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The Assesment Of The Celestial Body Influence On The Geodetic Measurements / Dangaus kūnų įtakos geodeziniams matavimams vertinimasPopovas, Darius 12 January 2012 (has links)
The research work presents the carried out investigations on the effect of the celestial bodies on the gravity field elements and the analysis was made on the Moon’s and Sun’s effect on the geodetic measurements. The results of the research are advised to be implemented for the assessment of the effect of the celestial bodies regarding the geodetic, measurements as well as when selecting the surfaces of the Earth and geoid and the system of gravity.
The dissertation consists of introduction, four chapters and the summation of the results.
The introduction depicts the topicality of the chosen research, determining the relevance of the investigated issue. There are described the objective of the work as well as the tasks, there is revealed the scientific novelty of the work ant etc.
Chapter one deals with the review of the scientific literature. The chapter also presents the analysis of the available methods of the assessment of the Earth’s tides and their accuracies. The scientific literature was analysed extensively in terms of the effect of the celestial bodies on the Earth’s gravity field and on the issues of the geodetic measurements. The problems were indicated concerning the assessment of the effect of the celestial bodies and the tasks were specified for the research work to be investigated.
Chapter 2 deals with the theoretical research. The author presents the analysis of the effect of the members of the series of the tide potential caused by the celestial bodies on... [to full text] / Disertacijoje pateikti dangaus kūnų įtakos sunkio lauko elementams tyrimai ir nagrinėjamas Mėnulio ir Saulės poveikis geodeziniams matavimams. Pagrindinis disertacijos tikslas – ištirti ir įvertinti dangaus kūnų poveikį sunkio lauko elementams ir patobulinti dangaus kūnų poveikio geodeziniams matavimams įvertinimo metodikas.
Atlikto darbo rezultatus galima panaudoti vertinant dangaus kūnų poveikį geodeziniams, gravimetriniams ir geodezinės astronomijos matavimams, taip pat pasirenkant Žemės ir geoido paviršius bei sunkio sistemą, dangaus kūnų poveikio įvertinimo atžvilgiu.
Disertaciją sudaro įvadas, keturi skyriai ir rezultatų apibendrinimas.
Įvadiniame skyriuje pagrindžiama tiriamoji problema, apibrėžiamas problemos aktualumas, formuluojamas darbo tikslas bei uždaviniai, aprašomas mokslinis darbo naujumas, pateikiami ginamieji disertacijos teiginiai pristatomos autoriaus publikacijos ir pranešimai konferencijose, aprašoma disertacijos struktūra.
Pirmasis skyrius skirtas literatūros analizei. Jame nagrinėjami esami Žemės potvynių įvertinimo metodai ir jų tikslumas. Išanalizuota mokslinė literatūra dangaus kūnų poveikio Žemės sunkio laukui ir geodeziniams matavimams klausimais. Identifikuotos problemos dangaus kūnų poveikio vertinime ir suformuluoti uždaviniai, kuriuos disertaciniame darbe tikslinga išspręsti.
Antrajame disertacijos skyriuje pateiktas teorinis tyrimas. Nagrinėjamas dangaus kūno lemiamo potvynio potencialo eilutės narių poveikis sunkio lauko elementams:... [toliau žr. visą tekstą]
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Sedimentological and ichnological characteristics of Dur At Tallah siliciclastic rock sequence, and their significance in the depositional environment interpretation of tidal-fluvial system (Upper Eocene, Sirt Basin, Libya)Abouessa, Ashour 19 December 2013 (has links) (PDF)
