However some erosion events form part of a cycle of behaviour for a particular ... in coastal zone the barrier system follows a morphological cycle of erosion and.
Monitoring the Morphodynamic Behaviour of a Breached Barrier Beach System and its Impacts on an Estuarine System Michael O’Shea, Dr Jimmy Murphy, Patricia Sala Hydraulics and Maritime Research Centre, University College Cork, Cork, Ireland Abstract - Coastal erosion is often attributed to significant meteorological driven events, climate change, human interference etc. However some erosion events form part of a cycle of behaviour for a particular coastal system that is not specifically associated with any of the above. From an assessment point of view it is important to be able to identify such cycles of behaviour and then determine the best course of action. The barrier beach at Rossbeigh, County Kerry, Ireland, started to erode rapidly in the early 2000’s. By 2008 approximately 1.5million m3 of sand had been eroded and during the winter period of that year the dune was finally breached resulting in a small barrier island and a new tidal inlet. The initial breach length was 500m and it has continued to expand. As there was no immediate or potential infrastructure losses associated with this erosion, a policy of no interference was adopted by the coastal authority. This thus provided the opportunity to study the evolution of a natural dynamic system at a time of significant change. However since then there has been anecdotal evidence of increased flooding in the estuary and changes to tidal channels reported. A research project has been ongoing at the Hydraulics and Maritime Research Centre of University College Cork since the breaching event. It aims at understanding the specific morphodynamic evolution and hydrodynamic behaviour of this coastal system and its impacts on the estuarine system protected by it. Preliminary indications suggest that the erosion rate is reducing and that a self healing process is commencing on the breach area. In addition a long term cycle of behaviour has been identified. Initial numerical modelling results indicate a change in current patterns as a result of the breaching. It is envisaged that combining long-term analysis with specific short term monitoring campaigns will add significantly to understanding of the morphological response to this dune breach and its effects on the estuarine Castlemaine Harbour. The analysis at several spatial scales will provide an insight into the effect the breaching has on the entire coastal/estuarine system. This data will also be used to calibrate the numerical model, which will predict the evolution of Rossbeigh barrier beach after breaching under various meteorological and hydrodynamic conditions and its effects further landward in the estuary. Keywords: Morphology, Dunes, Barrier Beach, Breaching, Numerical Model
I.
INTRODUCTION
Barrier beaches perform a critical role in coastal zone dynamics. Their primary function is to protect vulnerable coastlines from open ocean forcing such as waves, wind and tidal currents. In combination with inlets, barrier beaches also form a dynamic flow regulation system. Adapting to the changes in coastal zone the barrier system follows a morphological cycle of erosion and aggradation. It is common for barrier beaches to move along the coastline and Inlets to move or even multiply as part of a cycle. In certain cases the cycles can change abruptly and a period of significant dynamic instability ensues, before the system reverts to gradual change again. Such events are rare and difficult to predict without continuous monitoring as morphodynamic cycles of barrier beach systems can be at a centenary scale and significant dynamic events can last only years. Monitoring the evolution, specifically the breaching of coastal barrier systems has been conducted at various locations around the world. The extent of the monitoring has ranged from large scale, long term remote sensing approaches to short term, intensive field campaigns and combinations of both. Various sites studied include barrier dune beach systems similar to the InchRossbeigh system, barrier islands, shingle barrier leys and intermittently closed and open lagoon systems. The evolution of a barrier breaching in Nauset barrier system, Cape Cod, M.A.,USA, was documented by [1]. A previous model, developed in 1978, of the system had failed to predict the emergence of a northern inlet in 2007 and as a result the future morphology of the system. A re-development of the conceptual model for the barrier system was undertaken and enhanced due to the availability of reliable data extracted from decades of coastal monitoring. The authors predict another inlet migration phase commencing in 30 years, although anthropogenic influences and increased storminess due to sea level rise are not accounted for in the conceptual model. It was acknowledged that the next breaching events could be triggered much earlier in the cycle could be due to these factors. The influence of anthropogenic interference in the form of groynes on breaching, inlet development and infilling of a barrier island in Long Island, N.Y., USA was documented by [2] document. Two inlets were formed as a result of an extra tropical storm, the initially larger breach, Pikes inlet, was 250m wide and closed within two months of breaching by mechanical means, infilling was aided by the fact that it was far enough (1.4km) down drift of the nearest groyne for sediment flow to accrete. However, Little Pikes inlet, initially only 30m in width, grew exponentially to a breach length of 1.5km, the channel deepened and flow became
