Dissertations / Theses: 'Fluvial environments'

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Grashion, Anton R. "Computer aided analysis of ancient fluvial depositional environments." Thesis, Staffordshire University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241509.

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Newell, Andrew John. "Sedimentological controls on vertebrate taphonomy in Triassic fluvial environments." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317467.

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Dawson, Martin. "Late Devensian fluvial environments of the Lower Severn Basin, U.K." Thesis, University of Leicester, 1986. http://hdl.handle.net/2381/34480.

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Coarse grained, late-Devensian, fluvial deposits underlie river terraces along the lower River Severn and in tributary valleys. Borehole evidence indicates that individual terrace features may be correlated downstream, supporting previous stratigraphic interpretations. Examinations of the terrace sediments were carried out at 10 major sections enabling comparisons to be made between 'paraglacial' and 'periglacial' deposits. Interpretations of the depositional environments are based upon detailed descriptions of the sediments and considerations of genetic relationships between lithofacies types, determined through Markov chain and architectural element analyses. Five depositional sub-environments may be identified; channel zone units, overbank deposits, unitary channel forms, slope and alluvial fan deposits. The occurrence of the latter two sub-environments depends on the pre-existing valley topography, whilst the characteristics of the channel-zone and overbank deposits vary in relation to the local aggradation rate, discharge regime, proximal to distal controls on the sediment size distribution and channel slope. The fluvial sequences were predominantly deposited by low sinuosity gravel bed rivers, often with braided planforms. However, the Worcester Terrace aggraded partly under sandy braided conditions. Channel zone lithofacies in a modern braided river are shown to develop through the formation and agglomeration of complex lateral and medial bar forms. These comprise bar-platform units representing primary, in-channel (unit-bar), sedimentation, and supra-platform sediments which are superimposed on, and modify, the bar-platform deposition. Mean annual flood discharges in the basin, and possible error limits, are estimated using palaeohydraulic and morphometric techniques. Palaeodischarges in the Severn and Avon are shown to have been similar, with maxima occurring during deglaciation. Avon discharges may have been up to 25 times present values, although in the lower Severn mean annual floods may only have reached 4 times present. The development and preservation of Pleistocene terrace deposits is considered within a model emphasizing differences apparent in the sedimentary sequences. A similar model explains the development of channel zone depositional features, and the origins of gravel stratification types are discussed in relation to observations of terrace and modern sediments.

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Crimes, Angela C. "Modelling of thin bed sands in fluvial-deltaic environments of the Southern Cooper Basin, South Australia /." Title page, abstract and contents only, 1995. http://web4.library.adelaide.edu.au/theses/09SB/09sbc929.pdf.

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Thesis (B. Sc.(Hons.))--University of Adelaide, National Centre for Petroleum Geology and Geophysics, 1996? Volume 2 is boxed and consists of 1 folded map and 9 folded correlations. Includes bibliographical references (leaves 39-40).

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Lee, Mui-fa Alison, and 李梅花. "Sedimentary facies of fluvial-marine transition environments in Hong Kong: Ting Kok and Pak Nai Deltas." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31221270.

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Lee, Mui-fa Alison. "Sedimentary facies of fluvial-marine transition environments in Hong Kong : Ting Kok and Pak Nai Deltas /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21021211.

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Calvani, Giulio [Verfasser], Hans Matthias [Akademischer Betreuer] Schöniger, and Luca [Akademischer Betreuer] Solari. "Riparian vegetation in fluvial environments : linking timescales through flow uprooting / Giulio Calvani ; Hans Matthias Schöniger, Luca Solari." Braunschweig : Technische Universität Braunschweig, 2021. http://d-nb.info/1225038294/34.

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Workman, Terry W. "PALEOWETLANDS AND FLUVIAL GEOMORPHOLOGY OF QUEBRADA MANI: RECONSTRUCTING PALEO-ENVIRONMENTS AND HUMAN OCCUPATION IN THE NORTHERN ATACAMA DESERT." Miami University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=miami1345055481.

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Sousa, Eliete dos Santos. "Fluxo evasivo de CO2 em ambientes fluviais no sudoeste da Amazônia, Acre, Brasil." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/64/64135/tde-04092013-142901/.

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Na maior bacia hidrográfica do Planeta, o rio Amazonas transporta para os oceanos grande quantidade de carbono particulado e dissolvido. Esta visão tradicional dos rios, como carreadores de carbono para os oceanos, tem sido revista nas últimas décadas, em função de novos resultados que mostram emissões de CO2 destes sistemas para atmosfera superiores ao transporte na descarga em até uma ordem de grandeza. Diversos trabalhos já foram realizados com o objetivo de avaliar os processos que controlam essas emissões. No entanto, os mesmos ainda permanecem como uma grande fonte de incertezas. O objetivo principal deste trabalho foi quantificar os fluxos de CO2 em rios e igarapés do sudoeste da Amazônia (bacia do rio Purus, estado do Acre), levando em consideração as características químicas e físicas de cada sistema, bem como a sazonalidade da região e, assim, contribuir para melhorar as estimativas das emissões de carbono em toda a bacia Amazônica. Os resultados mostraram que durante o período de estiagem os rios apresentam águas com concentrações relativamente elevadas de bicarbonato, indicando a importância do intemperismo de carbonatos como fonte de carbono. Análises da composição isotópica do carbono inorgânico dissolvido corroboraram estes resultados. Nos igarapés, no entanto, a principal fonte de carbono é a matéria orgânica do solo. A sazonalidade exerce forte influência na pCO2 e, consequentemente, nos fluxos de CO2, com os maiores valores ocorrendo no período chuvoso. No entanto, não foi encontrada variabilidade sazonal nas taxas respiratórias o que mostra que, além da respiração, outros fatores também estão influenciando os fluxos de CO2. No período seco, o aumento significativo das concentrações de clorofila a pode indicar que processos fotossintéticos também desempenham um papel importante no balanço de C destes sistemas In the largest basin of the planet, the Amazon river carries large amounts of particulate and dissolved carbon to the oceans. This traditional view of rivers as carriers of carbon to the oceans has been reviewed in the last decades due to new results showing that CO2 emissions to the atmosphere from these systems can surpass C transport in discharge in one order of magnitude. Several studies have been conducted to evaluate the processes controlling these emissions. However they still remain a major source of uncertainty. The main objective of this study was to quantify CO2 evasive fluxes in rivers and streams of Southwestern Amazon (Purus river basin, Acre state), taking into account chemical and physical characteristics of each system, as well as seasonality in this region and, thus, contribute to improve estimates of carbon emissions throughout the Amazon basin. The results showed that during low water the rivers have relatively high bicarbonate concentrations, indicating that carbonate weathering is an important carbon source. Dissolved inorganic carbon isotopic composition corroborated these results. However, in streams the main carbon source is soil organic matter. Seasonality has a strong influence on pCO2 and consequently on CO2 fluxes, with the highest values occurring in the rainy season. However there was no seasonal variability in respiration rates, which shows that other factors than respiration are also influencing CO2 fluxes. During the dry period, increases in chlorophyll a indicate that photosynthetic processes also play an important role in the C balance of these systems.

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Bartz, Melanie [Verfasser], Helmut [Gutachter] Brückner, and Olaf [Gutachter] Bubenzer. "Quaternary fluvial environments in NE Morocco inferred from geochronological and sedimentological investigations / Melanie Bartz ; Gutachter: Helmut Brückner, Olaf Bubenzer." Köln : Universitäts- und Stadtbibliothek Köln, 2017. http://d-nb.info/1151298247/34.

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Barral, Fraga Laura. "Arsenic and fluvial biofilms: biogeochemistry, toxicity and biotic interactions." Doctoral thesis, Universitat de Girona, 2017. http://hdl.handle.net/10803/461201.

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Based on the current knowledge about biofilm ecotoxicology and arsenic biogeochemistry in freshwater ecosystems, this thesis studied, under realistic environmental concentrations, i) the role of benthic biofilms in the bioavailability and detoxification of arsenic, ii) the toxic effects of Arsenic on the structure and function of river benthic biofilms, paying special attention to the responses of diatoms, and iii) the interaction between these primary producers and higher organisms such as fish, exposed to arsenic. Arsenic inhibited algal growth, with diatoms being adapted by a significant reduction in cell biovolume (chapter 1). The biofilm aggravated the effects of arsenic on fish (chapter 2) but was also able to detoxify through methylation of inorganic arsenic species (chapter 3). The results of this thesis provide valuable information to understand the contribution of biofilms to biogeochemistry and arsenic toxicity in freshwater systems. Basándonos en los conocimientos actuales sobre la ecotoxicología del biofilm y la biogeoquímica del arsénico en ecosistemas dulceacuícolas, esta tesis estudió, bajo concentraciones ambientales realistas, i) el papel de los biofilms bentónicos en la biodisponibilidad y destoxificación del arsénico, ii) los efectos tóxicos del arsénico sobre la estructura y función de los biofilms bentónicos fluviales, prestando especial atención a las respuestas de las diatomeas, y iii) la interacción entre estos productores primarios y organismos superiores como los peces, expuestos a arsénico. El arsénico inhibió el crecimiento algal, pudiendo las diatomeas adaptarse mediante una significativa reducción de su biovolumen celular (capítulo 1). El biofilm agravó los efectos del arsénico en peces (capítulo 2) pero también fue capaz de destoxificar metilando especies inorgánicas de arsénico (capítulo 3). Los resultados de esta tesis proporcionan información valiosa para comprender la contribución de los biofilms a la biogeoquímica y toxicidad del arsénico en sistemas dulceacuícolas. CAT: S'han extret de la tesi doctoral el contingut del cap. 1 General introduction i Cap. 4 General discussion; part del capítol 3 que inclouen articles en preparació. També s'han extret els Annexos 1 i 2 que incloïen els pdf editor d'articles ja publicats.----- ENG: The content of Chapter 1. General introduction and Chapter 4 General discussion; part of Chapter 3 that have articles in preparation have been extracted from the doctoral thesis pdf. Appendices 1 2 that included the pdf editor of articles already published have been extracted from the doctoral thesis too.

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Khadka, Mitra B. "Variation in Trace Metal Concentrations in A Fluvial Environment, Ottawa River, Toledo, Ohio." Bowling Green State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1281396632.

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Zhang, Zhi. "Developing video monitoring technique in riverine environment : automatic and continues detection." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEN087.

