Yes / Ice cover formed on an alluvial channel can significantly alter the flow characteristics, such as the vertical distributions of streamwise velocity and shear stress, and hence the water and sediment transport process. The vertical profile of the suspended sediment concentration in the ice-covered alluvial channels with steady uniform flows is investigated in this study. To calculate the suspended sediment concentration, we are based on the Schmidt O’Brien equation and deduce an analytical model that employs an existing eddy viscosity model and a modified formula of the sediment fall velocity considering the common effects of the upper and lower boundaries. The proposed analytical model is then validated by using available experimental data reported in the literature. The predicted accuracy of the proposed model is evaluated through error statistics by comparing to previous modeled results. The relative concentration profiles of the suspended sediment are subsequently simulated by applying the validated analytical model with different characteristic parameters. Results show that the relative concentration decreases with the increase of both the ice cover roughness and the sediment fall velocity. The uniformity of the relative concentration distribution is closely related to the value of the proportionality parameter σ, revealing the physical mechanism that the more prominent the turbulent diffusion effect is, the more uniform the relative concentration profile is. / This work was supported by the National Natural Science Foundation of China (grant 604 numbers 52020105006 and 11872285) and the Open Funding of State Key Laboratory of Water Resources and Hydropower Engineering Science (WRHES), Wuhan University (Project number 2018HLG01).

Os processos hidrossedimentológicos são complexos e dependem de diversos fatores. Entendê-los requer alto grau de especialização de mão de obra, além da utilização de equipamentos e técnicas ainda incipientes no país. O monitoramento hidrossedimentológico com dados confiáveis de concentração de sedimentos em suspensão pode ser problemático quando são empregados métodos convencionais, pois geralmente os mesmos apresentam medições com quantidade de postos e frequências inferiores aos desejáveis, limitando estudos e a gestão de recursos hídricos quando se trata de reservatórios. Nesse contexto, esta dissertação apresenta um estudo realizado no reservatório da Pequena Central Hidrelétrica Mogi-Guaçu (SP) na qual realizou-se a correlação dos dados de concentração de sedimentos em suspensão mensuradas com dispositivo automático (LISST-100X) e por amostragem convencional (Garrafa Van Dorn). Por meio de regressões lineares e testes estatísticos avaliou-se a eficiência da técnica de difração à laser, e se estimaram as concentrações de sedimentos em suspensão para as duas campanhas realizadas. Analisando os resultados obtidos, confirmou-se estatisticamente que dentre todos os cenários de regressões lineares adotados, o modelo que divide o reservatório em setores apresentou melhores estimativas de concentração, inferindo-se que a concentração do sedimento em suspensão possui um comportamento característico ao segmento do reservatório de Mogi-Guaçu. Notou-se também, a redução da concentração entre as duas campanhas realizadas, decorrente principalmente pela redução da velocidade do fluxo d\'água. Desse modo, a sonda LISST-100X, se mostrou viável para o estudo de caso. Ressalta-se que a utilização desta sonda possibilitou a obtenção de um número maior de dados do que os obtidos por meio do emprego de técnica convencional, possibilitando uma análise mais completa do reservatório e reduzindo significativamente o trabalho de campo, laboratório e escritório. / Hydrosedimentological processes are complex and depend on many factors and understanding them requires a high degree of labor specialization, as well as the use of equipment and techniques still incipient in Brazil. The hydrosedimentological monitoring with reliable sediment concentration data may be problematic when conventional methods are used. Its measurements are usually undertaken at a number of stations and frequencies below the desired ones, which limit studies and the management of water resources of reservoirs. This dissertation reports on a study on the Mogi-Guaçu (SP) Small Hydroelectric Plant reservoir and the correlation between the suspended sediment sample data measured by an automatic device (LISST-100X) and conventional sampling conducted by a Van Dorn sampler. The laser diffraction efficiency was evaluated by linear regression and statistical tests and the concentration of suspended sediment was estimated for the two campaigns. The results show the model that divides the reservoir into sectors provided better estimates of concentration and the concentration of suspended sediment exhibited a characteristic behavior for the segment of Mogi-Guaçu reservoir. A reduction in the concentration, caused mainly by a decrease in the water flow speed, was also observed between the two campaigns and laser diffraction proved feasible for the case study. This methodology enables the obtaining of a larger amount of data than that achieved by conventional techniques, a more complete analysis of the shell and significant reductions in the field, laboratory and office work.