Dur At Talah sedimentary sequence, located at the southern side of the Sirt Basin in central Libya, is composed of 150 m thick of mainly siliciclastic rocks. The importance of this sequence is linked to the importance of the Sirt Basin as one of large hydrocarbon reservoirs in Libya. The sequence is also an excellent site for vertebrate fossils of Late Eocene, the age of the sequence. Previous studies, though very limited compared to the importance of this area, are focused on its paleontological content. Sedimentology received only scant attention before this project. This thesis is an outcrop based study in which the focus is given to the sedimentary and biogenic (trace fossils) structures, aiming at defining and interpreting depositional facies which building up the sequence. The study is mainly based on field data which are analyzed on the light of related published literature and on the comparison with modern sedimentary environments. Results of facies analysis have led to splitting the entire sequence into three genetically related intervals. The oldest, we called the New Idam Unit (around 80m), is composed of very fine sandstones to mudstones. New Idam Unit is unconformably overlain by the Sarir Unit (around 50m), composed of medium grained cross bedded sandstones (the lower 25-30 m) changes up to very coarse and microconglomeratic sandstone (the upper 20-30 m). Thus, the Sarir Unit is split into the lower Sarir Subunit and upper Sarir subunit. The New Idam Unit presents both classical and unusual sedimentary and biogenic indicators that attribute this unit to estuarine depositional environment. It starts with outer estuarine (the lower 35 m) and ends up with inner estuarine (the upper 45 m). Maximum flooding surface is located in between. Above this surface the fluvial indicators increase and tidal indicators decrease, thus providing clue for basinward (North) migration of the shoreline. The lower Sarir subunit which was previously interpreted as fluvial deposits, preserves multi-scale sedimentary structures that undoubtedly belong to tidal processes. This is especially evidenced at the lower part of the lower Sarir Subunit (LLS). Fluvial indications over dominates the tidal ones in the upper part of the lower Sarir (ULS). Due to this configuration the whole lower Sarir subunit is interpreted as shallow marine, deltaic, depositional system, occurred during sea level ¨normal¨ regression. This time, maximum flooding surface is located between the LLS and ULS. The lower Sarir subunit is terminated by subaerial unconformity, with evidences of subaerial exposure preserved at the top of the ULS. These are intruded by the upper Sarir subunit which presents clear evidences of strictly fluvial environment of deposition. The deposits of the upper Sarir subunit record the low stand system tract part of the Dur At Talah sequence. In addition to the outlined results, the sequential pattern of the depositional events is suggested for the entire sequence of Dur At Talah. This study provides a valuable information regarding the depositional and sequential aspects of the Sirt Basin during the late Eocene, it also provide an unique case study for the better understanding of the shallow marine tidal deposits.
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Integration of wave and tidal power into the Haida Gwaii electrical gridBoronowski, Susan M. 31 August 2009 (has links)
Rising energy demand, fossil fuel costs, and greenhouse gas emissions have led to a growing interest in renewable energy integration. Remote communities, often accompanied by high energy costs and abundant renewable energy resources, are ideal cases for renewable energy integration. The Queen Charlotte Islands, also known as Haida Gwaii, are a remote archipelago off the northwest coast of British Columbia, Canada that relies heavily on diesel fuel for energy generation. An investigation is done into the potential for electricity generation using both tidal stream and wave energy in Haida Gwaii. A mixed integer optimization network model is developed in a Matlab and GAMS software environment, subject to set of system constraints including minimum operational levels and transmission capacities. The unit commitment and economic dispatch decisions are dynamically solved for four periods of 336 hours, representing the four annual seasons. Optimization results are used to develop an operational strategy simulation model, indicative of realistic operator behaviour. Results from both models find that the tidal stream energy resource in Haida Gwaii has a larger potential to reduce energy costs than wave energy; however, tidal steam energy is more difficult to integrate from a system operation point of view and, in the absence of storage, would only be practical at power penetration levels less than 20%.