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bidirectional. This was primarily because it was within the shadow of the last groyne and therefore was receiving very little sediment transfer. The inlet was eventually closed after emergency works 8 months later. Steel sheeting was combined with extensive beach nourishment from an offshore source. It took over 1million m3 of sand to fill the inlet. Slapton Sands in south Devon has been subject to several coastal geomorphological studies. This barrier beach fully encloses a lagoon and hence does not possess an inlet, increased erosion in the centre of the barrier beach reported in FUTURECOAST, which is not consistent with the long term evolution cycle of Slapton Sands. This erosion resulted in damage to a road and overtopping in 2001. Using aerial photography, sediment samples, hydrodynamic models and topographical surveys, [3] found that the damage was caused by overall beach line retreat due to a differential long shore transport rates and a 1 in 25 year storm event. It disagrees with the widely held hypothesis that the shingle back will be breached irreversibly in the next 30 to 50 years, the research also predicts overtopping may have a return of 5 years and breaching will have a much longer return period. This demonstrates that even with intensive monitoring and analysis the prediction of barrier systems remains laden with complexities and unknowns. The dynamics of inlet evolution and their drivers has also been the subject of extensive research. The importance of inlet position, number and size are all critical characteristics to be considered when analysing the morphodynamics of barrier system and hence impacts of its evolution on the greater estuarine/coastal system. A study of an embayed tidal inlet with no external sediment budget was conducted by [4]. The site, Five Finger Strand, Co. Donegal, Ireland, is significant, in that it is relatively free of the major drivers of coastal morphology (storms, sediment supply, sea level rise.) It was found that the location of the ebb channel and its ebb tidal delta had alternated on a north-south axis over a decadal scale with zones of accretion and erosion varying in sync with the location of the channel and delta. An important conclusion from this study was the influence of the size and position of ebb tidal deltas as a morphodynamic indicator. It was determined that traditionally assumed drivers were not necessary to implement coastal change and that it can occur in the absence of these drivers. A study of the Arcachon tidal inlet in south west France was undertaken by [5]. The research concentrates on the channel between sea and tidal lagoon. A two stage conceptual model based on an extensive data set which includes fluorescent sand tracing is presented. The first stage of this model a single channel is present in the south with the ebb tide delta eroding and the up drift and down drift coasts prograding. A northern channel breaks through the delta and changes the processes with the coasts eroding and the ebb tidal delta prograding and two channels formed moving away from each other. The influence that the inlet has on adjacent coasts is significant. The inlet appears to dictate the erosion/accretion regime for both updrift and down drift coasts. While considerable research into barrier and inlet dynamics has been conducted, there remains a large knowledge gap, the effect breaching and inlet changes has on the larger system be it estuarine or coastal. The focus of research to date has been on quantifying and predicting the morphology of the immediate area where change has occurred. Monitoring of possible change to the larger system as a result of major coastal changes such as breaching, has been sparse and relatively undocumented. In this paper the monitoring of a barrier breaching, is discussed. The study site is analysed at a long term scale of the overall cycle and at a short term scale immediately after the breaching event. The impacts on the estuarine system that the barrier is protecting are examined and quantified. The long term cycle of the barrier system is identified and a short term morphodynamic conceptual model of the breach is proposed. II.