Large amounts of sediment transported by rivers, coming from the erosive action of water on the basin soil, causing degradation of water bodies and significant damages to the population, to socioeconomic development and to the natural environment. The processes of sediment production and deposition along a watershed are natural phenomena, but its effects can be magnified by the man influence through the disordered deforestation, construction, mining and improper management of agricultural activities. During the sediments transport and deposition in water bodies there is a color change in the water due to the concentration of dissolved or suspended materials. The water bodies color is directly linked to their inherent optical properties of absorption and spreading. These properties change according to the concentration, nature and types of dissolved and particulate materials in the water. The Normalized Difference Water Index (NDWI) is a method developed by McFeeters (1996) with the purpose of delineates features in the water, such as Active Optical Components, highlighting their presence, and found by digital images processing. The author modified the NDVI formula reversing the variables and using the green band instead of the red band in order to obtain better results attentive on water analysis. In this sense, the work is presented in order to promote by analyzes, descriptions, maps and systematic studies, the assessment of water quality NDWI method in the reservoirs of Caçu and Barra dos Coqueiros Hydropower Plants (HPPs), in Claro river, located in the southwestern portion of Goiás state - Brazil, evaluating the determination of suspended sediments method in lentic environments by multispectral images. Analyses of NDWI indices produced visually coherent data, but could not find an index for correlations between real data or even a calibration value to help in the determination of suspended sediment concentration. The NDWI method enables visual inspection of sediment yield characteristics for a given location, but must be in the same scene from the same date to become comparable. It is possible to make notes of places with higher sediment production and flow spread. Is found in the statistical analysis a low correlation between the suspended sediments concentration obtained from field sampling and from values of NDWI processing. The visual analysis of maps with the NDWI results is valid to indicate regions of interest for field sampling, analyzing patterns of sediment behavior also in rainfall seasonality periods. / As grandes quantidades de sedimentos transportadas pelos cursos de água, provenientes da ação erosiva da água sobre o solo da bacia, provocam a degradação dos corpos d água e prejuízos significativos à população, ao desenvolvimento socioeconômico e ao ambiente natural. Os processos de produção e deposição de sedimentos ao longo de uma bacia são fenômenos naturais, mas que têm seus efeitos potencializados pela influência do homem, por meio de desmatamentos desordenados, construções, mineração e manejo inadequado das atividades agrícolas. Durante a fase de transporte e deposição dos sedimentos em corpos hídricos há a mudança da coloração da água devido à concentração do material dissolvido ou em suspensão. A cor dos corpos d água está diretamente ligada às suas propriedades ópticas inerentes, de absorção e espalhamento. Estas propriedades variam conforme a concentração, natureza e tipos de materiais dissolvidos e particulados presentes na água. O Índice da Diferença Normalizada de Água (Normalized Difference Water Index NDWI) é um método desenvolvido por McFeeters (1996) com o intuito de delinear feições na água, como os Componentes Opticamente Ativos, e realçar a presença destes, sendo obtido por meio de processamentos em imagens digitais. O autor modificou a fórmula do NDVI invertendo as variáveis e usando a banda verde ao invés da banda vermelha, a fim de obter melhores resultados voltados à análise da água. Nesse sentido, o trabalho se apresenta no intuito de promover por meio de análises, descrições, mapeamentos e estudos sistematizados, a avaliação do método do NDWI da qualidade da água dos reservatórios das Usinas Hidrelétricas (UHEs) Caçu e Barra dos Coqueiros, no Rio Claro, localizadas na porção sudoeste do estado de Goiás, avaliando o método de determinação de sedimentos em suspensão em ambientes lênticos por meio de imagens multiespectrais. As análises dos índices de NDWI geraram informações visualmente coerentes, porém não foi possível encontrar um índice para correlações entre dados reais ou mesmo um valor de calibração para auxílio na determinação da concentração de sedimentos em suspensão. O método NDWI possibilita inspeções visuais das características de produção de sedimentos de um dado local, porém devem estar em uma mesma cena de uma mesma data para se tornarem comparáveis. É possível estabelecer apontamentos dos locais com maior aporte de sedimentos e avanço do fluxo. Nas análises estatísticas encontrou-se uma correlação baixa entre a concentração de sedimentos em suspensão obtidos de coletas de campo e os valores do processamento NDWI. A análise visual de mapas com os resultados do NDWI é valida para apontar áreas de interesse para coletas de campo, analisando padrões de comportamento dos sedimentos também em períodos de sazonalidade pluviométricas. / Mestre em Geografia

