Orientador: Archimedes Perez Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-17T01:53:32Z (GMT). No. of bitstreams: 1 Storani_DanielLuis_M.pdf: 3427686 bytes, checksum: d091724232d53b90596c22f2e23b3314 (MD5) Previous issue date: 2010 / Resumo: A Bacia Hidrográfica do Rio Mogi Guaçu compreende uma área de 14.653 km² na porção nordeste do estado de São Paulo e atravessa diferentes compartimentos geomorfológicos do estado paulista. Além da Mata Atlântica, originalmente as terras drenadas pela bacia apresentam áreas recobertas por fisionomias de cerrado. Traçar explicações sobre como a atual caracterização da área se deu envolve o estudo de diferentes componentes do ambiente natural, exigindo, assim, a análise das componentes que compõem o que se conceitua como geossistema. Os métodos existentes na atualidade para datação absoluta de solos permitem, por exemplo, atribuir a períodos específicos da evolução terrestre a origem de determinadas condições conhecidas ou modeladas. A fragilidade de determinados ambientes pode ser explicada, então, a partir da origem das componentes naturais do geossistema. O uso da interpretação geomorfológica das paisagens é essencial, então, para o entendimento da seqüência de acontecimentos que atribuíram à paisagem determinadas características. Ao longo das oscilações climáticas do Quaternário, o cerrado (no sentido lato sensu) corresponderia a uma vegetação adaptada a condições de clima mais seco e com solos arenosos e distróficos. Apesar da discussão ainda existente quanto ao conjunto de características ambientais que permitiriam o surgimento e manutenção dessa vegetação em porções específicas do território brasileiro e do estado de São Paulo, o presente trabalho busca relacionar as condições ambientais e geomorfológicas pretéritas (do Quaternário, especificamente do Pleistoceno) de alguns pontos da bacia hidrográfica do Mogi Guaçu/SP com o cerrado, por meio de técnicas de datação e correlação desses dados com características da evolução da paisagem e datações relativas de outros estudos. Foram utilizadas técnicas de datação absoluta por Luminescência Opticamente Estimulada (LOE) para datar níveis específicos de áreas cobertas por cerrado, para posterior relação com datações relativas levantadas por trabalhos clássicos da literatura geomorfológica, o que permitiu relativizar tais explicações. Propõe-se que as superfícies de aplainamento e níveis de terraço podem ser consideradas geossistemas específicos, pela íntima relação entre seus elementos num determinado período de tempo / Abstract: The Mogi Guaçu River Basin comprises an area of 14,653 km² in northeastern São Paulo state and across different geomorphological compartments. Originally, beyond the Mata Atlântica vegetation, the lands drained by the basin have areas covered by cerrado. The explanation of how the current characterization of the area occurred involves the study of different components from the natural environment, thus requiring the analysis of the components that make up what is conceptualized as geosystem. Existing methods for absolute dating of soils allow, for example, assign specific periods of development land to the origin of certain conditions known or modeled. The fragility of certain environments may be explained, then, from the origin of the natural components of geosystem. The use of geomorphological interpretation of the landscape is essential, then, to understand the sequence of events that they attached to certain landscape features. Throughout the Quaternary climatic oscillations, the cerrado (in lato sensu) would be a type of vegetation adapted to drier climate conditions and sandy and dystrophic soils. Although the discussion still exists on the set of environmental characteristics that would allow the emergence and maintenance of vegetation in specific portions of Brazil and the state of Sao Paulo, this paper seeks to relate the environmental conditions and geomorphologic preterit (in the Quaternary, especially in the Pleistocene) of some areas of Mogi Guaçu River Basin with cerrado vegetation, through techniques of dating and correlation of these data with characteristics of landscape evolution, and relative dating of other related studies. Techniques used for absolute dating were Optically Stimulated Luminescence (OSL) for dating specific levels of the areas covered by cerrado, for later discussion with on relative dating relationship raised by classic works of geomorphological literature, allowing relativize such explanations. It is proposed that the surfaces of planing and terrace levels can be considered specific geosystems, by the close relationship between its elements in a given period of time / Mestrado / Análise Ambiental e Dinâmica Territorial / Mestre em Geografia