STUDY AREA
Dingle Bay, located in County Kerry, Ireland contains a complex dynamic barrier dune system which includes the mid bay barrier beaches of Inch and Rossbeigh, Fig. 1, Inch extends from the north to south across the bay and approximately 5km long. Rossbeigh located seaward of Inch, is over 4km in length and runs in the opposite direction propagating from the southern coast running North. This barrier beach system encloses Inner Dingle Bay to form the estuarine Castlemaine Harbour which contains another barrier, Cromane Point. This entire area is a designated a Special Area of Conservation, while part of the harbour is designated a Special Protection Area. Inch and Rossbeigh are also Wildfowl Sanctuaries. The Harbour itself encompasses an area of approximately 5,300 hectares. It is fed by three rivers, the Carragh, the Laune and the Maine. Inch and Rossbeigh are separated by a tidal inlet 2km wide with a well developed ebb tidal delta. The barrier dune system consists of sandy and coarse sediments from both fluvial and glacial sources. The dunes at Inch have been aged at less than 600 years by [6] using luminescence dating techniques. Tidal flats containing salt marsh extend behind both barrier beaches. Mussel and Clam fishing are significant activities within the estuary and tidal flats, the majority of the harvest is landed at Cromane. The Carragh, Laune and Maine rivers are important Salmon and Trout fisheries. Changes in flow regime, wave climate and sediment transport characteristics within the estuary as a result of breaching may have a detrimental effect on these important activities.
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HWM - - - - 1842 - - - - 1894 - - - - 2000 Fig 1. Study Area –Inch, Rossbeigh and Castlemaine Harbour
Fig 2. Centennial scale map of outer estuary
Combining aerial photography, digitised historical maps and GIS software a centennial scale morphological map of the outer Estuary was created. The high water mark of historical maps of the estuary from 1842 and 1894 were compared to that of the high water mark of 2000 and overlaid on to satellite image from 2010 (Fig. 2). A clear landward movement of the Rossbeigh dune system over the 164 year timeframe is evident on initial analysis of Fig. 2. The positional stability of Rossbeigh between 1894 and 2000 suggests an equilibrium phase was reached. There is a distinct similarity between the 1842 outline and the prebreaching profile while the thin throat of the 1842 dune is in a similar area to the location of the breach 156 years later. The shoreline changes at Inch have previously been documented by [7] using the 1842, 1894 historical maps and 1949,1967 1973 and 1993 aerial maps. The 2000 high water mark seems to agree with the 30-50 year cycle of erosion and progradation occurring at Inch proposed by [6]. A similar cycle occurring at Rossbeigh cannot be ruled out due to the absence of data between 1894 and 2000 for Rossbeigh. Although it is unlikely as sedimentation analysis of the estuary undertaken by [8] confirmed that Rossbeigh is moving landward. It is possible that both cycles are interrelated. The similarity of the location of the HWM at Inch in 1842 and 2000 are significant as it corresponds to the beginning of highly erosive conditions at Rossbeigh. The stratographic analysis undertaken [7] also indicated that Rossbeigh breached just after 3000 cal year BP. The effect of which was detectable throughout the estuary including the inner harbour eastward of Cromane point. The analysis suggests that the barrier re-established itself thereafter, as sediment deposition characteristics resumed to a pre 3000 cal year BP state. The presence of a sand deposit layer on the salt marsh to the rear of Rossbeigh 800 years ago could also be considered a breaching event or over washing of the barrier system. III.
Breaching of Rossbeigh
The northern end of Rossbeigh barrier dune was subject to intense erosion leading to a breaching of the dune in the winter of 2008, Fig. 3. The breaching in effect divided the dune into two distinct sections, a northern island and the remaining attached dune system. The breach marks a significant morphological change in the barrier systems morphodynamic cycle but potentially a change also in the dynamics of the entire estuary. The impacts of which may effect both the inner and outer Castlemaine harbour as suggested by geological analysis of the historical breaching events. Recording the evolution of Rossbeigh post breaching and monitoring the impacts of the breach on the estuary will provide essential data required to create a predictive model of the estuarine system. This model will predict the impacts and evolution of the barrier system.