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Eco-sedimentological environments of an inter-tidal reef platform, Warraber Island, Torres StraitHart, Deirdre E., Physical, Environmental & Mathematical Sciences, Australian Defence Force Academy, UNSW January 2003 (has links)
This thesis examines functional relationships between the morphologic, hydrodynamic, ecological and sedimentological characteristics of the Warraber reef platform, an inter-tidal reef island system, Central Torres Strait, Australia (10[degrees] 12??? S, 142 [degrees] 49??? E). Hydrodynamic and sediment-transport experiments were conducted on the reef flat using current meters, water level recorders and directional sediment traps. Results showed dominantly SE flows during the dry season and more variable NW to SE flows during the wet season. Topography and reefal water levels modulated the direction and strength of currents and the generation of wind-waves on the reef flat as well as the passage of waves over the reef rim. These hydrodynamic conditions are sufficient to induce significant transport of moderately fast to slow settling sediment (>-5.25 symbol psi) on the reef flat, though the platform as a whole is a relatively closed transport system. Carbonate production was estimated based on the key ecological variables of live assemblage distribution and cover. Overall, only 24% of the reef flat was occupied by carbonate-producing organisms. The average estimated carbonate-production rate for the reef was 1.6 kgm -2y-1 (0.07-4.37 kgm-2y-1). Production is dominated by coral (73%), with subordinate proportions contributed by coralline algae (19%). And molluscs, foraminifera and Halimeda (<4%) though actual reef-flat sediments did not reflect this potential. Instead, they were dominated by molluscs (35-55%), coralline algae (16-26%), coral (8-13%), Halimeda (7-8%) and foraminifera (5-10%). Differential rates of carbonate to sediment conversion meant the reef-platform sediments were more closely related to the cover of live organisms than to the contribution of carbonate production by each parent organism. The settling properties of the least altered particles of the five commonest constituents were measured and these provided the basis for an eco-sedimentological model of the reef-platform system. Modelled textures were compared to the actual textures, indicating the degree of textural alteration resulting from a combination of biological and physical processes, including sediment production, hydraulic sorting and mechanical breakdown. This analysis, integrated with the hydrodynamic, exposure and other data, was used to determine reef-platform surface-sediment sources, sinks and transport pathways. In using both the textual and constituent compositional properties of sediments, as well as information on local biological and physical processes, the model approach developed offers progress towards an integrative, interdisciplinary analysis of carbonate environments.
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Évolution morphologique actuelle d'une flèche littorale holocène : le Cap Ferret, à l'embouchure du Bassin d'Arcachon / Ongoing morphological evolution of a Holocene coastal barrier spit : the Cap Ferret, at the entrance of the Bay of ArcachonNahon, Alphonse 05 October 2018 (has links)
La flèche littorale du Cap Ferret s'est édifiée au cours des derniers 3 000 ans, à la faveur du ralentissement de l'élévation du niveau global des océans. Depuis 250 ans, les cartes marines révèlent une importante instabilité de l'extrémité libre de la flèche, à laquelle les travaux présentés dans ce mémoire tentent d'apporter une explication physique. Dans un premier temps le croisement des données cartographiques avec des données environnementales révèle la synchronisation des déplacements de la flèche avec d'une part l'Oscillation Nord Atlantique (NAO), et, d'autre part, les structuations décennales à multidécennales de la vitesse de l'élévation du niveau de l'Atlantique Nord-est. Les processus sous-jacents à cette synchronisation sont alors détaillés avec un modèle numérique de transport sédimentaire. Puis, l'érosion chronique de la flèche entre 1986 et 2016, ainsi que les mécanismes d'évolution de la plage océanique de la Pointe du Cap Ferret sont décrits et quantifiés à l'aide de données topographiques. A l'échelle locale, ces résultats apportent des preuves tangibles du rôle du climat dans l'érosion actuelle de la Pointe du Cap Ferret. D'un point de vue plus général, ces travaux contribuent à la meilleure description des processus contrôlant l'évolution des systèmes de barrières holocènes, dans le contexte actuel d'accélération de l'élévation du niveau de la mer. / Low rates of global sea level rise have allowed the Cap Ferret coastal barrier-spit to develop since about 3 000 years ago. Over the last 250 years, navigation charts attest of a significant instability of the distal end of the spit, to which the present study aims to provide a physical explanation. First, the crossing of cartographic data with meteoceanic data reveals a strong relationship of the spit-end behaviour with, on the one hand, the North Atlantic Oscillation (NAO), and, on the other hand, decadal to multidecadal variations in the rate of sea level rise in the Northeast Atlantic. Underlying processes were then investigated using a numerical model for sediment transport. Finally, the chronic erosion of the spit between 1986 and 2016, as well as the evolution mechanisms of the oceanic beach of the spit-end are described and quantified by means of topographic data. Locally, these results support the role of climate in the ongoing erosion of the spit-end. From a wider perspective, this study brings new insigths on the processes controling the evolution of Holocene barrier systems, in the present context of an accelerating sea level rise.