Orientador: Francisco Sérgio Bernardes Ladeira / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-18T07:37:54Z (GMT). No. of bitstreams: 1 Celarino_AndreLuizdeSouza_M.pdf: 6577902 bytes, checksum: d76059e9c39490c344571bfeab4259c6 (MD5) Previous issue date: 2011 / Resumo: O rio Mogi Guaçu apresenta, no trecho próximo a Estação Ecológica de Jataí, em Luis Antônio-SP, elevada sinuosidade do canal e inúmeros meandros abandonados causados pela migração lateral e posterior avulsão do curso principal. Essa situação proporcionou uma configuração específica para os solos localizados no terraço e na planície aluvial do rio. Para entender melhor a morfopedogênese desse local, foi feita uma sequência de perfis e tradagens para a investigação da continuidade lateral dos horizontes pedológicos, para depois serem realizadas análises químicas, granulométricas, mineralógicas, micromorfológicas e datações. Identificou-se horizontes ricos em matéria orgânica que ocupam toda a várzea e antigo terraço fluvial, que estão se desenvolvendo sobre um depósito residual de 130.000A.P, conforme datação realizada em um dos perfis. Esses horizontes possuem gêneses diferentes. Um deles, classificado como hístico (H), se desenvolveu preenchendo um antigo meandro abandonado, enquanto os horizontes acima dele, compostos por uma sequência de horizontes A húmicos, foram depositados posteriormente em ambiente de maior energia do rio, num dado momento onde ele já tinha incidido seu talvegue em alguns metros e se deslocado no sentido contrário ao de sua planície aluvial. Esse horizonte foi enterrado por sedimentos aluviais e a preservação da matéria orgânica foi eficiente, apesar de apresentar menores quantidades de carbono orgânico que o horizonte H. A mineralogia mostrou que a Caulinita é o mineral predominante na fração argila, apesar de ocorrerem também Gibbsita e VHE. Esta última seria resultado de neoformação, indicando atual situação de drenagem livre, ou, sua presença é de origem alóctone. A micromorfologia mostrou feições redox ainda preservadas na base do perfil 3, porosidades fissurais associadas à processos de perda de água pela superfície e grandes diferenças granulométricas entre os perfis apresentados, a principal delas se refere à diminuição latente do grau de seleção dos grãos do esqueleto no sentido da vertente para a planície aluvial. As razões molares apontaram para descontinuidades no horizonte 2A em P5 e P3, e entre os horizontes Ah e H, no perfil 4, mostrando distintas condições de pedogênese dentro dos perfis. Os processos de formação desses horizontes estão ligados à migração lateral do rio Mogi Guaçú e incisão do seu talvegue, que proporcionaram condições redutoras para o acúmulo de matéria orgânica, resultando em momentos de maior e menor acúmulo. Com as datações foi possível propor a cronologia da formação do paleoterraço e da planície aluvial nos últimos 130.000 anos e dos solos associados, no entanto, as considerações feitas a respeito da influência do paleoclima e de fatores estruturais não são conclusivas, devido à dinâmica geológica e geomorfológica da área, que é bastante específica / Abstract: The Mogi Guaçu river, near to Estação Ecológica de Jataí (Luis Antônio-SP), shows high sinuosity on its channel and many abandoned meaders caused by lateral migration and main course's avulsion. This situation is responsible by a specific configuration for the soils which are localized at terrace and at the river's alluvial plain. For a better understanding of the local morphopedogenesis, a profiles' sequence and some boreholes were made in order to investigate the lateral continuity of the soil horizons, and then perform chemical analysis, particle size distribution, mineralogy, micromorphology and datings.This process enabled the identification of horizons rich in organic matter which fills the lowland and the old's alluvial plain, which are developing above residual deposits of 130.000B.P, in according to the dating of one of the profiles. These horizons have different genesis. One of them, classified as histic horizon (H), developed filling an older abandoned meander, while the horizons above, compound by a sequence of humic A horizons, were deposited later on high energy river environment, at some point where it has been cut its thalweg in some meters and moved away of the alluvial plain. This horizon was buried by alluvial sediments and the preservation of organic matter was efficient, despite of showing lower amounts of organic carbon than H horizon.The mineralogy has shown that Caulinite is the predominant mineral in clay fraction, although Gibbsite and HIV also exist. HIV may be the result of neoformation, indicating an actual situation of free drainage, or, its presence is allochthounous. The micromorpholy has shown preserved redox lineament on the bottom of profile 3, porosities associated to water loss processes by surface and big granulometric differences between the profiles. One of the biggest differences refers to the grain selection's reduction of the skeleton in the direction of the slope to the alluvial plain. The molar ratios indicated gaps on 2A horizon in the P5 and P3, and between Ah and H horizons, on profile 4, showing different profile conditions of soil forming. The formation process of those horizons is linked with lateral migration of the river Mogi Guaçu and incision of its thalweg, which provides reducing conditions for the amount of organic matter, resulting in higher and lesser moments of accumulation.By datings was possible propose paleoterrace and alluvial plain formation chronology of last 130.000 years and associated soils, although, the considerations made about paleoclimate and structural factors influence aren't conclusive, due to geologic and geomorphologic dynamic of area, that is much specific / Mestrado / Análise Ambiental e Dinâmica Territorial / Mestre em Geografia

Na presente pesquisa investiga-se a geomorfologia da planície fluvial do rio Pinheiros entre os bairros de Pinheiros, Butantã e Cidade Jardim, na cidade de São Paulo. Para tal, propõe-se uma carta geomorfológica de detalhe deste setor da planície na escala de 1:20.000, confeccionada a partir de pesquisa arquivística prévia e, principalmente, de fotografias aéreas e de mapas antigos. A análise da carta e a sua correlação com informações sedimentológicas e estratigráficas encontradas, principalmente, em recentes relatórios de engenharia para a construção do Metrô de São Paulo, permitem a caracterização do sistema fluvial deste setor do rio Pinheiros, bem como de parte da morfodinâmica atuante no sistema antes da perturbação antrópica de alto impacto decorrente da urbanização que ali se instalou a partir da década de 1930. A pesquisa permitiu também a interpretação de uma provável sequência de eventos geomorfológicos atuantes no setor estudado durante o Pleistoceno Superior e o Holoceno. Parâmetros morfométricos tais como índice de sinuosidade de canais e paleocanais e largura da planície no trecho estudado evidenciaram aspectos da influência da estrutura geológica em sua evolução. O reconhecimento de sistemas geomorfológicos em seu estágio préperturbação antrópica é essencial para a compreensão dos processos atuais, principalmente em meios intensamente modificados como as áreas urbanas. A pesquisa apresenta então este tipo de reconhecimento, colaborando assim na compreensão dos processos antecedentes às grandes rupturas que se instalam no sistema a partir das ações antrópicas na superfície. / This research investigates the geomorphology of part of Pinheiros River fluvial plain in São Paulo city. This study main result is a detailed geomorphologic map - 1:20,000 - that used ancient aerial photographs and maps obtained from formal archival surveys. The descriptions of floodplain units were associated to stratigraphic and sedimentologic data obtained from recent engineering projects reports of São Paulo underground (such as subway). This association allows the understanding of part of Pinheiros River fluvial system and morphodynamic before urbanization. The research also allowed offering a sequence of geomorphological events related to the floodplain and channel systems over the Holocene. Morphometric parameters, such as width and sinuosity index of channels and paleo-channels of floodplain meandering system, appear as an evidence of the structural influence in geomorphological evolution of this system. The recognition of geomorphologic systems in pre-disturbance stage is essential for understanding the current processes, mainly in environments greatly modified by human actions, such as urban areas. This research presents this kind of recognition and contributes to the understanding of processes in the system before human actions in the surface.

Made available in DSpace on 2017-07-10T17:51:34Z (GMT). No. of bitstreams: 1 Karl_Heins_Ewald.pdf: 3570741 bytes, checksum: c5bdd80e061dc3f0dc6cf78e808ab2d3 (MD5) Previous issue date: 2013-05-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Rivers are important agents working in the sculpturing of relief, through its high transport capacity of sediments originary from slopes and marginal erosion. The modeling occurs through the processes of erosion and deposition of sediments, which depend on variables such as lithological composition, slope, and flooding. The processes that originate topographic forms are widely described in the literature of alluvial-bed rivers, however little is known about the occurrence of these forms in mixed bed channels (alluvial-rock) and bedrock channel. In this context, this research aims to describe the topographic forms of the valleys on the Cascavel Plateau. The method for the recognition of these forms is the topographic mapping of cross sections in different parts of the channel located at the top, middle and lower course. The mapping is performed with a set level and optical sights. Were mapped four fluvial channels, two channels in areas with altimetric elevations below 400 meters, and two other channels with elevations above 700 meters. The channels have floodplains with varying lengths. Topographic forms were found as dikes, point bars, flood inundation basins, pools and riffles. The data collected show strong channel incision in the sections corresponding to the upper parts of the channels, and that in the course stretches of low flood plains are well developed. Channel meandering is a characteristic feature of the Cascavel Plateau. The formation of point bars is directly associated with the channel marginal erosion, whereas the dikes are the result of sediment settling. The pool-riffle sequences occur by the reduction of the flow velocity in some places, and, in others, by the presence of woody debris. In some parts of the river where are rock outcrop was observed the formation of pot-holes / Os rios são importantes agentes atuando na esculturação do relevo por meio da sua alta capacidade de transporte de sedimentos originários das vertentes e dos processos de erosão marginal. A modelagem ocorre através dos processos de erosão e deposição de sedimentos, que dependem de variáveis como composição litológica, declividade e cheias. Os processos que originam as formas topográficas são descritos vastamente na literatura sobre rios de leito aluviais, no entanto pouco se sabe sobre a ocorrência dessas formas em canais de leitos mistos (aluviais-rochosos) e leitos rochosos. Nesse contexto esta pesquisa objetiva a descrição das formas topográficas de fundos de vale no Planalto de Cascavel. O método para o reconhecimento dessas formas topográficas consiste no mapeamento de seções transversais em trechos distintos do canal localizados no alto, médio e baixo curso. O mapeamento é realizado com um conjunto de nível ótico e mira. Foram mapeados quatro canais fluviais, sendo dois canais em áreas com cotas altimétricas inferiores a 400 metros e, outros dois canais com cotas superiores a 700 metros. Os canais apresentam planícies de inundação com extensões variadas. Foram encontradas formas topográficas como diques, barras em pontal, bacias de inundação, soleiras e depressões. Os dados coletados mostram que há forte incisão do canal nos trechos correspondentes ao alto curso dos canais, e, que nos trechos de baixo curso as planícies de inundação são bem desenvolvidas. O meandramento de canais é uma característica do Planalto de Cascavel. A formação de barras em pontal está associada diretamente a erosão marginal, enquanto que os diques são resultantes da decantação de sedimentos. As sequências de soleiras-depressões ocorrem pela diminuição da velocidade do fluxo em alguns trechos, e, em outros, pela presença de detritos lenhosos. Nos trechos rochosos onde há afloramento rochoso foi observada a formação de marmitas

Orientador: Archimedes Perez Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-23T09:03:41Z (GMT). No. of bitstreams: 1 Trivellato_FredTeixeira_M.pdf: 5413027 bytes, checksum: 921b3bd39c22a86ef3b6831e64e54979 (MD5) Previous issue date: 2013 / Resumo: Esta pesquisa analisa as transformações na geometria hidráulica do rio do Peixe ocorrida em período de 106 anos. Os dados históricos de referência são da extinta Comissão Geográfica e Geológica do Estado de São Paulo, em sua expedição de 1906, quando toda extensão da bacia hidrográfica ainda estava livre da ocupação urbana e exploração agrícola intensiva. Os exploradores realizaram descrições da paisagem que circunda o rio (vegetação, relevo, solo e população indígena) e também perfis transversais no seu canal a fim de verificar largura, profundidade e descarga, os quais são refeitos pela presente pesquisa. Foram coletados dados em campo obtidos em cinco perfis, distribuídos entre o médio e baixo curso, localizados nos municípios de Tupã, Bastos, