A technique to extract the shoreline from optical satellite images has been developed, evaluated and applied to the case study site of Progreso, Yucatán, México. This site was chosen as it is frequently subject to hurricanes, shows shoreline erosion and has a paucity of coastal data. The area under investigation is an 8 km length of shoreline that faces north into the Gulf of México. A novel method to extract satellite-derived shorelines (SDS) was developed ensuring the maximum contrast between sea and land. The SDS was validated using quasisimultaneous in situ shoreline measurements from one day in two different years (2008 and 2010). The in situ shoreline measurements recorded the instantaneous shorewards extent of the wave run-up when walking along the beach. The validation of SDS revealed that the SDS locates consistently seawards of the in situ shoreline, explained by: a) the water depth that an optical satellite image requires to identify a pixel either as sea or land, and b) the shorewards extent of the wave run-up. At Progreso, the overall distance between SDS and in situ shoreline is 5.6 m on average and standard deviation of 1.37 m (in the horizontal) over 8 km of shoreline. For an accurate location of the mean SDS, estimation of the shorewards extent of the wave run-up, tidal level and inter-tidal beach slope were required. In situ measurements regarding the beach profile, shoreline location and water levels were taken into consideration to achieve this. The shoreline change observed over a 6.5 year period allowed the estimation of intraannual and inter-annual shoreline changes and progressive changes in the shoreline location. The intra-annual shoreline change revealed seasonality in the shoreline position. The shoreline position from late winter (March 20, 2004) was landwards (approx. 5 to 9 m) in relation to the earlier winter shoreline position (November 11, 2003). The assessed SDSs from the hurricane season (June to November) are at the landwards envelope limit during the year, between -30 to 15 m in relation to the estimated mean SDS. The largest landward movement (100 m) is related to Hurricane Ivan, detected 13 days after the hurricane passed by Yucatán. The inter-annual shoreline change highlighted that an approximate length of 6 km of shoreline is retreating at a rate between -2.4 and -1.2 m per year. Such estimates of shoreline change would not be possible using other available coastal information at this site. The results of this research show that optical satellite images can be used to study shoreline change over large spatial scales (> 5 km), as well as in short (< 1 yr) and long (> 5 yrs) temporal scales.

Orientador: Milene Fornari / Resumo: Os cordões litorâneos da planície costeira da Jureia incluem-se entre os mais bem preservados alinhamentos de cordões do litoral sul do estado de São Paulo, porém, são pouco estudados sob os aspectos sedimentológico e estratigráfico. A meta deste estudo é reconstruir no tempo e espaço os eventos de formação dos alinhamentos de cordões litorâneos e feições associadas, inferindo possíveis controles exercidos pelo nível relativo do mar (NRM), clima e dinâmica sedimentar costeira. Através da análise de fotografias aéreas e imagens de satélite, foram reconhecidos quatro feixes de cordões litorâneos e quatro pontais recurvados. O feixe 1 é formado por cordões curvilíneos, enquanto que os feixes 2, 3 e 4 são constituídos por alinhamentos mais retilíneos e desenvolvem-se sincronicamente à formação de pontais recurvados. Estes, em planta, diferem-se por geometria côncava na forma de cordões recurvados, que mostram inversões cíclicas no padrão de transporte sedimentar por deriva litorânea, ora para NE e ora para SO. Em seção GPR observa-se que internamente, os feixes de cordões são formados por refletores com configuração sigmoide de amplitude alta a moderada, que estendem-se lateralmente por centenas de metros com mergulho suave para o mar. Esses refletores incluem fácies de areia média com estratificação cruzada acanalada sobreposta por fácies de areia média a fina com estratificação plano-paralela. Galerias de Ophiomorpha nodosa atribuídas ao crustáceo Callichirus major ocorrem ao l... