Dissertations / Theses on the topic 'Coast changes'
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1
Paone, Laura Clare. "Hazard sensitivity in Newfoundland coastal communities : impacts and adaptations to climate change, a case study of Conception Bay South and Holyrood, Newfoundland /." Internet access available to MUN users only, 2003. http://collections.mun.ca/u?/theses,170975.
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Keblinsky, Corinn C. "The Characteristics that Control the Stability of Eroding Coastal Bluffs in Maine." Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/KeblinskyCC2003.pdf.
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Zoulas, James Gary. "Beach changes in the San Pedro Littoral Cell, Southern California, 1930-2007." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1666392701&sid=28&Fmt=2&clientId=1564&RQT=309&VName=PQD.
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Ishikawa, Rei. "Historical shoreline change and beach morphodynamics at Rapahoe Bay, West Coast, New Zealand." Thesis, University of Canterbury. Geography, 2008. http://hdl.handle.net/10092/1507.
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This thesis utilises a range of methodologies to investigate the historical shoreline change and beach morphodynamics at Rapahoe Bay, West Coast, New Zealand. Rapahoe Bay is a small embayment located 15 km north of Greymouth, and contains a complex and dynamic environment under a dominant swell condition. The objectives of this thesis include the investigation the coastline history through aerial photographs and relevant literature, identify and quantify historical shoreline change and the processes that have induced change, examine the short term and seasonal changes in beach profile, identify and quantify wave and transport process and to test the applicability of the zeta shoreline curve on a composite beach. This combined approach investigates the dynamics and process drivers involved in coastline change. This thesis contributes to the research gap of understanding morphodynamic behaviour and controls of composite beach under a dominant swell. Composite beaches types are a variation from mixed sand and gravel beaches with distinct morphological differences. This thesis provides an insight in to the morphodynamic behaviour of composite beaches. The study area contains a small village based by the shoreline and the potential coastal hazard that threatens people, property and infrastructure. Therefore the results from this thesis have an important management implication towards mitigating coastal hazards. The historical coastline change was induced through a combination of wave processes and transport, composite beach morphodynamic behaviour, anthropogenic influence and planform shape. Results show that human infrastructure restricted the retreat of a small hapua landward of the gravel barrier. A combination of change in sediment supply, consistent sediment transport and a high wave energy environment resulted in rapid landward retreat through gravel rollover and coastal erosion. The gravel barrier morphodynamics include increase in crest elevation, steeper shore gradients as a response to high swells resulting in erosion or rollover. The wave environment includes a sediment transport hinge point due to a dominant wave refraction and changes in the shoreline orientation, which further induces coastal erosion. The valid applicability of the zeta planform shape concludes that the shoreline may further iii retreat due to geological controls, potential sediment transport and the transgressive nature of the composite beaches. The combination of methods and results provide both quantified historical change and also potential future scenarios of coastline reshaping. These methods and results are applicable not only to Rapahoe but along other West Coast composite beaches, and the validity of the combination of methods provides a greater understanding of the behaviour of morphodynamic composite beaches and provides quantified results of historical shoreline change and sediment transport at the field site.
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Hasbrouck, Emerson G. "The influence of tidal inlet migration and closure on barrier planform changes : Federal Beach, NC /." Electronic version (PDF), 2007. http://dl.uncw.edu/etd/2007-3/r1/hasbroucke/emersonhasbrouck.pdf.
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Cullen, Andrew Blinn. "The North New Guinea Basin, Papua New Guinea : a case study of basin evolution at a modern accretionary plate boundary /." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1990.
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Conforto, Sesto Juan R. "Erosion in Southern Monterey Bay." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Mar%5FConfortoSesto.pdf.
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Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, March 2004.Thesis advisor(s): Edward B. Thornton, James MacMahan. Includes bibliographical references (p. 37). Also available online.
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Massey, Anthony Carl. "Holocene sea-level changes along the Channel coast of south-west England." Thesis, University of Plymouth, 2004. http://hdl.handle.net/10026.1/476.
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A Holocene relative sea-level (RSL) history for the south Devon coast is reconstructed through an analysis of twelve cores extracted from the coastal back-barrier environments of Bantham Sands, North Sands, Slapton Sands and Blackpool Sands. Foraminifera preserved in the sediments are assigned an indicative meaning based on the vertical distribution of their modem counterparts from contemporary salt marsh and mudflat environments in the Erme and Salcombe-Kingsbridge estuaries. The contemporary data provide the first inter-tidal (-2.6 to +2.6 m MTL) foraminifera-based transfer function for south-west England from which sea-level changes can be predicted with good precision (RMSEP = ±0.29 m). Sea-level index points (SLIPs) from basal facies provide the longterm (103 yr) RSL history. SLIPs derived from non-basal minerogenic and peat sequences are subject to post-depositional consolidation and a vertical correction, using the Paul and Baffas (1998) method, was therefore applied to these index points. The vertical displacement of fine minerogenic sediments ranges from <0.1 m above basal facies to >1 m at minerogenic-peat contacts, increasing to >2 m in organic peat facies. The age of each SLIP is obtained by AMS 14C dating of bulk sediment or plant material. The electrical resistivity method of geophysical survey provides additional subsurface mapping information of the back-barrier sediments, and the lithostratigraphic results support the view that a complex barrier-lagoon system existed along the south Devon coastline during the early Holocene. Almost 13 m of RSL rise occurred along the south Devon coastline ca. 9000 to 4400 cal years BP. The rate of early Holocene RSL rise is -5.4 ± 2.1 m/ka and -1.1 ± 0.2 m/ka during the mid- to late Holocene. The pattern and rate of RSL rise is similar to other sea-level curves produced for the region. Lambeck's (1993a, b, 1995) geophysical model predictions fit the data well during the early Holocene but Peltier's (1998) model is the best overall fit of the robust data used to reconstruct the early to mid- Holocene RSL history. Rates of middle to late Holocene sea-level rise are generally faster than the models predict. The area is still undergoing glacio-isostatic adjustment (GIA) equating to a coastal land subsidence of -1.16 m/ka since ca. 4400 cal years BP. The dataset increases the current Holocene SLIP database for the south-west peninsula and southern Britain by 23% and for south Devon by almost fivefold.
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Cavalcante, Eider de Olivindo. "Selective modernization of the coast: conflicts, changes and permanebcies in cumbuco county." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8622.
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FundaÃÃo de Amparo à Pesquisa do Estado do CearÃA presente pesquisa procura tornar inteligÃvel a modernizaÃÃo estratÃgica e seletiva do estado do Cearà a partir do que se denominou vetores de modernizaÃÃo, focalizando principalmente a modernizaÃÃo do litoral que se realiza, principalmente, por meio do turismo e da urbanizaÃÃo. Atà os finais da dÃcada de 1970, que marcaram o surgimento dos primeiros conflitos com especuladores imobiliÃrios e grileiros, o litoral do Cearà representava um sinÃnimo de liberdade para remanescentes indÃgenas e outros agrupamentos humanos que historicamente habitaram o litoral ou que decidiram migrar, fugindo de conflitos agrÃrios e de outros processos que funcionalizavam fortemente outras particularidades do estado. Entretanto, no contexto da busca de novos territÃrios e setores para a acumulaÃÃo capitalista, como tambÃm da subordinaÃÃo do tempo livre e das demais relaÃÃes sociais que escapavam à lÃgica da (re)produÃÃo das relaÃÃes sociais de produÃÃo capitalistas, o litoral passou a ser fortemente funcionalizado como territÃrio turÃstico. Tal fato motivou uma situaÃÃo atual em que as possibilidades de apropriaÃÃo encontram-se cada vez mais sufocadas pelo conflito com a dominaÃÃo do aparato estatal-empresarial. Nesse contexto, destacou-se a localidade do Cumbuco â histÃrica comunidade pesqueira marÃtima localizada no municÃpio de Caucaia â enquanto recorte espacial, procurando compreender os conflitos, as mudanÃas e as permanÃncias da localidade diante da referida modernizaÃÃo. O foco central do trabalho à a mudanÃa do modo de vida no/do Cumbuco, modo que atà dÃcadas passadas era caracterizado pelo tempo lento, pelas atividades ligadas a pesca artesanal, confecÃÃo de bordados, labirintos e crochÃs, cultivo de vazante, religiosidade, e por todo um leque de prÃticas e representaÃÃes de mundo. No desenrolar histÃrico, entretanto, esse modus vivendi foi subordinado à lÃgica da mercadoria e estilhaÃado em vÃrios percursos e atraÃÃes para turistas, veranistas e investidores. Com a forte aÃÃo dos especuladores imobiliÃrios e o elevado preÃo da terra, observou-se, tambÃm, a re-territorializaÃÃo de parte dos cumbuqueiros no Parazinho â uma ocupaÃÃo precÃria sobre o campo de dunas, oriunda da saÃda de pescadores e/ou filhos de pescadores de suas antigas residÃncias. Nesse sentido, entendendo que a discussÃo està longe de ser esgotada e que a processualidade histÃrica nunca finda, procura-se contribuir com alguns subsÃdios para o entendimento da modernizaÃÃo do litoral cearense, sobretudo do Cumbuco.
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Aramuge, Adérito Celso Félix. "Storm surge changes along the coast of Mozambique for future climate scenarios." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/23620.
