The present study utilizes a geographic information system (GIS) to examine the spatial relationships between the assemblages of major artifact and ecofact categories at the Late Ceramic Age (AD 400-1400) site of Grand Bay, Carriacou. In addition, the study examines how these assemblages formed through various cultural and natural formation processes and have been affected by recent episodes of coastal erosion. Previous archaeological research for this region of the Caribbean is lacking, but with the determined efforts of the Carriacou Archaeological Field Project, Grand Bay's role has been brought to the forefront of current investigations answering questions about pre-Columbian migration and colonization of the Lesser Antilles, inter-island exchange systems, maritime adaptations, and subsistence economies. With the rapid destruction of Grand Bay's archaeological resources through coastal erosion exacerbated by illegal sand mining, the site also has the potential to provide information on site management and preservation practices of coastal and island archaeological and historical sites that has created open and continuous discourse between archaeologists, lawmakers, landowners, and other key stakeholders. As Grand Bay is one of the most intensively occupied sites in the southern Lesser Antilles, its value to Caribbean archaeology is undeniable. Thus, its immediate study and preservation are imperative before what information can be gleaned from the site is lost forever. Using data gathered from four field seasons at Grand Bay and spatial autocorrelation and cluster analysis, the present study aims to identify spatial patterns within the distributions of major archaeological materials categories. These two forms of spatial analysis focus on identifying clusters and individual outliers within the assemblages that are then used to examine site formation processes, identify potential activity areas, and interpret the overall spatial organization and distribution of archaeological materials at Grand Bay. Analysis of Grand Bay's archaeological assemblage shows that three main material categories - ceramics, vertebrate remains, and shell - are, in general, spatially correlated and form the majority of the midden deposits at Grand Bay. Clustering of these materials shows that different areas of the site were used more intensively over time resulting in patterns of higher artifact concentration in these areas. The possible clustering of coral artifacts can likely be explained by the storage of this resource for use in tool manufacture. Areas of clustering and outliers among shell and vertebrate assemblages can be explained by differing excavation techniques and the effectiveness of wet-screening to recover smaller constituents vital to understanding Grand Bay's subsistence economies. Within the assemblages recovered in the habitation area at Grand Bay, clustering of the three main material categories may indicate the primary deposition of refuse or the spread of the midden deposits into this space. Further analysis of diagnostic ceramics is required to fully understand this clustering pattern. The separate cluster of stone artifacts may represent a lapidary and or tool manufacture activity area. Although some inconsistencies were revealed in the data, and a lack of data for deeper midden deposits did not allow for further analysis, overall this study provides evidence to support basic inferences about the formation of the midden deposits at Grand Bay through cultural processes and the effect coastal erosion has on these interpretations. A final purpose of the study is to demonstrate how spatial analysis of the data supports and/or refutes these interpretations. Results from the analyses in this study should not be viewed as definitive, but as a stepping stone for future research at Grand Bay.

The arctic region is undergoing the most rapid environmental change experienced on Earth, and the rate of change is expected to increase over the coming decades. Arctic coasts are particularly vulnerable because they lie at the interface between terrestrial systems dominated by permafrost and marine systems dominated by sea ice. An increased rise in sea level and degradation of sea-ice as predicted by the Intergovernmental Panel on Climate Change in its most recent report and as observed recently in the Arctic will likely result in greater rates of coastal retreat. An increase in coastal erosion would result in dramatic increases in the volume of sediment, organic carbon and contaminants to the Arctic Ocean. These in turn have the potential to create dramatic changes in the geochemistry and biodiversity of the nearshore zone and affect the Arctic Ocean carbon cycle. To calculate estimates of organic carbon input from coastal erosion to the Arctic Ocean, current methods rely on the length of the coastline in the form of non self-similar line datasets. This thesis