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Le bois flotté joue un rôle important à la fois sur l'écologie et la morphologie d'une rivière. Par conséquent, la quantification de la quantité de bois dans les rivières est une question importante. Ces dernières années, la surveillance vidéo en bord de rivière a été introduite comme une technique pour évaluer la quantité de bois en milieu fluvial. Outre de nombreuses avancées, il reste encore de nombreuses questions à résoudre concernant cette technique. Par conséquent, dans cette étude, nous nous sommes concentrés sur trois objectifs majeurs. Dans un premier temps, nous avons étudié la relation entre flux de bois et débit d'écoulement afin de créer un modèle de prévision du flux de bois sur une période durant laquelle la caméra ne peut enregistrer le flux vidéo. Le bois dans les cours d'eau peut présenter des caractéristiques différentes lors de certains événements critiques, comme par exemple, lors de deux crues à plusieurs pics, le flux de bois sur le premier pic de débit est supérieur au second, et en cas d'inondation après une journée venteuse plus forte, le flux de bois peut être activé par l'élévation de l'eau. En outre, le deuxième objectif majeur était la mise en œuvre et la validation de l'application d’un logiciel de détection automatique. Après avoir entrainé l’algorithme de détection, il est utilisé pour extraire automatiquement les flux de bois de manière continue. Le troisième objectif majeur était d'évaluer les incertitudes d'origine humaine dans la surveillance vidéo en raison de deux principaux facteurs. La détection manuelle est extrêmement fastidieuse et longue et nécessite ainsi d’envisager une stratégie d'échantillonnage des vidéos. Le second problème nécessitant une évaluation de l’incertitude est lié à la capacité souvent variable de l'opérateur à détecter les flottants, qui se traduit par un biais de mesure entre les différents opérateurs. Nous espérons que les résultats de cette thèse permettront de diffuser l’usage de la technique de surveillance vidéo fluviale à des fins pratiques Drift wood plays a significant role both on the ecology and morphology of a river. Therefore, quantifying the amount of wood in rivers is an important issue. During recent years, streamside video monitoring has been introduced as a feasible technique to evaluate the amount of wood in riverine environment. Beside many advances, there are still many questions needed to be address concerning this technique. Therefore, in this study, I focused on three major objectives. Firstly, I studied the relation between wood flux and flow discharge in order to create a model for predicting wood flux on invisible period of camera sight. Wood in-stream can show some different characteristics in some critical events, such as in two multi-peak floods, wood flux on the first peak of discharge is more than second one, and in a flood after a stronger windy day, wood flux can be activated by water elevation arise. In addition, the second major objective was implementation and validation the application of an automatic detection software. After training the software, it is used to extract wood flux automatically by its own surveillance. The third major objective was evaluating human-based uncertainties in video monitoring due to two limitations, first time limitation which results in sampling the videos and second limitation in visibility of the operator which results in bias between different operators. I expect the results of this thesis develop the application of streamside video monitoring technique for practical concerns

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Laneville, Michael Warren. "Subsurface Depositional Systems Analysis of the Cambrian Eau Claire Formation in Western Ohio." Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu154220482332536.

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Smith, Kathleen Ann. "Quaternary environmental changes in the fluvial and faunal history of central Northamptonshire." Thesis, University of Northampton, 1999. http://nectar.northampton.ac.uk/2996/.

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This dissertation is an analysis of the Quaternary fluvial history of central Northamptonshire. It uses new freshwater ostracod data which are interpreted using information on Quaternary and present day habitats and examines in detail associated patterns of environmental change in coarse sediments from which the ostracods were extracted. Stratigraphic, lithological and sedimentological data, supported by a study of geological maps, borehole logs and papers, are employed to produce a new hypothesis to explain the Quatemary development of the Milton River and the River Nene. The alignment of the Milton Formation Valley is established to have proceeded to the east of, but parallel with, the Nene Valley between Northampton and Higham Ferrers, where it turned to the south-east. It comprises locally derived deposits which are shown to be pre-Anglian Glaciation and, at the time of the deposition of the ostracods studied here, an interglacial environment prevailed. However, during a ‘cooling phase”, Milton Formation sediments were incised and the channel became partially infilled with fossiliferous boreal sediments. Further sedimentation continued to produce a non-fossiliferous, periglacial sand, which is typical of the Milton Formation. It is argued that this period of deposition was followed by two glacial episodes, the latter relating to the Lowestoft Formation. Stratigraphic, sedimentological and lithological evidence from the Nene valley shows vestigial terrace gravels exist between Northampton and Wellingborough. The oldest gravels of these features pre-date the Anglian age, sub-glacial tunnel valley” at Northampton, implying the Nene Valley existed prior to glaciation. Before glaciation it is suggested that the Milton River became confluent with the Nene at Northampton and, concurrently, diverted to the north-east at Higham Ferrers. This is believed to be associated with the simultaneous abandonment of the Milton Valley to the south-east of Higham Ferrers and the upstream stretch at Northampton. Evidence presented of downcutting, lateral migration, gravel reworking and changes in the ostracod assemblages in the Nene Valley confirm a history of several climatic oscillations which took place in the pre-Devensian, Devensian and Holocene. These oscillations are tentatively correlated with stages of deposition in the Nene established downstream at Peterborough. This revised fluvial history elaborates the course and age of the Milton River and establishes a pre-Devensian age for much of the Nene Valley sediment. The significance of this new understanding of the upper Nene Valley has been compared with that of the lower Nene Valley at Peterborough, Cambridgeshire. The combined evidence is used to produce a pattern of river development within the Quaternary which may be used as a model when reconstructing the palaeogeography of other rivers and their floodplains by means of their sedimentary structures and related fossils. This idea is explored to a small extent in the thesis, but is more applicable to future work. The new ostracod data throws new light on previous studies from other sites in England. Ostracod species new to the Pleistocene record are to be added to a worldwide data base

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Gasparini, Nicole Marie 1972. "Equilibrium and transient morphologies of river networks : discriminating among fluvial erosion." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29755.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003. Includes bibliographical references (p. 217-232). We examine the equilibrium and transient morphology of alluvial and bedrock river networks. We apply analytical methods and an iterative model to solve for equilibrium slope-area and texture- area (in alluvial networks) relationships under different tectonic and climatic forcings. Transient morphology resulting from a change in uplift or precipitation rate is simulated using the CHILD landscape evolution model. In alluvial networks, it is well recognized that both channel slope and mean grain size usually decrease downstream. These variables play an important role in determining sediment transport rates, and their mutual adjustment to a change in the forces that drive erosion can yield surprising results. Adjustments in grain size can lead to spatially variable channel concavity and larger trans port rates on shallower slopes. As a consequence, equilibrium channel slopes may decrease under higher uplift conditions (or, similarly, faster base-level lowering). Selective erosion and deposition can cause transient channel slopes to both increase and decrease and surface texture to both coarsen and fine, all in response to a single change in forcing. In bedrock rivers, increasing attention has been given to the role of sediment flux on incision processes. We find that all applied erosion rules (stream-power and three sediment-flux models) produce similar equilibrium morphologies, although some details lead to differences in sensitivity. (cont.) On the other hand, the transient response can be much more complicated than a simple knickpoint migration when the integrated response of the sediment flux is considered. Both increasing and decreasing channel slopes can result from a single change in forcing. Although some of the processes described by the different erosion models in this study represent conditions in very different types of rivers, two important common principles hold. First, concave graded river profiles appear to be a robust element of the landscape and fairly insensitive to the details of the erosion process. However, downstream variations in channel erodibility can alter equilibrium sensitivity to boundary conditions in ways that had not previously been considered. And second, transient conditions in the main channel are highly dependent on the entire network response. The results can be complex and counter-intuitive, highlighting that rivers are not independent of the tributaries that feed them. by Nicole Marie Gasparini. Ph.D.

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Hu, Mengyu. "Plio-Pleistocene environmental variations inferred from thick sediment sequences in the North China Plain." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363619.

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McCreary, Alan Frederick. "Anatomy of select fluvial deposits in the Mauch Chunk Group, Southern West Virginia, USA." Thesis, The University of North Carolina at Charlotte, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10601199.

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The Mauch Chunk Group has been interpreted as a product of multiple transgressions and regressions (Miller and Eriksson, 2000; Beuthin and Blake, 2004). An outcrop containing the upper Hinton Formation and Princeton Formation, the middle two formations of the Mauch Chunk Group, occurs along US-460 in Princeton, West Virginia, 2.6 kilometers east of the Interstate 77 Princeton exit. In order to understand the sedimentology and depositional history at those outcrops, sedimentologic logs were compiled, facies were identified and bundled into facies associations, photographic panoramas with line drawing overlays were constructed, and rock samples were taken. From the logged sections and facies architecture, a depositional history was interpreted. That history was supplemented with a provenance study where the samples were analyzed with a scanning electron microprobe to document oxide weight percentages. The upper Hinton Formation and the Princeton Formation were deposited through a combination of autocyclic and allocyclic processes. The mineralogy does not conclusively tie the sandstone deposits to the same source; however, mineral identifications did indicate the provenance to be an area with both igneous and metamorphic rocks. The presence of growth faulting indicates that the location of the cross-bedded sandstone that comprises the Princeton Formation at the US-460 outcrop may have been influenced by syn-depositional tectonism.

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OLIVEIRA, LUIZ FELIPE DAUDT. "DIAGNOSIS OF SOCIAL AND ENVIRONMENTAL DOMAIN OF THE PARAÍBA DO SUL RIVER FLUVIAL ISLANDS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2014. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=26638@1.

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No curso médio inferior da degradada Bacia Hidrográfica do Rio Paraíba do Sul, na região Noroeste do Estado do Rio de Janeiro, existe um segmento fluvial denominado Domínio das Ilhas Fluviais, que mantém biodiversidade bem conservada em relação aos segmentos localizados rio acima e que drenam os estados de São Paulo, Minas Gerais e Rio de Janeiro. Os domínios geoambientais do Paraíba do Sul localizados rio acima foram degradados por desflorestamentos, barragens, erosão, sedimentação, introdução de espécies exóticas e poluição industrial e doméstica. Embora estes fatores também ameacem as Ilhas Fluviais, este domínio obteve a reputação de local estratégico, instituída pelo Instituto Chico Mendes de Biodiversidade (ICMBio) devido à sua biodiversidade e por manter espécies ameaçada de extinção. Cabe a este Instituto executar as ações do Sistema Nacional de Unidades de Conservação e fomentar e executar programas de pesquisa, proteção, preservação e conservação da biodiversidade, além de exercer o poder de polícia ambiental para as Unidades de Conservação federais. Os levantamentos sobre a ocupação da bacia hidrográfica do rio Paraíba do Sul em relação àqueles relacionados a região abrangida pelo Domínio das Ilhas Fluviais, a importância dos seus peixes para as comunidades ribeirinhas, a pesquisa científica, as interações ecológicas dos sistemas fluviais, e as características ambientais, espaciais, físicas e biológicas deste segmento do Rio Paraíba do Sul interessam o presente estudo. In the final segment of the geographical unit named Lower Middle Course of the Paraíba do Sul River (Ab Saber, 1958), located in the Fluminense area of the state of Rio de Janeiro, there is a subunit named Domain of the River Islands, which has well-preserved biodiversity when compared to the more developed areas in the states of Rio de Janeiro and São Paulo found upstream. With the exception of the Domain of the Mountain Ranges and Plateau, in the Upper Valley of the Paraíba do Sul River, the upstream areas have been degraded especially in the highly developed areas in the states of Rio de Janeiro and São Paulo, due to their elevated population and industrial densities (COELHO, 2012; ICMBio, 2011). The sprawl translates into industrial and household pollution, large deforested areas, harmful effects on the aquatic biota caused by the proliferation of dams, erosion, sedimentation, introduction of alien species and toxic leaks (ARAUJO, 2004; ARAUJO et al., 2005). Although these factors originating in border waters also threaten the River Islands, the area was recognized as a strategic location by the Chico Mendes Institute for Biodiversity (ICMBio, 2011) due to its rich biodiversity (BIZERRIL, 2001) and a number of endangered species found in the area (CARAMASCHI et al, 1991; BIZERRIL, 2001). This Institute shall enforce the actions established by the National System of Conservation Units, foster, and carry out programs of research, protection, conservation and preservation of the biodiversity, and exercise the power of environmental police in the federal Conservation Units. Existing surveys on the occupation of the Paraíba do Sul Basin are of particular interest to this study, including those pertaining to the Domain of the River Islands region, the importance of local fish species for the riparian communities, the ecologic interactions between river systems, the environmental, spatial, physic and biological characteristics of this area of the Paraíba do Sul River, as well as other scientific studies. The aim of this dissertation is to collect data by reviewing existing literature and experiences gathered in the field, in order to pool information and present reflections on how the river segment of Domain of the River Islands is able to maintain, within the polluted and degraded Paraíba do Sul Basin, a relatively well-preserved ecosystem, which therefore must be protected.