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The strandplain in Jureia comprises the best preserved ridges in the southern São Paulo state. However, they have been poorly studied from the sedimentologic and stratigraphic aspect. This study aims to reconstruct the events of ridge alignments development of, in time and space, inferring possible controls related to relative sea level (RSL), climate and coastal sedimentary dynamics. The analysis of aerial photographs and satellite images enabled the identification of four ridge sets and four recurved spits. Ridge set 1 is composed by curved ridges in the inner portion of the coastal plain, while ridge sets 2, 3 and 4 comprise plan-parallel ridges which were developed synchronically to recurved spits. The spits are distinctive for the concave geometry, which shows cyclic inversions in the pattern of sedimentary transport through longitudinal drift currents, alternating the main direction between NE and SO. In GPR sections it can be observed that the ridges are internally formed by sigmoidal reflectors, with high to moderate amplitude, which extend for hundreds of meters with smooth seaward dip. These reflectors comprise sedimentary facies of cross stratified medium sand overlaid by plan-parallel medium and fine sand. Ophiomorpha nodosa burrows, attributed to the arthropod Callichirus major, are present throughout the layers but become rare towards the top. These deposits have been interpreted as shoreface facies association in gradual contact with the foreshore facies associ... (Complete abstract click electronic access below) / Mestre

Increasing human activities have brought about a global warming trend, and cause global sea level rise. Investigations of variations in coastal margins of Antarctica and in the glacial dynamics of the Antarctic Ice Sheet provide useful diagnostic information for understanding and predicting sea level changes. This research investigates the coastal dynamics of the Antarctic Ice Sheet in terms of changes in the coastal margin and ice flow velocities. The primary methods used in this research include image segmentation based coastline extraction and image matching based velocity derivation. The image segmentation based coastline extraction method uses a modified adaptive thresholding algorithm to derive a high-resolution, complete coastline of Antarctica from 2000 orthorectified SAR images at the continental scale. This new coastline is compared with the 1997 coastline also derived from orthorectified Radarsat SAR images, and the 1963 coastline derived from Argon Declassified Intelligence Satellite Photographs for change detection analysis of the ice margins. The analysis results indicate, in the past four decades, the Antarctic ice sheet experienced net retreat and its areal extent has been reduced significantly. Especially, the ice shelves and glaciers on the Antarctic Peninsula reveal a sustained retreating trend. In addition, the advance, retreat, and net change rates have been measured and inventoried for 200 ice shelves and glaciers. A multi-scale image matching algorithm is developed to track ice motion and to measure ice velocity for a number of sectors of the Antarctic coast based on 1997 and 2000 SAR image pairs. The results demonstrate that a multi-scale image matching algorithm is much more efficient and accurate compared with the conventional algorithm. The velocity measurements from the image matching method have been compared with those derived from InSAR techniques and those observed from conventional ground surveys during 1970-1971. The comparison reveals that the ice velocity in the front part of the Amery Ice Shelf has increased by about 50-200 m/a. The rates of ice calving and temporal variation of ice flow pattern have been also analyzed by integrating the ice margin change measurement with the ice flow velocity at the terminus of the outlet glacier.

The knowledge of the agents acting on coastal dynamics is very important for the management and the adequate use of the littoral zone. The ADCP is an instrument that was using successfuly since some years (decade of â80) for water current measurements in ocean and estuarine areas. In this work, the ADCP was aplicated in coastal areas (between Fortaleza and PecÃm) and two estaurine areas, in the Jaguaribe river (Cearà State) and Mamanguape river (ParaÃba State). In the metropolitan region of Fortaleza, the two current surveys made in two different periods, showed a flux directed to the beach in May 2005, and a flux parallel to the littoral in July 2005. In PecÃm currents measurements showed the protection effect of the harbour, where current speed was between 0,04 and 0,15 m/s, while offshore it was between 0,17 and 0,41 m/s. The ADCP use in estuarine zone, showed the estratification of Mamanguape river, and allowed a comparation between vertical current profile of salt wedge and well mixture estuaries.