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Fig.3 Rossbeigh barrier breach and erosion of navigation tower
A comprehensive analysis of the short term changes to the coastal system is possible due to the availability of recent imagery and data collected in the field. Satellite imagery, topographical surveying, hydrodynamic monitoring and sediment analysis are combined to quantify the evolution of the breach. An erosion rate of 12m/year between 2000 and 2006 was calculated. This led to the estimated removal of 52,000m3 of dune sediment per year in that period. This erosion rate increased to 530,000m3/yr between 2006 and 2009 with the breach width growing to almost 700m. The shore line vegetation of the dune was used as a reference to analyse the recent movements of Rossbeigh (Fig. 4). Aerial photographs provided the references from 2000 and 2007 while the latest dune positions were recorded using GPS surveying techniques. The continued landward migration visible at the centennial scale is also evident in the decennial scale with migration visible from 2000 to 2007 pre breaching. The significant changes occur after the breaching event from 2009 to the 2000 2011, when the division of Rossbeigh into two distinct land forms occurs. The 2000 northern terminus is cut off from the main dune body forming an island inaccessible at high tide. However, there appears to be a slow down in breach growth, the 2010 & 2009 2011 dune line terminates in the same location at the end of the connected dune. The 2010 island erosion rate is reduced significantly. The appearance and growth of mid breach 2011 spits in June 2010 suggests that the breach may be infilling. An inlet close to the new Inlet island section is visible on the image. This inlet initially connected the back barrier channel with the open sea post breaching but has since infilled. During the winter of 2010 the destruction of an 18th century navigation tower (Fig. 3) occurred. This could also be due to the large flux in hydrodynamic and sediment conditions of the previous decade. The breaching of the dune has resulted in large deposition of sediment into the back barrier channel. This is discussed in greater detail in the next section.
Fig. 4 Dune vegetation line
IV.
Impact on the Estuary
The breaching of Rossbeigh beach, impacts the estuary in several ways. The sediment once contained within the barrier dune is redistributed within the coastal cell. This affects the bathymetry both seaward and shoreward of the dune system. The prevailing hydrodynamics are affected both by a change in bathymetry and also the emergence of a new inlet through the breach. The change in tidal channels shoreward of the dunes and a resulting increase in tidal prism in the estuary could potentially increase the area at risk of erosion, for example Cromane point. Flood risk could also potentially increase in certain areas of the estuary behind the barrier, with increased bed height and larger tidal flows resulting from the breaching event. Satellite imagery and numerical modelling were utilised to assess the initial impacts of the breach on the larger scale of Castlemaine Harbour and Dingle Bay.