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Bertrand, Fabienne. "Fluvial erosion measurements of streambank using Photo-Electronic Erosion Pins (PEEP)." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/642.

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Fluvial erosion incites significant bridge scour and large-scale bank erosion causing estimated $1.1 billion damage in the Midwest. Conventional, manual, field monitoring methods, typically erosion pins, cross-section resurveys or terrestrial photogrammetry, used to monitor fluvial erosion rates merely provide a net change in bank surface retreat since the previous measurement. If mass wasting has occurred, the ongoing fluvial erosion would be masked. Erosion event timing, and the precise bank response to individual flow or flow hydrograph changes, is generally uncertain. Thus, a technique that automatically quantifies bank erosion on a continuous basis is needed. This study will monitor the bank response to individual flow (i.e., fluvial erosion) using the Photo-Electronic Erosion Pin (PEEP) sensors in Clear Creek Iowa. It attends to monitor a full episode of bank change, including event timings and magnitude information for specific erosion and deposition events, which can be compared to flow discharges and hydrographs. If exploited, this method can lead to more detailed analysis of bank erosion related to temporal fluctuations in the suspected hydraulic forces.

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Nash, David J. "The development and environmental significance of the dry valley systems (mekgacha) in the Kalahari, central southern Africa." Thesis, University of Sheffield, 1992. http://etheses.whiterose.ac.uk/5976/.

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The dry valley systems in the Kalahari of southern Africa are traditionally considered to have developed as a result of past fluvial activity. However, it has also been suggested that erosion by groundwater processes (sapping and deep-weathering) had an important role in development. This thesis aims to establish the relative role of each of these process areas in mekgacha evolution using a combined geological and geomorphological approach. The study area is restricted to the valley systems of Botswana, eastern Namibia and the Northern Cape Province of South Africa, which can be subdivided into exorcic and endoreic systems directed towards the Orange River and the continental interior, respectively. Field studies, analyses of remotely-sensed imagery and a consideration of network orientation identify evidence for the role of both fluvial and groundwater processes in valley development. However, whilst both groups of processes have operated, the importance of each is suggested to have varied both spatially and temporally. Fluvial processes are indicated by sequences of sediments, relict channels and terrace levels, and appear to have operated most recently. Sapping processes are implied in the formation of certain valley systems, primarily from morphological properties and the presence of relict spring lines. Deep-weathering processes are implicated from the close parallelism of many valleys with geological structures now buried beneath thicknesses of Kalahari Group sediments. Borehole records also indicate deep-weathering of bedrock beneath valleys developed above fracture zones, which is suggested to have operated over the longest timescales. Thin-section studies of duricrusts from valley flanks, together with duricrust profiles and records from lithological boreholes, indicate the role of groundwater in their formation. Results suggest an intrinsic link between duricrust formation and valley development. Geochemical and thin-section analyses of duricrusts further suggest that previous considerations of the palaeoenvironmental significance of Kalahari silcretes based upon TiO2 levels may not be wholly appropriate.

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Dunn, Frances Eleanor. "Multidecadal fluvial sediment fluxes to major deltas under environmental change scenarios : projections and their implications." Thesis, University of Southampton, 2017. https://eprints.soton.ac.uk/417782/.

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Deltas are important climate change hot spots that provide critical locations for human populations, agriculture, and aquaculture, as well as ecosystems and the services they provide. However, they are vulnerable systems as the sediment inputs which have historically oset relative sea level rise in undisturbed deltas appear to be threatened by anthropogenic activities. This thesis contributes to the understanding of future delta sustainability by projecting sediment delivery to a set of 47 signicant deltas worldwide. This is the rst study of future sediment uxes to such a large group of major deltas, and for some of these individual deltas the projection of future sediment ux has never been done before. The hydrological model WBMsed was chosen after a review of possible models to project uvial sediment delivery to each delta annually up to the year 2100. The model was forced by scenarios of climate change (RCPs 2.6, 4.5, 6.0, and 8.5), socioeconomic change (population and GDP data derived from SSPs 1, 2, and 3), and projected dam construction. On average, across all 47 deltas, uvial sediment delivery is predicted to decrease by 36-41%, dependent on scenario, during the 21st century. The largest overall contributor to decreasing sediment delivery is reservoir construction. However, for some individual deltas socioeconomic changes can cause a larger decline in the supply of uvial sediment than dam construction. In comparison, climate changes have a much smaller eect than both dam construction and socioeconomic changes, but the inuence of climate change is generally of opposing sign (for 39 of 47 rivers), thereby increasing future sediment supply. There are large dierences between the sediment ux changes projected between individual deltas, with some increases, but the majority of deltas (32 of 47) display decreases in sediment ux on average. The signicance of the sediment delivery changes for each river was assessed by developing a new Sediment Starvation Risk Index (SSRI), which considers absolute sediment ux change versus delta area. The SSRI highlights those deltas most at risk from sediment delivery losses over the 21st century and also shows a correlation between the dominant drivers of sediment ux change for each delta and the degree of sediment starvation risk. Those deltas with sediment ux changes driven by socioeconomic change are likely to be at greater risk of sediment starvation, whereas those driven by climate change are likely to be at less risk. This research assesses projected changes in sediment load to deltas, the key drivers of these changes, and the potential signicance of these changes for individual deltas using globally consistent methods. The research suggests widespread challenges for delta management and sustainability due to reduced sediment inputs over the 21st century.

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Saup, Casey Morrisroe. "Biogeochemical Cycling in Pristine and Mining-Impacted Upland Fluvial Sediments." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1593664378874682.

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Silva, Pedro José da. "Estrutura para identificação e avaliação de impactos ambientais em obras hidroviárias." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-29062004-233707/.

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A crescente preocupação com questões ambientais, contemporaneamente, pode ser entendida como uma tendência nebulosa, resultado de uma expressão muito rica de significado e muito mais conveniente para nós, que vivemos sem o distanciamento histórico, pois torna menos definitiva, sob uma perspectiva futura, às adjetivações realizadas, expressão esta identificada como globalização. A globalização conduz a uma natureza propagandista, direcionada à preservação e não à conservação da porção bio-geo-física do meio ambiente, que se refere, em especial, neste trabalho às águas contidas nos rios. A natureza propagandista das questões ambientais, nos faz crer que muitos dos impactos ambientais em um curso dágua, são devidos ao uso das águas e, principalmente quando este uso é para a navegação. A contenda do impacto ambiental, devido ao uso dágua para navegação, não é assunto esgotado quando se aborda somente o Gerenciamento do Recurso Hídrico, ele vai muito além, tem sua origem na Bacia Hidrográfica e, portanto é abordado no Gerenciamento da Bacia Hidrográfica. No desenvolvimento desta tese, será possível perceber, que entre os vários modais de transporte, a navegação fluvial, é a menos impactante ambientalmente, pois, até a via é de origem natural e não antropogênica, como em alguns outros modais. A necessidade da execução de obras hidroviárias, pode ser entendida em algumas situações como parte integrante de um Programa de Mitigação de Impactos Ambientais, não no rio, mas sim na bacia hidrográfica, que pelo não atendimento ou pela inexistência de um plano diretor, sofreu uma ocupação desordenada, resultando em inúmeros impactos ambientais nas porções do meio ambiente. Os capítulos apresentados a seguir, no corpo desta tese, estão vinculados entre si, pois, entendemos que só o estudo simultâneo nos permitirá obter a minimização dos impactos ambientais na bacia hidrográfica, bem como a minimização dos impactos ambientais quando da execução das obras hidroviárias. The growing concern about the environmental questions nowadays, can be understood as a nebulousness tendency, a result of a very rich expression of meaning and more convenient to us, who live without the historical distance, because it makes less definite under a future perspective, such expression is identified as globalization. Globalization conducts to a propagandist nature, towards preservation and not the conservation of the bio-geo-physics of the environment, that refers specially in this work about the water in rivers. The propagandist nature of the environmental questions, make us believe that most of the environment impacts in a flow of water, are due to water usage and mainly when this usage is navigation. The dispute of the environmental impact, due to the usage of water to navigation, is not a exhausted subject when talking only about the Hydric Resources Management, it is beyond, it has its origin at the River Basin and is discussed at the River Basin Management. In this theses it will be possible to notice that among the several means of transportation, the fluvial shipping is the less impactant because even the mean is natural and not anthropogenic like in other means. The necessity of hydrographic basin can be understood in some situations as a part of a Environmental Impacts Mitigation Program, not only in the river but in the river basin, that by the no consideration or because it does not exist a director plan, they suffered a disordered occupation, resulting in several environmental impacts. The chapters presented here are all interconnected, because we understand that only the simultaneous study will allow us to get the decrease of impacts at the river basin, as well as the decrease the environmental impact when performing the hydrographic basin.

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Boaz, Lindsey E. "Influences of fluvial geomorphology on aquatic-to-terrestrial Hg transport: evidence from protected and urban streams of central Ohio, USA." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1420822467.

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26

Bainbridge, Rupert. "Lost landslides : rock-avalanche occurrence and fluvial censoring processes on South Island, New Zealand." Thesis, Northumbria University, 2017. http://nrl.northumbria.ac.uk/32621/.