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Doutoramento em FísicaMoçambique é afetado por ciclones tropicais que se formam na bacia do Oceano Índico. Cerca de dois terços da população total de Moçambique vive ao longo da costa que se estende por 2700 km e que cuja região, com altitude inferior a 50 m, ocupa várias dezenas de quilómetros em direção ao interior. O aumento do nível médio do mar e um aumento provável da intensidade e/ou frequência de ciclones tropicais, associados a alterações climáticas de origem antropogénica, podem aumentar o risco de cheias ao longo da costa.Neste estudo, estamos principalmente preocupados com a estimativa de alterações das propriedades da sobrelevação do nível do mar ao longo da costa de Moçambique, sob o cenário de mudança do clima RCP8.5. Para atingir tal objetivo, aplicamos um modelo analítico a dados observados de ventos e pressão atmosférica, para estimar a maré meteorológica e a sobrelevação do nível do mar na região. O modelo analítico é validado por comparação dos seus resultados com dados semelhantes obtidos por marégrafos em alguns locais na costa. De seguida, é usado um conjunto de simulações climáticas realizadas pelo modelo climático MPI-ESM-LR. Dados de pressão atmosférica e ventos simulados foram usados no modelo analítico e séries temporais da maré atmosférica foram produzidas para sete locais ao longo da costa. As propriedades estatísticas destas séries e as sobrelevações do nível do mar associadas foram comparadas com aqueles obtidos usando o mesmo modelo analítico e dados meteorológicos observados. Isto foi feito para o período histórico de 1986-2005. Após uma validação com sucesso de ambos os modelos, o analítico e o climático, o modelo analítico foi utilizado com dados meteorológicos simulados pelo MPI-ESM-LR para o cenário RCP8.5, para três períodos distintos nomeadamente, futuros próximo (2016-2035), médio (2046-2065) e distante (2081-2100). As propriedades da sobrelevação do nível do mar para estes períodos foram comparadas com aqueles relativos ao período histórico. Os resultados sugerem um aumento da intensidade da sobrelevação do nível do mar ao longo de toda costa de Moçambique sobretudo devido aos aumento da intensidade dos ciclones tropicais. Com a subida do nível medio do mar, espera-se que aumente a altura do qual o STS inicia a sua propagação. O nivel do mar calculado (STS+TC+SLR) para o período historico, futuro proximo, medio e longo são iguais a 0.93 m, 1.19 m, 1.42 m e 1.74 m respectivamente. Esta metodologia é útil porque se recorre a um modelo analítico simples e dados meteorológicos na ausência frequente de dados de nível do mar registados por marégrafos. Permite também a estimativa de alterações futuras de sobrelevação do nível do mar com recurso a variáveis meteorológicas simuladas por modelos climáticos, facilmente disponíveis, em vez de recorrer a modelos físicos ao cálculo da sobrelevação do nível do mar.
Mozambique is affected by tropical cyclones which are formed in the Indian Ocean basin. About two-thirds of total population of Mozambique lives along the coast which has 2700 km long and low lying areas (below 50 m height) extend several tens of kilometers inland. Sea level rise and the eventual increase of the intensity and/or frequency of tropical cyclones expected to occur in the future, associated with anthropogenic climate change may increase the risk of coastal flooding. Here, we are mainly concerned with the estimation of changes of storm surge properties along the coast of Mozambique under the RCP8.5 climate change scenario. To achieve this we applied an analytical model which uses observed winds and atmospheric pressure near the surface data to estimate the meteorological tide and storm surges in the region. This model is validated against atmospheric tides obtained from sea level measured by tide gauge observations at some locations along the coast. Next, we used a set of climate simulations performed by the MPI-ESM-LR earth systems model. Simulated winds and atmospheric pressure data were used with the analytical model and atmospheric tide time series were constructed for seven locations along the coast. The statistical properties of these series and the associated storm surges were compared with those obtained by using the same analytical model and meteorological observed data. This was done for the 1986-2005 historical period. After a successful validation of both the analytical and the climate model, the analytical model was used with meteorological data simulated by the MPI-ESM-LR for the RCP8.5 scenario for three distinct periods, namely, near-term (2016-2035), medium-term (2046-2065) and long-term (2081-2100). The storm surge properties for these periods were compared to those from the historical period. The results suggest an enhancement of storm surge intensity along the whole coast of Mozambique mainly due to an increase of tropical cyclone intensity. The SLR will add the point by which the STS starts its propagation. The calculated SL (STS+ TC+SLR) for the historical, near tem, medium and long term are equal to 0.93 m, 1.19 m, 1.42 me 1.74 m respectively. This methodology is very useful since it uses a simple analytical model and meteorological data in the absence of tide gauge records. It can also be used to estimate future storm surge climate changes using meteorological variables easily available rather than using storm surge physical models.
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Punwong, Paramita. "Holocene mangrove dynamics and sea level changes : records from the Tanzanian coast." Thesis, University of York, 2013. http://etheses.whiterose.ac.uk/4035/.
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Tanzanian mangrove ecosystems have been, and are presently, influenced by changes in climate and sea level. Fluctuations in these environmental conditions lead to adaptations and changes in ecosystem structure and composition. In this thesis mangrove environments are investigated and used to unravel the Holocene environmental history of the Tanzanian coast. Palaeoecological data from sediments abstracted from three different mangrove locations (the Rufiji Delta, Makoba Bay and Unguja Ukuu) are analysed for fossil pollen and charcoal and combined with stratigraphical investigations and radiocarbon dating allow a detailed environmental reconstruction to be undertaken. The relationship between pollen in surface samples and the surrounding vegetation is used to interpret fossil pollen records. Changes in the relative proportions of mangrove pollen under different inundation regimes are used to reconstruct mangrove dynamics and provide estimates of past sea level changes and infer specific changes in sea level altitude. Palaeoecological records reveal that mangroves in the Rufiji Delta occurred at the central sites from at least ~5600 cal yr B.P. until the late Holocene when mangroves covered the landward site and were succeeded by terrestrial vegetation to the present day. The Zanzibar records reveal fluctuating mangrove compositions from ~8000 cal yr B.P. to the present day with noticeable changes in mangrove composition during the mid Holocene. A reconstructed sea level curve from the three sites document an early-mid to mid Holocene sea level rise from ~ 8000 cal yr B.P. to around 4600 cal yr B.P. with potential highstands at 5800 cal yr B.P. and 4700 cal yr B.P. Sea level fluctuations occurred in the last thousand years with a potential highstand at ~ 530 cal yr B.P. before falling to a lower than present level at ~140 cal yr B.P. The earliest intensive human interactions within the mangroves was recorded in Zanzibar after ~530 cal yr B.P; a time of increased settlements and overseas trade along the Swahili coast. The Rufiji Delta records also demonstrate the impacts of damming and the destruction of mangrove areas for rice cultivation during the last millennium. The palaecological data have helped unravel the environmental history of the Tanzanian coast and have the potential to assist in the development of policies and/or public awareness for the sustainable utilization and management of mangrove ecosystems under predicted future sea level and climate changes.
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Hinis, Mehmet Ali Weggel J. Richard. "Cnoidal and sinusoidal wave reflection from a laboratory sand beach /." Philadelphia : Drexel University, 2003. http://dspace.library.drexel.edu/handle/1721.1/100.
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Eberhardt, Ellen. "Dynamics of intermediate-size stream outlets, northern Oregon coast." PDXScholar, 1988. https://pdxscholar.library.pdx.edu/open_access_etds/3787.
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This study measured and evaluated the relation of coastal foredune morphology to stream beach outlets, and investigated the processes associated with the stream outlet. Intermediate-size streams were studied, and defined as those that flow across the beach most of the year but have no tidal influence. Fifty-four of these streams were found along the northern Oregon coast between the Columbia River and Yaquina Bay. Crescent Lake Outlet, Saltair Creek and Daley Lake Outlet were chosen as study streams for further investigation.
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Rennie, Alistair Flett. "The role of sediment supply and sea-level changes on a submerging coast past changes and future management implications /." Thesis, Connect to e-thesis, 2006. http://theses.gla.ac.uk/843/.
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Thesis (Ph.D.) - University of Glasgow, 2006.Ph.D. thesis submitted to the Department of Geographical and Earth Sciences, University of Glasgow, 2006. Includes bibliographical references. Print version also available.
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Dang, Van To Civil & Environmental Engineering Faculty of Engineering UNSW. "Development of a mathematical N-line model for simulation of beach changes." Awarded by:University of New South Wales. School of Civil and Environmental Engineering, 2006. http://handle.unsw.edu.au/1959.4/27394.