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Assessing flood risk will require more data then is presently available, although it is part of the objectives for the overall research project. The impacts discussed here are those currently quantifiable. A. Satellite Imagery Analysis Satellite imagery was analysed to assess the changes to the outer estuary at the mesoscale. Images, Fig. 5, from 2000, 2007 and 2010 were compared. Two areas of significant change were identified, the alignment of the tidal inlet and the location of the estuarine channels to the rear of Rossbeigh. Inch and its associated ebb tidal delta showed little response to the breaching event, although analysis of barrier system as a whole over a longer timescale may prove otherwise. In the pre-breaching phase (2000) the inlet has a distinctive S curve as it exits the mouth of the estuary. There are large ebb tidal bars on both sides of the channel. These bars are formed by deposition of sediments from the channel as it bends. A shore parallel sand bar is clearly visible in front of Rossbeigh. This bar actively dissipates wave action and is fed by sediment from the seaward ebb tidal bars. The bar protects the dunes from erosive wave action. The estuarine channel to the rear of Rossbeigh follows the contour of the dune with no obvious deviations. The inlet channel straightens in the breaching phase (2007), depositing less sediment causing the ebb tidal delta in front of Rossbeigh to shrink. This affects the shore parallel bar adversely, the continued wave action and reduced sediment supply leads to the erosion of the bar and eventually a deep channel is formed in front of Rossbeigh. The replacement of the wave dissipating sand bar with a deeper channel provides the conditions for increased erosion and barrier breaching. As the dune is eroded the back barrier estuarine channel does not follow inwards towards the breaching location, instead the route of the 2007 channel remains similar to that of 2000. This suggests the channel to the rear of Rossbeigh possesses a degree of geological stability. Post breaching phase is characterised by the inlet beginning to return to its pre-breaching S curve route. The re emergence of ebb tidal deltas is apparent in the 2010 image. Although the deeper channel in front of Rossbeigh remains, it appears shallower and broader suggesting infilling is occurring. As the breach develops sand is transported into the estuarine channel to the rear of the dunes. The channel is diverted for the length of the breach but returns to its pre breaching course thereafter. It remains to be seen if this channel will eventually reset to the pre breaching course for its entire length. The increased sediment at the rear of Rossbeigh could have significant consequences for clam farming conducted in the area. Changes in water quality and bed composition as a result of the additional sediment could impact negatively on these valuable habitats. Anecdotal evidence from clam fishermen claim there is an increase in the sedimentation is effecting harvesting since the breaching. It is unclear whether the intensively farmed mussel beds, located eastward of Cromane point, have been affected by changes to the estuary. The minimal changes to the shoreline, back barrier and ebb tidal delta of Inch suggests that a cycle of sediment supply and demand exists exclusively between Rossbeigh, the inlet and the southern ebb tidal bar. A three phase cycle could explain the breaching event and predict the future morphology of the estuary and barriers. As the inlet channel forms a more pronounced S curve similar to that of its 2000 pre-breaching route, the current trend of ebb tidal bar growth would continue and the shore parallel bar may be restored. This would prevent further erosion of the breached area which is already displaying signs of regeneration. The additional back barrier sediment which is responsible for altering the course of estuarine channel would provide the material for the growth of the ebb tidal bar, shore parallel bar and eventually breach repair. The time scale and extent of the breach repair is unclear. Further monitoring and numerical modelling would be required to attempt such a prediction.
Fig. 5 Mesocale view of outer estuary in 2000, 2007 & 2010
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B. Numerical Modelling The numerical modelling was undertaken using the MIKE 21 modelling software suite. The MIKE 21 HDFM and MIKE 21 SW modules were utilised to provide hydrodynamic simulations. Bathymetry for Dingle bay was formulated from several sources due to the lack of a complete dataset. Three separate bathymetries were produced to represent distinct phases of the morphological phases of Dingle bay. A deep water Mulitbeam echo survey up to the 10m contour was coupled with 3 different MIKE 0 digitization of Images from aerial and satellite sources, Fig. 6. The 3 phases represented are a pre breaching (2000) breaching (2006) and post breaching (2009). The 2009 topographical survey was also integrated into the 2009 bathymetry. The hydrodynamic conditions used was typical wave climate parameters for Dingle bay of peak period 8s, significant wave height of 4m and mean direction of 270°. These parameters were derived after analysis of data from two sources. Data was obtained from the offshore M3 directional wave buoy and a near shore Valeport gauge deployed 1.5km in front of Rossbeigh in 2007. The model was run over a spring tide for each of the 3 bathymetries in both a wave only and wave and current coupled mode. Isolating the tidal current regime at mid flood, Fig. 7, the changes to the outer estuary become obvious. The increase in velocity in the inlet flow at the northern end of Rossbeigh is in the order of 0.5m/s between 2000 and 2006 bathymetries. This increase in velocity is maintained into the estuary and in the back barrier channel. The model produces an expected change of current regime in 2009 with the breached area forming a second flood pathway. This results in an increased tidal flood flow of up to 1m/s in the estuary to the rear of Rossbeigh with a slight decrease in flow