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Rock-avalanches (RAs) are a large (typically > 106 m3) and extremely rapid (30 - >100 m/s) type of landslide. RAs pose a significant hazard as they can runout over long distances and generate secondary hazards such as tsunami and unstable, cross-valley dams. Previous research on the distribution of rock-avalanche deposits (RADs) on the South Island, New Zealand has suggested that there are fewer deposits than would be expected for a seismically active, high-mountain region. This is due to their removal from the sedimentary record (censoring) by fluvial erosion, glacial entrainment, vegetation cover, sub-aqueous occlusion and deposit misidentification. Censoring of deposits skews magnitude-frequency relationships of RA occurrence and hinders hazard planning. This research examines processes acting to fluvially censor RADs on the South Island. 268 known, and 47 possible RADs were identified to provide the first RAD inventory for the entire South Island. The temporal distribution of RADs indicates censoring of the record over the Holocene. >500 year intervals exist between RA events from 12,000 to 2,000 years ago; a more complete record is shown for the last 1,000 to 100 years with intervals of > 50 - < 150 years. The last 100 years shows phases of co-seismic RAD generation, a period of RAD quiescence and a recent increase in aseismic RAD occurrence. The spatial distribution of RADs suggests that the West Coast, Fiordland and Nelson could have experienced fluvial censoring of deposits. The sediment routing characteristics of catchments in these regions, where the majority of rivers have direct pathways from RADs to the ocean, suggest that fluvially reworked RAD material could be stored within alluvial flats and braidplains. Agglomerate grains (microscopic grains which are diagnostic of RAs) were used to identify fluvially reworked RAD material. Grains were detected in dam-breach flood terraces up to 1km downstream of known RADs. Contemporary river sediment samples showed no agglomerate presence, this suggests that 1) agglomerates break down under extended fluvial transport, 2) they are not supplied to river systems outside of flood events, 3) agglomerates become diluted by other river sediment or 4) they become buried in discrete sedimentary layers. In order to investigate the redistribution of coarse RAD material within South Island rivers, a micro-scale flume model was developed. Using ultra-violet sand as a novel analogue for a RAD, the redistribution of material through an idealised South Island catchment could be examined. The model showed that RAD material is deposited in discrete aggradational layers in dam proximal locations. Downstream, the sedimentary signal is rapidly diluted by ordinary river sediment flux. The research shows that the RAD record for the South Island is incomplete and that fluvial censoring is prevalent within the West Coast, Nelson and Fiordland. The agglomerate tracing method can be used to identify the presence of RADs in fluvial systems proximal to RADs but the signal is undetectable after ~1km from the deposit. Both field sampling and flume modelling show that localised flood derived aggradational layers, close to deposit locations, will archive reworked RAD material. These results have important implications for understanding the magnitude and frequency of RADs within New Zealand and other similar high-mountain, tectonically active regions of the globe.

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Sipola, Maija Eliina. "Formation of the Ngandong paleoanthropological site and Solo River terrace sequence, Central Java, Indonesia." Diss., University of Iowa, 2018. https://ir.uiowa.edu/etd/6286.

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The early human paleoanthropological site at Ngandong, Central Java, Indonesia has significant impact on the models for human migration and evolution out of the African continent. Located on an abandoned stream bank above the Solo River, Ngandong archaeological digs have uncovered fourteen Homo erectus fossils that, based on their unique shape, are believed to have lived more recently than any other known examples of Homo erectus. However, this hypothesis has not been substantiated by previous studies at Ngandong due to a general lack of understanding about the formation of the site as a whole. This study seeks to overcome the limits of these previous studies by thoroughly examining the grain size, grain shape, mineralogy, geochemistry, and stratigraphy of the site to understand how it formed, and in turn, provide a necessary geological context to the Ngandong Homo erectus fossils. The results outlined in this dissertation suggest the fossil-bearing layers were deposited at the site (at the time a channel bottom) over a short period of time and were sourced from the volcanic arc that forms the southern portion of Java island.

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28

Allen, Phillip Paul. "Geomorphic response of upslope and fluvial systems to Holocene environmental change : Brandon Mountain Massif, Dingle Peninsula, Southwest Ireland." Thesis, Coventry University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.419760.

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Niemann, Jeffrey D. (Jeffrey Dean). "Scaling, modeling, and interpolation of fluvially eroded topography." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/84214.

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30

Lavest, Pascal. "Modélisation de la structure interne des réservoirs de type fluviatile : application sur un site de stockage de gaz en aquifère." Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_LAVEST_P.pdf.

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La modélisation géologique des réservoirs de type fluviatile est un domaine dans lequel de nombreuses techniques ont été développées, qui correspondent chacune à un contexte particulier, souvent déterminé par la nature et la densité des données disponibles. Dans le cadre de cette thèse, nous nous situons par rapport à l'étude d'un site de stockage de gaz naturel de type aquifère. La densité et la diversité dont nous disposons ici nous permettent d'envisager la construction d'un modèle déterministe. Pour cela, nous avons développé de nouveaux outils de modélisation, regroupés autour de trois thèmes : - la modélisation géométrique et la caractérisation volumique de séquences stratigraphiques. C’est le sens de la création d'un nouvel objet, que nous avons baptisé le gstack. - la création d'un outil de type grille régulière, auquel nous avons associé de nouvelles fonctionnalités. Celles-ci permettent, dans le cadre d'un projet de modélisation géologique complexe ou plusieurs types de maillages différents sont utilisés à différentes étapes de ce projet, d'intégrer l'ensemble des résultats obtenus sur un support de travail commun. - le développement d'un nouvel algorithme d'interpolation, basé sur la méthode D. S. I. , qui permet de contraindre par un champ non uniforme d'anisotropies l'estimation d'une propriété physique sur une grille régulière. Ces outils ont été testés et validés par la construction du modèle géologique d'un site de stockage en aquifère. Ce travail nous a également permis de montrer comment il était possible d'intégrer sur un seul modèle plusieurs sources d'informations différentes (données sismiques, données de puits, connaissance du géologue, etc)

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31

Ershadnia, Reza. "Hydro-thermo-chemo-mechanical Modeling of Carbon Dioxide Injection in Fluvial Heterogeneous Aquifers." University of Cincinnati / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1627666029684891.

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32

Silva, Jefferson Gil da Rocha. "Os canoeiros do ambiente urbano-fluvial: entre o porto da Ceasa e Careiro da Várzea." Universidade Federal do Amazonas, 2010. http://tede.ufam.edu.br/handle/tede/2569.

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Made available in DSpace on 2015-04-11T13:54:27Z (GMT). No. of bitstreams: 1 DISSERTACAO JEFFERSON GIL.pdf: 18869906 bytes, checksum: 76e688d451f0dd1e0d278eaeb7df1cd2 (MD5) Previous issue date: 2010-03-23 Fundação de Amparo à Pesquisa do Estado do Amazonas The waterfront city of Manaus extends from the mouth of the Tarumã river to the Puraquequara river. For a distance of 43 km long, at the left of the Negro river there are various ports, public or private, other small and private, generally improvised and environmentally degraded in the interim between the river and the city move the daily lives of manauense and people living in towns surrounding the capital. Among them, there is the port of Ceasa, located on the East Zone of Manaus. It composes and is part of the BR 319, that connects the capital till Porto Velho, and other regions of the Amazon and Brazil. In this thesis, we are focusing our attention to the work of the brigade leading the small boats typically regional that transport people and goods in an intense back-and-forth between the port of Ceasa till another one in the city of Careiro da Várzea, called Km 0. Our intention is to characterize the daily work environment and this segment of workers who live in the world of informality. We seek to understand its identity, its importance to the mobility of people and regional economic life. This port has a great importance in the movement of products done in the Industrial Pole of Manaus PIM, because of the ferries that across the Negro river towards the port of Careiro da Várzea, the marketing of regional products and the departure and arrival of the boats carrying passengers towards Manaus and cities surrounding the capital and vice versa. It is a place of confluence of these movements of intense rhythms during the day. Also, today is a territory occupied by dense business and the informal work where you can find everything: regional delicacies, fish and fruit that come from rural areas of the Amazon. In this environment are the leading canoe their boats in the movement back and forth under the sun and rain, facing the regional weather, with no fixed schedule and long hours in an urban river (in) sustainable and characterized by improvisation and the public neglect there demonstrated being stage of capacity of the Amazon man. A beira-rio da cidade de Manaus abrange desde a foz do rio Tarumã até o rio Puraquequara. Num percurso de 43km de extensão, às margens esquerdas do rio Negro, encontram-se vários portos, públicos ou privados; outros pequenos e particulares, em geral, improvisados e ambientalmente degradados, que no intermédio entre o rio e a cidade movimentam a vida cotidiana dos manauenses e das populações que vivem nas cidades do entorno da capital. Entre eles, situa-se o porto da Ceasa, localizado na Zona Leste de Manaus. Ele faz parte da BR 319, que liga a capital a Porto Velho, além de outras regiões da Amazônia e do Brasil. Nesta dissertação, centramos nosso olhar no trabalho dos canoeiros que conduzem os pequenos barcos tipicamente regionais que transportam pessoas e mercadorias num intenso vaivém entre o porto da Ceasa e o porto do município do Careiro da Várzea, denominado de km 0. Nosso objetivo é caracterizar o trabalho cotidiano e o ambiente desse segmento dos trabalhadores que vivem no mundo da informalidade. Procuramos compreender sua identidade, sua importância para a mobilidade das pessoas e para a vida econômica regional. Esse porto tem uma importância fundamental na circulação da mercadoria produzida no Polo Industrial de Manaus PIM, por meio das balsas que atravessam o rio Negro e Solimões até o porto do Careiro da Várzea, do escoamento dos produtos regionais e da saída e chegada dos barcos que transportam os passageiros no sentido Manaus-cidades ribeirinhas do entorno da capital, e vice-versa. Ele é um lugar de confluência desses movimentos de ritmos intensos durante o dia. Além disso, é hoje um território ocupado por empresas e pelo denso trabalho informal em que se vende tudo: guloseimas regionais, peixes e frutas que chegam das zonas rurais do Amazonas. Nesse ambiente, estão os canoeiros conduzindo os seus barcos no movimento de ida e vinda, sob o sol e a chuva, enfrentando as intempéries regionais, sem horário fixo e com longas jornadas num ambiente urbano fluvial (in)sustentável e caracterizado pela improvisação, pelo descaso público ali demonstrado, configurando-se como palco de resistência do homem amazônico.

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33

Waldschläger, Kryss [Verfasser], Holger [Akademischer Betreuer] Schüttrumpf, and Henner [Akademischer Betreuer] Hollert. "Transport processes of microplastic particles in the fluvial environment : erosion, transport and deposition / Kryss Lisanne Waldschläger ; Holger Schüttrumpf, Henner Hollert." Aachen : Universitätsbibliothek der RWTH Aachen, 2020. http://d-nb.info/1226303870/34.