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The development of a new N-Line model, which provides a practical tool for simulating regional beach changes induced by short and long-term processes, is described in this thesis. The new N-Line model consists of four main modules that together describe the hydrodynamic and morphological responses. The four constituent modules have been integrated based on a wide range of research including the utility and function of commercial or freeware models. They are RCPWAVE wave module, time-averaged and depth-integrated current module, sediment transport module based on Bailard (1981) and contour change morphological module. Two different time-scales and two staggered grid systems for hydrodynamic and morphological simulations were adopted alternatively. For short-term 2D profile changes, new N-Line model applicability has been examined using data from the laboratory to the field. For ideal beaches, new N-Line can simulate an offshore storm bar generation or an onshore accretion due to high or low energy waves. For SUPERTANK large-scale flume data, the predicted profile matched the measured profile well, especially the bar height and position. For beach profile data from the Gold Coast, storm-induced variations of barred profiles were reasonably modelled. The new N-Line model compared well with other commonly used cross-shore models such as SBEACH and UNIBEST. A new schematisation for a non-monotonic profile and DUNED inclusion were introduced. Sensitivity tests on cross-shore sediment coefficient (Kq), smoothing parameter (??s) and water level fluctuations were performed. For long-term 3D beach changes, the new N-Line model applicability has been tested with various boundary conditions using idealized and real field data. Two periods, 17 and 16 months, of beach changes before and after a major bypass plant commenced operation in 2001 at Letitia Spit were simulated. The profile and shoreline changes were predicted reasonably well. Empirical model parameters were determined after a range of sensitivity and calibration testing. The new N-Line model showed its better performance compared to one-line models. It can handle various boundary conditions, especially bypass conditions. The N-Line model is not only capable of modelling planform variations but also cross-shore profile changes.
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Brouillette-Jacobson, Denise. "Analysis of coastal erosion on Martha's Vineyard, Massachusetts a paraglacial island /." Connect to this title, 2008. http://scholarworks.umass.edu/theses/176/.
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Fortunato, Andre ́Bustorff. "Three-dimensional modeling of coastal flows using unstructured grids /." Full text open access at:, 1996. http://content.ohsu.edu/u?/etd,203.
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Savant, Gaurav. "Prediction of estuarine morphological evolution." Diss., Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-06202008-102016.
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Ahmed, Afzal. "Portuguese trade and socio-economic changes on the western coast of India (1600-1663) /." Delhi : Originals, 2000. http://catalogue.bnf.fr/ark:/12148/cb401128685.
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Smith, Albert William S. "The function and behaviour of natural beaches." Thesis, Queensland University of Technology, 1986. https://eprints.qut.edu.au/36454/1/36454_Smith_1986_Vol-1.pdf.
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This study may well be considered to represent a rather simplistic
contribution, towards the science of coastal engineering. This is in
fact, perhaps as it should be, because the mathematics involved, are
of the most basic kind, and no profound theories have been expounded.
This work has nothing to do with the development of existing theories
or existing dogma, within the current realms of the particular discipline.
That must remain for others.
This writer is not a scientist within any stretch of the classification,
he remains a simple engineer, who has spent most of his life, in the
role of being that of a basic observer. This status is often regarded
as being that of a semi-professional technician, and perhaps that is
rightly so. On the other hand, the common observer, in recording his
observations, might still well contribute something of value. He might
for example, document his prototype experiences particularly where he
finds that classical theory does not fit the "facts" as he sees them.
He might also well ponder why these theories appear to predict natural
process phenomenon, that cannot be seen on the prototype, or where the
real prototype can be readily seen to be doing something different.
These things are what this study is made from.
In dealing with coastal process observations, the writer's first introduction
to the subject occurred late in 1938, on the Paekakariki coast
of New Zealand. At that time, very profound changes were affecting the
entire fabric of this coastal area, after many decades of relatively
prior stability. At that time, a coastal recession of 50m in one year
was obvious, as was the degradation of a previous completely sandy beach,
into a residual boulder remnant within three years. These things exerted
an immense impact on this writer as a juvenile - he could appreciate
the dramatic effect of Nature even then - guided no doubt by his engineer
father, a Marine Engineer of vast experience.
At least the writer's family, always expounded the thesis, that an ounce
of observation was often worth a pound of theory, and perhaps sometimes,
even a ton. In very many ways, it may well be reasonable to conclude
that this very primitive concept, may still hold some reasonable value.
This work therefore, is an attempt to record the results of a lifetime's observations of natural coastal processes, together with a rather
hesitant approach towards postulating the mechanisms, that are the
central essence of these processes.
If much of this work is orientated towards interpretating, the subtle
interactions of Nature, in addressing coastal engineering actions and
responses, then this has been deliberate. This in many ways, is only
a crude representation of how Nature really works. Nature, it might
be noted, appears quite benign for most of the time, such that when
an extreme event hits us, we often consider this an extraordinary event,
in fact often as an "Act of God". This is not Nature's way at all.
In everything that Nature does, she displays a very single minded,
pragmatic, quite re~entless and ruthless approach to every natural
reaction. Every natural resource is treated for the maximum of economy
of resources - nothing is ever wasted. If any action cannot be counterbalanced
by the available reaction resources, then these current resources
are instantly discarded (to be used later for other purposes) and another
line of defence mechanisms are immediately called into action. The more
one may consider these natural processes, then the more obvious the
fantastic inter-relationship~ that are called into action - may become
obvious.
Mankind, in its engineering arro5c:illce, often chooses to ignore Nature's
action, and response mechanisms. Coastal engineers are particularly
prone to fall into this error. They only so often conclude that their
small scale hydraulic flumes, may completely eliminate the total fury
of Nature, on the prototype, as a hazard. In this, they have to date,
proven to be sadly in error. The dramatic failures at Keelung, Sines,
Bilbao, San Ciprian (and others) all attest to this miss-placed, self
appointed, over-confidence in engineering interpretations, of Nature's
real and often unexpectedly "raw" behaviour. It seems that the design
of major coastal structures, is commonly accepted as being capable of
conclusion within offices and laboratories, far remote from the site.
It is tendered here, that this isolationist approach, must be an open
invitation to the unexpected, and thus to total failure. Such, only
happens so often, in real coastal engineering practice.
This work therefore, is entirely related towards an attempt to interpret
and explain Nature's processes, and all based upon observations on the prototype. For certain, many of the interpretations made, may later
be shown to be in error. However, one must start somewhere, and this
is at least an attem:pt to do so. Many of the things said herein,
may appear to the more orthodox, to be irrational, unprecedented or
even nonsense. As such, the conventional orthodox are welcome to their
own opinions. What is set-out herein, is entirely the writer's opinions,
and he will stand by them. These opinions however, are not the resultants
of reading only other people's publications nor interpreting only
other people's data. What is recorded here is the results of sim:ple
site observation on dozens of prototypes, over a period of forty years
or more. Whether these observations are of any value, must in the end,
be up to the reader. Only time will tell.
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Zhu, Zhaoxu. "Storm Induced Beach Profile Changes along the Coast of Treasure Island, West-Central Florida, U.S.A." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6608.
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Storms play a significant role in beach morphodynamics. Storm-induced beach-profile changes and their longshore variations are investigated in this study. The impacts of four summer tropical storms and two series of winter storms over the last 10 years along the coast of Treasure Island were documented. Tropical storms Alberto in 2006, Fay in 2008, Debby in 2012, Hermine in 2016 and winter storms in winter seasons of 2014 and 2015 are discussed in this study. In general, the Treasure Island beach experienced more erosion generated by tropical storms with greater intensity, but shorter duration, as compared to winter storms due to lower waves, weaker wind and smaller storm surge. Winter storms typically do not generate high storm surge and generally do not cause erosion at the dune and back beach unless the pre-storm beach is very narrow. Based on pre- and post-storm beach-profile surveys along the coast of Treasure Island, the northern end of the barrier island, located directly downdrift of the John’s Pass tidal inlet, experienced erosion along the entire profile during the storms. Along the middle part of Treasure Island, dry beach suffered erosion during both the tropical storms and winter seasons while the nearshore zone suffered erosion during the tropical storms and experienced deposition during the winter seasons. Sunset Beach at the southern end experienced severe erosion during tropical storm Debby, but not during other storms. Winter seasons caused relatively small changes to the morphology of Sunset Beach. Deposition happened in the nearshore zone along Sunset Beach during winter storms. Survey line R143 at the very south end of Treasure Island suffered erosion in tropical storm Alberto, Debby and Hermine. Beach profile changes induced by Tropical storm Fay was different as compared to other tropical storms. Considerably less beach erosion occurred due to the large distance of the storm path from the study area.
Overall, Sunshine Beach, bounded by John’s Pass inlet at northern end of Treasure Island, was influenced both by wave conditions and the tidal flows. Sediment transport was to the north along the coast of Sunshine Beach when wind direction was from south, e.g. during tropical storm Fay. However the northward sediment transport was blocked by the John’s Pass jetty. Therefore, deposition occurred at Sunshine Beach during tropical storm Fay. When wind direction was from north (e.g. during tropical storms Alberto and during the winter seasons), southward sediment transport was generated. Erosion occurs during the northerly approaching storms. The morphodynamics of the middle section of Treasure Island are influenced by the sand supply at the attachment point of John’s Pass ebb delta. Sunset Beach experienced various levels of erosion during the tropical storms not only because of the high wave, strong wind and high water level generated by storms, but also due to the higher waves associated with an offshore dredged pit.
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Parker, Nausheena. "Interannual changes in abundance and distribution of jellyfish along the west coast of South Africa." Thesis, University of the Western Cape, 2015. http://hdl.handle.net/11394/5187.
