Magister Scientiae - MSc (Dept. of Chemistry) / Fly ash and AMD samples were characterised by standard analytical methods for selection of the test materials. Active treatment by means of mixing fly ash with AMD in beakers and a large tank at pre-determined ratios have shown that fly ash is capable of neutralising AMD and increasing the pH beyond neutral values, which optimises the removal of heavy metals and ions. The trend was: the more fly ash added the quicker was the reaction time and higher the pH values achieved. Iron was reduced by as much 99 % in beaker scale experiments via Fe(OH)3 precipitation at pH values >4.0. A 99 % decrease in aluminium concentration was observed which was attributed to the precipitation of primarily gibbsite and various other mineral phases at pH values >5.5. As the pH increases, sulphate is adsorbed via Fe(OH)3 and gypsum precipitation at elevated pH. Sulphate attenuation with fly ash was excellent, achieving 98 % attenuation with beaker scale experiments and 1:1 fly ash:AMD ratio. Sulphate attenuation with fly ash was comparable to membrane and ion exchange systems and exceeded the performance of limestone treatment. Except for the larger volumes of fly ash needed to neutralise the AMD, fly ash proved to be a feasible and cost efficient alternative to limestone treatment. Fly ash produced competing results to limestone concerning acidity removal and sulphate attenuation. The comparison highlighted the advantages of utilising fly ash in comparison to limestone and demonstrated its cost effectiveness. The results of this study have shown that fly ash could be successfully applied for the neutralisation of acid mine drainage (AMD) and effectively attenuate the sulphate load in the treated water. The critical parameters to this technology are the variations of chemical composition and mineralogy of fly ash, which could influence the pH, contact time of the neutralisation reaction, and the same is true if the AMD quality varies. / South Africa

Masters of Science / Over the years, South Africa has produced over 468 million tons of mine waste yearly, in which gold mining waste accounted for 221 million tons (47%) of all mine waste produced, making it the largest, single source of waste and pollution. The exposure of these mine wastes such as tailings dams, waste rocks to oxidation and leaching has been the source of heavy metal release into the environment. This study assessed the magnitude of possibly leachable metals, its distribution and associations and predicted the AMD load discharge over time, from Mogale’s tailings dam into the environs in Randfontein area, Witwatersrand Basin, South Africa. Fifty-one tailings dam samples were analysed for their mineral and multi-elements contents. Petrography studies was done by X-Ray Diffraction (XRD) technique to determine the mineralogical composition. X-ray fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) techniques were used to determine the multi-elements content in the tailings dam samples. The dataset were evaluated using multivariate statistics, Geographical Information Systems (GIS) and geochemical mass balance techniques. From the results, the tailings dam lithology was grouped into four distinct layers. The uppermost oxidized layer is siliceous and contains the highest SiO2 (87.32%) contents, which is with the lowest contents in Tot/S, U, As, Zn, Ni, Co, and Cu. A downward decrease in SiO2 (76.39%) contents occurs, coupled by an increase in Fe2O3, Tot/S, U, As, Zn, Ni, Co, and Cu, reaching maximum contents in layer 3. Layer 4 is the least weathered horizon. The cluster analysis grouped the samples into four sub-clusters based on the variation in SiO2 and Al2O3 contents. Factor analysis (83.542% total data variance) related the four controlling factors of element distribution to the occurrence in ore elements (sulphides), silicates, mining additives and refractory minerals. Elements of the same origin show a similar concentration trend down hole in the GIS interpolation analysis. The geochemical mass balance showed variable gain and loss of oxides and trace elements within each layer. Based on the variation patterns of the Tot/S contents and other mobile elements, about 0.164kg/tonne/yr(±0.02) of the tailings materials are leached yearly. Layer 1 is the most altered. This assessment and prediction study therefore gives an insight to the geochemical behaviour of an abandoned tailings dam, highlighting its extent of oxidation. However, the interaction between the oxidized zone and transition zone should be given more attention, to determine the actual extent of damage.