however emphasizes that using shorelines drawn at different scales can induce changes in the amount of sediment released by 30% in some cases. It proposes a substitute method of computations of erosion based on areas instead of lengths (i.e. buffers instead of shoreline lengths) which can be easily implemented at the circum-Arctic scale. Using this method, variations in quantities of eroded sediment are, on average, 70% less affected by scale changes and are therefore a more reliable method of calculation. Current estimates of coastal erosion rates in the Arctic are scarce and long-term datasets are a handful, which complicates assessment and prognosis of coastal processes, in particular the occurrence of coastal hazards. This thesis aims at filling the gap by providing the first long-term dataset (1951-2006) of coastal erosion on the Bykovsky Peninsula, North-East Siberia. This study shows that the coastline, which is made of ice-rich permafrost, retreated at a mean annual rate of 0.59 m/yr between 1951and 2006. Rates were highly variable: 97.0 % of the rates observed were less than 2 m/yr and 81.6% were less than 1m/yr. However, no significant trend in erosion could be recorded despite the study of five temporal subperiods within 1951-2006. The juxtaposition of wind records could not help to explain erosion records either and this thesis emphasizes the local controls on erosion, in particular the cryostratigraphy, the proximity of the Peninsula to the Lena River Delta freshwater plume and the local topographical constraints on swell development. On ice-rich coastal stretches of the Artic, the interaction of coastal dynamics and permafrost leads to the occurrence of spectacular “C-shaped” depressions termed retrogressive thaw slumps which can reach lengths of up to 650 m. On Herschel Island and at King Point (Yukon Coastal Plain, northern Canada), topographical, sedimentological and biogeochemical surveys were conducted to investigate the present and past activity of these landforms. In particular, undisturbed tundra areas were compared with zones of former slump activity, now stabilized and re-vegetated. This thesis shows that stabilized areas are drier and less prone to plant growth than undisturbed areas and feature fundamentally different geotechnical properties. Radiocarbon dating and topographical surveys indicated until up to 300 BP a likely period of dramatic slump activity on Herschel Island, similar to the one currently observed, which led to the creation of these surfaces. This thesis hypothesizes the occurrence of a ~250 years cycle of slump activity on the Herschel Island shoreline based on the surveyed topography and cryostratigraphy and anticipates higher frequency of slump activity in the future. The variety of processes described in this thesis highlights the changing nature of the intensity and frequency of physical processes acting upon the arctic coast. It also challenges current perceptions of the threats to existing industry and community infrastructure in the Arctic. The increasing presence of humans on Artic coasts coupled with the expected development of shipping will drive an increase in economical and industrial activity on these coasts which remains to be addressed scientifically. / In der Arktis sind die derzeit stärksten Umweltänderungen weltweit zu beobachten, und es wird angenommen, dass sich deren Ausmaß sogar noch verstärken wird. Aufgrund ihrer Lage zwischen terrestrischen, von Permafrost geprägten Systemen und marinen, von Meereis geprägten Systemen, sind arktische Küstenregionen im Zuge dieses Wandels besonders sensibel. Ein verstärkter Meeresspiegelanstieg und der Rückgang des Meereises, wie vom letzten Bericht des Intergovernmental Panel on Climate Change (IPCC) vorhergesagt und in letzter Zeit in der Arktis beobachtet, werden zu erhöhten Küstenrückzugsraten führen. Ein Anstieg der Küstenerosion würde zu einer drastischen Erhöhung von Sedimentfracht, organischem Kohlenstoff und von Schadstoffen im Arktischen Ozean führen. Durch diese wiederum drohen dramatische Änderungen in der Geochemie und Biodiversität der küstennahen Zone sowie Veränderungen im Kohlenstoffkreislauf des Arktischen Ozeans. Modelle zur Berechnung des Eintrags organischen Kohlenstoffs in den Arktischen Ozean infolge von Küstenerosion basieren auf der Länge der Küstenlinie in Form von „non self-similar“ Datensätzen. Die vorliegende Arbeit zeigt jedoch, dass die Nutzung von Küstenlinien unterschiedlicher Maßstäbe Abweichungen in der berechneten Sedimentfracht von bis zu 30 % zur Folge haben kann. Es wird daher eine alternative Methode zur Berechnung von Erosionsraten vorgeschlagen, die auf Flächen, nicht auf Längenangaben basiert (z.B. Pufferzonen anstelle von Küstenlinien) und die auf einfache Art und Weise für die Zirkum-Arktis angewandt werden kann. Durch diese Methode ist die Variation der berechneten Erosionsmengen um durchschnittlich 