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>Magister Scientiae - MScHydromedusae are mostly carnivorous planktivores that under ideal conditions can reproduce and accumulate to form dense masses of jellyfish, known as blooms. These jellyfish blooms may have various impacts on their surrounding biota and in severe cases have the potential to result in ecosystem-wide changes. This study investigated assemblages of hydromedusae within the southern Benguela ecosystem, between the years 2000 and 2006. The samples analyzed were collected as part of routine Spawner Biomass Surveys conducted by the Department of Environmental Affairs: Ocean and Coasts (previously Marine and Coastal Management) using Bongo nets. Two hundred and forty two of the samples collected during the spring months, October and November, were analyzed. Environmental variables including (amongst others) sea surface temperature (SST), sea surface salinity (SSS), sea surface oxygen (SSO) and fluorescence (as a proxy for Chlorophyll a concentration) were measured to observe their influence on medusoid assemblages, distribution, abundance and diversity. Assemblages of hydromedusae were represented by 69 species and were dominated by Siphonophora and Leptomedusae. Mean abundance of hydromedusae were highest in 2005 (3.15 ind.m-³, SD 3.21) and lowest in 2002 (0.50 ind.m-³, SD 0.70). Trends in abundance displayed a general bell-shaped curve relationship with SST. The random-effects meta-analysis model revealed, across all years and all medusaoid classes that SSS (R=0.469), latitude (R=0.223), bottom fluorescence (R=0.533), mean fluorescence (R=0.338) and volume filtered (R=-0.408) were all significant factors in driving medusoid abundance at p<0.05. Medusoid diversity displayed a positive correlation to both temperature and salinity. A BIOENV analysis was used to explore the environmental factors that best described the variation observed in the biological assemblages. The results from this analysis suggest that SSS and bottom oxygen (BO) are the environmental factors that most influence the composition of medusoid assemblages.
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Sedigh, Mahnaz. "Analysis of the Hydrodynamics and Morphological Changes of the Gold Coast Seaway Ebb-Tidal Delta." Thesis, Griffith University, 2017. http://hdl.handle.net/10072/366044.
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The Gold Coast Seaway (GCS), known as the Nerang River Entrance (NRE) prior to stabilisation, is located at one of Australia’s premier tourist centres, and consequently, the provision of a safe navigation channel is significantly important for recreational boating and commercial craft activities between the ocean and the estuary. The tidal regime in the area is semi-diurnal with neap and spring tidal ranges of 0.3m to 2m respectively, and the entrance has a minor ebb dominant current regime. The dominant offshore wave climate is south to south east, and the beaches have a wave dominated, double bar morphology. The entrance location had undergone drastic changes due to natural processes prior to its stabilisation in 1986. These changes were significantly influenced by the dominant northward wave condition which, in combination with the resultant longshore sediment transport (LST), resulted in the entrance’s net northward migration prior to the stabilisation. The entrance has experienced an alteration in the inlet tidal prism since stabilisation and the implementation of the artificial bypassing system. As a result, the extent of the ebb-tidal delta offshore and its equilibrium volume have changed.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Engineering
Science, Environment, Engineering and Technology
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Zhao, Ruoshu. "Comparison of Beach Changes Induced by Two Hurricanes along the Coast of West-Central Florida." Scholar Commons, 2018. https://scholarcommons.usf.edu/etd/7388.
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The beach profiles pre-and post-the Hurricane Hermine (2016) and Irma (2017) along the Sand Key barrier island were collected to quantify longshore variations in storm induced beach changes as well as to compare the beach changes caused by hydrodynamic conditions of the two different hurricanes.
Cross-shore beach profile are examined in 4 sections including dune field, dry beach, sand bar and whole beach to calculate beach change. The volume change for each section and shoreline contour change before and post the hurricane was computed. Hydrodynamic conditions were obtained from adjacent NOAA’s tide and wave gauges.
Both hurricanes generated high offshore waves, with Hurricane Hermine generated waves mostly from southwest, and Irma generated waves dominantly from northeast. Hurricane Hermine generated a storm surge of up to 1 m. While hurricane Irma generated negative surge of -1.1 m.
Several beach profile parameters such as the foreshore slope, as well as volume changes of dune field, dry beach and sand bar induced by the two hurricanes were computed. Under both storms, the foreshore slope became steeper after the storm north of the headland, while the foreshore slope became gentler south of the headland. Storm surge plays an important role in inducing beach erosion. Hurricane Hermine with 1 m surge caused significant dune erosion in terms of dune volume loss and dune line retreat. On the other hand, hurricane Irma with negative surge only caused minor dune erosion. Sand bar moved seaward during both hurricanes, with Irma induced a much greater offshore movement than that of Hermine. In addition, the sand bar height decreased significantly during Irma. In contrast, during Hermine the sand bar height remained largely similar before and after the storm.
Large alongshore variations in beach erosion was observed during both hurricanes as influenced by background erosion rate and direction of incident waves as they approaching the curved shoreline. For both storms, the erosional hot spot at North Sand Key with the highest background erosion rate suffered the most sand loss over the entire profile. More sand was eroded from the dry beach along the broad headland than along the beaches both north and south of it. Corresponding to the higher volume of dry beach erosion, shoreline retreat was also the largest around the headland. During Hurricane Hermine, the headland sheltering of the southerly approaching waves resulted in more erosion to the south than to the north. The opposite happened during Hurricane Irma with northerly approaching wave. More erosion occurred to the north of the headland than that to the south. Systematic measurement of beach profile beach and after hurricanes can improve our understanding on beach morphodynamics on storm induced beach changes.
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Horn, Diane Patricia. "A numerical model for shore-normal sediment size variation (with particular reference to the north coast of the Isle of Man)." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.316786.
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Crane, Dakota A. "Future Changes to Species' Range along the South American Coast Based on Statistically Downscaled SST Projections." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555352153855504.
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Doughty, S. David. "The influence of inlet modifications, geologic framework, and storms on the recent evolution of Masonboro Island, NC /." Electronic version (PDF), 2006. http://dl.uncw.edu/etd/2006/doughtys/sdaviddoughty.pdf.
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Kaszuba, John Paul. "Polyphase deformation and metamorphism in the Penobscot Bay Area, Coastal Maine." Thesis, Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/91036.
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Metasediments from portions of two of the six lithologic terranes in the Penobscot Bay area of coastal Maine, the Late Precambrian (?) to Ordovician(?) Copeland Formation and the Rider Bluff member of the Copeland Formation at the eastern margin of the Passagassawakeag (PGW) terrane and the Silurian (?) to Devonian (?) Bucksport Formation of the adjacent Bucksport terrane, shared a common history of four phases of ductile deformation (D₁, D₂, D₃, and D₄) and interdeformational metamorphism and granitic plutonism. D₁ (early Acadian ?) produced tight to isoclinal folds and an axial plane foliation that deform all three metasedimentary units and contacts between these units. These units and therefore the PGW and Bucksport terranes must have been together by the time of D₁ at the latest. No observed structural or metamorphic gradient coincides with this terrane boundary in the Penobscot Bay area, but in southeast Maine it is mapped as a pre-metamorphic thrust fault. Intrusion of the 412± 14 Ma Stricklen Ridge granite and amphibolite facies metamorphism occurred between D₁ and D₂ . D₂ (Acadian) produced open, upright folds and a strong, hinge-parallel mineral elongation lineation under upper greenschist to lower amphibolite conditions. D₃ ductile strike-slip shear zones formed under upper greenschist to lower amphibolite conditions, and D₄ open, steeply-reclined folds formed under greenschist facies conditions. D₃ and D₄ are probably related to the same stress system as the dextral strike-slip Norumbega Fault Zone (Alleghanian) and probably represent a continuum of deformation. Brittle faults exploit D₃ shear zones and may also be related to the same stress system.M.S.
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Muteveri, Tinashe. "Effect of pleistocene climatic changes on the evolutionary history of South African intertidal gastropods." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/79791.
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Thesis (PhD)--Stellenbosch University, 2013.ENGLISH ABSTRACT: Historical vicariant processes due to glaciations, resulting from the large-scale environmental changes during the Pleistocene (0.012-2.6 million years ago, Mya), have had significant impacts on the geographic distribution of species, especially also in marine systems. The motivation for this study was to provide novel information that would enhance ongoing efforts to understand the patterns of biodiversity on the South African coast and to infer the abiotic processes that played a role in shaping the evolution of taxa confined to this region. The principal objective of this study was to explore the effect of Pleistocene climate changes on South Africa′s marine biodiversity using five intertidal gastropods (comprising four rocky shore species Turbo sarmaticus, Oxystele sinensis, Oxystele tigrina, Oxystele variegata, and one sandy shore species Bullia rhodostoma) as indicator species. Sequence data obtained from partial segments of the mitochondrial cytochrome oxidase c subunit 1 (COI), and the nuclear ribosomal DNA (encompassing part of 5.8S, second Internal Transcribed Spacer and part of 28S, hereinafter called ITS2; or comprising part of the first Internal Transcribed Spacer, 5.8S, second Internal Transcribed Spacer and part of 28S, hereinafter called ITS), were used as genetic markers to construct phylogeographic patterns and to investigate demographic histories of the taxa. Population structure was investigated using haplotype network analyses, pairwise ΦST statistics, analysis of molecular variance (AMOVA), isolation by distance analyses, Bayesian analysis of population structure (BAPS) and coalescent analysis of gene flow. Demographic history was analysed through Fu′s Fs tests, mismatch distributions, and Bayesian skyline plots. Demographic analyses suggest that all five intertidal gastropods studied experienced demographic expansions dating to the late Pleistocene. The sandy shore direct developer B. rhodostoma began expansion after the LGM (c. 15 kya) whereas for the four rocky shore broadcast spawners (T. sarmaticus, O. sinensis, O. tigrina, and O. variegata) the onset of expansion coincided with or preceded the LGM (c. 25, 60, 50, 40 kya, respectively). Consistent with recent range expansions and gene flow patterns, the population genetic structure in all species was characterised by shallow or a lack of population differentiation. Oxystele variegata was an exception as it showed a deep disjunction, of late Pleistocene origin, between individuals in the west coast Namaqua Bioregion and those in the south coast Agulhas Bioregion. These results provide strong evidence of the vital role that Pleistocene climatic changes and current regimes played in shaping the nature and distribution of biodiversity on the South African coast. In addition, gene flow in all species, except O. tigrina, was remarkably asymmetrical with the regions around Cape Infanta and Port Elizabeth acting as source populations. Considering the generally weak population genetic structure and gene flow patterns detected for most gastropod species studied here, it is recommended that T. sarmaticus, O. sinensis, O. tigrina and B. rhodostoma be managed as panmictic populations, and that the region encompassing Cape Infanta, and Port Elizabeth should be prioritised for conservation as it appears to harbour source populations. Oxystele variegata was the only species showing distinct population structure and in this instance, species specific conservation efforts should recognize this divergence by treating the two genetic assemblages as distinct management units.