Submitted by (lucia.rodrigues@ufrpe.br) on 2016-08-17T10:40:03Z No. of bitstreams: 1 Wagner Luis da Silva Souza.pdf: 1386439 bytes, checksum: 827a26efa0bbda4b3565625f0858d0a2 (MD5) / Made available in DSpace on 2016-08-17T10:40:04Z (GMT). No. of bitstreams: 1 Wagner Luis da Silva Souza.pdf: 1386439 bytes, checksum: 827a26efa0bbda4b3565625f0858d0a2 (MD5) Previous issue date: 2011-02-22 / The sediments produced in watersheds are transported by rivers towards the coastal zones. Many researchers have tried to estimate the amount of sediment produced on the continent and transported toward the ocean since the 60's. Moreover, many anthropogenic activities influence in transport capacity which may result in an accumulation or deficit of sediment in coastal areas. The state of Pernambuco shows along its coastline stretches susceptible to coastal erosion, where the coast of the Metropolitan Region of Recife (RMR) receives delivery of sediment produced in various rivers, such as, Beberibe, Capibaribe, Jaboatão and Timbó. The current study had the aim of determinate the current rate of the sediment yield in Capibaribe watershed. Thereby, collect measurement were carry out during the rainy season and non-rainy years of 2009 and 2010 following the methodology of equal width increment (IIL) sampling through the DH-48 sampler for suspended sediment sampling and for bedload sampling was used the U.S. BLH-84. The occurrence of higher concentrations of suspended sediment was observed during the rainy season with an amount equivalent to 594.95 mg L-1 for the years 2009 and 1071.55 mg L-1 to 2010. The suspended sediment yield of the rainy season was 3.42 t km-2 year-1 and 3.75 t km-2 year-1, respectively, for the years 2009 and 2010. The bedload of Capibaribe had uniform distribution a long the bed and distributed well-graded as well. The total sediment yield in Capibaribe watershed in the years 2009 and 2010 was low due to the action of the sediment retention dams, generating a deficit of sediment flux, both suspended and bedload, in the coastal zone in the Metropolitan Region of Recife. / Os sedimentos produzidos nas bacias hidrográficas são transportados pelos rios em direção as zonas costeiras. Muitos pesquisadores, desde a década de 60 tentam estimar a quantidade de sedimentos produzidos no continente e transportados em direção aos oceanos. Muitas atividades antrópicas influenciam nessa capacidade de transporte o que pode acarretar em um acúmulo ou déficit de sedimento nas zonas costeiras, e com isso ocasionando os processos de deposição ou erosão. O Estado de Pernambuco apresente ao longo do seu litoral trechos susceptível a erosão costeira, onde a costa da Região Metropolitana do recife (RMR) recebe aporte de sedimento produzindo das bacias hidrográficas dos rios Beberibe, Capibaribe, Jaboatão e Timbó. O presente trabalho teve como objetivo determinar a atual taxa de produção de sedimentos da Bacia Hidrográfica do Rio Capibaribe. Para tal foram realizadas campanhas de medição direta durante o período chuvoso e não-chuvoso dos anos de 2009 e 2010 seguindo a metodologia da amostragem por igual incremento de largura (IIL), utilizando-se o amostrador DH-48 para amostragem do sedimento em suspensão e para amostragem do sedimento de fundo o amostrador o US BLH-84. Observou-se a ocorrência de maiores concentrações de sedimento em suspensão no período chuvoso com um valor equivalente a 594,95 mg L-1 para o ano de 2009 e 1.071,55 mg L-1 para o ano de 2010. A produção de sedimento em suspensão do período chuvoso foram de 3,42 t km- 2 ano-1 e 3,75 t km-2 ano-1, respectivamente, para os anos de 2009 e 2010. Os sedimentos de fundo do Rio Capibaribe tiveram distribuição uniforme ao longo do leito e distribuída de forma bem graduada. A produção de sedimentos total do Rio Capibaribe nos anos de 2009 e 2010 foi baixa, por conta da ação da retenção de sedimentos pelas barragens, geradoras de déficit do fluxo de sedimentos, tanto suspenso quanto de fundo, na Zona Costeira da Região Metropolitana do Recife.