70 % weniger von Maßstabsänderungen betroffen. Damit kann eine deutlich höhere Zuverlässigkeit in den Prognosen erreicht werden. Aktuelle Abschätzungen von Küstenerosionsraten in der Arktis sind spärlich und es gibt nur sehr wenige Langzeitdatensätze, so dass Einschätzungen und Prognosen zu Prozessen im Küstenbereich, insbesondere von dessen Gefährdung, schwierig sind. Die vorliegende Arbeit soll dazu beigetragen, diese Lücke zu schließen, indem der erste Langzeitdatensatz (1951-2006) zu Küstenerosionsraten auf der Bykovsky Halbinsel in Nordost-Sibirien bereitgestellt wird. Die Arbeit zeigt, dass die Küstenlinie auf der Bykovsky Halbinsel, die durch eisreichen Permafrost geprägt ist, im Zeitraum 1951-2006 um durchschnittlich 0,59 m pro Jahr zurückging. Die Rückzugsraten waren dabei äußerst variabel: 97 % aller ermittelten Raten betrugen weniger als 2 m und 81,6 % weniger als 1 m pro Jahr. Ein signifikanter Trend in den Erosionsraten konnte dabei jedoch trotz Analyse von fünf verschiedenen zeitlichen Epochen nicht festgestellt werden. Auch die Gegenüberstellung von Winddatensätzen kann die Erosionsraten nicht erklären. Deshalb stellt diese Arbeit die Bedeutung lokaler Kontrollmechanismen wie Kryostratigraphie, die Nähe der Bykovsky Halbinsel zum Lena-Delta und seinen Süßwasservorkommen sowie die lokale Topographie und deren Einfluss auf Wellengang und Wellenbildung heraus. Innerhalb eisreicher arktischer Küstenabschnitte führt die Interaktion zwischen Küstendynamik und Permafrost zur Ausprägung eindrucksvoller, „C-förmiger“ Depressionen, sogenannten regressiven auftaubedingten Rutschungen, die Längen von bis zu 650 m erreichen können. Auf Herschel Island und am King Point (Yukon Küste, Nordkanada) wurden topographische, sedimentologische und biogeochemische Aufnahmen durchgeführt, um die rezente und vergangene Dynamik dieser Landschaftsformen nachvollziehen zu können. Insbesondere wurden ungestörte Tundrenareale mit ehemals aktiven Rutschungszonen, die heute stabil und wiederbewachsen sind, verglichen. Die vorliegende Arbeit zeigt, dass diese ehemaligen, heute stabilisierten Rutschungszonen trockenere und für Pflanzenwachstum weniger geeignete Standorte darstellen als ungestörte Bereiche und überdies fundamental andere geotechnische Eigenschaften aufweisen. Radiocarbon-Datierungen und topographische Aufnahmen weisen darauf hin, dass es auf Herschel Island und am King Point bis vor 300 Jahren eine Periode ausgeprägter, auftaubedingter Rutschungsaktivitäten ähnlich denen, die derzeit auf der Insel beobachtet werden können, gegeben haben muss, die zur Ausbildung dieser Oberflächenstrukturen geführt haben. Diese Arbeit stellt auf Grundlage der untersuchten Topographie und Kryostratigraphie die Hypothese auf, dass an der Küstenlinie von Herschel Island ein etwa 250-jähriger Zyklus von Rutschungsaktivitäten existiert und antizipiert eine höhere Frequenz im Auftreten dieser Rutschungsaktivitäten für die Zukunft. Die Vielfalt an Faktoren, die in dieser Arbeit beschrieben wurden, hebt die veränderte Intensität und Frequenz der auf arktische Küsten einwirkenden physikalischen Prozesse hervor. Dadurch werden auch aktuelle Auffassungen zur Bedrohung bestehender Industrie und Infrastruktur in der Arktis hinterfragt. Im Zusammenhang mit dem erwarteten Ausbau der Schifffahrt treibt der zunehmende anthropogene Einfluss die ökonomische und industrielle Entwicklung in arktischen Küstenregionen an, die Gegenstand einer wissenschaftlichen Betrachtung sein sollten.

Galveston Island, Texas has been experiencing high rates of erosion in recent years, spawning an interest in developing complex beach management programs. However, before any effective management project can be implemented we must understand all of the processes that control the shoreface. It is only recently that scientists have begun to recognize the importance of the role that the geologic framework plays on the coastal evolution of the shoreline. In this region, it is the antecedent geology as well as the anthropogenic obstructions which are the key factors controlling the formation of the modern shoreface. This study defines the extents to which these antecedent and anthropogenic factors influence the shoreface as well as refines the geologic interpretations offshore of Galveston Island. Using sidescan sonar, CHIRP seismic sonar, multibeam bathymetry data and sediment cores, the shoreface and subsurface geology were modeled. It was determined that the thickness, extent and slope of the modern sediment in the nearshore environment is controlled by the topography of the Beaumont Clay, a consolidated clay deposited during the Pleistocene. Anthropogenic obstructions, including the Galveston Seawall, groin and jetty system, have changed the sediment transport patterns in the region and have created a system of erosion and accretion not only along the shoreline, but for the entire length of the shoreface.

