Este estudo trata da caracterização hidromorfodinâmica de um setor paulista da planície fluvial meândrica do rio Ribeira de Iguape, abordando-se os três níveis da pesquisa geomorfológica de acordo com a concepção de HART (1986), a saber: (a) o nível descritivo da morfologia; (b) o nível descritivo dos materiais superficiais e solos; e (c) o nível analítico interpretativo dos processos, que, no caso, são hidrodinâmicos. Os resultados possibilitaram compreensão da hidromorfodinâmica das planícies fluviais meândricas em ambientes tropicais úmidos e, principalmente, da planície de inundação, podendo servir de subsídios no planejamento físico territorial regional, tendo em vista a importância da ocupação humana dentro desses setores. / The objective of this research is the hydromorphodynamic characterization of the Paulista River Ribeira de Iguape sector, approaching three levels of the geomorphology research according HART (1986), to know: (a) the morphology descriptive level; (b) the superficial materials and ground descriptive level; and (c) the processes interpretation analytical level, or hydrodynamic processes. With these surveys and systematization was possible the partially understanding humid tropical environments hidromorphodynamics trends and, mainly, of the flooding plain, which can be used in the regional territorial physical planning, in view of the importance of the occupation human being on these sectors.

A pesquisa teve como objetivo compreender o papel dos rearranjos de drenagem à evolução do relevo e da drenagem na bacia hidrográfica do Rio Capivari, situada no reverso da Serra do Mar, em São Paulo-SP. Parte-se da hipótese de que esses fenômenos seriam responsáveis por inúmeras anomalias de drenagem observadas, como: inflexões em ângulos retos, padrões de drenagem anômalos, colos, rupturas em perfis longitudinais e subdimensionamento de cursos dágua em relação aos vales. Especial ênfase foi dada à inflexão do alto Rio Capivari, localizada na confluência com o Ribeirão Embura, possível remanescente de uma captura fluvial, o qual melhor preserva as evidências de um rearranjo em toda a bacia. Os principais fatores dos rearranjos de drenagem na área foram: o forte gradiente hipsométrico proporcionado pela Serra do Mar, a densa trama de foliações e fraturas presentes no embasamento geológico, movimentações tectônicas recentes e as oscilações paleoclimáticas do Quaternário tardio. Sob influência dessas forças, alguns tributários da drenagem litorânea teriam se aproveitado de sua vantagem erosiva frente aos rios de planalto, produzido uma marcha de erosão regressiva em direção ao interior, com interferências nos canais situados em níveis sucessivamente mais elevados. Com base nas propostas metodológicas de Small (1972), Bishop (1995), Zaprowski et al. (2002) e Oliveira (2003), buscou-se a identificação de elementos morfológicos e sedimentológicos sugestivos desses processos, por meio de: análise de Modelos Digitais do Terreno (MDE) por métodos geomorfométricos; observação de fotografias aéreas; trabalhos de campo para descrição e coleta de materiais sedimentológicos; análise granulométrica, morfoscópica e mineralógica de sedimentos fluviais; e datação de sedimentos fluviais por Luminescência Óptica Estimulada para se estimar a idade da captura do alto curso do Rio Capivari. Os dados apresentados corroboram a hipótese de que o alto curso desse rio sofreu uma captura há cerca de 8.000 anos, no máximo, e que diversos outros casos de rearranjos de drenagem, entre eles reversões de grandes sistemas fluviais, seriam responsáveis pelas anomalias de drenagem observadas no interior da bacia estudada. / The aim of this research was to understand the role of drainage rearrangements on the evolution of relief and drainage in the Capivari River basin, located on the reverse of Serra do Mar range, in the state of São Paulo, Brazil. It is assumed that these phenomena would be responsible for numerous drainage anomalies observed, such as: river inflections at right angles, anomalous drainage patterns, cols, knickpoints and river underfitting, considered as indicative for drainage rearrangements. Special emphasis will be given to the inflection of the Capivari River at the confluence with the Ribeirao Embura, a possible remnant of a stream capture, which best preserves the evidence of a rearrangement throughout the basin. The main factors of the drainage rearrangements in the area would be: the strong hypsometric gradient provided by Serra do Mar range, the set of foliations and fractures densely present in the geological basement, recent tectonic movements and climatic oscillations of the Quaternary. Under the influence of these forcings, some tributaries of the coastal drainage would have taken erosive advantage over the plateau upside rivers, producing a regressive erosion march towards the interior of the continent, leading to interferences in the river systems situated at successively higher levels. Based on the methodological proposals of Small (1972), Bishop (1995), Zaprowski et al. (2002) and Oliveira (2003), we seek the identification of morphological and sedimentological elements that are suggestive of these processes, by means of: Digital Elevation Models (DEM) analysis by geomorphometric methods; observation of aerial photographs; fieldwork for description and collection of sedimentological materials; granulometric, morphoscopic and mineralogical analysis of fluvial sediments; and dating of fluvial sediments by Optically Stimulated Luminescence to estimate the age of capture of the upper reaches of the Capivari River. The presented data corroborate the hypothesis that the high course of the Capivari river was captured at least 8,000 years ago and that several other cases of drainage rearrangements, including reversals of large river systems, would be responsible for the observed drainage anomalies.