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Considerada a primeira capital do CearÃ, o MunicÃpio de Aquiraz, dotado de caracterÃstica Ãmpar, guarda em seu entorno um arcabouÃo histÃrico e cultural, possui belas praias, morfologias e importantes ecossistemas, dos quais se integram e resultam numa complexidade geoambiental, do qual faz parte costa leste do Estado do CearÃ, dista da capital em 24,7km e apresenta um litoral com 10,5 km representados pelas praias da Prainha, PresÃdio, Iguape e Barro Preto. AtraÃdos pela beleza deste espaÃo, provocou um crescimento repentino da populaÃÃo abastarda de Fortaleza ocupando setores do litoral sem a mÃnima infra-estrutura e suporte ambiental iniciado no fim da dÃcada de 1960. As casas de veraneio foram o ponto de partida na construÃÃo sobre as dunas, faixa de praia e margens dos recursos hÃdricos, seguidas por investimentos pÃblicos e privados ligados ao turismo na implementaÃÃo de estruturas de grande porte a nÃvel internacional. Desprovidos de compromisso para com o meio ambiente e desrespeito as comunidades tradicionais, apoiado pelo poder pÃblico, refletiram numa sÃrie de degradaÃÃes ambientais com alteraÃÃes na dinÃmica sedimentar costeira. Nessa perspectiva, a pesquisa se deu em compreender os processos morfodinÃmicos local de forma a permitir tendÃncias de erosÃo e/ou progradaÃÃo da linha de costa. O monitoramento promoveu a caracterizaÃÃo das variÃveis intrÃnsecas nos processos de suprimento e retirada dos sedimentos da faixa de praia. Associando as atividades humanas, foi realizado um levantamento do processo de ocupaÃÃo no litoral e dos aspectos socioeconÃmicos, bem como na aplicaÃÃo de questionÃrios as comunidades e turistas. Problemas como: poluiÃÃo das Ãguas, retirada da mata ciliar e do mangue, desmonte de dunas, compactaÃÃo da areia de praia, dÃficit sedimentar e avanÃo do mar, desvio do curso d Ãgua, invasÃo da areia sobre as casas e conflitos sociais, foram os impactos negativos encontrados na Ãrea mediante a falta de leis ambientais e uso irracional dos recursos naturais.Urge a adoÃÃo de medidas preventivas e corretivas que contemplem o ordenamento territorial e a elaboraÃÃo do plano de gestÃo costeira para o litoral leste de Aquiraz criando Ãreas de proteÃÃo aos ambientes de importÃncia ecolÃgica e vulnerÃveis à ocupaÃÃo visando à qualidade de vida e sobrevivÃncia das comunidades locais e dos que deles provirÃo. / Considered the first capital of CearÃ, the City of Aquiraz, with unique feature, saves a framework in their environment and cultural history, has beautiful beaches, morphologies and important ecosystems, which are integrated and result in environmental complexity, which is part east coast of Cearà State, located 24.7 kilometers from the capital in and presents with a 10.5 kilometers coastline represented by the beaches of Prainha, Presidio, Iguape and Barro Preto. Attracted by the beauty of this area, caused a sudden growth of the population of Fortaleza corrupt occupying the coastal areas without any infrastructure and environmental support starts at the end of the 1960s. The houses of summer were the starting point in building on the dunes, beach and range of margins of water bodies, followed by public and private investments related to tourism in the implementation o structures of large internationally. Lack of commitment to the environment and disrespect the traditional communities, supported by the public, reflected in a number of environmental damage with changes in coastal sediment dynamics. Accordingly, the research was to understand the local morphodynamic processes to enable trends of erosion and / or advanced line of coast. Tracking promoted the characterization of the variables inherent in the processes of sediment supply and removal of the strip of beach. Involving human activities, a survey was performed of the occupation on the coast and the socioeconomic aspects as well as the application of questionnaires communities and tourists. Problems such as water pollution, deforestation of riparian forest and mangrove, removal of sand dunes, the compaction of beach sand, sediment deficit and advance of the sea, diversion of water courses, the invasion of sand on the homes and social conflicts were negative impacts found in the area by the lack of environmental laws and irrational use of natural resources. It is urgent the adoption of preventive and corrective measures that address the planning and development of coastal management plan for the east coast of Aquiraz creating areas of protection of the environment and vulnerable ecological importance to the occupation to the quality of life and survival of local communities and they will come.