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34

Roebuck, J. Alan Jr. "Environmental Dynamics of Dissolved Organic Matter and Dissolved Black Carbon in Fluvial Systems: Effects of Biogeochemistry and Land Use." FIU Digital Commons, 2018. https://digitalcommons.fiu.edu/etd/3755.

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Black carbon (BC) is an organic residue formed primarily from biomass burning (e.g., wildfires) and fossil fuel combustion. Until recently, it was understood that BC was highly recalcitrant and stabilized in soils over millennial scales. However, a fraction of the material can be solubilized and transported in fluvial systems as dissolved BC (DBC), which represents on average 10% of the global export of dissolved organic carbon (DOC) from rivers to coastal systems. The composition of DBC controls its reactivity, and it has been linked with a variety of in-stream processes that induce both carbon sequestration and evasion of CO₂ from aquatic systems, which suggest DBC may have a significant contribution within the global carbon cycle. The primary objectives for the thesis were to elucidate environmental factors that control the fate and transport of DBC in fluvial systems. Ultra-high resolution mass spectrometry was used to characterize DBC on a molecular scale whereas benzenepolycarboxylic acids were used to quantify and characterize BC in both dissolved and particulate phases (PBC). Sinks for polycondensed DBC were linked to a series of in-stream biogeochemical processes (e.g., photodegradation, metal interactions); whereas photooxidation of particulate charcoal led to production of DBC, suggesting photodissolution as a previously unrecognized source of DBC to fluvial systems. Coupling of DBC with PBC, however, was hydrologically constrained with sources varying over temporal scales and land use regimes. For DBC in particular, an enrichment of heteroatomic functionality was observed as a function of anthropogenic land use. Furthermore, land use coupled with stream order (a proxy for in-stream processing as defined by the River Continuum Concept) could explain significant spatial variability in organic matter (e.g., DOC) composition within an anthropogenically impacted system. With an increase in wildfire frequency projected with on-going climate change trends, parallel projections for increases in BC production are also expected. Furthermore, conversion of natural landscapes for urban and agricultural practices is also expected to continue in the coming decades. Thus, it is imperative to reach a comprehensive understanding of processes regulating the transport of DBC in fluvial systems with efforts to constrain future BC budgets and climate change models.

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35

Evans, Lisa J., and n/a. "The Influence of fluvial geomorphology on riparian vegetation in upland river valleys: south eastern Australia." University of Canberra. School of Resources Environmental and Heritage Sciences, 2003. http://erl.canberra.edu.au./public/adt-AUC20050404.112525.

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Healthy riparian vegetation has a positive impact on the adjacent river. Unfortunately, riparian vegetation is often threatened by human impacts such as dam construction and clearing. To gain the knowledge underlying the effects of such impacts and to aid riparian rehabilitation, the objective of this thesis was: to determine riparian vegetation association with, and response to, variation in fluvial geomorphology over several scales and consequently to fluvial disturbance. Only woody riparian plant species were considered. Flood disturbance was the unifying theme of this thesis. Linked to this theme and arising from the main objective was the supposition that plant interactions with the abiotic environment, but not biotic interactions between species, control riparian species distribution because of frequent fluvial disturbances. Woody riparian vegetation and riverine environmental variables were recorded along the upper Murrumbidgee River at three spatial scales based on a geomorphic hierarchy for Chapter 2. Multivariate analysis was used to group species and to associate environmental variables with vegetation at the three spatial scales. Observations at the two larger scales, of river segment (site) and riparian reach (transect), identified a river-longitudinal speciescomposition gradient associated with geology, river width and stream channel slope. Observations at the smallest scale of geomorphic units (plot) identified a lateral riparian gradient and also the longitudinal gradient; these gradients were associated with geomorphic variation, land use, plot elevation and also river longitudinal variables. Using the same data set, but varying the spatial scale of analysis caused the species composition pattern to change between scales. Increase in scale of observation, that is from geomorphic unit to reach and segment scales, resulted in disproportionate importance of rarer species and decreased importance of some key riparian species at the larger scales. It would appear that in this instance the geomorphic unit scale best described patches of different species composition because this scale had high spatial resolution and was also able to identify multiple gradients of environmental variation. It was recommended that riparian sampling take place at scales that represent dominant gradients in the riparian zone. These gradients are represented by geomorphic scales, indicating the appropriateness of using geomorphic based scales for observation of riparian vegetation. Chapter 3 considered whether there is a geomorphic template upon which riparian vegetation is patterned and whether it is associated with process variables, such as flooding and soil type. This question was investigated at different spatial scales in three ways: i) by an experiment to determine whether soil nutrient condition affects plant growth; ii) by graphical analysis of trends between geomorphic units, species and process variables; and iii) by analysis of vegetation distribution data. The smallest scale (meso) found experimental differences in plant growth because of soil type. Plants growing in sand had the lowest performance, with an average plant Relative Growth Rate (RGR) of 0.01, compared to plants growing in soils with small amounts of silt or clay particles, with an average plant RGR of 0.04. This pattern was attributed to differences in nutrients. Clear relationships were demonstrated at the larger geomorphic unit scale between species distribution and process variables. For example, hydrology and substratum type were found to be associated with geomorphic units and species. The largest scale considered in Chapter 3 was the riparian reach scale. At this scale species were clearly grouped around reach type. Therefore, geomorphology was considered to be a template for riparian species distribution. Findings in this chapter suggested that geomorphic variables should be good predictors of riparian species distribution. This hypothesis was tested and supported in Chapter 6. The experiments reported in Chapter 4 aimed to determine whether inundation depth and duration affected plant performance and survival for five common riparian zone species. Riparian seedling patterns in the field were also compared with experimental results to test whether species performance was reflected by field distribution. The experiments that were conducted included an inundation period and depth experiment, and a survival period test whilst under complete inundation. Biomass and height relative growth rates were determined, and the results were analysed using factorial Analysis of Variance. Obligate riparian species (Callistemon sieberi, Casuarina Cunninghamiana, Leptospermum obovatum) were found to be tolerant of inundation duration and depth, to the point where inundation provided a growth subsidy. On the other hand, non-obligate riparian species (Acacia dealbata, Kunzea ericoides) were either just tolerant of inundation or showed a negative growth response. For instance, C. sieberi demonstrated an average height RGR of 0.04 after complete inundation and 0.007 when not inundated, while A. dealbata had an average height RGR of 0.001 after complete inundation and 0.01 when not inundated. These experimental findings were found to closely reflect both seedling and adult plant distribution in the field such that inundation tolerant species were found close to the river and intolerant species further away. Thus, the conclusion was drawn that riparian species establishment and distribution is affected by inundation and that change to the flood regime could have serious impacts on riparian zone plant composition. The other aim of this chapter was to determine whether optimum germination temperatures were associated with flood or rainfall. Growth chamber germination trials were conducted at air temperatures of 15�C, 20�C and 25�C to determine the 'best' germination temperature. These germination patterns at different temperatures were then related to annual variation in field temperature, flooding period and rainfall. No evidence was found to suggest a relationship between ideal germination temperature and flood season, rather it was suggested that germination was patchy through time and may simply reflect recent rainfall. Investigations that were reported in Chapter 5 aimed to elucidate relationships between species and flow velocity variables. Two experiments were conducted: i) a flume experiment to determine the effect of flow velocity on plant growth; and ii) an experiment to observe the response of plants to damage (imitating flood damage) and inundation. Field observations of species distribution and flow velocity related variables were also conducted to put the flume results into a real-world context. Treatments for the flume experiment were fast flow velocity (0.74 m s-1), slow velocity (0.22 m s-1) and no velocity (control) but still inundated. All treatments were flooded completely for four days. Subsequent biomass and height relative growth rates were determined, and the results were analysed using factorial Analysis of Variance. Results were unexpected, given that obligate species exposed to the fastest velocity had the highest growth rate with an average height RGR of 0.046, compared to plants in still water, which grew the least with an average height RGR of 0.013. It was hypothesised that this response was because relatively greater carbon dioxide and oxygen levels were available in the moving water compared to the still water. With regard to shoot damage, the species that were nonobligate riparian species lost more leaves from velocity treatment than the obligate riparian species. The cut and flood experiment found growth of the obligate species (Casuarina cunninghamiana) to be greater after cutting than the non-obligate species. Flooding was not found to have an effect in the cut and flood experiment, probably because the period to sampling after flood treatment was longer (4 weeks) than other flooding experiments (3 weeks). Field observations were found to support the experimental findings, with a gradient of species across the riparian zone that reflected potential flood velocities. Therefore, velocity is one of a suite of riparian hydrological factors that are partially responsible for the gradient of species across the riparian zone. Potentially the absence of flooding could result in a homogeneous mix of species, rather than a gradient, except on the very edge of the river. The study that was reported in Chapter 6 investigated a technique for predicting riparian vegetation distribution. One of the aims of this investigation was to address a current riparian rehabilitation shortfall, which was how to objectively select species to plant for rehabilitation. Field data were collected from three confined river valleys in south-eastern New South Wales. Using data on plant species occurrence and site and plot measures of soils, hydrology and climate, an AUSRIVAS-style statistical model, based on cluster and discriminant analysis, was developed to predict the probability of species occurrence. The prediction accuracy was 85 % when tested with a separate set of plots not used in model construction. Problems were encountered with the prediction of rarer species, but if the probability of selection was varied according to the frequency of species occurrence then rarer species would be predicted more often. Various models were tested for accuracy including three rivers combined at the geomorphic unit (plot) scale and riparian reach (transect) scale in addition to a Murrumbidgee River plot scale model. Surprisingly, the predictive accuracy of the all rivers and single river models were approximately the same. However, the difference between the large scale and small scale models pointed to the importance of including small scale flood-related parameters to predict riparian vegetation. When these riparian predictions were compared to predictive outcomes from a hill slope model, which was assumed to be affected by fewer disturbances (i.e. flooding), predictive accuracies were not very different. Overall though, predictive accuracy for riparian vegetation was high, but not good enough to support the supposition that riparian vegetation is abiotically controlled because of frequent flood disturbance. Nevertheless, geomorphology and consequently flood effects are still important for the determination of the riparian community composition. Overall, riparian vegetation was found to be closely linked to its environment (evidenced in Chapters 2, 3, 4, 5) in a predictable manner (Chapter 6). Species pattern relied on flood disturbance affecting species distribution. Some riparian species were found to be highly tolerant of flooding and gained a growth advantage after flooding (Chapters 4 and 5). Therefore, flood tolerance was important for the formation of a species gradient across the riparian zone. These species tolerances and growth requirements reflect riparian geomorphic pattern (Chapter 3), which was suggested to form a template on which riparian vegetation is structured.

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36

Long, Hazel Elizabeth. "New insight into the drivers, magnitude and sources of fluvial CO2 efflux in temperate and arctic catchments." Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7963/.