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Modelování globálních barotropních oceánských slapů v časové oblasti / Time-domain modelling of global barotropic ocean tidesEinšpigel, David January 2017 (has links)
Traditionally, ocean tides have been modelled in frequency domain with forcing of selected tidal constituents. It is a natural approach, however, non-linearities of ocean dynamics are implicitly neglected. An alternative approach is time-domain modelling with forcing given by the full lunisolar potential, i.e., all tidal constituents are included. This approach has been applied in several ocean tide models, however, a few challenging tasks still remain to solve, for example, the assimilation of satellite altimetry data. In this thesis, we present DEBOT, a global and time-domain barotropic ocean tide model with the full lunisolar forcing. DEBOT has been developed "from scratch". The model is based on the shallow water equations which are newly derived in geographical (spherical) coordinates. The derivation includes the boundary conditions and the Reynolds tensor in a physically consistent form. The numerical model employs finite differences in space and a generalized forward-backward scheme in time. The validity of the code is demonstrated by the tests based on integral invariants. DEBOT has two modes for ocean tide modelling: DEBOT-h, a purely hydrodynamical mode, and DEBOT-a, an assimilative mode. We introduce the assimilative scheme applicable in a time-domain model, which is an alternative to existing...
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Componentes estruturais abiótico e biótico e caracterização do grau de trofia de gamboas do litoral sul do Paraná, Brasil.Siqueira, Adriana 02 June 2006 (has links)
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Previous issue date: 2006-06-02 / Universidade Federal de Sao Carlos / Studies related to the quality of the water in coastal environments as bays, estuaries and
tidal creeks are important due to the high productivity and intense influence of anthropic
activities in these areas. This study aims the physical, chemical and microbiological
characterization of diverse tidal creeks along Paraná coast. We analized seasonal
variations in four tidal creeks and differences among rainy and dry periods in two tidal
creeks. The cellular density of the pico, nano and microplanktonic fractions in different
trophic conditions, differentiating the auto and heterotrofic compartments were
performed. The temperature, salinity, pH, alkalinity, CO2, dissolved oxygen, nitrite,
nitrate, ammonium, phosphate, silicate, suspended matter, particulate organic and humic
matter, total chlorophyll, total coliforms and Escherichia coli were analyzed. The pico-
and the nanoplankton were analyzed by direct counting under epifluorescence
microscopy, while the microphytoplankton and the protozooplankton were through the
Utermöhl method. In relation to the physico-chemical and biological characteristics the
Perequê tidal creek exhibited larger saline intrusion, and in the Olho d´Água tidal creek
was detected great amount of discharged domestic effluents. Among the pico- and
nanoplanktonic fractions prevailed the heterotrophic compartment, in both phases. On
the other hand, the abundance of the phytoplankton prevailed under the
protozooplankton in the microplanktonic fraction along the whole study. Differences
between dry and rainy periods were confirmed. In the rainy period was observed in the
two tidal creeks an increase in nitrite, suspended matter, organic particulate matter and
picoplankton and a reduction of nitrate, chlorophyll, nanoplankton (auto- and
heterotrophic) and of the autotrophic microplankton. Increase of phosphate, ammonium
and humic substances were only observed in Barranco tidal creek and of dissolved
oxygen and E. coli in Olho d´Água. These results show that in periods of high
pluviosity elevated amounts of nutrients are exported by the tidal creeks to the adjacent
internal continental shelf. It was not possible to define a pattern for none of the variables
in relation to the tide and to the day and night periods. / xi
Estudos relacionados com a qualidade da água em ambientes costeiros como baías,
estuários e gamboas são importantes por serem regiões de alta produtividade e
influenciadas por atividades antrópicas. Neste estudo foram avaliadas variáveis físicoquímicas
e biológicas em diversas gamboas ao longo da costa do Estado do Paraná.