Os processos hidrossedimentológicos são complexos e dependem de diversos fatores. Entendê-los requer alto grau de especialização de mão de obra, além da utilização de equipamentos e técnicas ainda incipientes no país. O monitoramento hidrossedimentológico com dados confiáveis de concentração de sedimentos em suspensão pode ser problemático quando são empregados métodos convencionais, pois geralmente os mesmos apresentam medições com quantidade de postos e frequências inferiores aos desejáveis, limitando estudos e a gestão de recursos hídricos quando se trata de reservatórios. Nesse contexto, esta dissertação apresenta um estudo realizado no reservatório da Pequena Central Hidrelétrica Mogi-Guaçu (SP) na qual realizou-se a correlação dos dados de concentração de sedimentos em suspensão mensuradas com dispositivo automático (LISST-100X) e por amostragem convencional (Garrafa Van Dorn). Por meio de regressões lineares e testes estatísticos avaliou-se a eficiência da técnica de difração à laser, e se estimaram as concentrações de sedimentos em suspensão para as duas campanhas realizadas. Analisando os resultados obtidos, confirmou-se estatisticamente que dentre todos os cenários de regressões lineares adotados, o modelo que divide o reservatório em setores apresentou melhores estimativas de concentração, inferindo-se que a concentração do sedimento em suspensão possui um comportamento característico ao segmento do reservatório de Mogi-Guaçu. Notou-se também, a redução da concentração entre as duas campanhas realizadas, decorrente principalmente pela redução da velocidade do fluxo d\'água. Desse modo, a sonda LISST-100X, se mostrou viável para o estudo de caso. Ressalta-se que a utilização desta sonda possibilitou a obtenção de um número maior de dados do que os obtidos por meio do emprego de técnica convencional, possibilitando uma análise mais completa do reservatório e reduzindo significativamente o trabalho de campo, laboratório e escritório. / Hydrosedimentological processes are complex and depend on many factors and understanding them requires a high degree of labor specialization, as well as the use of equipment and techniques still incipient in Brazil. The hydrosedimentological monitoring with reliable sediment concentration data may be problematic when conventional methods are used. Its measurements are usually undertaken at a number of stations and frequencies below the desired ones, which limit studies and the management of water resources of reservoirs. This dissertation reports on a study on the Mogi-Guaçu (SP) Small Hydroelectric Plant reservoir and the correlation between the suspended sediment sample data measured by an automatic device (LISST-100X) and conventional sampling conducted by a Van Dorn sampler. The laser diffraction efficiency was evaluated by linear regression and statistical tests and the concentration of suspended sediment was estimated for the two campaigns. The results show the model that divides the reservoir into sectors provided better estimates of concentration and the concentration of suspended sediment exhibited a characteristic behavior for the segment of Mogi-Guaçu reservoir. A reduction in the concentration, caused mainly by a decrease in the water flow speed, was also observed between the two campaigns and laser diffraction proved feasible for the case study. This methodology enables the obtaining of a larger amount of data than that achieved by conventional techniques, a more complete analysis of the shell and significant reductions in the field, laboratory and office work.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Naiqian Zhang / Suspended sediment concentration (SSC) in water is one of the most important parameters to evaluate water quality. Monitoring SSC provides important information on determining sediment transport for soil erosion research and soil/water conservation practices. Sediment mass transported at a given time can be assessed by simultaneous SSC and water flow velocity measurements. Fouling, including bio-fouling, has damaging impact on optical SSC measurements over the long term. In this study, an inexpensive, real-time, self-cleaning, optical sediment and flow velocity sensor was developed. Laboratory experiments were conducted on a previously designed SSC sensor. A light modulation algorithm was designed to reduce the influence of ambient light, especially sunlight, on measurement accuracy. Statistical models to predict SSC based on measured light intensities were established and compared with neural network models. The statistical analysis showed that soil texture played an important role in SSC measurement accuracy while the designed sensor was capable of reducing the effect of water color on sensor performance. Neural-network models can further remove the influence of soil texture type on SSC measurement. The sensor design was