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Freshwater systems are generally found to be sources of CO2 to the atmosphere and evasion of CO2 from fluvial systems is now recognised to be a significant component of the global carbon cycle. However detailed understanding of fluvial carbon dynamics and controls on the system is lacking and global coverage of published data is sparse, but thorough understanding across a broad range of locations is crucial if global carbon budgets are to be refined. This research addresses this lack of understanding by investigating the magnitude, controls and sources of CO2 efflux across five catchments with different catchment characteristics, global locations and climate-change sensitivities. In doing so new understanding is used to explore a novel method for large-scale upscaling of CO2 efflux, time series reconstruction of the source and magnitude of CO2 efflux and incorporation of an Arctic region into the global fluvial carbon budget. The magnitude of and controls on CO2 efflux are not well understood, although it has been suggested that increased flow velocity and turbulence can enhance CO2 efflux rates. This research uses direct and contemporaneous measurements of CO2 efflux (range: -3.53 to 107 μmol CO2 m−2 s−1), flow hydraulics (e.g. mean velocity range: 0.03 to 1.39 m s-1; shear Reynolds number range: 350 to 174000), and water chemistry (e.g. pCO2 range: 388 to 4660 ppm), at sites in three UK catchments to assess whether flow intensity (a term which is used to describe one or more measures of flow strength and turbulence) is a primary control on CO2 efflux. These field sites have been chosen as they have contrasting size and land use: Drumtee Water (DW), 5.7 km2 and rural, the River Kelvin (RK), 335 km2 and urban, and the River Etive (RE), remote and snow-melt influenced. At the more soil-dominated sites DW and RK, a strong positive logarithmic relationship exists between CO2 efflux and measures of flow intensity (e.g. shear Reynolds number, overall R2 = 0.69), but this relationship is strengthened by including pCO2 (overall R2 = 0.72). Flow intensity may have a key influence on CO2 influx, although data are limited. A method using visual classification of flow intensity shows promise for supporting large-scale upscaling of fluvial CO2 efflux, if classification of water surface state can be standardised. Movement of dissolved inorganic carbon (DIC) through the hydrological cycle is an important component of global carbon budgets, and how they may respond to changing climatic conditions. However uncertainty remains about the hydrological and biogeochemical controls on DIC transmission through a catchment. Using contemporaneous measurements of DIC concentration ([DIC]) and stable carbon isotope composition of the DIC pool (δ13CDIC), fluvial DIC at more soil dominated sites, DW and RK, is found to vary considerably in response to changes in catchment hydrology. At low flow groundwater dominates, and has similar composition in both systems ([DIC]: 1.5 mmol L-1 DW, 2.0 mmol L-1 RK; δ13CDIC: -9 ‰ DW and RK) indicating a common hydrogeological inheritance in DIC, that is comparable to that of other temperate and tropical locations. Differences in composition at high flow ([DIC]: 0.1 mmol L-1 DW, 1.0 mmol L-1 RK; δ13CDIC: -23 ‰ DW, -14 ‰ RK) reflect catchment land use, and a lower contribution of soil water to the DIC pool in the more urban catchment (RK). Measured diel cycles in DIC pool composition at DW indicate biological processes modify the pool, and time series reconstructions of pool composition and CO2 efflux at DW reveal seasonal- and flow-related patterns in this biological activity. Time series reconstructions also reveal that at DW terrestrial-aquatic-atmospheric carbon cycling is rapid during event flows, with large amounts of CO2, of soil-origin, effluxed to the atmosphere in relatively short periods of time. Conversely, at low flows, CO2 efflux is of smaller magnitude and primarily fuelled by groundwater, and terrestrial-aquatic-atmospheric carbon cycling is slower. The reconstructions allow for inter-year comparisons which are useful in assessing for behaviours in CO2 source and feedback that might be typical under climate change-induced changes in hydrology (e.g. wetter winters, drier summers, more frequent large flow events). Global ice melt and permafrost thaw are increasing due to climate change, effects of melting ice and thawing permafrost on the global carbon cycle, and carbon cycling dynamics of the melt/thaw waters are not well understood. Data from the River Etive has few similarities to that of DW and RK and indicates that snow- and ice- dominated systems may behave very differently to more soil-dominated systems in terms of magnitude and controls on efflux and sources and mixing of the DIC pool. This is confirmed by data collected from the melt/thaw waters of two cryospheric systems in Greenland: a Greenland Ice Sheet (GrIS) drainage river (Akuliarusiarsuup Kuua River, or AR) and the local permafrost-landscape surface-drainage systems (PLST). CO2 efflux appears independent of flow controls in both systems, and instead seems to be pCO2 limited (average pCO2: 115 ppm AR, 596 ppm PLST), with spatial variation in AR (efflux decreases downstream) and temporal variation in PLST (efflux decreases with melt season progression). The frequent occurrence of CO2 influx (measured in 64% and 14% of cases in AR and PLST respectively), which has rarely been reported from other rivers globally, reveals that Arctic fluvial systems can periodically act as net sinks of CO2 and this should be incorporated into global carbon budgets. The occurrence of CO2 influx, and dominance of air-water CO2 exchange in these low pCO2 systems, is reflected in the DIC pool composition which is 13C-enriched and approaches isotopic equilibrium with the atmosphere (~0 ‰), and indicates that soil and ground water contributes little to the DIC pool under frozen ground conditions. Radiocarbon analysis gives further insight into the source of carbon in these systems, revealing that the GrIS is releasing old DOC (~5200 to 6600 yrs BP) upon melting, which is considered to be highly biolabile and may prime bacterial activity and feedback to climate change, and meltwaters are returning old carbon (800 to 960 yrs BP) to the atmosphere via CO2 efflux. Thus it appears that climate change (via melting ice sheets) may be a driver of the age of atmospheric carbon composition. The effluxed CO2 being less old than the DOC indicates the source of CO2 efflux is a mixed pool of respired/UV-oxidised old DOC and modern atmospheric CO2 from drawdown. In contrast to GrIS meltwaters, and the permafrost of other global locations (e.g. the Siberian Yedoma deposits), the permafrost landscape of the Kangerlussuaq region of Greenland is cycling modern carbon and appears not to be degrading, as old carbon is not found in, or degassed from, the fluvial systems. In summary this research contributes to a greater understanding of fluvial carbon dynamics and the processes controlling the return of CO2 to the atmosphere via efflux, across an array of catchment types, sizes, land uses and global locations, and makes contributions of novel data to a number of areas of fluvial carbon cycling research where there are scarcities. Marked differences in the fluvial carbon cycling dynamics of cryospheric and snow-melt dominated systems compared to soil-dominated terrestrial systems are uncovered, novel upscaling attempts made using new findings of the research, and a number of exciting new research directions and opportunities that could enhance the findings of this work are identified. Overall, this research takes steps towards a greater understanding of fluvial carbon cycling dynamics on a global scale and improved projections of the likely response of fluvial systems to climate change, ultimately aiding the community to be more prepared for what our shifting climate will bring.

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Padovezi, Carlos Daher. "Conceito de embarcações adaptadas à via aplicado à navegação fluvial no Brasil." Universidade de São Paulo, 2003. http://www.teses.usp.br/teses/disponiveis/3/3135/tde-26112003-154811/.

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É elaborada uma proposta de procedimentos de projetos de comboios fluviais adaptados às condições existentes das vias navegáveis, a partir de uma visão ampliada da necessidade de obtenção de menores custos de transporte, com níveis adequados de segurança e de respeito ao meio ambiente. Uma análise das inter-relações técnicas entre hidrovias e embarcações, assim como dos condicionantes e implicações do conceito de embarcações adaptadas às vias navegáveis, orientou a elaboração do modelo. Este foi estruturado em módulos, com o objetivo de reproduzir, um a um, os fatores mais importantes que influenciam a eficiência, a segurança e o nível de interferência ambiental do transporte de cargas por comboios. Um programa computacional foi desenvolvido como instrumento de aplicação do modelo, consolidando os procedimentos propostos para a escolha das melhores alternativas de projeto e de operação de comboios. Resultados experimentais com comboios em escala real e com modelos em tanques de provas, foram utilizados para validação dos procedimentos adotados. Dados de acidentes com comboios em várias hidrovias do mundo foram utilizados como bases para avaliações de risco. O modelo foi aplicado aos casos de transportes de soja pela hidrovia Tietê-Paraná e pelo rio Araguaia, exemplificando as formas de análise e de escolha das alternativas de soluções de projeto. Ao final, os resultados obtidos comprovaram a utilidade da adoção de um enfoque mais abrangente do processo de projeto de comboios fluviais. It is proposed a procedure model for design of barges push-tow adapted to waterway actual conditions, with the purpose of minimize transportation costs but always making verifications of navigation safety and ambient interferences levels. An analysis of inter-relations on inland waterways and cargo ships and, also, detailed conditionings and implications of waterway adapted ships concept, was used for model elaboration. It was structured in blocks to reproduce, one to one, the most important factors that modify efficiency, safety and environmental interference levels of barges push-tow cargo transportation. A computational program was developed to consolidate the proposed model and to apply procedures to choose best design and operational alternatives. Results of full scale and towing tank tests with push-tows were used to verify the mathematical and semi-empirical models. Barges push-tows accidents data from waterways of the world was used as risk model basis. To evaluate its effectiveness, the model was applied to bulk grain transportation cases by Tietê-Paraná waterway and by Araguaia river. The results shows that the special emphasis on three factors (efficiency, safety and ambient) improves the quality of barges push-tow design process.

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Silva, Rui Pedro Guerreiro Duarte Rivaes da. "Exploring riparian vegetation interactions with flow regime and fluvial processes for an improved river management and conservation." Doctoral thesis, ISA/UL, 2018. http://hdl.handle.net/10400.5/17516.

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VanDeVelde, David M. "INTERPRETATION OF THE DEPOSITIONAL ENVIRONMENT AND PALEOCLIMATE OF DINOSAUR SITES, BRUSHY BASIN MEMBER OF THE JURASSIC MORRISON FORMATION, EAST-CENTRAL UTAH." Bowling Green State University / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1155136956.

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Hurley, Rachel. "Metals and microplastics in the 'first industrial city' : fluvial sediment contamination in the upper Mersey and Irwell catchments, UK." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/metals-and-microplastics-in-the-first-industrial-city-fluvial-sediment-contamination-in-the-upper-mersey-and-irwell-catchments-uk(c610089c-6ad3-439a-87fa-e6576698ced3).html.