Foram analisadas variações sazonais em quatro gamboas e diferenças entre períodos
secos e de alta pluviosidade em duas das gamboas. A densidade celular das frações pico,
nano e microplanctônicas, em diferentes condições tróficas e diferenciando os
compartimentos auto e heterotróficos, foi avaliada. Foi realizada a análise de
temperatura, salinidade, pH, alcalinidade, dióxido de carbono, oxigênio dissolvido,
nitrito, nitrato, amônio, fosfato, silicato, material particulado em suspensão, matéria
orgânica particulada, substâncias húmicas, clorofila total, coliformes totais e de
Escherichia coli. O pico e o nanoplâncton foram analisados por contagem direta em
epifluorescência, enquanto que o microfitoplâncton e o protozooplâncton foram
determinados pelo método de Utermöhl. Em relação às características fisico-químicas e
biológicas, foi detectada uma maior intrusão salina na Gamboa Perequê e a Gamboa
Olho d´Água se diferenciou por causa da grande quantidade de efluentes domésticos
que recebe. Entre as frações pico e nanoplanctônicas predominou o compartimento
heterotrófico, em ambas as fases. Prevaleceu à abundância do fitoplâncton sob o
protozooplâncton na fração microplânctonica ao longo de todo o estudo. No estudo
sazonal confirmaram-se as diferenças entre os períodos seco e chuvoso. No período
chuvoso foi observado aumento de nitrito, material particulado em suspensão, matéria
orgânica particulada e picoplâncton e redução de nitrato, clorofila, nanoplâncton (auto e
heterotrófico) e do microplâncton autotrófico nas duas gamboas. Foram observados
aumento de fosfato, amônio e substâncias húmicas na Gamboa Barranco e de oxigênio
dissolvido e E. coli na Gamboa Olho d´Água. Estes resultados mostram que em
períodos de alta pluviosidade são exportadas pelas gamboas quantidades mais elevadas
de nutrientes para a plataforma continental interna adjacente. Em relação à maré e aos
períodos diurno e noturno, não foi possível definir um padrão para as diferentes
variáveis analisadas.
Palavas-chave: gamboa, picoplâncton, nanoplâncton, fitoplâncton, protozooplâncton,
maré, estado trófico.
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Estudo de relaÃÃes ecolÃgicas em planÃcies hipersalinas (apicum) do estado do Cearà / Ecologica relations in hypersaline tidal flats (apicum): a study based in Cearà state estuariesRaiana Lira Cabral 14 December 2015 (has links)
CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This study investigates ecological process and dynamic of the hypersaline tidal flats (HTF, locally knowns as âapicumâ). The HTF systems are characterized by flat landscape and hypersaline soil conditions that may occour in arid and semiarid regions of the world. Usually HTF can be found inside mangrove forest or as a transitional system between mangrove and dry land ecosystem. These areas are highly important for advances of mangrove forest in case of sea level increase. Besides, HTF have great economic value, as prioritarian areas to install aquaculture or saline ponds. Also it represents security zones for traditional populations, as artisanal fishermen. However, the ecological process which drives the HTFs systems remain poorly knew. The studies presented in this doctoral dissertation aim to fulfill some lacks of knowledge about ecological process that could drive the HTF dynamic. The chapter 1 is a bibliographical review about this system. On chapter 2 were evaluated possibles mechanisms used by plants in order to improve their survival in such stressed environment through the study of rhizosphere soils and comparison with bulk soils. On chapter 3, through an experimental study in the field, the possible effect of two crab species bioturbation on HTFs soils and it possible effects on soil properties were evaluated. The chapter 4 registered the evaluation of ecological interactions among biotic and abiotic fractions of the system using ecological modeling tools. In this sense, a structural ecological model was designed using microrelief elevation, soil properties, two plant species biomass and the covering areas of two crab species. Based on results obtained in these studies, it was possible to conclude that HTFs have a particular ecological dynamic and have close relation with mangrove forests due the nutrients, material and animal population flux shared by them. The plant community of HTFs areas is componed mainly by pioneersâ clonal halophytes species. These species seemed to have different strategies to deal with saline stress, an important limitant factor for