AFRIKAANSE OPSOMMING: Historiese vikariante prosesse kan toegeskryf word aan glasiasie, en het tot gevolg gehad dat grootskaalse veranderinge in die omgewing plaasgevind het tydens die Pleistoseen (,012 - 2.6 miljoen jaar gelede, Mjg). Dit het 'n beduidende impak gehad op die geografiese verspreiding van spesies, veral ook in die mariene stelsels. Die motivering vir hierdie studie was om nuwe data te voorsien wat sal bydrae tot die voortgesette pogings om die patrone van biodiversiteit langs die Suid-Afrikaanse kus te verstaan. Dit sou ook help om die abiotiese prosesse af te lei wat 'n rol gespeel het in die evolusie van taksa wat in hierdie streek voorkom. Die hoofdoel van hierdie studie was om die effek van die Pleistoseen klimaatsveranderinge op Suid-Afrika se mariene biodiversiteit te bepaal deur gebruik te maak van vyf intergety slak spesies as indikatore (vier wat in rotsagtige gebiede voorkom: Turbo sarmaticus, Oxystele sinensis, Oxystele tigrina, Oxystele variegata en 'n sanderige strand spesies: Bullia rhodostoma). Volgorde data verkry vanaf gedeeltelike segmente van die mitochondriale sitochroom oksidase c subeenheid 1 (COI), en die kern ribosomale DNA (bestaande uit 'n deel van 5.8S, tweede interne getranskribeerde spasieërders en 'n deel van 28S), hierna genoem ITS2 is gebruik as genetiese merkers om filogeografiese patrone te dokumenteer en ook om die demografiese geskiedenis van die spesies te ondersoek. Bevolking struktuur is ondersoek deur gebruik te maak van haplotipe netwerk analise, paarsgewyse ΦST statistiek, analise van molekulêre variansie (AMOVA), isolasie deur afstand analise, Bayesiaanse analise van die bevolking struktuur (BAPS) en analise van gene vloei. Demografiese geskiedenis is ontleed deur Fu se Fs toetse, misparing verdelings, en Bayesiaanse luglyn kurwes. Demografiese ontleding dui daarop dat al vyf die intergety slakke wat ondersoek is demografiese uitbreidings ervaar het wat terugdateer tot die einde van die Pleistoseen. Die sanderige strand direkte ontwikkelaar, B. rhodostoma, het die uitbreiding begin na die LGM (c. 15 Kya), terwyl vir die vier rotsagtige kusbewoners wat eiers oor 'n uitgebreide gebiede versprei (T. sarmaticus, O. sinensis, O. tigrina, en O. variegata) het die aanvang van die bevolkings uitbreiding saamgeval met die laaste galsiasie of dit voorafgegaan (c. 25, 60, 50, 40 Kya, onderskeidelik). In ooreenstemming met die onlangse reeks bevolkings uitbreidings, is die bevolking genetiese struktuur in alle spesies gekenmerk deur weinig differensiasie. Oxystele variegata was 'n uitsondering en het 'n ontwrigting van laat Pleistoceen oorsprong getoon tussen individue langs die weskus Namaqua Biostreek en dié in die suid kus Agulhas biostreek. Hierdie resultate voorsien sterk bewyse van die belangrike rol wat die Pleistoseen klimaatsveranderinge gespeel het in die vorming en verspreiding van biodiversiteit langs die Suid-Afrikaanse kus. Daarbenewens, geen vloei in alle spesies, behalwe O. tigrina, was merkwaardig asimmetries. Kaap Infanta en Port Elizabeth verteenwoordig moontlik die bron bevolkings. Met inagneming van die geringe bevolking genetiese struktuur en geenvloei patrone wat waargeneem is vir die meeste slak spesies wat bestudeer is, word dit aanbeveel dat T. sarmaticus, O. sinensis, O. tigrina en B. rhodostoma bestuur word as 'n panmiktiese bevolking, en dat die streek wat Kaap Infanta en Port Elizabeth insluit geprioritiseer moet word vir bewaring. Oxystele variegata was die enigste spesie wat duidelike bevolking struktuur getoon het en in hierdie geval, moet spesie spesifieke bewaringspogings aangewend word.
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Makame, Makame Omar. "Vulnerability and adaptation of Zanzibar east coast communities to climate variability and change and other interacting stressors." Thesis, Rhodes University, 2014. http://hdl.handle.net/10962/d1011895.
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Climate variability and change as well as sea level rise poses significant challenges to livelihoods, water and food security in small island developing states (SIDSs) including the Zanzibar Islands. Thus, without planned strategic adaptation, the future projected changes in climate and sea level will intensify the vulnerability of these sensitive areas. This thesis is based on research conducted in two sites located in the north eastern parts of each island, namely Kiuyu Mbuyuni, Pemba Island and Matemwe, Unguja Island. The research focused firstly on assessing the vulnerability of these two coastal communities to climate variability and change and other stressors. This included investigation of (1) the perceptions of fishers, farmers and seaweed farmers regarding climate stressors and shocks and associated risks and impacts, (2) existing and possible future water and food security issues, and (3) household's access to important livelihood assets. This was followed by an exploration of the coping and adaptive responses of farmers, fishers and seaweed farmers to perceived shocks and stresses and some of the barriers to these responses. Lastly, an analysis of the implications of the findings for achieving sustainable coastal livelihoods and a resilient coastal community was undertaken. The general picture that emerges is that local people along the east coasts of both islands are already vulnerable to a wide range of stressors. Although variability in rainfall is not a new phenomenon in these areas, increasing frequency of dry spells and coastal floods resulting from the influence of El Niño and La Niña events exert enormous pressures on local activities (fishing, farming and seaweed farming) which are the crux of the local economy. The main argument of the study is that the nature and characteristics of these activities are the main source of sensitivity amongst these communities and this creates high levels of vulnerability to climate shocks and trends. This vulnerability is evidenced by the reoccurrence of localised food shortages and the observed food and water insecurity. The study found that food insecurity is a result of unreliable rainfall, drought and seasonality changes. These interacted with other contextual factors such as poor soil, low purchasing power and the lack of livelihood diversification options. In addition to exposure to these almost unavoidable risks from climate variability, the vulnerability of the local communities along the east coasts is also influenced by the low level of capital stocks and limited access to the assets that are important for coping and adaptation. Despite this, some households managed to overcome barriers and adapt in various ways both within the three main livelihood sectors (fishing, farming and seaweed farming) as well as through adopting options outside these sectors resulting in diversification of the livelihood portfolio. However, the study found that most of the strategies opted for by fishers, farmers and seaweed farmers were mainly spontaneous. Few planned adaptation measures supported by state authorities were observed across the sites, with the exception of the provision of motorised boats which were specifically meant to increase physical assets amongst fishers, reduce pressure in the marine conservation areas and prevent overfishing in-shore. Furthermore, numerous strategies that people adopted were discontinued when further barriers were encountered. Interestingly, some of the barriers that prevented households adapting were the same ones that forced households that had responded to abandon their adaptations. To increase resilience amongst east coast communities to current and future predicted changes in climate and sea level, the study argues that traditional livelihood activities (fishing, farming and seaweed farming) need to be better supported, and access to a range of livelihood assets improved. This may be achieved through increased access to local sources of water and facilitation of rainwater harvesting, expanding the livelihood options available to people and increasing climate change awareness, and access to sources of credit.
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de, la Vega Leinert Anne Cristina. "Flandrian coastal environmental changes : evidence from three sites in Mainland Orkney, Scotland." Thesis, Coventry University, 1998. http://curve.coventry.ac.uk/open/items/8e4ae838-181f-4a9d-9b99-48fd40dff69f/1.