in the main tidal channel when compared to 2006 current regime. This increase in tidal flood current may also affect the clam fishing industry that is focussed in this area. It has already been noted that there is a significant increase in sediment in the area due to the breach evolution. Combining this with an increase in tidal flood currents in the direction of clam harvesting beds is further evidence of impact in the estuary. A slight decrease in flood flow over the ebb tidal delta is also apparent. This may contribute to further deposition although it is still too early to confirm. Examining the coupled wave and current output at high tide, Fig. 8, provides another interesting set of results from the model. It is clear that the reduction of the protective swash platform in front of Rossbeigh between 2000 and 2007 allows waves action to directly interact with the dunes causing erosion and ultimately leading to the breaching. The increase of wave action through the main channel in 2007 is pertinent when considering the sediment cycle of inlet, ebb tidal bar and Rossbeigh dune presented earlier, even more so when the 2009 wave climate is analysed and a reduction on 2007 heights through the main channel and over the ebb tidal bar is observed. The other notable result from the 2009 model is the shoaling of waves through the breach. Despite the influence of wave action in the vicinity of the breach, there is little interference further into the estuary and significantly absent from the area where tidal current increased dramatically. This would suggest that the estuary may not be under an immediate erosion threat from increased wave forcing due to the breach as was initially feared. If the breach were to continue to erode and widen the current study would have to be revised. There is significant evidence from the numerical modelling that an increased tidal flow could cause concern for stakeholders in the estuary. The potential for tidal flooding is significant considering the area protected by the dune system is extremely low lying. Flooding events have been recorded pre- and post-breaching. Historically, the coastline from Cromane to directly behind Rossbeigh has been the most susceptible in the estuary. Considering the new flow regime now in place in the estuary it is highly likely that flooding could occur, prompted by meteorological conditions more benign than those responsible for previous flood events, therefore increasing the periodicity and range of conditions flood damage is likely to occur. To assess the flood risk definitively a larger model domain is required with up to date bathymetry and comprehensive data acquisition required for model validation purposes. These are discussed further in the final section.
Fig. 6 Model Domain
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2000
2000
2006
2006
2009
2009
Fig. 7 Mid flood tidal regime
Fig. 8 Wave climate at high tide
Fig. 7 Mid flood tidal regime
Fig. 8 Sample wave conditions at high tide
V.
CONCLUSIONS
The present study has contributed to the fundamental understanding of the coastal processes active at Rossbeigh and the effects on the estuary protected by the barrier beach system. A long-term morphological cycle along of the barrier beach and outer estuary has been presented. The cycle is characterised by long term stability followed by short term intense change. The impact of the breaching appears to be initially isolated to directly in front of and immediately behind Rossbeigh. The significant changes to the estuary occurred in the form of a shore parallel bar being eroded over a 10 year time frame and a back barrier estuarine channel being forced to change course. This is primarily due to wave action pushing sediment through breach shoreward. The formation of a second inlet in the system through the breach appears to have been temporary. While it remains to be seen if the shore parallel bank and back barrier channel will be reinstated to a pre breaching composition. The characteristics of the estuary’s main inlet channel were shown to be an important driver when considering the morphology of the breach. The inlet’s route seaward of barrier system and subsequent size and location of ebb tidal bars appear to be linked with erosion rates of Rossbeigh. A conceptual model of breach repair and evolution of the surrounding estuary was developed based on this internal link between inlet channel, ebb tidal bar and dune. It is suggested that sediment originating from the breach dune was transported shoreward. It is currently deposited in the back barrier estuarine channel, obstructing the natural flow path and interfering with aquaculture practises in the area will be transported on the ebb tide into the main inlet channel of the estuary and deposited on the ebb tidal bar in front of Rossbeigh. Wave action reorganises this sediment and will gradually fill
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the shore parallel channel in front of Rossbeigh, restoring the pre breach conditions of the estuary. This could eventually result in a re-growth of the breach and possible restoration of Rossbeigh dunes to pre breaching levels. It was found that the possibility of increased erosion in the estuary as a result of increased wave action due to breaching is low. An increase in wave height in the estuary was shown to be restricted to a small region close to the breach. If the breach were to widen further this analysis would have to be re-evaluated. Concerning the increased flood risk in the estuary attributed to the breaching, several factors still remain unclear. It is not known if the bathymetry and tidal prism have been significantly affected by the breaching event. The minor alteration of an estuarine channel directly behind the breach and an increase in sediment deposition are the only significant physical changes recorded to date. The breaching has resulted in an increased tidal flood flow in the estuary according to numerical modelling; further modelling is required before definitive conclusions can be made on flood risks directly attributed to the breaching event and morphology influenced by breaching. VI.