their growing and distribution. The seasonal effects were noteworthy mainly in bulk soils. In this sense, it is possible that plant estabilize the environment in their benefit. The crabs were able to affect biogeochemical dynamic in HTF soils. However, the burrouing effects of crab species on soil properties were different and seemed reflect the species habit. Although bioturbation effects were important, the modifications on HTF soil properties were less evident than in mangrove forests. Environmental process related to salinity and nutrients availability are among the main factors to drive crabs distribution and plant growth in HTFs. These processes were dependent of microrelief variation. A combination of abiotic factors (microrelief elevation and soil properties) and positive relations among plant species seems to guide the ecological dynamics in HTFs systems. Conservation strategies of coastal environments areas must include the HTF protection due their importance for coastal environments on climate change scenario and economic importance, but mainly because their unique ecological characteristics. / Esse estudo teve como objetivo geral investigar processos ecolÃgicos e a dinÃmica do apicum. Esses sistemas se caracterizam por serem planÃcies hipersalinas que ocorrem em zonas costeiras de regiÃes Ãridas onde podem ser identificadas dentro de bosques de mangue ou entre o manguezal e ecossistemas de terra seca, como mata seca ou restinga. Os apicuns sÃo Ãreas estratÃgicas para recuo das florestas de mangue em caso de aumento do nÃvel do mar. AlÃm disso, possuem grande importÃncia econÃmica, visto que sÃo Ãreas preferenciais para instalaÃÃo de empreendimentos de aquicultura e salinas e por que representam zonas de seguranÃa para populaÃÃes tradicionais. Entretanto, muito pouco se sabe sobre os processos ecolÃgicos que regulam a dinÃmica do sistema. Os estudos compilados nessa tese visam de algum modo suprir lacunas sobre os processos ecolÃgicos que regem a dinÃmica desse sistema. O capÃtulo 1 traz uma ampla revisÃo bibliogrÃfica sobre esse sistema. No capÃtulo 2 foram avaliados possÃveis mecanismos utilizados pelas plantas para sobreviverem ao ambiente limitante atravÃs do estudo dos solos rizosfÃricos e comparaÃÃo com solos nÃo colonizados por plantas. No capÃtulo 3, atravÃs de um estudo experimental de campo foram avaliados os efeitos da bioturbaÃÃo de duas espÃcies de caranguejos nos solos de apicum e seus possÃveis efeitos sobre as condiÃÃes edÃficas. O capÃtulo 4 aprofunda-se na avaliaÃÃo das interaÃÃes ecolÃgicas que ocorrem entre o solo, microrelevo e a biota do sistema (plantas e animais). Nesse sentido, um modelo ecolÃgico estrutural foi construÃdo utilizando variaÃÃes na elevaÃÃo do relevo, propriedades do solo, biomassa das plantas e Ãrea de cobertura de caranguejos. Com base nos resultados, concluiu-se que o sistema apicum possui dinÃmica ecolÃgica muito prÃpria e possui uma relaÃÃo com os bosques de mangue graÃas ao compartilhamento de fluxos de matÃria, nutrientes e populaÃÃes de animais. A comunidade de plantas do apicum à composta, sobretudo por espÃcies clonais halÃfitas pioneiras e que parecem possuir estratÃgias diferenciadas para lidar com o estresse salino, fator limitante do seu crescimento e distribuiÃÃo. O efeito da sazonalidade à notÃvel, sobretudo nas Ãreas nÃo colonizadas por plantas, indicando que possivelmente as plantas estabilizam o sistema solo em seu beneficio. Diferentes espÃcies de caranguejos sÃo capazes de afetar a dinÃmica biogeoquÃmica do solo. A bioturbaÃÃo do solo pelas espÃcies estudadas provocou diferentes efeitos nas propriedades do solo, os quais parecem estar intimamente ligados as hÃbitos das espÃcies. Entretanto, as seus efeitos nos apicuns, embora importantes, sÃo menos intensos que em Ãreas de manguezais. Processos ambientais ligados à salinidade do solo e à disponibilidade de nutrientes estÃo entre os principais fatores que regem a distribuiÃÃo de caranguejos e crescimento das plantas nos apicuns. Esses processos sÃo intimamente dependentes das variaÃÃes do microrelevo. Uma combinaÃÃo entre fatores abiÃticos (elevaÃÃo do relevo e propiedades do solo) e relaÃÃes positivas entre espÃcies de plantas parecem se os princiapis agentes na dinÃmica ecolÃgica dos apicuns. EstratÃgias de conservaÃÃo de sistemas costeiros devem incluir a proteÃÃo dos apicuns visto seu importante papel ecolÃgico no cenÃrio de mudanÃas climÃticas e importÃncia para economia local, sobretudo por conta suas caracterÃsticas ecolÃgicas Ãnicas.