O estudo de bacias hidrográficas no meio tropical úmido, tem adquirido grande importância nas últimas décadas, devido a crescente demanda por planejamento de recursos hídricos. Entretanto, muitos desses trabalhos têm confundido o conceito de bacias hidrográficas, acreditando ser esta, uma mera rede de canais interconectados que formam a hidrografia dos terrenos, portanto, tomando-a como simples unidade cartográfica de estudo. Este fato tem banalizado em muito o uso de conceitos relacionados aos estudos de bacias, provocando sérios equívocos nas produções acadêmicas atuais. Partindo do princípio de que as bacias hidrográficas são espaços territoriais de circulação vertical e horizontal dágua, tendo a rede interconectada de canais, como um dos seus principais elementos, que escolhemos a bacia hidrográfica do Rio Benevente para estudo da relação entre a dinâmica fluvial desta e os seus condicionantes estruturais e morfológicos. Fundamentado no método da associação e indeterminação geomorfológica de Leopold e Langbein (1970), e, através de informações oriundas dos procedimentos técnico-operacionais de compartimentação geomorfológica e compilação de dados de parâmetros hidrográficos, foi possível descobrir que os sub-sistemas de drenagem que compõem a hidrografia total da bacia, evoluem condicionados por litoestruturas cristalinas e tectônicas do proterozóico, portanto, de organização antiga, e, que, aparentemente, demonstram não sofrer reativações modernas, a ponto de intervir na evolução dos sub-compartimentos de relevo regionais e na evolução hidrográfica da rede de canais. Chega-se desta forma, à conclusão de que os processos de encaixamento da drenagem, capturas fluviais, seccionamento de litoestruturas, gênese de knickpoints e evolução dos perfis longitudinais fluviais estão associados à dinâmica de processos geomórficos diferenciais, sob litoestruturas de forte natureza anisotrópica e complexa organização geotectônica. Fato que responde pela diversidade de sub-compartimentos de relevo e configuração evolutiva dos sistemas fluviais de dinâmicas diferenciais. / The study of watersheds in the humid tropical environment, has acquired great importance in recent decades due to growing demand for water resources planning. However, many studies have confused the concept of watersheds, believing that this was simply a network of interconnected channels that form the hydrography of the land, thus making it as simple cartographic unit of study. This commonplace is the use of concepts related to the studies of basins, causing serious confusion in the current academic productions. Assuming that the basins are territorial spaces of vertical and horizontal movement of water, the interconnected network of channels, as one of its main elements, we chose the basin of Rio Benevente to study the relationship between the dynamics of this river and its structural and morphological constraints. Based on the method of the Association and indeterminacy in geomorphologic Leopold and Langbein (1970), and through information from the technical and operational procedures of geomorphological partitioning and compilation of data from hydrographic parameters, could find that the sub-drainage systems that make up the total of the hydrographic basin, driven by evolving litoestruturas crystal and the tectonic proterozóico, therefore, the old organization, and that, apparently, show not suffer reactivations modern as to intervene in the evolution of sub-compartments of regional importance and the evolution of the network of river channels. Enough is thus concluded that the processes to fit the drainage, catch river, sectioning of litoestruturas, gênesis of knickpoints and evolution of longitudinal river profiles are associated with the dynamic of geomorphic processes differential,under litoestruturas of strong anisotropic nature and complex organization geotectônica. Fact responsible for the diversity of sub-compartments of important configuration and evolutionary dynamics of river systems of differential.