simplified based on a stepwise selection analysis. Long-term field experiments were conducted in Kansas and Georgia to evaluate the sensor performance, the effect of fouling, including bio-fouling, on sensor lenses, and the effect of temperature on the measurement. Methods of removing the fouling effect through data correction were developed. Results indicated that the designed optical SSC sensor was capable of providing rapid response to SSC fluctuations in water flow. Temperature of the water body has an insignificant impact on SSC measurement. In order to reduce fouling, an air-blast cleaning mechanism was integrated into the optical sediment sensor. Laboratory experiments in a manually created fouling environment were conducted to observe the fouling process on sensor cases made of different materials, and to verify the effectiveness of air-blast cleaning in reducing fouling. Results indicated that air-blast cleaning mechanism was capable of reducing clay/silt fouling on sensor signals. The duration and frequency of air-blast cleaning can be determined and adjusted depending on actual field conditions. An air pressure drop test was conducted on the hose carrying pressurized air. Results showed negligible pressure drop.A flow velocity measurement function based on the cross-correlation principle was integrated into the optical sediment sensor. An experiment was conducted in laboratory to examine the sensor performance on velocity measurement using a closed circulation system. A solution of blue colorant, Brilliant Blue FCF, was used as an artificial source to absorb light emitted by LEDs in the sensor and the signal variation patterns were measured. The results indicated that the cross-correlation-based velocity sensor was capable of measuring water flow velocity within in a certain velocity range using the dye injection method.

The tidal stream industry has seen large growth in recent years, and the number of pre-commercial scale devices currently being tested reflects this development. However, commercialising this technology whilst showing that their environmental impacts is minimal remains a challenge. The impact on benthic communities is not considered to be a key strategic consenting issue, yet it is anticipated that the benthic habitat will change as a result of the presence of tidal turbines. To date, only single tidal turbine devices have been installed to demonstrate the application of tidal stream technology but despite successful tests there are still uncertainties surrounding the quantitative impacts these turbines have on local benthic communities. Unlike the wind industry, where physical effects of wind turbines have been catalogued through deployment of thousands of turbines, the tidal stream industry lacks these array scale quantitative data. Local impacts are known, but understanding the scale of the impacts and their relative significance of large arrays remains unknown. Tidal turbines (both single and arrays) interact with the hydrodynamics by decreasing the near field current flow directly in its wake through energy extraction and the drag caused by the physical structure. However, turbines may also affect the far field hydrodynamics, altering bed characteristics, sediment transport regimes and suspended sediment concentrations. As benthic habitats are closely linked to the physical seabed composition and the hydrodynamic conditions, the benthic environment is affected by to changes in the current flow. This thesis presents a series of studies investigating the interaction between tidal turbines and the benthic environment. Based on the hydrodynamic modelling software, TELEMAC2D, a numerical model has been developed to investigate the hydrodynamic impact of a single tidal array at Ramsey Sound, Pembrokeshire as well as the cumulative impact of multiple tidal developments in the Irish Sea. Based on the results of the models, the hydrodynamic outputs were used as inputs to drive a species distribution model, based on the software MaxEnt, to investigate how the distribution of benthic species altered in the presence of a 10MW tidal array at Ramsey Sound. Results of the study showed the development would have a minimal negative impact on the benthic environment.