidal ridge and runnel systems and subtidal crescents that border the southwest coast of France. Maps were obtained from 16 Spot images recorded between 1986 and 2000. Ridge and runnel shapes, with regard to a reference level, were delineated using a watercolor reflectance code parameterized and validated with field data. Crescent plan shapes, which appear on the images due to water transparency or breaking-induced foam, were directly extracted. The spatial maps show that, in conformity with field surveys, the mean aLongshore spacing of intertidal systems and crescents range from 370 ± 146 m (variability is indicated by standard deviation) to 462 ± 188 m, and from 579 ± 200 to 818 ± 214 m, respectively. Several couples of images also show that ridge and runnel systems and crescents move in the Longshore Drift direction (southward) by about 2.4–3.1 and 1 m day−1, respectively. ALongshore migration rates of intertidal systems are confirmed by field surveys, whilst crescent dynamics cannot be validated because there is no in situ data available. To complete these measurements, an analysis of the influence of wave climate on both the shape and movements of these rhythmic sedimentary patterns is proposed in a companion paper.
Hélène Howa - One of the best experts on this subject based on the ideXlab platform.
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morphodynamics of nearshore rhythmic sandbars in a mixed energy environment sw france 2 physical forcing analysis
2005Co-Authors: Virginie Lafon, Bruno Castelle, Hélène Howa, Remi Butel, Helene Dupuis, Denis Michel, D De Melo ApolucenoAbstract:Abstract The morphology and migration of rhythmic intertidal ridge and runnel systems, and subtidal crescentic bars that border the southwest coast of France were characterized using in situ surveys and maps obtained by remote-sensing methods. The period from 1986 to 2000 was investigated. A total of 35 km of coast was mapped. This data set shows several specificities, the origin of which are examined in the present report using hydrodynamic data. A complete analysis of the influence of wave climate on both the shape and the movements of these rhythmic sedimentary patterns was performed. In addition, SWAN and MORPHODYN-coupled numerical models were used to provide quantification of both wave breaking and Longshore currents for wave parameters that were representative of the mean values and of the energetic conditions. This study demonstrated the short time response of intertidal systems to the wave forcing. When the offshore significant wave height ( H s ) was lower than 2.5 m, regular coastal ridge and runnel systems developed in the intertidal zone and migrated in the Longshore-Drift direction at a rate of 1.7–3.1 m day −1 . By contrast, the ridge and runnel system morphology abruptly changed when the H s exceeded 2.5 m, and after the storm, the typical ridge and runnel rhythmic topography was recovered within 5–9 days. The crescentic bars, which had a convex seaward shape, were affected by waves with H s values greater than 3 m (slightly less for short waves). Depending on the wave orientation, the crescentic bars moved in the Longshore-Drift direction at a rate that reached 1 m day −1 . The data suggested a slight negative correlation between the mean aLongshore length of the crescentic bar and the mean H s . Finally, it seemed that increasing the wave obliquity with respect to the coast resulted in the flattening of the crescentic bars. Thus, coupling Spot and in situ mapping to hydrodynamic records allow the characterization of coastal morphology and dynamics, with time and space samplings that are particularly well adapted to the little studied aLongshore morphodynamics. This approach should improve the difficult parameterization of morphodynamic models in high-energy environments.
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morphodynamics of nearshore rhythmic sandbars in a mixed energy environment sw france i mapping beach changes using visible satellite imagery
2004Co-Authors: Virginie Lafon, Hélène Howa, Helene Dupuis, Denis Michel, D De Melo Apoluceno, Jeanmarie FroidefondAbstract:Abstract This paper presents a new method to analyze the morphology and migration of shallow water sandbanks based on the retrieval of maps from high-resolution Spot satellite imagery. This approach was applied to the study of intertidal ridge and runnel systems and subtidal crescents that border the southwest coast of France. Maps were obtained from 16 Spot images recorded between 1986 and 2000. Ridge and runnel shapes, with regard to a reference level, were delineated using a watercolor reflectance code parameterized and validated with field data. Crescent plan shapes, which appear on the images due to water transparency or breaking-induced foam, were directly extracted. The spatial maps show that, in conformity with field surveys, the mean aLongshore spacing of intertidal systems and crescents range from 370 ± 146 m (variability is indicated by standard deviation) to 462 ± 188 m, and from 579 ± 200 to 818 ± 214 m, respectively. Several couples of images also show that ridge and runnel systems and crescents move in the Longshore Drift direction (southward) by about 2.4–3.1 and 1 m day−1, respectively. ALongshore migration rates of intertidal systems are confirmed by field surveys, whilst crescent dynamics cannot be validated because there is no in situ data available. To complete these measurements, an analysis of the influence of wave climate on both the shape and movements of these rhythmic sedimentary patterns is proposed in a companion paper.
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Sediment transport pattern at the Barra Nova inlet, south Portugal: a conceptual model
2001Co-Authors: Yann Balouin, Hélène HowaAbstract:The Barra Nova inlet, in south Portugal, is known to migrate progressively southeastwards under wave action. The morphodynamics of this system during a representative year suggests that this long-term evolution is dependent on a seasonal behavior of the tidal inlet which can be described through a three-stage model of post-storm, transition and extended fair-weather conditions. Processes involved in this evolution indicate that the historical migration of the Barra Nova is not dependent on the Longshore Drift forcing constricting the channel on the upDrift coast, but rather on the adjustment of the system to a major erosion of the downDrift coast during short storm events.