Changing environmental conditions often impose stressful growing conditions in plant communities. Until now, morphological plasticity, i.e. polymorphic growth physiognomies of plants, has not been sufficiently studied as a pivotal strategy for the whole ecosystem adaptation to environmental stress. We consider mangrove ecosystems as suitable models to provide insights on this subject. In the thesis, I investigate the ecological significance of tree morphological plasticity in the structural development and the dynamics of mangrove forests. I conducted field experiments in two regions located on both sides of the Amazon River mouths i.e. in French Guiana and North Brazil. Forest inventories were carried out in contrasting mangrove stands in both regions. The thesis combines empirical analysis of field data, terrestrial laser scanning (TLS), and mechanistic, individual-based computer simulations. We published results that proved the TLS-based analysis of individual tree structure useful for a better knowledge on biomass allocation between trunk and branches in tall and large Avicennia germinans mangrove trees reaching 45 m high and 125 cm of trunk diameter. Combining structural descriptions of A. germinans trees found in both sites, I highlighted the site-specific differences in tree allometries. The study suggests that regional differences in mangrove tree structure and function could be captured through better description of crown metrics, and that selected indicators of local morphological plasticity and consequent stand structure could generate a plus-value in the understanding of mangrove stand dynamics across contrasting coastal environments. Beyond the extension of allometric models to large Avicennia trees, we proposed new biomass equations with improved predictive power when crown metrics is taken into account. Additionally, we developed a novel software tool, named Lollymangrove, based on the AMAPStudio suite of software, with the objective of maximizing the potential of further field descriptions and modeling works. Lollymangrove allows standardized forest data capture, 3D visualization of structural data, aboveground biomass computations from a configurable module and export formats for forest dynamics and remote sensing models. Simulation experiments were conducted by means of the spatially explicit, individual-based stand model BETTINA_IBM. This model describes the important mechanism of water uptake limited by salt stress, and revealed insights into the relation between environmental conditions, allometric variations and biomass partitioning of mangrove trees, and stand characteristics. The simulation results suggest close matches with observed ecological patterns (e.g., tree allometries, mortality distributions, and self-thinning trajectories) under higher salinity. In low salinity conditions, however, the current parameterization underestimates the maximum tree height and diameter, and consequently, aboveground biomass and self-thinning trajectories of forest stands. This suggests that the morphology of trees under low levels of salinity are explained by further regulation mechanism(s) that still need to be addressed in a subsequent model improvement. Overall, this work has essentially pointed out the need to elucidate how morphological plasticity relates with structural development of forest stands. It establishes that TLS measurements and structural data analysis associated to efforts for integrative software and mechanistic modelling works could link mangrove dynamics to fast-changing coastal processes.

Made available in DSpace on 2015-05-14T12:17:00Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 6878309 bytes, checksum: 6058c39fd583a4322f9a05d01047b337 (MD5) Previous issue date: 2009-09-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The coastline of the municipality of João Pessoa (PB) extends for about 25 km, consisting of a succession of open bays and sandy spits cuspate foreland, these generally associated to the shelter of the rocky reefs (beach rocks) and / or seaweed / coral reefs. Similar to other coast regions of the globe, the coast of Paraíba shows processes of coastal erosion at various levels, resulting from a complex web that links natural and social elements. This research aims to comprehend