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The Orcadian coastline is characterised by a high energy paraglacial environment, where remobilisation of abundant glacigenic sediment has favoured the building of numerous barriers. To date, there has been little work on either patterns of relative sea-level change or coastal processes affecting Orkney during the Flandrian. The present research provides an understanding of Flandrian coastal environmental changes in three areas of Mainland Orkney. Detailed morphological, lithostratigraphical and biostratigraphical work was undertaken and has revealed distinctive back-barrier sequences which illustrate the diversity of coastal responses to complex interactions between relative sea-level trends, sediment supply and coastal configuration. Scapa Bay provides direct evidence of relative sea-level rise and coastal retreat during the early Flandrian. There, a freshwater marsh was flooded by the sea c.8.5 kyrs BP at c.-5.4 m 0.0. Abundant sediment supply from nearby drift cliffs was remobilised inland by wave refraction before c.7 kyrs BP, and led to the formation and rapid progradation of swash-aligned barriers (SAB) across the valley mouth. By c.6.6 kyrs BP, direct marine influence was restricted in the back-barrier area, although saltmarshes persisted until c.5 kyrs BP. The enclosed lagoon was then progressively infilled by terrestrial sediments and a freshwater marsh was formed. The multiple barrier complex at Scapa Bay demonstrates land progradation against the backdrop of long-term rising relative sea level. This was facilitated by continuous sediment supply in a sheltered embayment. At the Bay of Carness, a single SAB was built during the early Flandrian. Between c.6.5 and 5.4 kyrs BP, marine influence was at its highest and a saltmarsh formed between c.-3.2 and -2.57 m 0.0. No direct marine flooding has, however, been recorded at the site. Later, a brackish lagoon occupied the coastal depression indicating a rising water table. This lagoon was gradually infilled by terrestrial sediments as soil erosion occurred in the the catchment. Slow inland migration of the SAB during the late Flandrian has been related to complex barrier and lagoon interactions in a context of sediment starvation. The sheltered setting of the site enabled the barrier to keep cohesiveness throughout its inland translocation. However, its present morphology shows clear signs of instability. The Bay of Skaill is the most exposed and dynamic coastal environment of the sites investigated. Abundant sand supply led to the building of a dune ridge during the middle Flandrian and to the pending of a freshwater loch in the back-dune area. By c.6.1 kyrs BP, aeolian processes became dominant and the dune ridge progressively migrated landward, while machair developed inland. After c.4.4 kyrs BP, the bay was gradually formed as the dune ridge retreated to its present position. Moreover, a SAB developed and eroded the seaward dune edge. At present, the SAB is migrating rapidly inland due to sediment starvation and exposure to storm activity. The Flandrian vegetational history around the three sites was also investigated. This accorded with that already established for the islands. Herbaceous vegetation was initially dominant, although a Betula-Corylus woodland, including Salix, Alnus and possibly Quercus, developed during the early Flandrian. This reached its maximum extent c.5 kyrs BP. Anthropogenic impact from Neolithic onwards is believed to have significantly affected the landscape studied, primarily via woodland clearance and mixed farming practices. Between c.4 and 2.5 kyrs BP, a combination of natural and anthropogenic factors led to the spreading of heathland and to a possible decline of anthropogenic activities.
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Chiba, Keita. "Relation Between Focal Mechanism Changes and Moment Release for the 2011 off Pacific Coast of Tohoku Earthquake." 京都大学 (Kyoto University), 2014. http://hdl.handle.net/2433/188493.
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Le, Roux F. G. "The lithostratigraphy of Cenozoic deposits along the south-east Cape coast as related to sea-level changes." Thesis, Stellenbosch : Stellenbosch University, 1989. http://hdl.handle.net/10019.1/67134.
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Thesis (MSc)--University of Stellenbosch, 1989.AFRIKAANSE OPSOMMING: Senosoiese sedimente langs die suidooskus van die Kaapprovinsie is periodiek deur verskeie outeurs vir meer as 'n eeu bestudeer. In hierdie aanbieding word die Iiteratuur saamgevat en vele dubbelsinnige stratigrafiese onderverdelings en definisies opgeklaar. Die Senosoiese afsettings kan volgens oorsprong geklassifiseer word as marien, eolies en fluviaal. Die mariene afsettings, synde strand-, nabystrand-, estuarien of lagunale afsettings geassosieerd met transgressiewe/ regressiewe kusIyne, word nou op grond van kenmerkende litologiese, paleontologiese sowel as ouderdomsverskille onderverdeel in die Paleogeen Bathurst, Neogeen Alexandria en Kwaternere Salnova Foraasies. Die Laat-Plioseen tot Vroeg-Pleistoseen Nanaga Formasie, Middel- tot Laat- Pleistoseen Nahoon Formasie en die Holoseen Schel• Hoek Formasie vorm die kus-eoliese afsettings. AI die mariene en marienverwante (eoliese} formasies, gekenmerk deur kalkige klastiese afsettings, is saamgegroepeer in 'n nuutgedefinieerde Algoa Groep. Fluviale afsettings word onderverdeel in die Martindale, Kinkelbos, Bluewater Bay, Kudus Kloof en Sunland Formasies. Die onderskeie afsettings word gekorreleer met verskillende seevlakstande deur geologiese tye. Die vroegste Senosoiese transgressiewe/regressiewe siklus het in die Vroeg-Paleoseen begin en die hoogste aangetekende elevasie vir die era bereik. Die Bathurst Formasie is waarskynlik gedurende hierdie regressie afgeset. 'n Tweed~ kleiner transgressie/ regressiesiklus het plaasgevind gedurende die Laat-Eoseen tot Vroeg-Oligoseen. Sover tans bekend, kan geen afsetting in die dagsoomgebied van die Algoa Groep definitief met hierdie siklus in verband gebring word nie. Die volgende siklus, wat 'n transgressiewe maksimum van c. 250 m bereik het, het begin in die Middel-Mioseen en verstryk in die Vroee Plioseen. Mariene planasie van die kusplatform het gedurende die transgressie plaasgevind terwyl die Alexandria Formasie wat tans bo 120 m geleë is, gedurende die regressie afgeset is. Die Vroeg-Plioseen transgressie het waarskynlik 'n maksimum huidige hoogte van c. 120 m bereik, waartydens o.a. die 120 m branderstoep en "Humansdorpterras" gekerf is. Die Alexandria Formasie tans geleë tussen 60 en 120 m, is afgeset gedurende die Laat-Plioseen regressie. Hierdie regressie het verskeie relatief lang stilstande, wat waarskynlik die 106-m, 90- tot 100-m en 84-m branderstoepe verklaar, ondervind. Selfs die 60-m en 52-m kuslyne kon tydens hierdie regressie gevorm het. Voorlopige paleontologiese getuienis dui egter daarop dat die 60-m kuslyn 'n transgressiewe maksimum van 'n daaropvolgende siklus verteenwoordig, gevolg deur 'n regressie met minstens een beduidende stilstand by 52 m. Die Alexandria Formasie geleë tussen c. 60 en 30 m, is waarskynlik gedurende hierdie regressie gedeponeer, waartydens ook die Bluewater Bay, Kinkelbos en Kudus Kloof Formasies afgeset is. Gedurende die Kwaternêre transgressie/regressiesiklusse, waarvan minstens vier aangedui word, is die Salnova Formasie (afwesig bo 30 m) afgeset. Die Nahoon Formasie, wat ook op groot skaal op die kontinentale bank ontwikkel is, is gedeponeer gedurende die laaste twee Pleistoseen glasiale toe seevlakke tot benede -100 m gedaal het. Die Schelm Hoek Formasie wat tans nog afgeset word, het ontstaan uit die transgressiewe maksimum van die Flandriese transgressie aan die begin van die Holoseen.
ENGLISH ABSTRACT: Cenozoic sediments along the south-east coast of the Cape Province have been studied intermittently for more than a century by various authors. In this presentation the literature is reviewed and many ambiguous stratigraphic subdivisions and definitions are clarified. The Cenozoic deposits can be classified, according to origin, as marine, aeolian and fluvial. The marine deposits, being lagoonal deposits either beach, nearshore, estuarine or associated with transgressive/regressive shorelines, are now subdivided on the grounds of distinct lithological, palaeontological as well as age differences into the Palaeogene Bathurst, Neogene Alexandria and Quaternary Salnova Formations. The Late Pliocene to Early Pleistocene Nanaga Formation, the Hiddle to Late Pleistocene Nahoon Formation and the Holocene Schelm Hoek Formation constitute the coastal and marine-related aeolian deposits. All the marine (aeolian) formations, which are characterised by calcareous clastics, have been grouped together in a newly defined Algoa Group. Fluvial deposits are subdivided into the Martindale, Kinkelbos, Bluewater Bay, Kudus Kloof and Sunland Formations. The various deposits are correlated with different stands of sea-level through geological time. The earliest Cenozoic transgression/regression cycle started in the Early Palaeocene and reached the highest recorded altitude for the era. The Bathurst Formation was probably deposited during this regression. A second lesser transgression/regression cycle occurred in the Late Eocene to Early Oligocene. As far as is presently known, no deposit in the outcrop area of the Algoa Group can be definitely related to this cycle. The next cycle, which reached a transgressive maximum of c. 250 m, started in the Middle Miocene and terminated in the Early Pliocene. Marine planation of the coastal platform took place during the transgression, whilst the Alexandria Formation presently situated above 120 m, was deposited during the regression. The Early Pliocene transgression is considered to have reached a maximum present-day elevation of c. 120 m, during which the 120 m marine bench and "Humansdorp Terrace", amongst others, were carved. The Alexandria Formation presently situated between 60 and 120 m, was deposited during the Late Pliocene regression, which experienced several relatively long stillstands which probably account for the 106 m, 90 t.o 100 m and 8.4 m benches. Even the 60 m- and 52 m-shorelines could have been formed during this regression. Preliminary palaeontological evidence, however, suggests that the 60 m shoreline represents a transgressive maximum of a subsequent cycle followed by a regression with at least one significant stillstand at 52 m. The Alexandria Formation situated between c. 60 and 30 m, was probably deposited during this regression, which also saw the deposition of the Bluewater Bay, Kinkelbos and Kudus Kloof Formations. During the Quaternary transgression/regression cycles, of which at least four are indicated, the Salnova Formation (absent above 30 m) was deposited. The Nahoon Formation, which is also extensively developed on the continental shelf, was deposited during the last two Pleistocene glacials, when sea-levels receded to less than -100 m. The Schelm Hoek Formation, which is still being deposited, originated from the transgressive maximum of the Flandrian transgression at the start of the Holocene.