Este trabalho faz parte do processo de investigação e conhecimento da evolução da paisagem a partir da interação solo-relevo, isto é, de uma abordagem pedogeomorfológica. Como tais estudos são escassos no semiárido brasileiro e, considerando o interesse em contribuir com o conhecimento e disseminação da geo e biodiversidade deste domínio, foi selecionada para estudo uma área localizada no setor nordeste do estado da Bahia, próxima ao município de Nova Soure. O recorte espacial adotado foi a bacia de drenagem, por entender que a bacia é, mesmo em condições semiáridas, uma unidade importante para a compreensão das relações entre formas e materiais, como a cobertura pedológica. A bacia selecionada é a do Riacho Natuba, que está, geologicamente, localizada na bacia sedimentar do Tucano Sul, que integra o rifte Recôncavo-Tucano-Jatobá. Geomorfologicamente está inserida nos Tabuleiros do Itapicuru, formados por modelados de aplainamentos e dissecação. O estudo foi realizado a partir de etapas de gabinete, campo e laboratório, que incluíram: revisão bibliográfica e conceitual, levantamento de materiais cartográficos, processamento de imagens e produção de mapas através do geoprocessamento, trabalhos de campo com reconhecimento da área, descrição e coleta de perfis de solos, análises laboratoriais e estudos microscópicos de seções delgadas. Diferentes escalas foram adotadas para o estudo da relação solo-relevo. Na escala da bacia, o estudo foi realizado a partir da identificação e descrição dos compartimentos morfopedológicos. Na escala da vertente, o estudo foi realizado a partir da descrição e caracterização de solos ao longo de transectos entre os compartimentos morfopedológicos e na escala de detalhe foram observadas as microestruturas em lâminas com o auxílio de microscópios petrográficos. Os resultados indicaram que a bacia é pedodiversa e que essa variedade e distribuição de solos possui íntima relação com a variação de litofácies da Formação Marizal e com processos do relevo, como a erosão seletiva superficial e subsuperficial de finos (argilas). Os solos de maior ocorrência nas partes altas da bacia são os Neossolos Quartzarênicos, que se diferenciam pelo conteúdo de argila, composição mineralógica e arranjos do fundo matricial. Essas distinções foram interpretadas como produtos da influência da circulação da água, atestando a importância do relevo na sua gênese. Nas partes baixas da bacia, a diversidade de solos é maior, ocorrendo Argissolos, Luvissolos, Chernossolos, Neossolos Fluvicos e Planossolos. Todos refletem propriedades dos materiais de origem sob condições de intemperismo típicas do semiárido, como a fertilidade, a mineralogia e as organizações micromorfológicas. Além disso, também estão relacionados aos processos erosivos atuantes nas vertentes, que formam, por exemplo, o gradiente textural, seja através da elutriação (Argissolos e Luvissolos) ou através da sedimentação (Planossolos). De maneira geral, os solos da bacia estão interligados entre si, e essa ligação se dá a partir da redistribuição de material ao longo das dinâmicas do relevo. Este contexto expressa a importância de considerar conjuntamente a pedogênese e morfogênese na evolução da paisagem semiárida. / This work is part of the process of research and knowledge of the evolution of the landscape from the interaction between soil and relief, i.e., a soil geomorphological approach. Aiming to contribute to and disseminate the knowledge of the geo- and biodiversity of the Brazilian semiarid, where studies such as this one is rare, we investigated an area in the northeast of Bahia, near the Nova Soure municipality. The drainage basin was picked as the unit of spatial analysis because, even in semiarid conditions, we understand it to provide the best comprehension of the relationships between shapes and materials, such as soil coverage. The Natuba stream drainage basin we investigate in this study is geologically situated in the Tucano Sul sedimentary basin, itself part of the Recôncavo-Tucano-Jatobá rift. Geomorphologically, the basin is part of the Itapicuro tablelands, formed by surfaces of planation and dissection. The investigation involved office, field, and laboratory stages, including: literature and conceptual review, gathering of cartographic material, image processing, geoprocessing to produce maps, area survey and fieldwork, profile description and sampling, laboratory analysis, and thin section microscopy. We adopted different scales to study the soil-relief relationship. At the basin-scale, the study comprised