and quantify the variations of coastal dynamic on the beaches of Seixas and Penha-PB, as well as, interference from the relation between society and nature in this environment, with reference to the process of urbanization and tourism in João Pessoa. The theoretical and conceptual basis is based on the systems theory, in the discussion of the relation of hostile reciprocity between society and nature, in order to understand the origins of environmental degradation, especially of coastal erosion on these beaches. The methodological procedures used for preparation of this work were: survey on specific literature and documents, stages of field and laboratory. The literature review focused on the search for and understanding of the concepts of nature, complexity and place. As well, we research the current concepts that permeate the literature inherent in Coastal Geomorphology, seeking dialogue with authors of Geography and related fields. The stages of field and laboratory were complementary, at this stage we monitor the vertical morphological variations of short-term (Beach Profile), from three points along these beaches, raised data related to the hydrodynamic (wave height, wave period, speed of coastal current, direction of the current drift, wind speed, temperature, and humidity), we collected sediment samples in three beach compartments (shoreface, foreshore and backshore) for then, in the laboratory, we carry out the analysis of sediments, finally, designed the characterization of the natural elements that influence coastal dynamics. The above-mentioned survey covered: geology, geomorphology, soils, vegetation, hydrography, and the elements of weather. With regard to social aspects, we discuss the process of urbanization in the coastal area of João Pessoa with emphasis on human settlements and its environmental impacts on the edge; we treat the tourist attraction rate on the beaches of Penha and Seixas through interviews and questionnaires conducted with tourists, travel agents and locals, which amounted a total of 65 questionnaires on the beach of Penha and 75 at beach of Seixas, where the main objective was to determine the origin of locomotion of this public and the elements which attract them to those beaches. The compiled data showed a erosive tendency for these beaches, where the uncontrolled urban occupation of the coastal zone and the tourism contribute to aggravate the problem, as the urban elements occupy areas belonging to coastal dynamics and do not comply with environmental laws. / O litoral do município de João Pessoa (PB) estende-se por aproximadamente 25 Km, constituído por uma sucessão de enseadas abertas e pontais arenosos (cúspides), geralmente associados ao abrigo dos recifes rochosos (beach rocks) e/ou recifes algálicos/coralíneos. Semelhante a outras regiões costeiras, o litoral paraibano apresenta processos de erosão costeira em vários níveis, decorrentes de uma teia complexa que articula elementos naturais e sociais. A presente pesquisa tem por objetivo compreender e quantificar as variações da dinâmica costeira nas praias da Penha e do Seixas-PB, bem como, as interferências resultantes da relação sociedade e natureza nessas praias, tomando como referência o processo de urbanização e o turismo em João Pessoa. A base teórico-conceitual fundamenta-se na teoria dos sistemas, na discussão da relação de reciprocidade hostil entre a sociedade e a natureza, a fim de compreender as origens da degradação ambiental, mormente da erosão costeira nas referidas praias. Os procedimentos metodológicos utilizados para elaboração do presente trabalho consistiram em: pesquisa bibliográfica e documental, etapas de campo e de laboratório. O levantamento bibliográfico enfocou a busca e compreensão dos conceitos de natureza, complexidade, e lugar. Além disso, pesquisamos os conceitos atuais que permeiam a literatura inerente a Geomorfologia Costeira, procurando dialogar com autores da Geografia e áreas afins. As etapas de campo e laboratório foram complementares. Nesta etapa monitoramos as variações morfológicas verticais de curto prazo (perfil praial) a partir de três pontos ao longo das referidas praias, levantamos dados relativos à hidrodinâmica (altura de onda, período de onda, velocidade da corrente litorânea, direção da corrente