FURTHER WORK
The monitoring of the estuary through topographic surveys and remote sensing will continue for the duration of the 3 year project. In addition to this detailed hydrodynamic data collection is planned. The recording of the tidal prism throughout the estuary will provide data for future modelling as well as indicate changes to the estuary. Characterising the inlet channel and ebb tidal bars will be a priority. It is planned to undertake current and wave recordings in several locations in the estuary, breach and in open sea of Dingle bay. The use of seismic and sediment analysis is also scheduled. The role of aeolian transport on the dune’s regeneration will be investigated. The accuracy of the numerical model will be enhanced with new bathymetry and LIDAR survey to be conducted in 2011. The MIKE Cams module which simulates morphology will be added to the model. The model will be validated using the results the data monitoring programme. The relationship between the inlet location, ebb tidal bar and dunes will be thoroughly examined. Once validated, the updated model will be used to assess flood risk in the estuary by identifying potential flood zones under various metrological and hydrodynamic forcing. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8]
G. S. Giese, S. T. Mague, and S. S. Rogers, "A Geomorphological Analysis of Nauset Beach/Pleasant Bay/Chatham Harbour For the Purpose of Estimating Future Configurations and Conditions," Provincetown Center for Coastal Studies 2009. A. V. Terchunian and C. L. Merkert, "Little Pikes Inlet, Westhampton, New York," Journal of Coastal Research, vol. 11, pp. 697-703, 1995. H. K. A. J. Chadwick, W. R. Gehrels, A. C. Massey, D. O'Brien, D. Dales "A new analysis of the Slapton barrier beach system, UK," Proceedings of the ICE - Maritime Engineering, vol. 158, pp. 147 –161, 2005. J. A. G. Cooper, J. McKenna, D. W. T. Jackson, and M. O'Connor, "Mesoscale coastal behaviour related to morphological self-adjustment," Geology, vol. 35, pp. 187-190, February 1, 2007 2007. D. Michel and H. L. Howa, "Morphodynamic behaviour of a tidal inlet system in a mixed-energy environment," Physics and Chemistry of The Earth, vol. 22, pp. 339-343, 1997. A. G. Wintle, M. L. Clarke, F. M. Musson, J. D. Orford, and R. J. N. Devoy, "Luminescence dating of recent dunes on Inch Spit, Dingle Bay, southwest Ireland," The Holocene, vol. 8, pp. 331-339, April 1, 1998 1998. J. D. Orford, J. A. G. Cooper, and J. McKenna, "Mesoscale temporal changes to foredunes at Inch Spit, south-west Ireland," Zeitschrift fur Geomorphologie, vol. 43, pp. 439-461, 1999. C. Delaney, Jennings, S., Devoy, R.J.N., "Controls on medium to long term organogenic salt marsh sedimentation under rising relative sea-level along the western European (East Atlantic) margin: evidence from Dingle Bay, western Ireland. ," submitted.
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