Land subsidence and coastal erosion are worldwide problems, particularly in densely populated deltas. The Nile Delta is no exception. Currently, it is undergoing land subsidence and is simultaneously experiencing retreat of its coastline. The impacts of these long-term interrelated geomorphic problems are heightened by the economic, social and historical importance of the delta to Egypt. Unfortunately, the current measures of the rates of subsidence and coastal erosion in the delta are rough estimates at best. Sustainable development of the delta requires accurate and detailed spatial and temporal measures of subsidence and coastal retreat rates. Radar interferometry is a unique remote sensing approach that can be used to map topography with 1 m vertical accuracy and measure surface deformation with 1 mm level accuracy. Radar interferometry has been employed in this dissertation to measure urban subsidence and coastal change in the Nile Delta. Synthetic Aperture Radar (SAR) data of 5.66 cm wavelength acquired by the European Radar Satellites (ERS-1 and ERS- 2) spanning eight years (1993-2000) have been used in this investigation. The ERS data have been selected because the spatial and temporal coverage, as well as the short wavelength, are appropriate to measure the slow rate of subsidence in the delta. The ERS tandem coherence images are also appropriate for coastal change detection. The magnitude and pattern of subsidence are detected and measured using Permanent Scatterer interferometry. The measured rates of subsidence in greater Cairo, Mansura, and Mahala are 7, 9, and 5 mm yr-1, respectively. Areas of erosion and accretion in the eastern side of the delta are detected using the ERS tandem coherence and the ERS amplitude images. The average measured rates of erosion and accretion are -9.57 and +5.44 m yr-1, respectively. These measured rates pose an urgent need of regular monitoring of subsidence and coastline retreat in the delta. This study highlighted the feasibility of applying Permanent Scatterer interferometry in inappropriate environment for conventional SAR interferometry. The study addressed possibilities and limitations for successful use of SAR interferometry within the densely vegetated delta and introduced alternative strategies for further improvement of SAR interferometric measurements in the delta.

Coastal erosion, population decline, and economic deterioration, in the rural coastal community of Sydney Mines, Cape Breton, are concerns upon which the provincial government is focused. This thesis explores how ideas of permanence, adaptation, and sacrifice can engage the prevailing erosion of both the coastline and community, in terms of the physical cliff face, population, and economy. Articulating methods of responding to the various conditions of erosion enables an evolving and didactic architecture, which can become a catalyst to stimulate the economy and create stability for the town. Strategies of site placement, as well as technologies of geological formation, historic mining practices, and adaptation approaches, explored in this thesis, provide examples of how prototypical architecture and programmatic insertions can create a viable solution to erosion in this coastal town.

This thesis explores the geomorphic implications of large woody debris (LWD) residing in the backshore of beach-dune systems along the northeastern coasts of Haida Gwaii (Queen Charlotte Islands), British Columbia, Canada. Detailed topographic surveys were employed to quantify seasonal mass balance of the beach-dune systems along two distinctly different coastlines. Erosion and accretion potential models were applied to characterize sediment transport conditions. Holman’s (1986) R2% wave runup model was superimposed on total water levels, to model wave runup exceedence of the beach-dune junction elevation (6.5 m aCD). Modelled ‘erosion potential’ hours were demonstrated to correspond with observed erosion including removal of the LWD zone, resulting in decreased mass balance. Similarly, Fryberger and Dean’s (1979) Drift Potential model was used to model accretion potential hours. Modelled accretion potential hours were also able to effectively describe conditions when actual accretion occurred. The presence of LWD in the backshore offered two functions to the above processes: it acted effectively as an ‘accretion anchor’, promoting increased mass balance and rebuilding of the incipient foredune; and, it offered a mass of sediment fronting the foredune to protect the beach-dune system from storm wave attack and subsequent erosion.