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Kairis, Peter. "A spatially explicit relative elevation model for Padilla Bay, Washington /." Online access, 2008. http://content.wwu.edu/cdm4/document.php?CISOROOT=/theses&CISOPTR=280&REC=1.
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Aulinas, Silvia Batchelli. "Binding of iron and copper to humic-rich colloids in estuarine and coastal waters." Thesis, University of Aberdeen, 2010. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=165418.
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The main goal of this thesis was to develop a multi-technique approach to characterise high molecular weight (colloidal) dissolved organic matter (DOM) occurring in estuarine and coastal marine environments and to investigate how these bulk properties may relate to their ability to influence the physicochemical speciation of metals such as iron and copper. This characterisation was undertaken systematically on the pre-filtered (0.4 μm) estuarine or marine sample, referred to here as the ‘bulk’, as well as on the ultrafiltered (< 5 kDa) and colloidal (> 5 kDa) fractions. Three successive studies were carried out. The first one took place in the estuarine mixing zone of a high pH, low turbidity black water river (River Thurso) and the other two in the receiving coastal waters (Thurso Bay). The optical and size distribution properties of these waters were examined in detail in the first study while their iron and copper-binding properties were examined in the second and third studies, respectively. Size fractionation results showed that the proportion of colloidal to soluble organic carbon (DOC) tended to decrease from the upper estuary (~ 60%) to coastal waters (~ 20%). With respect to trace metals, similar trends were observed as one progressed from the mouth of the river towards the open sea. In relation to their molecular absorption, fluorescence and size fractionation properties, both River Thurso DOM and Nordic Reservoir NOM Reference Material presented the same characteristics and mixing behaviour, indicating the dominance of humic and fulvic substances in the Thurso river-ocean system. The river-borne, humic colloids underwent two types of transformations upon mixing with the seawater end-member. The first one was the coiling or contraction of individual macromolecules ―monomers― with increasing salinity. The second one was the concurrent aggregation of these small monomer units (d = 2 – 4 nm) to form entities that were still colloidal, i.e. smaller than 0.4 μm. As a result of extensive association of iron and copper with the colloidal and soluble fractions respectively, not only organic carbon but also iron and copper behave conservatively in the River Thurso estuary. Throughout the coastal region of freshwater influence (S = 29 - 35) colloidal iron accounted for 30 - 80% of total dissolved iron and was present as iron-humic complexes supplied by the river and showing a uniform stability constant (log KFe’HS’ = 11.3 0.1, i.e. log KFe3+ HS’ = 21.3 0.1). Soluble iron was found to be largely complexed to ligands of marine origin with log K’Fe’HS’ = 11.9 0.1, thus revealing for the first time a difference between the iron-binding strengths of colloidal and soluble ligands. Terrestrial colloidal iron was found to be entirely, if slowly (~ 10 hours), accessible to the added competing ligand 2-(2-thiazolylazo)-pcresol (TAC) used for the determination of K’Fe’HS’. Furthermore, iron appeared to play a role in holding these terrestrial colloids together. Evidence for this came from variations in humic fluorescence intensity over time in response to dissociation of the ironhumic colloidal associations induced by a chelating resin. These results are consistent with the concept that iron derived from a peat-draining river is strongly but reversibly bound to humic substances and remains so under marine conditions. In the same coastal region, two types of high-affinity ligands binding over 99.99% of total copper were detected. The stronger ligand (L1, log KCu2+L1’ = 15.5 - 16.1), of riverine origin, was present in very low concentrations of 1 - 4 nM that correlated with ―but systematically fell short of― total copper concentrations. Its conditional binding constant tended to increase with salinity, with most of the increase taking place in the near-field portion of the river plume. The weaker, more abundant ligand (L2, log KCu2+L2’ = 11.8 - 12.8) was present in total concentrations of 60 – 170 nM and had a controlling influence on the value of the labile (i.e. inorganic) copper concentration which ranged from 0.001 to 0.0001 nM. Both organic ligands were fairly evenly partitioned between soluble and colloidal phases but their sources appeared to differ significantly. Ligand L1 appeared to be of riverine origin (although one cannot exclude active microbial production, as opposed to passive release from peat) while ligand L2 distributions suggested in situ production within Thurso Bay.
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Baldwin, Jesse H. "Variability in beach topography and forcing along Oak Island, North Carolina." View electronic thesis, 2008. http://dl.uncw.edu/etd/2008-3/baldwinj/jessebaldwin.pdf.
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Cowart, Lisa Corbett D. Reide. "Analyzing estuarine shoreline change in coastal North Carolina." [Greenville, N.C.] : East Carolina University, 2009. http://hdl.handle.net/10342/1897.
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Thesis (M.S.)--East Carolina University, 2009.Presented to the faculty of the Department of Geological Sciences. Advisor: D. Reide Corbett. Title from PDF t.p. (viewed May 3, 2010). Includes bibliographical references.
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Wang, Yaoping. "Statistical Downscaling along the US Eastern Coast by Two Methods with Application on Intensity-Duration-Frequency curve Changes." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1417824178.
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Passalacqua, Walter Gino Angelo. "Changes in ENSO teleconnections under greenhouse-gas forcing implications for fisheries off the western coast of South America /." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p1463635.
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Thesis (M.S.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed June 16, 2009). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 70-80).
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Fehrenbacher, Fairlight Marie. "Predicting shoreline change due to nearshore dredging at Folly Island, South Carolina." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/21527.
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Rose, John W. "Impact of natural and artificial ebb channel position realignment on oceanfront shoreline change." View electronic thesis (PDF), 2009. http://dl.uncw.edu/etd/2009-3/r1/rosej/johnrose.pdf.
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Marsters, Teuvirihei Helene. "Beach stability on a tropical uplifted coral atoll : Niue Island : a thesis submitted to the Victoria University of Wellington in fulfilment of the requirements for the degree of Master of of Science (Hons) in Physical Geography /." ResearchArchive@Victoria e-Thesis, 2009. http://hdl.handle.net/10063/1216.
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Ivens-Duran, Morgan. "A spatial analysis of changes in recreational fishing pressure on the central coast of California subsequent to MPA implementation." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1303.
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Marine Protected Areas (MPAs) are implemented to address a variety of management concerns, including conservation and restoration of fisheries, but few studies assess how MPAs affect regional fishing patterns. Previous research suggests effort will intensify at MPA edges, but few datasets include sufficient pre-implementation data to quantify how MPAs alter fishing effort. We used recreational fisheries data collected by scientific observers aboard Commercial Passenger Fishing Vessels that target nearshore fish species, primarily rockfish. We assessed shifts in the spatial distribution of fishing effort over a 10-year period that includes pre- and post-implementation observations of the California MPA network along the Central Coast. We visually depict fine-scale annual fishing pressure, calculate total regional effort, and identify changing hot spots of fishing activity. While we found no evidence for “fishing the line”, MPA implementation was associated with changes in regional fishing patterns, including contraction of fishing effort away from the northern extent of the region and increased effort intensity in some pre-MPA fishing hotspots. Fishing effort redistribution should be considered in future management decisions regarding California’s MPA network.
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Charles, Sean Patrick. "Saltwater Intrusion and Vegetation Shifts Drive Changes in Carbon Storage in Coastal Wetlands." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3791.
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Coastal wetlands protect coastlines through efficient storage of organic carbon (OC) that decreases wetland vulnerability to sea level rise (SLR). Accelerated SLR is driving saltwater intrusion and altering vegetation communities and biogeochemical conditions in coastal wetlands with uncertain implications. We quantified changes in OC stocks and fluxes driven by 1) saltwater and phosphorous intrusion on freshwater and brackish marshes, 2) vegetation along an experimental saltmarsh to mangrove gradient, 3) saltwater intrusion and vegetation change across a marsh to mangrove ecotone, and 4) vegetation change and mangrove forest development along a marsh to mangrove ecotone. Increasing salinity in freshwater marshes decreased root biomass and soil elevation within one year. In brackish marshes, increased salinity decreased root productivity and biomass and increased root breakdown rate (k), while added salinity did not increase elevation loss. In our experimental marsh-mangrove ecotone, mangrove vegetation promoted higher organic carbon (OC) storage by increasing above and belowground biomass and reducing organic matter k. However, mangroves also increased belowground k, and decreased allochthonous marine subsidies, indicating the potential for OC storage trade-offs. In the Southeast Everglades, we identified strong interior-coastal gradients in soil stoichiometry and mangrove cover. Interior freshwater soil conditions increased k, while total soil OC stocks decreased toward the coast indicating that saltwater intrusion is driving large scale soil OC loss. In the southeast Everglades, mangrove expansion increased root biomass and root productivity, but did not mitigate the overall loss of OC stocks toward the coast. Similarly, in the southwest Everglades, saltwater intrusion drove a decrease in soil OC. However, mangrove encroachment drove a rapid recovery and increased OC stocks. Mangrove encroachment doubled aboveground biomass within the last ten years, increased it 30 times in the last 30 years, and doubled belowground biomass after 20 years. Our research shows that 1) moderate saltwater intrusion without mangrove encroachment will lead to a loss in OC stocks and potentially lead to wetland elevation loss and submergence, 2) in the absence of a change in saltwater intrusion, mangrove expansion can enhance OC storage 3) mangrove expansion can mitigate OC loss during saltwater intrusion, but this pattern depends on mangrove recruitment and ecosystem productivity.