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Rivers have been the recipients of waste for millennia. However, since the onset of industrial and urban development, major degradation of fluvial systems has been observed globally. This has encompassed a wide range of contaminants from numerous potential sources. Despite efforts to reduce inputs, contamination continues to persist in many catchments. Metal contamination of fluvial sediments is a well-established problem. Conversely, microplastics are an emerging contaminant, for which there is a paucity of data regarding their sources, behaviour, and fate. Based on the onset of industrialisation, Manchester is often heralded the 'first industrial city'. During the industrial period, the fluvial network became heavily contaminated. By the 1970s, it was amongst the most polluted river systems in Europe. Despite this background, no study has thus far undertaken a systematic, catchment-wide survey of sediment-associated contamination. This study assesses patterns of metal and microplastic contamination in fluvial sediments of the Irwell and upper Mersey catchments (1527 km2), which comprise the Manchester river network, from the onset of the industrial period to the present day. Five metal(loid)s have been studied and microplastics are assessed by type, size, and density for the first time. Metal concentrations in fine-grained bed sediments are heavily enriched across the entire fluvial network, even in headwater reaches. By examining spatial patterns, it is possible to attribute a portion of this to the reworking of historically-contaminated material; although, modern, urban sources are also important. Sources of metals to channel beds are numerous and spatially complex. This is also the case for microplastic contamination; although, microplastic particles are not bound to natural sediments and exert more transient behaviour in fluvial systems. Following an extreme flood event on Boxing Day 2015 and a sustained period of high flows (winter 2015/16), metal contamination was shown to present markedly conservative behaviour despite significant reworking of bed sediments. Metal mobility was generally low and was not affected in the long-term by hydrological processes. Despite this, the results indicate that bed sediment-associated metal contamination is likely to persist into the future at levels that exceed sediment quality guidelines. In contrast, flooding is very effective in flushing high concentrations of microplastics from channel beds. This suggests that microplastic contamination can be effectively reduced through source control. The environmental significance of microplastic contamination was directly observed through the ingestion of microplastics by freshwater Tubifex worms at the distal end of the Irwell system (Salford Quays). Microplastic concentrations within worm tissue were high, indicating an increased risk for trophic transfer. This also presents a potential link to the human food chain. Furthermore, both metals and microplastics accumulate in floodplain deposits. Floodplains are effective in preserving microplastics, recording the temporal evolution of microplastic contamination over the last 75 years. Maximum values are observed in the late 1960s/early 1970s. Conversely, elevated metal concentrations occur much earlier and reflect catchment-wide patterns of industrialisation and urban growth. Reworking of channel banks forms a secondary source of metals and microplastics to the active river channel and downstream environments that will persist long into the future. Thus far, microplastics have passed under the monitoring radar and sediment contamination is rarely given due consideration in assessments of river quality, such as in the Water Framework Directive. However, this study shows that both metals and microplastics within fluvial sediments are important contaminants and have significant implications for the health of the entire aquatic system.

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Colaço, Camila Destro [UNESP]. "Determinação da fração lábil de mercúrio em águas fluviais." Universidade Estadual Paulista (UNESP), 2012. http://hdl.handle.net/11449/92820.

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Made available in DSpace on 2014-06-11T19:26:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-10-05Bitstream added on 2014-06-13T19:13:09Z : No. of bitstreams: 1 colaco_cd_me_rcla.pdf: 563401 bytes, checksum: 150cea38baa3e27062588be6455a84cb (MD5) Neste trabalho foi desenvolvido um método para determinação da fração lábil de mercúrio (II) em águas fluviais com o uso da técnica de difusão em filmes finos por gradiente de concentração (DGT). Nesse contexto, alguns materiais não comumente utilizados na técnica foram investigados, a membrana P 81 como meio ligante e o gel de agarose como meio difusivo. Esses materiais foram avaliados em relação aos principais parâmetros interferentes na técnica de DGT, pH, força iônica, temperatura, presença de metais e substâncias complexantes. Em seguida, foram feitas aplicações in situ nos rios: Negro e Solimões – AM e Ribeirão Claro – SP. Os resultados indicaram que para valores de pH entre 3,5 – 8,5 e força iônica entre 0,5 e 100 mmol L-1, normalmente encontrados em águas naturais, o método pode ser utilizado. Os metais Ca, Mg, Fe, Zn, Mn e Cu, não interferiram na quantificação de mercúrio pela membrana P 81. A concentração lábil de mercúrio encontrada no rio Negro foi de 13 ± 1,4 x 10-3 μg L-1. A concentração lábil de mercúrio no rio Solimões ficou abaixo do limite de detecção, quanto ao Ribeirão Claro na imersão realizada no período seco a concentração lábil de mercúrio foi de 1,8 ± 0,71 x 10-3 μg L-1 e na imersão realizada no período chuvoso foi de 0,621 ± 0,024 x 10-3 μg L-1. Esses valores lábeis foram menores que os encontrados para concentração dissolvida de Hg nos rios estudados. Os dispositivos preparados com os materiais avaliados são de fácil manipulação, obtiveram bom desempenho diante dos principais interferentes da técnica e devido à capacidade de pré-concentração do sistema DGT, podem ser utilizados para medições de mercúrio em água de rio, mesmo para baixas concentrações de mercúrio A method for the determination of labile fraction of mercury in river waters by applying diffusive gradients in thin films technique (DGT), was developed in this work. An unconventionally used P81 cationic membrane and agarose gel (as binding and diffusive layers respectively) were evaluated against the main DGT technique parameters such as pH, ionic strength, temperature, potentially interfering metals and complexing substances. Then, the in situ immersions were done in the Negro and Solimões rivers – AM, and Ribeirão Claro river – SP. The results indicated that for pH values between 3.5 – 8.5 and ionic strength between 0.5 and 100 mmol L-1, normally found in natural waters, the method can be used. The metals Ca, Mg, Fe, Zn, Mn and Cu did not interfere in the measurements of mercury by P 81 membrane. The labile concentration of mercury found in Negro river was 13 ± 1.4 x 10-3 μg L-1, while in the Solimões river was lower than the detection limit. In the Ribeirão Claro river, immersions at dry and rain season were carried out, and the labile concentrations found were 1.8 ± 0.71 x 10-3 μg L-1 and 0.621 ± 0.024 x 10-3 μg L-1 respectively. Those labile values were smaller than the dissolved concentration of Hg in those three studied rivers. The DGT devices arranged with P 81 membrane and agarose gel are easily handled, and they also present a good performance in relation of the main interferences of DGT technique. Furthermore, due to its pre-concentration ability it can be applied to measure mercury in river waters, even at low concentrations

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Colaço, Camila Destro. "Determinação da fração lábil de mercúrio em águas fluviais /." Rio Claro : [s.n.], 2012. http://hdl.handle.net/11449/92820.

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Orientador: Amauri Antonio Menegario Banca: Jose Roberto Ferreira Banca: Marcelo Loureiro Garcia Resumo: Neste trabalho foi desenvolvido um método para determinação da fração lábil de mercúrio (II) em águas fluviais com o uso da técnica de difusão em filmes finos por gradiente de concentração (DGT). Nesse contexto, alguns materiais não comumente utilizados na técnica foram investigados, a membrana P 81 como meio ligante e o gel de agarose como meio difusivo. Esses materiais foram avaliados em relação aos principais parâmetros interferentes na técnica de DGT, pH, força iônica, temperatura, presença de metais e substâncias complexantes. Em seguida, foram feitas aplicações in situ nos rios: Negro e Solimões - AM e Ribeirão Claro - SP. Os resultados indicaram que para valores de pH entre 3,5 - 8,5 e força iônica entre 0,5 e 100 mmol L-1, normalmente encontrados em águas naturais, o método pode ser utilizado. Os metais Ca, Mg, Fe, Zn, Mn e Cu, não interferiram na quantificação de mercúrio pela membrana P 81. A concentração lábil de mercúrio encontrada no rio Negro foi de 13 ± 1,4 x 10-3 μg L-1. A concentração lábil de mercúrio no rio Solimões ficou abaixo do limite de detecção, quanto ao Ribeirão Claro na imersão realizada no período seco a concentração lábil de mercúrio foi de 1,8 ± 0,71 x 10-3 μg L-1 e na imersão realizada no período chuvoso foi de 0,621 ± 0,024 x 10-3 μg L-1. Esses valores lábeis foram menores que os encontrados para concentração dissolvida de Hg nos rios estudados. Os dispositivos preparados com os materiais avaliados são de fácil manipulação, obtiveram bom desempenho diante dos principais interferentes da técnica e devido à capacidade de pré-concentração do sistema DGT, podem ser utilizados para medições de mercúrio em água de rio, mesmo para baixas concentrações de mercúrio Abstract: A method for the determination of labile fraction of mercury in river waters by applying diffusive gradients in thin films technique (DGT), was developed in this work. An unconventionally used P81 cationic membrane and agarose gel (as binding and diffusive layers respectively) were evaluated against the main DGT technique parameters such as pH, ionic strength, temperature, potentially interfering metals and complexing substances. Then, the in situ immersions were done in the Negro and Solimões rivers - AM, and Ribeirão Claro river - SP. The results indicated that for pH values between 3.5 - 8.5 and ionic strength between 0.5 and 100 mmol L-1, normally found in natural waters, the method can be used. The metals Ca, Mg, Fe, Zn, Mn and Cu did not interfere in the measurements of mercury by P 81 membrane. The labile concentration of mercury found in Negro river was 13 ± 1.4 x 10-3 μg L-1, while in the Solimões river was lower than the detection limit. In the Ribeirão Claro river, immersions at dry and rain season were carried out, and the labile concentrations found were 1.8 ± 0.71 x 10-3 μg L-1 and 0.621 ± 0.024 x 10-3 μg L-1 respectively. Those labile values were smaller than the dissolved concentration of Hg in those three studied rivers. The DGT devices arranged with P 81 membrane and agarose gel are easily handled, and they also present a good performance in relation of the main interferences of DGT technique. Furthermore, due to its pre-concentration ability it can be applied to measure mercury in river waters, even at low concentrations Mestre

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Gradella, Frederico dos Santos. "Morfologia do relevo da porção sul do megaleque fluvial do Taquari, Pantanal da Nhecolândia, Brasil /." Rio Claro, 2012. http://hdl.handle.net/11449/102882.