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo teve como objetivo principal caracterizar os padrões de distribuição do material particulado em suspensão ao longo da baía de Sepetiba, associando as variabilidades espaciais e temporais com ciclos de maré. Além disso, o estudo também avalia a utilização de equipamentos acústicos como ferramentas à estimativa das concentrações de material particulado em suspensão. A aquisição de dados foi realizada num total de sete campanhas realizadas entre novembro de 2010 e dezembro de 2011. Sete estações foram posicionadas nas proximidades do canal principal de acesso à baía, ao longo de um transecto que se estende do seu interior até sua desembocadura. As sete campanhas amostrais se distribuem em duas séries longas, de 13 e 25 horas, de aquisição em um ponto fixo, e cinco amostragens ao longo das estações. A aquisição de dados envolve: coleta de amostras de água, utilizadas nas estimativas das concentrações de material particulado; coleta de sedimentos de fundo para caracterização granulométrica das estações amostradas; perfis de parâmetros físico-químicos; dados de correntômetria adquiridos junto ao fundo. O processamento das amostras de água e sedimentos foi realizado no laboratório de Geologia Marinha da Faculdade de Oceanografia da Universidade do Estado do Rio de Janeiro. As concentrações de material particulado em suspensão foram utilizadas na calibração de sensores acústicos e óticos, permitindo uma avaliação espaço-temporal mais detalhada dos padrões de distribuição junto ao fundo e ao longo da coluna dágua. Os dados observados permitiram identificar que as maiores concentrações de material particulado em suspensão ocorrem em condições de maré enchente, e estão associadas à assimetria de maré. A baía pode ser dividida em dois setores: um na porção mais interna, onde se observou maior influência do aporte fluvial, onde as concentrações de material particulado em suspensão respondem à propagação da pluma do canal de São Francisco; e outro que se estende da porção central até sua desembocadura, onde predomina o domínio marinho, com influência de eventos oriundos da plataforma continental. Também pode ser identificada a influência do fenômeno La Niña, que provavelmente foi responsável por: altas salinidades encontradas no interior da baía e ocorrência da Água Central do Atlântico Sul à baixas profundidades. Quanto à utilização de equipamentos acústicos nas estimativas das concentrações de material particulado, os dados se demonstraram ricos em detalhes, que permitiram avaliar o comportamento do material particulado junto ao fundo frente a diferentes condições de maré, turbulência e incidência de oscilações. / This study aimed to characterize the distribution patterns of suspended particulate matter along the Sepetiba Bay, linking spatial and temporal variability with tidal cycles. Furthermore, the study also evaluates the applicability of acoustic devices as tools for estimation of concentrations of suspended particulate matter. Data acquisition was performed in a total of seven campaigns carried out between November 2010 and December 2011. Seven stations were located near the main channel access to the bay along a transect that extends from its interior to its mouth. The seven sampling campaigns are distributed in two long series of 13 and 25 hours of acquisitions at a fixed station, and five campaigns along the transect. Data acquisition involves: collecting water samples to estimate the concentrations of particulate matter, bottom sediments collected to characterize particle size of the stations sampled; profiles of physicochemical parameters; current data obtained at the bottom. The processing of water samples and sediments was conducted in the Oceanografic Geology Laboratory Laboratório de Oceanografia Geológica of the Faculdade de Oceanografia - Universidade do Estado do Rio de Janeiro. The concentrations of suspended particulate matter were used for the calibration of acoustic and optical sensors, allowing an evaluation of more detailed spatial and temporal patterns of distribution along the bottom and along the water column. The analysis allowed to identify that the highest concentrations of suspended particulate matter occur in conditions of high tide, and are associated with tidal asymmetry (highest current velocities). The bay can be divided into two sectors: one in the northern area, where riverine characteristics are more pronounced, and concentrations of suspended particles respond to the spread of the plume of São Francisco channel, and another that extends from the central portion to its mouth, where dominate the marine domain, influenced by events from the continental shelf. It can also be identified the influence of La Niña, which was probably responsible for: high salinities found inside the bay and occurrence of South Atlantic Central Water at lower depths. Regarding the use of acoustic equipment in the estimation of concentrations of particulate matter, the results were rich in detail, which allowed us to evaluate the behavior of particulate material near the bottom for different tidal conditions, turbulence and incidence of oscillations.