the identification and description of morphopedological compartments. At the slope-scale, the study was derived from the description and characterization of soils along transects between morphopedological compartments. Finally, at the detail-scale we observed the microstructures on slides, using petrographic microscopes. Results indicate that the basin is soil-diverse and that its variety and distribution is intimately related to the variation of the lithofacies of the Marizal Formation and to relief processes such as superficial and subsuperficial erosion of fine material (clays). The Quartzarenic Neosols, more frequent in the higher regions of the basin, are differentiated by the clay content, mineral composition, and the relative distribution of groundmass. These distinctions were interpreted as products of the influence of water circulation, substantiating the importance of the relief in the soil genesis. At the lower regions of the basin, the soil is more diverse: Acrisols, Luvisols, Chernozems, Fluvisols, and Planosols occur. Fertility, mineralogy and micromorphological organization of the soils are typical of the original material enduring conditions of weathering that are characteristic of the semiarid. Furthermore, the soils are related to the erosive processes that affect the slopes and form, for instance, the textural gradient as a result of elutriation (Acrisols and Luvisols) or sedimentation (Planosols). Generally, the basin soils are interlinked via the redistribution of material throughout the landscape. This context, therefore, expresses the importance of considering both pedogenesis and morphogenesis when examining the evolution of the semiarid landscape.

Este trabalho apresenta a pesquisa realizada e os resultados obtidos durante o mapeamento geotécnico da porção média da Bacia do Rio Capivari, na escala 1:50.000, seguindo a metodologia adotada pela Escola de Engenharia de São Carlos (EESC/USP). Foi elaborada uma sistemática de estudo, onde buscou-se extrair informações pela definição dos atributos do meio físico relativos ao substrato rochoso, ao material inconsolidado e aos lnadforms, que foram classificados de acordo com sua ordem de importância para a definição do potencial ao escoamento superficial, do potencial à infiltração, da susceptibilidade à erosão e na elaboração zoneamento geotécnico geral da região. No auxílio à manipulação das informações e à combinação de mapas, foi utilizado o Sistema de Informações Geográficas - IDRISI. O resultado mostrou-se satisfatório, mesmo considerando-se as dificuldades e problemas decorrentes deste tipo de tratamento. Os produtos cartográficos gerados permitiram concluir que: a Bacia do Médio Capivari assenta-se sobre as litologias das formações ltararé e Serra Geral; o relevo é marcado pelo predomínio de baixas declividades; apresenta uma baixa densidade de drenagem; o material inconsolidado caracteriza-se pela textura siltosa com teores variáveis de areia e argila e espessuras máximas observadas em campo, na ordem de 7 m. Estas características condicionam os níveis de potencial ao escoamento superficial, do potencial à infiltração e da susceptibilidade à erosão, com zonas que variam desde muito baixas à altas; condiciona também o zoneamento geotécnico geral, delimitando regiões homogêneas quanto às suas características geotécnicas. Desta forma, este trabalho reúne uma quantidade de informações que podem auxiliar nas atividades de manejo, planejamento e ocupação da porção média da Bacia do Rio Capivari. / This research consists of the geotechnical mapping of the medium Capivari Basin. It was developed according to the adopted methodology at EESC/USP (Escola de Engenharia de São Carlos) compatible with the 1:50.000 scale requirements. This work realized a study about the geotechnical characteristics of the medium Capivari basin and summarizes the physical drainage network studies and the principals geotechnical mapping methodologies. The geographical informalion systems (IDRISI prograrn) was used in the treatment of cartographic products and physical attributes analysis. In this work was produced eleven cartographic products classified in two groups: basic documents and interpretative documents. In general the medium Capivari basin is represented for the Itararé Formation and Serra Geral Formation. The relief, the drainage network and the characteristics of the weathering profiles are the main responsible for the behavior of the superficial flow, of the infiltration potential and of the erosion susceptibility, observed in the area.