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Orientador: Juércio Tavares de Mattos Coorientador: Arnaldo Yoso Sakamoto Banca: Cenira Maria Lupinacci da Cunha Banca: Sérgio dos Anjos Ferreira Pinto Banca: Vitor Matheus Bacani Banca: Ericson Hideki Hayakawa Resumo: O Pantanal é uma região deprimida e plana que sofre inundações periódicas anuais causadas pelo fraco gradiente topográfico e pela capacidade limitada de escoamento das águas pelos canais fluviais durante e após o período que se concentram as chuvas (novembro a maio). A planície pantaneira está localizada no interior da Bacia do Alto Paraguai, que tem, portanto, como rio tronco o Paraguai. Como é uma bacia sedimentar, o Pantanal apresenta seu relevo formado por diversos sistemas deposicionais, como os leques fluviais e as planícies de inundação. Dentre os leques fluviais, o mais evidente é o formado pelo rio Taquari, cujo rio flui pelo Planalto de Maracajú-Campo Grande e ao adentrar a planície se torna um rio meandrante e mais a jusante apresenta drenagem distributária formando o lobo atual até alcançar as margens esquerdas do rio Paraguai. O presente trabalho se concentrou principalmente quanto ao aprimoramento dos conhecimentos da morfologia do relevo da região do Pantanal Sul-mato-grossense conhecida como Nhecolândia, que é a porção sul do leque fluvial do Taquari. Diversos autores já discutiram sobre os aspectos físicos presentes nesta região, porém, até então, não existia uma contribuição direta quanto a definição/padronização terminológica dos elementos do relevo, sendo este então a motivação para realização deste trabalho. Assim, o objetivo é identificação, classificação e padronização terminológica das feições do relevo; compreensão e associação das feições com as unidades da paisagem; e por fim, realizar uma compartimentação. Para a realização deste, utilizou-se produtos gerados através de processamento digital de sensores remotos em sistema de informação geográfica, trabalhos de campo para confirmação das informações obtidas pelos processamentos digitais e também... (Resumo completo, clicar acesso eletrônico abaixo) Abstract: The Pantanal wetland is a large floodplain with seasonal inundation caused small topographic variation and the limited capacity of runoff river channels during and after the period of concentration of rainfall (November to May), with the water river of the Upper Paraguay. How is a sedimentary basin the Pantanal presents its relief formed depositional systems, like as fans and floodplains. The Taquari fan is more expressive and the river through the Plateau-Maracajú Campo Grande and enter the plain becomes a meandering river and after the drainage is distributary until the Paraguay River. This study aimed to increase knowledge of the morphology of the relief of the Pantanal region of Mato Grosso do Sul state known as Nhecolândia southern portion of the of Taquari fan. Several authors did research about physical aspects present in this region but don't exist a direct contribution as the definition/terminology of elements of relief so this is the motivation for a to do this work. The aim is the identification, classification and terminology standardization of relief features; understanding of the features and association with the landscape and perform a subdivision. For a make this research was used products generated by digital processing of remote sensing in the geographic information system, field work to confirm the information obtained by digital processing and also collected sediment samples for granulometric characteristics, survey forms and raising the pH and conductivity of surface waters. Based on the literature it was possible to identify several definitions for the same feature of relief with local appointments as "cordilheiras", "baías", "salinas", "corixos" and "vazantes". The result it has several of these classifications were sometimes understood as a combination of elements of the physical environment, and the features of these... (Complete abstract click electronic access below) Doutor

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Rocchio, Andrea Michelle. "A Comparison of Rural and Urban Fluvial Systems as a Function of Land Cover Changes in Summit County, Ohio." University of Akron / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron1491401461044589.

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45

Porter, Steven. "The Relationship between Methylation of Mercury and the Fluvial Geomorphic Variables of Streams across the Continental United States." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1340125133.

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Hamshaw, Scott Douglas. "Fluvial Processes in Motion: Measuring Bank Erosion and Suspended Sediment Flux using Advanced Geomatic Methods and Machine Learning." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/827.

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Excessive erosion and fine sediment delivery to river corridors and receiving waters degrade aquatic habitat, add to nutrient loading, and impact infrastructure. Understanding the sources and movement of sediment within watersheds is critical for assessing ecosystem health and developing management plans to protect natural and human systems. As our changing climate continues to cause shifts in hydrological regimes (e.g., increased precipitation and streamflow in the northeast U.S.), the development of tools to better understand sediment dynamics takes on even greater importance. In this research, advanced geomatics and machine learning are applied to improve the (1) monitoring of streambank erosion, (2) understanding of event sediment dynamics, and (3) prediction of sediment loading using meteorological data as inputs. Streambank movement is an integral part of geomorphic changes along river corridors and also a significant source of fine sediment to receiving waters. Advances in unmanned aircraft systems (UAS) and photogrammetry provide opportunities for rapid and economical quantification of streambank erosion and deposition at variable scales. We assess the performance of UAS-based photogrammetry to capture streambank topography and quantify bank movement. UAS data were compared to terrestrial laser scanner (TLS) and GPS surveying from Vermont streambank sites that featured a variety of bank conditions and vegetation. Cross-sectional analysis of UAS and TLS data revealed that the UAS reliably captured the bank surface and was able to quantify the net change in bank area where movement occurred. Although it was necessary to consider overhanging bank profiles and vegetation, UAS-based photogrammetry showed significant promise for capturing bank topography and movement at fine resolutions in a flexible and efficient manner. This study also used a new machine-learning tool to improve the analysis of sediment dynamics using three years of high-resolution suspended sediment data collected in the Mad River watershed. A restricted Boltzmann machine (RBM), a type of artificial neural network (ANN), was used to classify individual storm events based on the visual hysteresis patterns present in the suspended sediment-discharge data. The work expanded the classification scheme typically used for hysteresis analysis. The results provided insights into the connectivity and sources of sediment within the Mad River watershed and its tributaries. A recurrent counterpropagation network (rCPN) was also developed to predict suspended sediment discharge at ungauged locations using only local meteorological data as inputs. The rCPN captured the nonlinear relationships between meteorological data and suspended sediment discharge, and outperformed the traditional sediment rating curve approach. The combination of machine-learning tools for analyzing storm-event dynamics and estimating loading at ungauged locations in a river network provides a robust method for estimating sediment production from catchments that informs watershed management.

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Schokker, Jeroen. "Patterns and processes in a Pleistocene fluvio-aeolian environment : Roer Valley Graben, south-eastern Netherlands /." Utrecht : Koninklijk Nederlands Aardrijkskundig Genootschap [u.a.], 2003. http://www.gbv.de/dms/goettingen/367600722.pdf.

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Bissell, Corrina. "Transportation of Trace Metals and Major Elements in the Ottawa River, Northwest Ohio." Bowling Green State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1342564813.

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Molina, Paredes María Ximena. "El paisaje fluvial en la gestión del recurso hídrico (Chile): Caso de estudio río Limari." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/97246.

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El agua bajo el enfoque ecosistémico es un recurso clave para el desarrollo socioeconómico y en Chile presenta problemas de escasez, como lo es para la cuenca del Río Limarí, IV Región (semiárida), localizada en una zona de transición climática, con precipitaciones en disminución desde 30 años. Proyecciones futuras, indican un aumento de su la demanda, siendo imprescindible compatibilizar los procesos de desarrollo de estas con la protección hídrica, bajo una gestión integrada. Se propone una metodología de evaluación en el marco de la norma secundaria de calidad de agua continental superficial, a través del Plan de Vigilancia Ambiental para aportar a la toma de decisiones para una gestión preventiva. El río posee una dinámica temporal y espacial, en su estructura hidromorfológica, física y química con consecuencias biológicas, dado por su propia naturaleza y las actividades antrópicas de la cuenca. Los ríos están conformados por parches heterogéneos que interactúan, y por si solos constituyen un paisaje fluvial, por lo que las escalas espaciales y temporales son cruciales de definir al evaluar sus estados ecológicos. Se evaluó la calidad del agua en seis subcuencas, elaborando previamente un modelo conceptual, basado en bioindicación, el cual se puso a prueba y se ajustó en dos campañas de terreno. Se levantaron datos del componente hidromorfógico (índice QBR e IHF), físico y químico (metodología estandarizada APHA.) y biológico (índices bióticos). Los resultados indicaron la influencia de actividades agrícolas y mineras en la calidad del agua, un aumento de perturbaciones hacia los tramos aguas abajo y bajo embalse. Los hábitat mas heterogéneos fueron los tramos de mayor altura, con valores de IHF (> 75 ) y QBR (buena calidad). Las estaciones aguas abajo presentaron pH más básicos (> 7.5), altas DQO > 40 mg/L y tendencia a eutrofización. El índice Ch SIGNAL reflejó aguas de mala calidad en los tramos más bajos, comparado con los de mayor altura, y correlación significativa positiva con índices hidromorfológicos, como criterio de validación. El modelo propuesto fue difundido y consensuado con actores de interés en la gestión. Se elaboró un protocolo de monitoreo, y se recomendó el índice biótico Ch SIGNAL para el Programa de Vigilancia. Se concluye que, los macroinvertebrados bentónicas, sirven de bioindicadores al constituir variables de estado, de cambios físicos y químicos del sistema, pueden ser una herramienta para evaluar el estado ecológico de los ríos, ante la norma secundaria de calidad de aguas continentales superficiales. According to the ecosystem concept approach, water is a key factor for the socioeconomic development and, in Chile it represents scarcity problems such as the case of the river Limarí, IV semi-arid Región (30°15’ - 31°20’ south latitude), located at an area of climatic transition with decreasing rainfall since the last 30 years indicating an increase in demand and showing that it is indispensable to find integral compatibility between the development and hydrological availability protection. An evaluation methodology under the frame of the secondary standard of surface freshwater quality through an Environmental Vigilance Plan that should help as prevention management determinations is proposed. This river presents a temporal and spatial dynamics in its hydromorphological, physic and chemical structure with biological consequences due to its own structure and anthropic activities at the basin. Rivers are structured as heterogeneous patchs, that interact and by themselves they conform a fluvial landscape, so that spatial and temporal characteristics are crucial to be assessed in evaluating river ecological state. Water quality was evaluated at six sub-basins, with a previous design of a conceptual model based on bioindication that was tested and adjusted in two field trips. Data on hydromorphological (QBR and IHF indexes) physical and chemical data (standard APHA methodology) and biology (biotic indexes). Results indicated the influence of agriculture and mining activities in water quality, such as an increase of the disturbances towards low waters and down a reservoir. The most heterogeneous habitats were the higher altitude sites, with high IHF values (> 75) and QBR (good river border quality). The lower sampling stations showed more basic pH (> 7.5), high DQO (>40 mg/L) and a tendency to eutrophication. The Ch SIGNAL index showed bad quality waters at lower sites compared to higher altitude and a positive correlation with hydromorphological indixes as a validation criteria. The proposed model was publicized and approved by interested management persons. A monitoring protocol was elaborated and the biotic Index Ch SIGNAL was recommended to be used in the Vigilance Program. Conclusions state that benthic macro invertebrates are systems useful bio indicators of physic and chemical state variables as a tool to evaluate the river ecological state, in relation with the secondary standard of surface freshwater quality.

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Johnson, Regina. "Stream baiting for sudden oak death : fluvial transport and ecohydrology of the invasive plant pathogen Phytophthora ramorum in Western Washington State /." Online pdf file accessible through the World Wide Web, 2008. http://archives.evergreen.edu/masterstheses/Accession86-10MES/2008Johnson_RMMESthesis.pdf.

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Dissertations / Theses on the topic 'Fluvial environments'

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