de deriva, velocidade dos ventos, temperatura, e umidade), coletamos amostras de sedimentos em três compartimentos praiais (antepraia, estirâncio e pós-praia) para depois, em laboratório, realizarmos a análise sedimentológica, por fim, elaboramos a caracterização dos elementos naturais que influenciam na dinâmica costeira. O referido levantamento abrangeu: geologia, geomorfologia, solos, vegetação, hidrografia, e os elementos do clima. No tocante aos aspectos sociais, abordamos o processo de urbanização na zona costeira de João Pessoa com ênfase para o incremento populacional e seus impactos ambientais na orla; tratamos do índice de atratibilidade turística na praia da Penha e do Seixas por meio de entrevistas e questionários realizados com turistas, agentes de turismo e moradores do lugar perfazendo um total de 65 questionários na praia da Penha e 75 na praia do Seixas. O objetivo precípuo foi averiguarmos a origem do deslocamento desse público e os elementos que o atraem para as referidas praias. Os dados compilados demonstraram uma tendência erosiva para as referidas praias, onde a ocupação urbana desordenada da zona costeira e o turismo contribuem para agravar o problema, na medida em que os elementos urbanos ocupam áreas que pertencem à dinâmica costeira e não respeitam as leis ambientais vigentes.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / The coastal plains are one of the most fragile ecosystems known, however, have the highest rate of use, occupation, urbanization and population density in the world. This fact demonstrates the need to require specific studies in this area so that your planning is done sustainably. Thus, the present thesis held in the coastal municipalities of Caucaia and Aquiraz, CearÃ, located in the metropolitan region of Fortaleza, aimed to analyze the socio-environmental dynamics of the coastal zone, assessing the levels of vulnerability to erosion of the site. The methodology was performed by monitoring the 12 points marked, in which they were made, field work with the realization of profiles transverse, measurements of height, period and direction of waves and sediment samples collected in the beach zone, dunes and frontal dunes to back morphoscopy and analysis granulometric, and survey data such as winds, rainfall, currents, temperature and tidal fluctuations. According to the results given that the coastal area studied had almost entirely, urbanization and occupation by tourist activities, and this in some specific environments have lower intensity due to unattractive and/or speculation has yet to be inserted so active on the beach. The evolution of the urban city of Caucaia occurred more intensely compared to the occupation of Aquiraz, even the latter has a history older than the first city, a fact proven by the characteristics social and economic. In the oceanographic aspects there was tidal amplitudes monthly maximum 3.1 minimum 2,3 m. In Caucaia the wave height ranged from 0,60 m to 2,10 m Aquiraz a variation of 1,5 m and 0,50 m wave predominance of type sea. The morphoscopy identified in dune environments and beach sediments matte and shiny, which demonstrate the existence of interaction between environments underwater and wind transport. As the modal states, the coast of Caucaia characterized by beaches with a tendency to intermediate stages, resulting in certain periods of the year in the reflective beach stages in Iparana and dissipative stages in Pacheco and IcaraÃ. Already in Aquiraz modal stages were also characterized by beaches tend to intermediate stages, only in getting internships reflective stages in Iguape. It was confirmed the retreat of the shoreline around the coastline studied based on the program DSAS 4.2, with rates ranging from -4,10 m/year to 0,35 m/year in Caucaia and -1,4 m/year to -0,25 m/year in Aquiraz. In view of the foregoing it was found that the coast of Caucaia showed average to high vulnerability to erosion taking place as a major problem in the forms of use and occupancy of interaction between environments of the coastal zone, while in Aquiraz was low to high along its entire length, with the most problematic areas of real estate speculation should be preserved. These implications may clarify why the erosion processes are more intense in coastal Caucaia in