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Dinâmica da desembocadura lagunar de Cananéia, litoral sul do estado de São Paulo / The dynamics of Cananéia inlet, south coast of São PauloBruna Garcia Ambrosio 23 August 2016 (has links)
As desembocaduras lagunares são sistemas costeiros dinâmicos e complexos em função de seu controle por diversos fatores ambientais, como amplitude de maré, energia de ondas e aporte fluvial. Essas variáveis atuam em conjunto produzindo condições hidrodinâmicas únicas e uma variedade de feições deposicionais. Estes sistemas, compostos por um canal principal e por deltas de maré, possuem fortes influências sobre a evolução da região costeira adjacente. O objetivo deste trabalho é avaliar a dinâmica da desembocadura de Cananéia, a fim de compreender os processos que governam as alterações morfológicas da região, considerando as prováveis influências do delta de maré vazante. Através de imagens aéreas e cartas náuticas históricas foi possível analisar as alterações morfológicas da desembocadura e do delta ao longo das últimas décadas. Posteriormente, foi aplicado o modelo numérico MIKE 21 para simular a propagação de ondas, a hidrodinâmica e o transporte sedimentar na região em duas situações batimétricas e em diferentes casos de ondas incidentes. Para tanto, utilizaram-se dados coletados in situ, resultados de modelos globais (WW3 e CFSR) e informações obtidas na literatura. Os resultados mostram alterações na morfologia da desembocadura com o predomínio de processos erosivos na margem norte, migração do canal e do delta para nordeste, aumento volumétrico do delta e avanço deste em direção ao oceano. Além disso, notou-se que a margem norte é exposta a maiores forças de onda e que, em ambas as margens, esta diminuiu ao longo do período analisado. Os resultados indicam a ação do delta de maré vazante como principal agente transformador de ondas, sendo a sua variação morfológica determinante para a ação das ondas nas margens do canal. A circulação é controlada predominantemente pela maré e o transporte de sedimentos, embora limitado, é aumentado sob o efeito sinérgico entre a ação de ondas e de maré. Devido a sua morfologia e hidrodinâmica, a margem norte é submetida à maior influência de ondas e de maré, resultando em processos erosivos. A dinâmica sedimentar reflete a complexidade deste ambiente. / Inlets are dynamic and complex coastal systems subjected to a variety of forces such as tidal range, wave energy and fluvial discharge. Combinations of these variables produce unique hydrodynamic conditions and a variety of depositional features. These systems, consisting of a main channel and tidal deltas, have strong influence on the evolution of the coastal zone. The aim of this study is to evaluate the dynamics of the Cananéia inlet in order to understand the processes that control the morphological changes in the region, considering the influence of its ebb-tidal delta morphology. Based on aerial photographs and historical nautical charts the morphological changes of the inlet and delta were analyzed over the last decades. Subsequently, the MIKE 21 numerical model was applied to simulate the wave propagation, the hydrodynamics and sediment transport in the region, for two different bathymetric situations and several wave scenarios. Therefore, we used in situ data, global model results (WW3 and CFSR) and information from the literature. Results show changes in the morphology of the inlet with the predominance of erosion on its northern margin, the migration of the channel and delta northeasterly, and the delta volume increase and its growth towards the ocean. Furthermore, it was noted that the northern margin is exposed to greater wave power and on both margins the wave power decreased over the analyzed period. The results show the action of the ebb tidal delta as the main transforming agent of the incoming waves and its morphological variation determines the action of the waves on the margins of the channel. The circulation is controlled predominantly by the tide and the sediment transport, although limited, is increased under the synergistic effect between the action of waves and tide. Due to its morphology and hydrodynamics, the northern margin is subjected to greater influence of waves and tide, resulting in erosional processes. The sediment dynamics reflects the complexity of this environment.