Problems of land use and occupation in urban areas may prevent the infiltration of water, thus increasing runoff. Bioretention techniques are solutions, which are emerging from the hydrology field to mitigate the consequences of increasing urbanization, including, flooding and contamination of rivers. The general objective of this research is to study the general efficiency of combined Compensatory Techniques (CT) with detention and bioretention control of diffuse pollutants from an urban drainage system. Specific objectives are defined in each chapter and relates to sizing and to the bioretention systems of modeling and monitoring, located in southeastern Brazil, São Paulo – São Carlos. The first chapter presents the general introduction of the thesis, the objectives and research hypotheses, as well as, the description of the general methodology for the thesis construction and the goals related to each chapter. The second chapter discusses the scope and some limitations of the classifications of terms frequently used in the theme of sustainable urban drainage. This chapter, in a way, approaches the other chapters, which composes this thesis, by providing them comprehensive database of references. The third chapter presents the design criteria used for the construction of experimental bioretention system and compares the design with the model HEC – HMS - Hydrologic Engineering Center - Hydrologic Modeling System. The fourth chapter talks about some criteria to identify areas for building bioretention systems and presents the GIS - Geographic Information System and ecohydrology indicators, in this characterization, considering the quantity and quality aspects in the urban drainage. The fifth chapter shows the use of PCSWMM model (Personal Computer Stormwater Management Model) to simulate future scenarios, assuming progressive modular expansion of CTs, modeling efficiency in qualitative and quantitative aspects diffuse pollution for scenarios 2015, 2025, 2050, 2100. The conclusion of this research is that compensatory techniques can be used not only to assess the impacts of diffuse pollution stemmed from urban drainage system, but as a contribution to the sustainability of watersheds and to mitigation of extremes risks derived by increased urban drainage demand. / Problemas decorrentes do uso e ocupação do solo em áreas urbanas podem dificultar a infiltração da água, aumentando o escoamento superficial. Técnicas de bioretenção são soluções decorrentes do campo da hidrologia para mitigar as consequências resultantes da crescente urbanização, entre elas, enchentes e contaminação de rios. O objetivo geral da pesquisa é estudar a eficiência generalizada de Técnicas Compensatórias (TCs) experimentais, adaptáveis combinadas de detenção e bioretenção para controle da poluição difusa da drenagem urbana. Objetivos específicos são definidos em cada capítulo e relacionam-se com o dimensionamento e monitoramento de modelagem de sistema de bioretenção, localizado no Sudeste do Brasil, São Paulo – São Carlos. O Primeiro capítulo apresenta a introdução geral da tese, objetivos e hipóteses, bem como, descreve a metodologia geral para construção da tese e relação dos objetivos com os respectivos capítulos. O Segundo capítulo discute os alcances e limitações de nomenclaturas sobre termos frequentemente utilizados na temática drenagem urbana sustentável. Este capítulo de certa forma aporta os demais capítulos que compõe esta tese, por propiciar vasto banco de dados referenciais. O Terceiro capítulo apresenta os critérios de dimensionamento utilizados para a construção de um sistema de bioretenção experimental e uma comparação com o dimensionamento com o modelo HEC – HMS - Hydrologic Engineering Center - Hydrologic Modeling System. O Quarto capítulo discorre sobre critérios de escolha de áreas propicias para a construção de sistemas de bioretenção usando Sistemas de Informações Geográficas para a caracterização de áreas, utilizando indicadores ecohidrológicos, considerando os aspectos de quantidade e de qualidade na drenagem urbana. O Quinto capítulo demonstra o uso do modelo PCSWMM – Personal Computer Stormwater Management Model, na simulação de cenários futuros assumindo expansões modulares progressivas da TC, modelando a eficiência para os aspectos qualitativos e quantitativos da poluição difusa para os 2015, 2025, 2050, 2100. Conclui-se com esta pesquisa que técnicas compensatórias podem ser empregadas não só para avaliação dos impactos da poluição difusa provindos da drenagem urbana, mas como forma de contribuir com a sustentabilidade de bacias hidrográficas e para mitigação de riscos de extremos advindos do aumento da demanda de drenagem urbana.

Analisando o potencial risco de contaminação das águas devido à falta de planejamento e de gestão integrada dos recursos hídricos, o trabalho desenvolvido, intitulado PLANO DIRETOR DE DRENAGEM URBANA EM CIDADES PLANEJADAS: Premissa de Zoneamento Baseado no Risco de Contaminação da Água Subterrânea, propõe que os Planos Diretores Municipais sejam elaborados visando à preservação quali-quantitativa não somente das águas superficiais, mas também das subterrâneas. Para isso, a pesquisa sugere técnicas de zoneamento urbano e adoção de alternativas de Drenagem BMPs (Best Management Practices) baseadas no risco de contaminação das águas subterrâneas, apresentadas como premissa na elaboração de Planos Diretores de Drenagem Urbana para cidades planejadas. Assim, o zoneamento de áreas urbanas foi analisado de forma a minimizar a contaminação de aquíferos, tanto pelo uso direto, quanto pela poluição difusa provocada pela precipitação. Servindo, de tal modo, como premissa na determinação das alternativas estruturais e não-estruturais a serem adotadas, principalmente quanto à adoção de dispositivos de drenagem com infiltração no solo. A análise integrada do mapa de vulnerabilidade existente (CPRM, 2001) com o Mapa de Fontes Potenciais de Contaminação, desenvolvido a partir do zoneamento urbano vigente, subsidiou a elaboração do Mapa de Zoneamento Baseados no Risco à Contaminação de Águas Subterrâneas. Este, por sua vez, deu base à elaboração do Mapa de Restrição às Soluções de Drenagem com Infiltração no Solo, que analisado juntamente com os critérios de escolha das medidas de controle na fonte definidos por São Paulo (2012c), deu origem ao Mapa de Implantação de Técnicas de Controle na Fonte. Neste estudo, a cidade de Palmas, capital do estado do Tocantins, é adotada como estudo de caso. A cidade surgiu em uma época em que o conceito de sustentabilidade estava em foco, contudo ela parece seguir os mesmos processos de desenvolvimento dos grandes centros urbanos, onde a urbanização não prevê impactos ambientais negativos e o adequado, portanto, pretende-se indicar soluções de drenagem adequadas para a cidade em desenvolvimento. / Analyzing the potential risk of water contamination due to the lack of planning and integrated management of water resources, the ongoing study, URBAN DRAINAGE MASTER PLAN FOR PLANNED CITIES: Zoning Premise Based on Risk of Groundwater Contamination, suggests that the Municipal Master Plans are proposed to be developed aiming to preserve the quality and the amount not only of surface waters but also groundwater. The study intends to approach techniques of urban zoning based on the risk of groundwater contamination as a premise in the development of urban Drainage Master Plans for planned cities. Thus, this study analyzes zoning techniques and the adoption of alternative drainage BMPs (Best Management Practices) based on the risk of groundwater contamination as a premise in the development of Urban Drainage Master Plans for planned cities. For this, the zoning of urban areas is analyzed in order to minimize the contamination of aquifers, by direct use and by diffuse pollution. Serving as a premise in the determination of structural and nonstructural alternatives to be taken, especially regarding the adoption of drainage devices with soil infiltration. The integrated analysis of the maps gave rise to the Map of Implementation of BMPs. The Brazil capital\'s newest came at a time when the concept of sustainability was in focus, nevertheless it seems to follow the same processes of development of major urban centers. Being a city in full development and urbanization of areas contained in its master plan, it is intended to contribute to the elaboration of master plans of the city.

Seepage is an important component of the water budget in closed basins that do not have surface water drainage features. In the shallow water table environment of Florida, internal drainage of soil controls flooding. With the recent rapid population growth and urban development in the state, a simple, field-based method is needed to estimate seepage rates. In this study five locations in Hillsborough County, Florida, were instrumented with wells with pressure transducers measuring water level fluctuations at 1 minute resolution. For closed basins with lakes, evaporation (E) rates were determined using data from a weather station and Penman-Monteith FAO56 method, and then seepage rates were calculated from a water budget. Seepage rates varied greatly depending on conditions specific to the site. The seepage rates found for the three surface water sites in this study were 1.1 cm/d for a retention pond surrounded with dense vegetation, 0.5-0.8 cm/d for a natural lake located close to a groundwater pumping site, and 0.4 cm/d for another natural lake with no groundwater pumping in the proximity. Two methods to estimate seepage rates into semi-confined aquifers were compared: (a) mass balance approach and (b) Darcy's equation. At one of the sites the rate was 0.1 cm/d, and at the other site (sinkhole) it ranged between 0.8 cm/d during the wet season and 0.2 cm/d during the dry season when the head difference between the surficial and Floridan aquifers became smaller. The results of the study indicate that simple and relatively inexpensive field methods can estimate seepage within a narrow range and give reasonable seepage predictions that can be used in flood modeling. The obtained values indicate that seepage does not provide adequate drainage relief in closed basins. Another important finding is the magnitude of the local recharge to the Floridan aquifer. Further sensitivity studies on hydrological models that use seepage as one of the inputs may indicate that lower data collection resolution or simpler ET estimation methods are acceptable.

This thesis includes two different studies in an attempt to investigate and better understand the key characteristics of landscape evolution. In the first study, the rate of surface particle creep was investigated through the use of Terrestrial lidar at an archaeological site in Grand Canyon National Park. The second study developed ways to quantify metrics of the Colorado River drainage and reports the role of bedrock strength in the irregular profile of the trunk Colorado River drainage. Archaeological sites along the Colorado River corridor in Grand Canyon National Park are eroding due to a variety of surficial processes. The nature of surface particle creep is difficult to quantify and managers of this sensitive landscape wish to know the rates of erosion in order to make timely decisions regarding preservation. In the first study, two scans of a single convex hillslope were collected over the span of 12 months through the use of a ground-based lidar instrument. The scans were used to track the movement of rock clasts. This study, with a relatively small data set, did not show the expected positive relations of creep rate to slope or clast size, but did not preclude the existence of these relations either. The remarkably irregular long profile of the Colorado River has inspired several questions about the role of knickpoint recession, tectonics, and bedrock in the landscape evolution of Grand Canyon and the region. Bedrock resistance to erosion has a fundamental role in controlling topography and surface processes. In this second study, a data set of bedrock strength data was compiled and presented, providing relations of bedrock strength to hydraulicdriving forces of the trunk Colorado River drainage. Results indicate that rock strength and topographic metrics are strongly correlated in the middle to lower reaches of the plateau drainage. In the upper reaches of the drainage, intact-rock strength values are ~25% higher without a matching increase in stream power. As more tensile strength samples are analyzed and appropriately scaled with respect to fracturing and shale content, we believe we will see a clearer and more consistent pattern in the upper reaches.

Spatially-distributed water consumption was modeled over a segment of the Lower Colorado River, which contains irrigated agricultural and Tamarisk-dominated riparian ecosystems. For the irrigation scheme, distributed evapotranspiration data were analyzed in conjunction with point measurements of precipitation and surface flow in order to close daily and annual water balance. The annual closure error was less than 1% of the total water diversion to the area. In addition, it was found that the soil water storage component of the water balance cannot be neglected if the analysis is performed over time frames shorter than annual (e.g. growing season). Water consumption was highly uniform within agricultural fields, and all the full-cover fields were transpiring close to their potential rates. Mapping several new and existing drainage performance indicators showed that neither soil salinization nor water-logging would be of concern in this irrigation scheme. However, the quality of high-volume return flow must be studied, especially since the degraded water quality of the western US rivers is believed to act in favor of the invasive riparian species in outcompeting native species. Over the Tamarisk forest, the remotely-sensed evapotranspiration estimates were higher than the results of an independent groundwater-based method during spring and winter months. This was chiefly due to the fixed satellite overpass time, which happened at low sun elevation angles in spring and winter and resulted in a significant presence of shadows in the satellite scene and consequently a lower surface temperature estimate, which resulted in a higher evapotranspiration estimate using the SEBAL model. A modification based on the same satellite imagery was proposed and found to be successful in correcting for this error. Both water use and crop coefficients of Tamarisk estimated by the two independent methods implemented in this study were significantly lower than the current approximations that are used by the US Bureau of Reclamation in managing the Lower Colorado River. Studying the poorlyunderstood stream-aquifer-phreatophyte relationship revealed that diurnal and seasonal groundwater fluctuations were strongly coupled with the changes in river stage at close distances to the river and with the Tamarisk water extraction at further distances from the river. The direction of the groundwater flow was always from the river toward the riparian forest. Thus the improved Tamarisk ET estimates along with a better understanding of the coupling between the river and the riparian aquifer will allow the Bureau of Reclamation to re-asses their reservoir release methodology and improve efficiency and water savings.