relation to coastal Aquiraz, mainly because of the position of the coastline, that is, how the elements studied oceanographic reached the coast, in the case, in coastal Caucaia these are much more intenseIt is concluded that, in comparative diagnosis of the two cities through the methodologies, the erosion indicators, the categories and morphodynamics that, the vulnerability to coastal together with conditions receding coast line and reduced sediment supply, is related mainly with the evolution of the occupation, the use and the forms of dynamic coastal area. / As planÃcies litorÃneas sÃo um dos ecossistemas mais frÃgeis conhecidos, que, no entanto, apresentam o maior Ãndice de uso, ocupaÃÃo, urbanizaÃÃo e densidade demogrÃfica em todo o mundo. Tal fato demonstra a necessidade dessa Ãrea requerer estudos especÃficos para que seu ordenamento seja feito de forma sustentÃvel. Dessa forma, a presente tese, realizada no litoral dos municÃpios de Caucaia e Aquiraz, CearÃ, localizados na regiÃo metropolitana de Fortaleza, teve como objetivo analisar a dinÃmica socioambiental da zona costeira, avaliando os Ãndices de vulnerabilidade à erosÃo do local. A metodologia foi realizada por meio do monitoramento de 12 pontos demarcados, nos quais foram feitos, trabalhos de campo com a realizaÃÃo de perfis transversais, mediÃÃes da altura, perÃodo e direÃÃo das ondas e coletas de amostras de sedimentos na faixa praial e campos de dunas mÃveis e frontais para posterior anÃlise granulomÃtrica e morfoscopia e levantamentos de dados como ventos, pluviometria, correntes, temperatura e oscilaÃÃes das marÃs. Nos resultados obtidos conferiu-se que, a zona costeira estudada apresentou em quase sua totalidade, ocupaÃÃo por urbanizaÃÃo e atividades turÃsticas, tendo esta em alguns pontos especÃficos menor intensidade devido possuir ambientes sem atrativos e/ou a especulaÃÃo imobiliÃria ainda nÃo ter se inserido de forma na praia. A evoluÃÃo urbana do municÃpio de Caucaia se deu de forma mais intensa se comparada à ocupaÃÃo de Aquiraz, mesmo esta Ãltima tendo um histÃrico mais antigo que a do primeiro municÃpio, fato comprovado pelas caracterÃsticas sociais e econÃmicas locais. Nos aspectos oceanogrÃficos verificou-se amplitudes de marÃs mensais com mÃximas de 3,1 m e mÃnimas de 2,3 m. Em Caucaia a altura da onda variou de 0,60 m a 2,10 m e em Aquiraz apresentou variaÃÃo de 1,5 m e 0,50 m e predominÃncia de ondas do tipo sea. A morfoscopia identificou nos ambientes dunares e praiais sedimentos foscos e brilhosos, o que constata a existÃncia da interaÃÃo entre ambientes de transportes eÃlicos e subaquÃticos. Conforme os estados modais, o litoral de Caucaia caracterizou-se com praias de tendÃncia a estÃgios intermediÃrios, obtendo em certos perÃodos do ano estÃgios reflexivos na praia de Iparana e estÃgios dissipativos nas praias de Pacheco e IcaraÃ. Jà em Aquiraz os estÃgios modais tambÃm caracterizaram-se por praias de tendÃncia a estÃgios intermediÃrios, obtendo estÃgios reflexivos apenas na praia do Iguape. Confirmou-se o recuo da linha de costa em todo o litoral analisado, com base no programa DSAS 4.2, com taxas entre -4,10 m/ano a 0,35 m/ano em Caucaia e de -1,4 a -0,25 em Aquiraz. Diante do que foi exposto constatou-se que o litoral de Caucaia apresentou vulnerabilidade mÃdia à alta à erosÃo tendo como problema maior no local as formas de uso e ocupaÃÃo dos ambientes de interaÃÃo entre a zona costeira, enquanto que em Aquiraz foi de baixa à alta em toda sua extensÃo, tendo como problemÃtica maior a especulaÃÃo imobiliÃria de Ãreas que deveriam ser preservadas. Tais implicaÃÃes podem esclarecer o porquà dos processos erosivos serem mais intensos no litoral de Caucaia em relaÃÃo ao litoral de Aquiraz, principalmente por causa da posiÃÃo da linha de costa, isto Ã, da forma como os elementos oceanogrÃficos chegam à costa estudada, no caso, no litoral de Caucaia estes sÃo bem mais intensos. Conclui-se que, no diagnÃstico comparativo dos dois municÃpios por meio das metodologias, dos indicadores erosivos e das categorizaÃÃes morfodinÃmicas que a vulnerabilidade costeira, em conjunto com as condiÃÃes de recuo da linha costa e a diminuiÃÃo do suprimento sedimentar, està relacionada, sobretudo, com a evoluÃÃo da ocupaÃÃo, das formas de uso e da dinÃmica costeira da Ãrea.