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Dingerson, Lynne M. "Predicting Future Shoreline Condition Based on Land Use Trends, Logistic Regression, and Fuzzy Logic." W&M ScholarWorks, 2005. http://www.vims.edu/library/Theses/Dingerson05.pdf.
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Keck, Jennifer R. "Changes in Coral Populations on the Northwest Coast of Roatan, Honduras, Subsequent to the 1998 Coral Bleaching Event and Hurricane Mitch." NSUWorks, 2004. http://nsuworks.nova.edu/occ_stuetd/280.
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Long term monitoring of coral reefs on the northwest coast of Roatán, Honduras, has documented significant changes in coral cover over a seven-year period. Twenty photographic quadrats were permanently installed at approximately 12 m depth at each of three study sites located on the northwest coast of Roatán. Photographs were taken at six or twelve month intervals from 1996 through 2003. This observation period included a massive bleaching event which began in late-September of 1998, and Hurricane Mitch which struck in October of the same year. A measurement of projected surface area (PSA, cm2) was used to estimate total coral coverage. Changes in colony number, percent cover, species diversity and recruitment of all scleractinian corals were monitored within the quadrats. During the seven-year period, living coral cover decreased significantly from 30-34% to 17-20%. This represents net losses ranging between 32% and 50%. The greatest loss occurred in the year following the bleaching event and Hurricane Mitch and was largely due to the decline of the dominant reef building species Montastrea annularis, M. faveolata, and M. franksi. These three species accounted for 56% of total hard coral cover in 1996 and only 32% at the conclusion of the observation period. A sharp reduction in the total number of living colonies in the quadrats was observed with 217 of the 532 original colonies (41%) suffering complete mortality. While 117 coral recruits were identified during this period, recruitment mortality was high (40%) with only two cases of the massive frame building Montastrea species recruiting into the photostations. A combination of at least three factors have contributed to changes in the benthic community observed during this investigation: (1) the massive coral bleaching event in the fall of 1998 which disproportionately affected Montastrea spp.; (2) a category 5 hurricane; and (3) increased anthropogenic stress in the form of sedimentation and nutrient enrichment as the result of new and unregulated development.
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Cambazoglu, Mustafa Kemal. "Numerical modeling of cross-shore sediment transport and sandbar migration." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31744.
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Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2010.Committee Chair: Kevin A. Haas; Committee Member: Emanuele Di Lorenzo; Committee Member: Hermann M. Fritz; Committee Member: Paul A. Work; Committee Member: Terry W. Sturm. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Herbert, Roger J. H. "Testing hypotheses related to changes in abundance and distribution of warm-temperate invertebrates on rocky shores along the South coast of England." Thesis, University of Southampton, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342772.
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Morio, Olivier. "Compréhension des dynamiques morpho-sédimentaires cohésives et non- cohésives des littoraux de Bretagne Sud (France) à différentes échelles spatio- temporelles." Thesis, Lorient, 2017. http://www.theses.fr/2017LORIS479/document.
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À l'échelle du monde, les littoraux peuvent se diviser en différentes catégories : les côtes rocheuses, sableuses, vaseuses et mixtes. Cependant, les littoraux meubles sableux et vaseux sont retrouvés régulièrement mélangés sur différentes façades côtières mondiales. Des apports de vases temporaires ou permanents sont en effet observés sur des plages sableuses. Ces environnements mixtes atypiques, qui couplent alors les processus d’érosions, de transports et de dépôts associés à la fois aux sédiments cohésifs et non cohésifs, ont été peu étudiés. Afin d’identifier les forçages des variations morpho-dynamiques sur des environnements sableux et mixtes, quatre plages sablo-vaseuses ou entièrement sableuses de type Low-Tide-Terrace ont été suivies mensuellement sur deux années en baie et estuaire de la Vilaine (Bretagne Sud). Des suivis hydro-morpho-sédimentaires spécifiques à haute résolution et des suivis par photogrammétrie ont été menés ponctuellement sur ces sites. À l'échelle régionale, ce travail met en évidence le rôle de la morphologie initiale et l’héritage géologique régional dans la réponse morphologique du littoral de la baie de Vilaine aux conditions d’énergie extrêmes. La capacité de résilience à moyen-terme du littoral des plages de Bretagne Sud a été démontrée. Dans une approche plus spécifique, un comportement morphodynamique d'une plage sablo-vaseuse proche de celle d'une plage uniquement sableuse a été observé lors des phases de haute énergie. Les variations d’altitudes du platier vaseux et des modelés sédimentaires en ridges and runnels sont principalement contrôlées par l’énergie des vagues mais également par les propriétés physiques des sédiments et particulièrement celles liées à l'interaction entre le sable provenant de la section réflective et la vase de la section dissipative. La capacité d’érosion du platier vaseux par les vagues est potentiellement diminuée au niveau des interfaces des sédiments cohésifs et non-cohésifsAt the world scale, coastal areas can be divided in several categories: rocky, sandy, muddy and mixed coasts. However, these sedimentary coasts are regularly found mixed. Temporary or permanent mud inputs are observed on the sandy beaches. These atypical mixed environments, coupling erosional, transports and deposits processes associated to cohesive and non-cohesive sediments have been poorly studied. So, understanding theirs morphological and sedimentary dynamics and the identification of regional and local forcings driving them are essential. Four sandy-muddy or fully sandy Low-Tide-Terrace beaches from the bay and estuary of Vilaine (South-Brittany) have been monthly monitored over two years to characterize their morphodynamics beahaviors. Specific monitoring of coupled hydrodynamics and morpho- sedimentary surveys and photogrammetry experiments have been conducted on mixed sandy- muddy or full sandy beaches. At a regional scale, this work highlights the role of the initial morphology and regional geology inheritance on the morphological response of the littoral zones to extreme energy conditions. Despite some erosion patterns in local parts of beaches, particularly close to shore protection structures, the mid-term recovery capacity of the south-Brittany coastal area after extreme wave energy conditions have been proved. In a more specific approach, the works regarding the sandy- muddy beach dynamic show a morphodynamics behaviour close to that of a fully sandy beach during high energy event. The mudflat elevation changes and the dynamic of the ridges and runnels sedimentary patterns are mainly controlled by the incoming waves but also by the own physical properties of the sediment, particularly those induced by the interaction between the sand from the reflective section and the mudflat. A sand deposit between mud layers potentially decreases the wave erosion capacity on the mudflat
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Eriksson, Britas Klemens. "Long-term changes in macroalgal vegetation on the Swedish coast : An evaluation of eutrophication effects with special emphasis on increased organic sedimentation." Doctoral thesis, Uppsala University, Plant Ecology, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-2676.
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In this thesis I examine and evaluate the effects of a documented large-scale eutrophication on macroalgal vegetation on the Swedish coast. During the past century the load of nutrients has increased manifold in the Baltic Sea area, increasing primary production and organic sedimentation significantly. By re-investigating a unique reference material of macroalgal vegetation from the 1940-60s and by conducting new diving studies at the same sites, I showed that long-term trends in macroalgal community composition and species’ distributions are consistent with changes expected from an increased nutrient availability. In the Öregrund archipelago (northern Baltic Sea), I documented a declined depth distribution of the dominant canopy forming alga, Fucus vesiculosus, and an increased abundance of opportunistic ephemeral algae compared to 52-53 years ago. In the Gullmar Fjord area (Skagerrak), trends included increased abundances of functional groups with opportunistic algae, decreased abundances of large perennial algae and a general decline in the depth distribution of the vegetation compared to 36-57 years ago. Sediment removal experiments in the northern Baltic Sea confirmed the hypothesis that sedimentation influences macroalgal community composition. Species depending on short periods of reproduction were clearly favoured by sediment removal, especially F. vesiculosus that seemed limited in depth by the local sediment load. Species with long continuous periods of dispersal by spores and/or fragments (for example the ephemerals Cladophora glomerata, Ceramium tenuicorne and Enteromorpha spp.) were more tolerant to the natural sediment load. In general, sediment removal favoured macroalgal establishment and development, indicating that variation in the natural sediment load is an important constraint for sublittoral rocky-shore macroalgal community development. I conclude by suggesting that the documented long-term changes in macroalgal vegetation on the Swedish coast partly are explained by an increased organic sedimentation in these areas.