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Brazilian coast has come to be valued and transformed into a landscape of consumption from the combination of socioeconomic factors occurred mainly after the war. The use and occupation of land held in an unplanned way become the main human influences responsible for the dismantling of the morphological structures important in the maintenance and protection of coastal environments. This dissertation aimed to analyze the transformations of the landscape through the use and occupation of land between the years 1965 to 2003, and to identify changes in the beach Caueira by monitoring the morphodynamic beach profile and the line coast carried out between January 2010 and January 2011. The methodological procedures used in the study told with literature relevant to the subject of cartographic documents and data collection in the field. From the knowledge of the geo-environmental conditions and mapping of the processes use and land cover of Holocene coastal plain of the city of Itaporanga D Ajuda four different times, it was found many changes resulting from the combination of natural phenomena and / or anthropogenic interference contributing to transformation and evolution of the landscape over five decades. Through the monitoring system praial in five sectors of the coast for a year, it was possible to identify the morphodynamic beach stage, the occurrence of periods of erosion and sediment deposition and morphological features of these successful processes. These indicators were associated with natural climatic conditions and the degree of anthropogenic interference. The crossing of this information points to know more susceptible to destruction unleashed by the combination of natural and anthopogenic factors. / O litoral brasileiro passou a ser valorizado e transformado como paisagem de consumo a partir da combinação de fatores socioeconômicos ocorridos principalmente no pós-guerra. A apropriação da zona costeira de forma não planejada, transformou-se no principal fator responsável pelo desmonte das estruturas morfológicas importantes na manutenção e proteção dos ambientes costeiros. A presente dissertação teve como principal objetivo analisar as transformações da paisagem do litoral de Itaporanga D Ajuda a partir da ocupação e entre os anos de 1965 a 2004, além de verificar as mudanças ocorridas na praia da Caueira através do monitoramento da morfodinâmica do sistema praial e da linha de costa realizado entre os meses de janeiro de 2010 e 2011. Os procedimentos metodológicos utilizados na pesquisa contaram com o levantamento bibliográfico e documentos cartográficos, atividade de gabinete e levantamento de dados em campo. A partir do conhecimento sobre o comportamento do sistema praial e das intervenções humanas, bem como, dos condicionantes geoambientais e do mapeamento dos processos de uso e ocupação do solo na zona costeira do referido município, constatou-se inúmeras alterações resultantes da combinação de fenômenos naturais e/ou das interferências antrópicas que contribuíram para a caracterização da paisagem ao longo de cinco décadas. O cruzamento dessas informações permitiu conhecer os pontos mais susceptíveis a erosão e a frequência com que estes fenômenos ocorrem. O modelo de ocupação utilizado na zona costeira ratificou a degradação ambiental evidenciada ao longo de meio século. Diante dos resultados obtidos concluiu-se que a zona costeira e o litoral de Itaporanga D Ajuda, estão vulneráveis ao mau uso e aos propósitos da exploração e especulação imobiliária.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Brazilian coast has come to be valued and transformed into a landscape of consumption from the combination of socioeconomic factors occurred mainly after the war. The use and occupation of land held in an unplanned way become the main human influences responsible for the dismantling of the morphological structures important in the maintenance and protection of coastal environments. This dissertation aimed to analyze the transformations of the landscape through the use and occupation of land between the years 1965 to 2003, and to identify changes in the beach Caueira by monitoring the morphodynamic beach profile and the line coast carried out between January 2010 and January 2011. The methodological procedures used in the study told with literature relevant to the subject of cartographic documents and data collection in the field. From the knowledge of the geo-environmental conditions and mapping of the processes use and land cover of Holocene coastal plain of the city of Itaporanga D Ajuda four different times, it was found many changes resulting from the combination of natural phenomena and / or anthropogenic interference contributing to transformation and evolution of the landscape over five decades. Through the monitoring system praial in five sectors of the coast for a year, it was possible to identify the morphodynamic beach stage, the occurrence of periods of erosion and sediment deposition and morphological features of these successful processes. These indicators were associated with natural climatic conditions and the degree of anthropogenic interference. The crossing of this information points to know more susceptible to destruction unleashed by the combination of natural and anthopogenic