O objetivo deste estudo foi caracterizar a dinâmica das ondas de areia presentes no interior da Baía de São Marcos em São Luís, estado do Maranhão, utilizando dados de campanhas de batimetria bimestral e granulometria, para determinar a geomorfologia de fundo, além de séries temporais eulerianas de velocidade e variação da maré dos anos de 2011 e 2012 para validar um modelo hidrodinâmico local. O posicionamento horizontal e vertical nos conjuntos de dados batimétricos, digitalizados em transectos longitudinais, forneceu corredores de transporte que concordaram com os obtidos por meio do modelo numérico. Foram registradas ondas de areia com comprimento e altura superiores a 342 m e 6 m, respectivamente. A migração horizontal chegou a 1,8 m/dia e as intensidades de corrente a 1.84 m/s sobre o campo de ondas de areia e 2.58 m/s nos canais adjacentes. O Cabeço do Mearim e a Ilha do Medo são os principais responsáveis pela divisão dos regimes hidrodinâmicos locais forçados pela maré, os quais controlam os padrões morfológicos e migratórios das feições de fundo. Os mapas residuais de velocidade aliados aos coeficientes de dominância de maré calculados demonstraram que as principais forçantes do sistema são intensas nos canais e ao sul da Ilha do Medo e menos pronunciadas nas planícies rasas do sistema estuarino. As técnicas utilizadas neste estudo possibilitaram o estabelecimento de um modelo conceitual de corredores de transporte que rege o equilíbrio dinâmico do sistema local. Esses corredores são formados principalmente pelo canal principal da Baía de São Marcos localizado na porção oeste das feições submersas, predominando o transporte das correntes de vazante, pelo Canal do Boqueirão no qual predominam as correntes de maré enchente e pelo canal transversal situado a leste das ondas de areia, responsável por fluxos principalmente de maré enchente que podem transportar sedimentos ou energia para o sistema de canais principais. Este modelo forneceu conhecimento basal para o planejamento de atividades de uso, exploração e conservação dos sedimentos na Baía de São Marcos / The aim of this study was to characterize sand wave dynamics in São Marcos Bay (Maranhão state). Using data obtained from consecutive bathymetry campaigns, bottom sediment distribution, tide level and stationary current meters time series at this site from 2011-2012 years, bed morphology evolution was determined and a process-based hydrodynamic model was validated. Registering consecutive sand wave positioning in longitudinal transects provided bed features migration, generating transport pathways that agreed with model results. Sand waves observed were up to 6 m high and 342 m long and migrate up to 1.8 m/day, under depth-averaged current conditions up to 1.84 m/s above the sand wave field and 2.58 m/s in the adjacent channels. Cabeço do Mearim and Medo Island represents the features responsible for separate both tidal hydrodynamic regimes that control bottom migration and morphologic patterns. Residual current distribution and tide dominance coefficients showed that the controlling hydrodynamic forces of the system are more intense in the main channels and southward Medo Island, while weaken as depth reduces eastward. The methods used in this study provide a reliable conceptual model of transport pathways that control the local dynamic equilibrium, composed by the main channel of Sao Marcos Bay, where ebb dominance occurs, by the Boqueirão Channel strongly dominated by flood currents and by the transversal channel located eastward the bottom features, also flood dominated and responsible for transport sediment and energy to the sand wave field. This approach provided the bases for planning activities regard use, conservation and exploitation of sediments in São Marcos Bay

A deriva litorânea é estudada no litoral sul do Espírito Santo através de diferentes técnicas: distribuição de Minerais Pesados (MP); modelo conceitual Análise de Transport de Sedimento (Sediment Trend Analysis - STA), através da variação de parâmetros texturais do sedimento; dados de clima de onda entre 1997 e 2010 do modelo global WaveWatch III propagados para a zona costeira através do modelo Delft-3D, fornecendo parâmetros necessários para as equações de deriva; e imagens de satélite e fotografias aéreas para avaliar a variação espaço-temporal da morfologia costeira. O modelo STA mostrou-se confiável apenas nos dois setores ao norte, enquanto nos demais os resultados foram mascarados por altos teores de MP e/ou carbonato e a entrada de outras fácies no sistema; as equações representaram bem a variação da morfologia costeira na área de estudos. De maneira geral, os setores ao sul apresentaram transporte longitudinal para sul, e os setores ao norte, para norte, fato relacionado à batimetria local. A orientação da linha de costa auxiliou na compreensão dos fenômenos erosivos, pois em sua maioria estão orientados no sentido NEN, formando 45º com as ondas dos setores de ESE e SE. / Longshore drift is studied in the southern portion of Espírito Santo through different techniques: Heavy Minerals (HM) distribution; the conceptual model Sediment Trend Analysis (STA) by sediment textural parameters fluctuation; wave climate data between 1997 and 2010 from WaveWatch III propagated to the coastal zone through Delft-3D model, providing the required data for longshore drift equations; and satellite images and aerial photograph to survey time-space coastline variations. The STA model appears to be trustworthy only within the northern sectors, as high HM and/or carbonate content and different facies input into the system may mask the results. Broadly speaking, the southern sectors showed longshore transport southward, while northern sectors showed northward longshore transport, which is related to local bathymetry. Shoreline azimuth helped understanding the location of erosive zones, since most of them are turned NEN, 45o with ESE and SE wave sectors.