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo teve como objetivo principal caracterizar os padrões de distribuição do material particulado em suspensão ao longo da baía de Sepetiba, associando as variabilidades espaciais e temporais com ciclos de maré. Além disso, o estudo também avalia a utilização de equipamentos acústicos como ferramentas à estimativa das concentrações de material particulado em suspensão. A aquisição de dados foi realizada num total de sete campanhas realizadas entre novembro de 2010 e dezembro de 2011. Sete estações foram posicionadas nas proximidades do canal principal de acesso à baía, ao longo de um transecto que se estende do seu interior até sua desembocadura. As sete campanhas amostrais se distribuem em duas séries longas, de 13 e 25 horas, de aquisição em um ponto fixo, e cinco amostragens ao longo das estações. A aquisição de dados envolve: coleta de amostras de água, utilizadas nas estimativas das concentrações de material particulado; coleta de sedimentos de fundo para caracterização granulométrica das estações amostradas; perfis de parâmetros físico-químicos; dados de correntômetria adquiridos junto ao fundo. O processamento das amostras de água e sedimentos foi realizado no laboratório de Geologia Marinha da Faculdade de Oceanografia da Universidade do Estado do Rio de Janeiro. As concentrações de material particulado em suspensão foram utilizadas na calibração de sensores acústicos e óticos, permitindo uma avaliação espaço-temporal mais detalhada dos padrões de distribuição junto ao fundo e ao longo da coluna dágua. Os dados observados permitiram identificar que as maiores concentrações de material particulado em suspensão ocorrem em condições de maré enchente, e estão associadas à assimetria de maré. A baía pode ser dividida em dois setores: um na porção mais interna, onde se observou maior influência do aporte fluvial, onde as concentrações de material particulado em suspensão respondem à propagação da pluma do canal de São Francisco; e outro que se estende da porção central até sua desembocadura, onde predomina o domínio marinho, com influência de eventos oriundos da plataforma continental. Também pode ser identificada a influência do fenômeno La Niña, que provavelmente foi responsável por: altas salinidades encontradas no interior da baía e ocorrência da Água Central do Atlântico Sul à baixas profundidades. Quanto à utilização de equipamentos acústicos nas estimativas das concentrações de material particulado, os dados se demonstraram ricos em detalhes, que permitiram avaliar o comportamento do material particulado junto ao fundo frente a diferentes condições de maré, turbulência e incidência de oscilações. / This study aimed to characterize the distribution patterns of suspended particulate matter along the Sepetiba Bay, linking spatial and temporal variability with tidal cycles. Furthermore, the study also evaluates the applicability of acoustic devices as tools for estimation of concentrations of suspended particulate matter. Data acquisition was performed in a total of seven campaigns carried out between November 2010 and December 2011. Seven stations were located near the main channel access to the bay along a transect that extends from its interior to its mouth. The seven sampling campaigns are distributed in two long series of 13 and 25 hours of acquisitions at a fixed station, and five campaigns along the transect. Data acquisition involves: collecting water samples to estimate the concentrations of particulate matter, bottom sediments collected to characterize particle size of the stations sampled; profiles of physicochemical parameters; current data obtained at the bottom. The processing of water samples and sediments was conducted in the Oceanografic Geology Laboratory Laboratório de Oceanografia Geológica of the Faculdade de Oceanografia - Universidade do Estado do Rio de Janeiro. The concentrations of suspended particulate matter were used for the calibration of acoustic and optical sensors, allowing an evaluation of more detailed spatial and temporal patterns of distribution along the bottom and along the water column. The analysis allowed to identify that the highest concentrations of suspended particulate matter occur in conditions of high tide, and are associated with tidal asymmetry (highest current velocities). The bay can be divided into two sectors: one in the northern area, where riverine characteristics are more pronounced, and concentrations of suspended particles respond to the spread of the plume of São Francisco channel, and another that extends from the central portion to its mouth, where dominate the marine domain, influenced by events from the continental shelf. It can also be identified the influence of La Niña, which was probably responsible for: high salinities found inside the bay and occurrence of South Atlantic Central Water at lower depths. Regarding the use of acoustic equipment in the estimation of concentrations of particulate matter, the results were rich in detail, which allowed us to evaluate the behavior of particulate material near the bottom for different tidal conditions, turbulence and incidence of oscillations.