O estudo da geodiversidade vem sendo desenvolvido desde a década de 1990 e visa o conhecimento, descrição e conservação do patrimônio natural, através da avaliação de aspectos geológicos (minerais, rochas e fósseis), geomorfológicos (formas de relevo, processos) e pedológicos. A presente pesquisa buscou demonstrar e avaliar o potencial de utilização de variáveis da geomorfologia fluvial como indicadores de geodiversidade, considerando a subtilização deste tipo de indicador em estudos ambientais no Brasil. Essa subtilização coloca-se especialmente para a região amazônica, onde o ambiente fluvial tem grande relevância, seja nos aspectos ambientais, culturais estéticos ou científicos. O objetivo central da tese é a caracterização morfológica e análise, por amostragem, de padrões de canais fluviais e de outros parâmetros da morfologia fluvial na Bacia Hidrográfica do Rio Xingu, a fim de demonstrar a relevância desta variável para a avaliação da geodiversidade na Amazônia. Apesar de ainda ser, em grande parte, protegida por Unidades de Conservação e por Terras Indígenas, a Bacia Hidrográfica do Xingu sofre graves pressões antrópicas, ocasionadas principalmente pela monocultura de soja, nas áreas de cabeceiras, e pela construção da Usina Belo Monte na chamada Volta Grande do Xingu, próxima à sede do município de Altamira- PA. A pesquisa foi desenvolvida em duas escalas. Na de maior detalhe (1:150.000), foram realizados mapeamentos da morfologia fluvial para 23 áreas selecionadas como representativas da diversidade de padrões de canais fluviais na bacia hidrográfica considerada. Essa caracterização comprovou a grande diversidade de padrões de canais fluviais na área de estudo, demonstrando a pertinência desse parâmetro como indicativo de geodiversidade, e servindo também como base para a inserção da variável mudanças de padrão de canais fluviais na metodologia de mapeamento dos índices de geodiversidade da Bacia Hidrográfica do Xingu. Na escala de menor detalhe, foi aplicado um método de quantificação da geodiversidade, em toda a Bacia Hidrográfica, baseado na mensuração e integração dos elementos abióticos espacializados em mapas temáticos em escalas que variam de 1:250.000 a 1:1.000.000, com auxílio de um grid da articulação sistemática 1:25.000. Nesta escala foi realizada, também, uma correlação entre os índices de geodiversidade e os índices de biodiversidade, inferidos pelo XI mapeamento da vegetação em escala 1:250.000 (IBGE, 2000c). As principais contribuições da pesquisa foram o enriquecimento de bases para o estudo de grandes rios amazônicos e a aplicação de um método de mapeamento dos índices de geodiversidade, que poderá servir como instrumento para o planejamento ambiental, especialmente na definição de áreas prioritárias para conservação na região amazônica. / The study of geodiversity has been developed since the 1990s and aims the knowledge, description and conservation of natural heritage, through the evaluation of geological (minerals, rocks and fossils), geomorphological (landforms, processes) and pedological aspects. This research has intended to demonstrate and evaluate the potential use of fluvial geomorphological variables as geodiversity indicators, in view of the underutilization of this kind of indicator in environmental studies in Brazil. This underutilization is a critical issue for the Amazon region, where fluvial environments have great relevance on diverse aspects (environmental, cultural, aesthetic and scientific). The central aim of the thesis is the morphological characterization and analysis of river channel patterns and other parameters of fluvial morphology in sampling areas in the Xingu River Basin, in order to demonstrate the relevance of these parameters for the assessment of geodiversity in the Amazon. Although still largely preserved by conservation units and indigenous lands, the Xingu Basin suffers severe anthropogenic pressures, mainly caused by soy monocultures in headwater areas and by the construction of the Belo Monte Dam in the \"Volta Grande do Xingu\", near the town of Altamira, in the state of Pará. This research was conducted at two different spatial scales. On a more detailed scale (1:150,000), maps of fluvial morphology were made for 23 selected areas, which were considered representative of the diversity of river channel patterns in the drainage basin. This characterization proved the great diversity of river channel patterns in the study area, demonstrating the relevance of this parameter as an indicator of geodiversity. Such a characterization was also useful as a basis for the inclusion of the variable \"change in channel pattern\" in the mapping methodology of the geodiversity indexes in the Xingu Drainage Basin. On a less detailed scale, a method to quantify the geodiversity was applied to the entire drainage basin, based on the measurement and integration of abiotic elements, spatially distributed on thematic maps with scales ranging from 1:250,000 to 1:1,000,000, with the aid of a systematic articulation grid 1:25,000. On this scale it was also performed a correlation between the geodiversity and the biodiversity indexes, the latter inferred by vegetation mapping on scale 1:250,000 (IBGE, 2000c). XIII The main contributions of this research are the enrichment of the knowledge basis about large Amazonian rivers, as well as the application of a method for mapping the geodiversity indexes, which can be useful as a tool for environmental planning, particularly in defining priority areas for conservation in the Amazon region.

A physical assessment of the Provo River Restoration Project was undertaken in order to determine how alterations to the channel were designed, the nature of as-built channel morphology, and the performance of the reconfigured channel in terms of achieving frequent (2-year recurrence) bankfull discharge and increasing transient storage. Measures of channelized and reconfigured channel morphology were obtained using total station survey, digital aerial photography, and pebble counts. Results of geomorphic analysis were compared with similar measurements made by a regional consulting company, and stream channel design data, in order to determine that intended mitigation included reducing channel capacity, increasing sinuosity, decreasing pool spacing, and decreasing the size of bed material. Reconfiguration of the channel resulted in somewhat enlarged cross-sections with reduced mean velocities, increased sinuosity, decreased pool spacing, and decreased bed substrate size. One-dimensional hydraulic modeling suggests that alterations to channel morphology have increased the bankfull channel capacity in most reaches. Modeling results illustrate the fact that the stage of the 2-year recurrence flood is below bankfull at most cross-sections. This result does not follow the intentions of channel design. However, we have observed floodplain inundation in most years since reconfiguration. The occurrence floodplain inundation is being facilitated by overbank flow at a few point locations illustrating the strengths of incorporating variability into design. Known geomorphic controls on transient storage were reconfigured in manner to potentially increase in-channel and hyporheic components of transient storage. Stream tracer tests were utilized in order to determine the degree to which these alterations affected transient storage. Numerical analysis of stream tracer tests suggests that while the relative area of transient storage increased, average residence time of water in storage, and the mass transfer rate of solute between storage and the stream did not change. This suggests that an extensive hyporheic zone may not have been established. Correlations between hydrologic and geomorphic parameters indicate that in-stream storage may have been increased, and quick-exchange hyporheic flowpaths may have been created. (295 pages)

River restoration is something that is often used to help restore watercourses that were historically used for timber floating. In these restorations, instream wood (IW) plays a big role in increasing biodiversity and habitat heterogeneity in watercourses. Uncrewed Aerial Vehicles (UAVs) have proven to be useful when monitoring changes following river restoration but there is a need for less time-consuming methods to detect IW. This study’s objective was to investigate IW following a river restoration in an alluvial reach in Vargån, Northern Sweden and how well UAVs can be used to do this. Manual digitizing of IW was done in GIS from orthomosaics of three different flight occasions: pre-restoration, directly after and one year after restoration. An object- and color-based automated image thresholding was done to investigate if it could be used to automatically detect IW. The results showed that there were differences in number of IW, volume, width, and length between the different flight occasions. There was also indication that there had been movement of IW as well as changes in cluster composition, with more clusters with a higher number of wood pieces in the latest flight occasion. The automated image thresholding was able to accurately detect IW with an accuracy of 47,4 %, but it had limitations due to natural conditions. However, it showed the possibility of using automated methods to detect IW and with improvements it could become a faster and more accessible way of detecting IW in river monitoring.

Recent advances in remote-sensing technologies and analysis methods, specifically airborne-LiDAR elevation data and corresponding geographical information system (GIS) tools, present new opportunities for automated and rapid fluvial geomorphic (FGM) assessments that can cover entire watersheds. In this thesis, semi-automated GIS tools are used to extract channel centerlines and bankfull width values from digital elevation models (DEM) for five New England watersheds. For each study site, four centerlines are mapped. LiDAR and NED lines are delineated using ArcGIS spatial analyst tools with high-resolution (1-m to 2-m) LiDAR DEMs or USGS National Elevation Dataset (NED) DEMs, respectively. Resampled LiDAR decreases LiDAR DEM resolution and then runs spatial analyst tools. National Hydrography Dataset (NHD) lines are mapped by the USGS. All mapped lines are compared to centerlines delineated from photography and LiDAR DEMs. Bankfull widths at each site are determined through three methods. Regional regression equations are applied using variables derived from LiDAR and NED DEMs separately, producing two sets of width results. Additionally, the Hydrogeomorphological Geoprocessing Toolset (HGM) is used to extract widths from LiDAR data. Widths are also estimated visually from aerial photos and LiDAR DEMs. Widths measured directly in the field or derived from field-data are used as a baseline for comparison. I find that with a minimal amount of preprocessing, specifically through DEM resampling, LiDAR data can be used to model a channel that is highly correlated with the shape and location of the mapped channel. NED-derived channels model the mapped channel shape with even greater accuracy, and model the channel location only minimally less accurately. No tool used in this study accurately extracted bankfull width values, but analysis of LiDAR data by the HGM toolset did capture details that could not be resolved using regression equations. Overall, I conclude that automated, computerized LiDAR interpretation needs to improve significantly for the expense of data collection to be cost-effective at a watershed scale.

No description available.

With over 800,000 dams occurring globally and the construction of thousands more being proposed, successful restoration of regulated rivers will depend on the creation of broadly applicable frameworks that provide management solutions by generalizing patterns in habitat and ecology. Based on the prevailing scientific literature, restoring natural stream flows in disturbed rivers is dependent upon developing quantitative, transferable stream flow-ecology relationships. The purpose of my dissertation was to apply a framework to regulated and unregulated streams within an eight-state region of the southeastern US to test its ability to generalize patterns in natural and altered stream flow and develop flow-ecology relationships. I created a simplified, 5-step version of the Ecological Limits of Hydrologic Alteration (ELOHA) framework (Poff et al. 2010). I carried out each of the steps in sequential order for unregulated and dam-regulated streams found in my region. The steps of my restoration framework are as follows: 1. Develop a natural flow classification of unregulated streams 2. Develop a tool that uses landscape characteristics to predict flow class membership 3. Use the predictive tool or pre-disturbance hydrologic information to classify regulated rivers to natural flow classes 4. Based on class membership, generalize patterns in hydrologic alteration 5. Relate ecological patterns to patterns in hydrologic alteration in relation tomorphology, temperature, and landscape disturbance Altogether, the results of steps 1-4 suggest that patterns in natural flow dynamics and hydrologic alterations can successfully be placed within a framework and generalized to provide the basis and context for environmental flow management; however, results of step 5 suggest that patterns in flow alteration were poorly related to fish assemblages relative to channel morphology, habitat fragmentation, temperature, and substrate. Thus, the development of patterns in hydrologic alteration using the existing frameworks (including mine) may not be ecologically-relevant. My results suggest that current regulated river restoration should not be dependent upon the development of flow-ecology relationships alone, but the interaction between flow, morphology, and temperature within a landscape disturbance context. These relationships should be incorporated within a hierarchical framework to guide restoration efforts in regulated rivers in the future. / Ph. D.

Master of Arts / Department of Geography / Melinda Daniels / Large woody debris, (LWD), defined as pieces measuring ≥ 1 meter in length and ≥ 10 centimeters in diameter (Swanson and Lienkaemper, 1978; Marston, 1982) is an influential stream component. Once stable LWD obstructs streamflow and regulates key processes, causing increases in storage capacity, scouring, and variations to the bed, the extent contingent upon LWD’s average length of residence time within a system. Several North American studies have acknowledged the effects of interactions between wood, sediment, and flow regimes (Bilby, 1981; Keller, E.A., and Swanson, F.J., 1979; Montgomery et al., 1995; Wohl, E., 2008), linking the triad to geomorphic changes, the redistribution of bed materials, and ecological benefits. A consensual baseline reference for LWD’s function over time does not exist however, partly due to previous research being primarily conducted in the Northeast and Pacific Northwest regions where historic actions of humans, particularly riparian logging and stream clearing, have greatly impacted the condition of the watersheds. Researchers having long-overlooked the Great Plains and other regions not commonly associated with woody vegetation has increased the ambiguity regarding the transferability of LWD findings between regions. By shifting the focus to a non-forested region, the goal of this thesis is to measure the dynamics and influence of a prairie stream’s wood load on sediment storage and bed morphology. The Kings Creek network study area is located on the Konza Prairie Biological Station in northeastern Kansas, and drains one of few remaining unaltered North American watersheds. Results document the ongoing forest expansion into the surrounding pristine grassland, and provide a temporal context of the regions changing climate representative of atypical stream conditions caused by drought. In total, 406 individual pieces of wood were measured. The wood load was lower than most forest streams referenced (13.05 m[superscript]³/100 m), though higher than expected resulting from the absence of streamflow. LWD stored 108 m[superscript]³ of sediment within the channel, and the cumulative volume of LWD-formed pools was 169 m[superscript]³. Additionally, statistical analysis showed longitudinal bed variations to be strongly associated to LWD abundance, further indicating that LWD influences prairie stream processes similarly to those in a forest stream.