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Nitrifikation i pulskärr : En studie av Forsmarks avloppsreningsverk med SBR och våtmarker / Nitrification in vertical flow intermittent loaded soil filter wetland : A study of Forsmark wastewater treatment plant with SBR and constructed wetlandsHalvarsson, Linus January 2017 (has links)
Avloppsreningsverket i Forsmark renar vattnet med aktivt slam i en satsvis biologisk rening (SBR) reaktor samt med våtmarker. Våtmarkerna består av fyra pulskärr och en damm. Pulskärren är utformade som bassänger fyllda med grus som filtermaterial där ytan är bevuxen. Pulskärren beskickas satsvis med 60 m^3 vatten när någon av SBR-reaktorerna töms, vattnet rinner då ut över ytan samtidigt som det perkolerar ner i bädden. När SBR-reaktorn har tömts är hela pulskärret mättat. Tömningen av pulskärret sker genom ett dränerande gruslager i botten och sedan flödar vattnet vidare ut genom ett ställbart dräneringsrör till slutdammen. Pulskärrens uppgift är att stoppa partiklar och att fungera som ett nitrifierande steg ifall verket i framtiden skulle få ökade reningskrav. I detta arbete har pulskärrens funktion som nitrifierare av ammonium undersökts. Detta genom att sammanställa befintliga driftdata från reningsverket, fältstudier samt en litteraturgenomgång. Målet med fältstudien var att mäta halten ammonium, nitrat och totalkväve i vattnet som gick in och ut ur pulskärret för att se hur halterna ändrades. Dessutom mättes temperatur, syrehalt, pH och konduktivitet. Provtagningen genomfördes på två pulskärr med tömningstiderna två respektive fyra timmar. Resultaten visade att ammoniumhalterna halveras i pulskärren. Inkommande ammonium till pulskärren var cirka 3 mg/l under studien men om ammoniumkoncentrationen skulle öka kommer nitrifikationen antagligen ske i liknande utsträckning. Detta då liknande system påvisat sådana resultat. Ökad tömningstid för pulskärren medför ökad nitrifikation, pulskärren bör därför ställas om så att tömning sker under cirka fyra timmar. För att hitta en optimal tömningstid bör vidare undersökningar göras. Forsmarks avloppsreningsverk möter de reningskrav som ställts med marginal. Trots att detta inte var syftet, avskiljs 80 % av inkommande kväve och det kunde konstateras att den största kväveavskiljningen sker i SBR-reaktorn. Kvävereduktionen har uppstått då verket haft låg belastning samtidigt som mycket syre tillsatts till processen. Då rening genom pulskärr sker efter att vattnet passerat genom SBR-reaktorerna borde luftningen kunna minskas för att istället utnyttja pulskärrens nitrifierande egenskaper. Svensk kärnbränslehantering AB har planer på att leda lakvatten till reningsverket för att avskilja kväverester, skulle detta ske kommer flödena över pulskärren att öka. Att den hydrauliska belastningen ökar borde inte utgöra några problem då flödena troligen inte kommer överstiga pulskärrens kapacitetsgränser. I extrema fall kan tömningstiden på pulskärren minskas. / Forsmark wastewater treatment plant treats wastewater using an active sludge process in sequencing batch reactors (SBR:s) and followed by constructed wetlands. The wetlands consist of four intermittent loaded soil filters (ILS:s) and a pond. The ILS:s is designed as pools filled with filter material and with a plant-grown surface. One of the ILS:s fills up with water when one of the SBR reactors is emptied. The water flows out over the surface as it percolates into the bed. When the SBR reactor is emptied, the entire ILS becomes saturated. The ILS then drains through a drainage gravel layer at the bottom and further through an adjustable drainage pipe into the dam. The purpose of the ILS:s is to work as extra filter for removal of the remaining particles and escaping sludge. They have also been thought to act as a nitrifying step if the plant would have tougher cleaning requirements in the future. In this report, the function of the ILS:s as nitrifying steps was investigated by compiling existing operating data from the treatment plant, with conducted field studies and through a literature review. The field study aimed at measuring ammonium, nitrate and total nitrogen in the water at the entering and the outlet in the ILS to see how the different nitrogen concentrations was affected. Temperature, oxygen, pH and electricalconductivity were also measured. The sampling was done on two ILS with different drainage time, two and four hours. The results showed that the ILS:s nitrifies the incoming water with an average efficiency of 50 % depending on the ammonium contentration in the incoming water. An increased drainage time for the ILS seamed to result in better nitrification. Therefore, the ILS:s should be changed to drain for at least four hours. Should the ammonium concentration increase above 3 mg/l the nitrification rate would probably be about the same. Similar systems such as have shown similar nitrification removal but with higher ammonia concentrations. Forsmarks wastewater treatment plant meets the purification requirements imposed on the plant with margin. It is remarkable that, without planning for any nitrogen removal, the removal is about 80 % of incoming nitrogen, most of which is removed in the SBR reactor. Svensk Kärnbränslehantering AB plans to lead leachate to the treatment plant for nitrogen removal. If this plan is fulfilled, the flows through the ILS will increase. This should not be a problem as the total flow trought the ILS will not exceed the capacity limits of the ILS. In case of high flows, the emptying time of the ILS:s can be reduced.
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