Resumo: O presente trabalho teve como objetivo principal analisar a influência da heterogeneidade espaçotemporal, em diferentes escalas, sobre a distribuição de comunidades de macroalgas em uma área localizada na região centro-sul do estado do Paraná. Para ambos os estudos (espacial e temporal) seguiram-se os mesmos procedimentos amostrais. As escalas espaciais avaliadas foram: bacia de drenagem (Rio das Pedras e Rio Marrecas), mesohábitat (remanso e corredeira) e microhábitat (unidades amostrais com área de 0,05 m2), além dos níveis de sombreamento (aberto e sombreado). As amostragens foram realizadas em locais que apresentavam visível crescimento de algas. Um número igual de unidades amostrais "sem alga" também foi aleatoriamente avaliado. Dentro de cada unidade amostral foram avaliados os parâmetros bióticos (riqueza e abundância de espécies) e as variáveis ambientais locais (irradiância, velocidade da correnteza, profundidade, riqueza e diversidade do substrato). Em adição, para cada riacho, foram tomadas medidas das seguintes variáveis ambientais regionais: temperatura da água, oxigênio dissolvido, condutividade, pH e turbidez. No estudo espacial, um total de dez riachos foram avaliados por bacia de drenagem, sendo identificados 29 táxons. As diferenças entre as escalas espaciais estiveram muito mais relacionadas com características particulares de cada grupo (divisão e tipo morfológico) do que propriamente com a composição das espécies. A única distinção observada na estrutura das comunidades esteve relacionada com os diferentes níveis de sombreamento, o que evidencia a importância do regime de luz como fator determinante na distribuição espacial destes organismos. Em adição, a velocidade da correnteza também foi importante neste aspecto, já que maior desenvolvimento algal foi observada nestes ambientes. Em síntese, as características locais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aimed to analyze the influence of spatial and temporal heterogeneity at different scales, the distribution of macroalgal communities in an area located in the mid-southern of Parana state. For both studies (spatial and temporal) followed the same sampling procediments. The spatial scales evaluated were: drainage basin (Pedras river and Marrecas river), mesohabitat (riffles and pools) and microhabitat (sampling units an area of 0,05 m2), beyond to shading levels (open and shaded). The sampling units were positioned in places that hat visible growth of algae. A same number of sample units "without algae" also were randomly evaluated. Within each sampling unit were evaluated biotic parameters (richness and abundance of species) and the local variables (irradiance, current velocity, depth, richness and diversity of substrate). In addition, for each stream were taken of the following regional variables: water temperature, oxygen saturation, specific conductance, pH and turbidity. In the spatial study, a total of ten streams were evaluated by drainage basin, being identified 29 taxa. The differences between the spatial scales were more related to particular characteristics of each group (division and morphological type) than properly with the species composition. The only difference observed in community structure was related to the different levels of shading, which shows the importance of light as a determining factor in the spatial distribution of these organisms. In addition, the current velocity was also important in this aspect, as greater algal development was observed in these environments. In summary, the local characteristics had the greatest influence that the regional variables in the spatial distribution of macroalgal communities evaluated. For the temporal study, one stream was monthly evaluated in each drainage basin. A total of 16 taxa were identified. Although... (Complete abstract click electronic access below) / Orientador: Ciro César Zanini Branco / Coorientador: Orlando Necchi Júnior / Banca: Antonio Fernando Monteiro Camargo / Banca: Denise de Campos Bicudo / Banca: Andrea Tucci / Banca: Carla Ferragut / Doutor