Construction sites are among the most common areas to experience soil erosion and sediment transport due to the mandatory foundation tasks such as excavation and land grubbing. Thus, temporary sediment barriers are installed along the perimeter to prevent sediment transport from the site. Erosion and sediment transport control measures may include, but not limited to, physical and chemical processes such as the use of a silt fence and polyacrylamide product. Runoff from construction sites and other impervious surfaces are routinely discharged into ponds for treatment before being released into a receiving water body. Stormwater harvesting from a pond for irrigation of adjacent lands is promoted as one approach to reducing pond discharge while supplementing valuable potable water used for irrigation. The reduction of pond discharge reduces the mass of pollutants in the discharge. In the dissertation, presented is the investigation of the effectiveness of temporary sediment barriers and then, development of a modeling approach to a stormwater harvesting pond to provide a comprehensive stormwater management pollution reduction assessment tool. The first part of the research presents the investigation of the performance efficiencies of silt fence fabrics in turbidity and sediment concentration removal, and the determination of flowthrough-rate on simulated construction sites in real time. Two silt fence fabrics, (1) woven and the other (2) nonwoven were subjected to material index property tests and a series of field-scale tests with different rainfall intensities and events for different embankment slopes on a tilting test-bed. Collected influent and effluent samples were analyzed for sediment concentration and turbidity, and the flow-through-rate for each fabric was evaluated. Test results revealed that the woven and nonwoven silt fence achieved 11 and 56 percent average turbidity reduction iv efficiency, respectively. Each fabric also achieved 20 and 56 percent average sediment concentration removal efficiency, respectively. Fabric flow-through-rates were functions of the rainfall intensity and embankment slope. The nonwoven fabric exhibited higher flow-throughrates than the woven fabric in both field-scale and laboratory tests. In the second part of the study, a Stormwater Harvesting and Assessment for Reduction of Pollution (SHARP) model was developed to predict operation of wet pond used for stormwater harvesting. The model integrates the interaction of surface water and groundwater in a catchment area. The SHARP model was calibrated and validated with actual pond water elevation data from a stormwater pond at Miramar Lakes, Miramar, Florida. Model evaluation showed adequate prediction of pond water elevation with root mean square error between 0.07 and 0.12 m; mean absolute error was between 0.018 and 0.07 m; and relative index of agreement was between 0.74 and 0.98 for both calibration and validation periods. The SHARP model is capable of assessing harvesting safe-yield and discharge from a pond, including the prediction of the percentage of runoff into a harvesting pond that is not discharged. The combination of silt fence and/or polyacrylamide PAM before stormwater harvesting pond in a treatment train for the reduction of pollutants from construction sites has the potential of significantly exceeding a performance standard of 85 percent reduction typically required by local authorities. In fact, the stringent requirement of equaling pre- and post-development pollutant loading is highly achievable by the treatment train approach. The significant contribution from the integration of the SHARP model to the treatment train is that real-time assessment of pollutant loading reduction by volume can be planned and controlled to achieve target performance standards.