factors. / O litoral brasileiro passou a ser valorizado e transformado como paisagem de consumo a partir da combinação de fatores socioeconômicos ocorridos principalmente no pós-guerra. A apropriação da zona costeira de forma não planejada, transformou-se no principal fator responsável pelo desmonte das estruturas morfológicas importantes na manutenção e proteção dos ambientes costeiros. A presente dissertação teve como principal objetivo analisar as transformações da paisagem do litoral de Itaporanga D Ajuda a partir da ocupação e entre os anos de 1965 a 2004, além de verificar as mudanças ocorridas na praia da Caueira através do monitoramento da morfodinâmica do sistema praial e da linha de costa realizado entre os meses de janeiro de 2010 e 2011. Os procedimentos metodológicos utilizados na pesquisa contaram com o levantamento bibliográfico e documentos cartográficos, atividade de gabinete e levantamento de dados em campo. A partir do conhecimento sobre o comportamento do sistema praial e das intervenções humanas, bem como, dos condicionantes geoambientais e do mapeamento dos processos de uso e ocupação do solo na zona costeira do referido município, constatou-se inúmeras alterações resultantes da combinação de fenômenos naturais e/ou das interferências antrópicas que contribuíram para a caracterização da paisagem ao longo de cinco décadas. O cruzamento dessas informações permitiu conhecer os pontos mais susceptíveis a erosão e a frequência com que estes fenômenos ocorrem. O modelo de ocupação utilizado na zona costeira ratificou a degradação ambiental evidenciada ao longo de meio século. Diante dos resultados obtidos concluiu-se que a zona costeira e o litoral de Itaporanga D Ajuda, estão vulneráveis ao mau uso e aos propósitos da exploração e especulação imobiliária.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A forma intensiva e desordenada com a qual as atividades antrÃpicas vÃm ocupando as regiÃes costeiras aliadas as crescentes alteraÃÃes advindas dos processos oriundos das mudanÃas climÃticas globais estÃo afetando a dinÃmica natural dos ecossistemas, conforme pode ser evidenciado atravÃs de diversos indicadores ambientais, sendo um dos principais a anÃlise da variabilidade temporal e espacial da linha de costa. Nas Ãltimas dÃcadas, pÃde ser evidenciado no litoral cearense um retrocesso generalizado da linha de costa, provocando prejuÃzos econÃmicos relevantes para a regiÃo por conta da destruiÃÃo de casas e estruturas em conseqÃÃncia desse fenÃmeno. Mediante esse fato, a adoÃÃo de estudos que visem determinar as taxas de recuo da linha de costa constituem uma ferramenta essencial para a correta tomada de decisÃes acerca do uso e gestÃo adequada da zona costeira. Partindo dessa premissa, o presente trabalho tem como objetivo calcular as taxas de recuo de linha de costa associando os resultados obtidos com os processos dinÃmicos pontuais, em uma anÃlise multitemporal utilizando imagens de sensoriamento remoto e fotografias aÃreas associadas a tÃcnicas de geoprocessamento. Para isso, foi utilizada a extensÃo Digital Shoreline Analysis System, para o software ArcGIS 9.0 que amplia as funcionalidades do programa, permitindo a automatizaÃÃo de grande parte das tarefas relacionadas com a anÃlise quantitativa da linha de costa, pressupondo como referÃncia uma linha de base. Foram tambÃm realizadas campanhas de campo a fim de obter registros fotogrÃficos das regiÃes que apresentaram atravÃs das anÃlises de gabinete elevados Ãndices de erosÃo. Os resultados evidenciam um forte carÃter erosivo em todas as regiÃes, apresentando Ãndices crÃticos para as praias da Caponga, Pacheco e Itarema onde foi constatada uma taxa de recuo mÃdio de linha de costa de -7.3 m/ano, -4 m/ano e -3.4 m/ano respectivamente. As demais regiÃes contempladas (IcaraÃ, Iracema, Iparana, Meireles) apresentaram taxas de recuo inferiores a -1.5 m/ano. Foi tambÃm analisada a variaÃÃo morfolÃgica na regiÃo da foz do rio Jaguaribe, onde foram evidenciados Ãndices de erosÃo na margem esquerda na ordem de -0.83 m/ano e deposiÃÃo na margem direita de +0.77 m/ano. A correlaÃÃo entre as taxas de recuo obtidas e a anÃlise dos parÃmetros ambientais dessas regiÃes demonstram que o comportamento espacial da linha de costa à diretamente afetado por uma junÃÃo de fatores ambientais, geolÃgicos e antrÃpicos. Desse modo, urge a necessidade de adoÃÃo de medidas sustentÃveis que visem o ordenamento da ocupaÃÃo das regiÃes litorÃneas no estado do Cearà com o intuito de mitigar os problemas oriundos da erosÃo costeira quanto ao uso indevido ou inadequado dessas Ãreas. / The intensive and disordered way as coastal regions are been occupied by antropic activities associated to increasing alterations generated by climatic changes, affecting the natural dynamics of ecosystems, made evident through several environmental indicators, among them the temporal and spatial variability analysis of the coastal line. During the last two decades was possible verify a general retrogadation of this coastal line, generating important economic damage to the regions by destructing houses and building. To study this problems and point out correct solutions e decisions to use and occupations of the littoral, it was necessary to know the rates of retreat of the coastal line through multi-temporal studies. From this point of view this study has as main objective calculate the coastal line retreat rates, associating the obtained results to the punctual dynamic processes in a multi-temporal analysis using satellite images and air photos in remote sensing and connected to geoprocessing. To this task, it was necessary to adapt the extension Digital Shoreline Analysis System â DSAS 3.2 to ArcMap 9.0. program to understand the evolution of coastal line during the last two decades. It was performed field trips to take notes and photos, in situ, about beaches erosion. The results show strong erosion in whole region, specially on Caponga, Pacheco and Itarema beaches, where the coastal line retreat rates were 7.3 m/y, 4 m/y and 3.4 m/y, respectively. The other places (IcaraÃ, Iracema, Iparana and Meireles), the rates were lower then 1.5 m/y. The estuary of Jaguaribe river was also studied, and the erosion index, on the left bank was 0.83 m/y, and deposition on the right bank 0.77 m/y. The correlation between the retreat rates obtained and the environment parameters analysis of these regions demonstrate that the coastal line spatial comportment is directly affected by a series of environmental factors, geologic and antropic. So, itâs necessary to adopt measures and proceedings that permit occupation in order of the coastal regions in Cearà State to mitigate the ocean action over continent.

O objetivo deste trabalho é avaliar as variações espaço-temporais da dinâmica morfo-sedimentar do sistema praial de Ilha Comprida-SP. Assim, para reconhecer os padrões de onda encontrados na região, resultados do modelo global de ondas WAVEWATCH III foram utilizados. Da mesma forma, levantamentos de campo periódicos foram realizados em cinco diferentes setores com obtenção de dados morfológicos e sedimentares. Simulações com o modelo numérico MIKE21 SW foram realizadas para reconhecer as tendências de transporte e distribuição de força de onda. Os resultados mostraram uma tendência geral de transporte para NE, com maiores valores para a região sul em relação a norte, com dois setores principais de divergência residual: centro-sul e norte. A divergência centro-sul apresenta um aumento e uma migração para sul nos meses mais energéticos, enquanto que a divergência norte apresenta uma manutenção espacial ao longo das estações. A distribuição de força de onda mostrou-se mais elevada nos setores centro-sul e norte, coincidindo com os pontos de divergência. Dados granulométricos mostraram baixa variabilidade temporal, mas possuem diferenças espaciais que refletem a hidrodinâmica local. Os dados volumétricos apresentam maiores valores médios nos setores centro-norte e menores no centro-sul e norte. De modo geral, os resultados mostram que ao longo de uma linha de costa exposta a um mesmo padrão de ondas, sua variabilidade é um reflexo de alterações hidrodinâmicas locais. Tais conclusões são importantes para o conhecimento do estado atual das praias e de sua evolução. / The aim of this study is to evaluate the spatial-time variations on the beach system of Ilha Comprida-SP. Therefore, the wave reanalysis database from the global wave generation model WAVEWATCH III was used to recognize the wave pattern for the region. Furthermore, periodic field works at five different sectors have been conducted to collect morphological and sedimentological data. The numerical model MIKE 21 SW has been applied to propagate waves onshore and recognize the transport tendency and the nearshore wave power distribution. Results show a transport trend to the NE, with the southern sector being larger than the northern sector in magnitude, with two main residual longshore drift divergence spots: in the central-southern and northern regions. Moreover, the central-southern divergence spot become larger and migrated to the south during the most energetic months, while the northern divergence spot kept its position throughout the year. Wave power results show two main areas with higher values that coincide with the observed longshore divergence spots. Sediment data presents low temporal variability, although spatial variations have been found reflecting the hydrodynamic conditions. The volumetric data shows largest values in the central-northern sector, being smaller in the central-southern and northern regions. In summary, the findings show that along this wide open stretch of coastline, exposed to the same offshore wave regime, its variability is a result of local hydrodynamic conditions. These results help in further understanding the island\'s long term evolution and current state of its beaches.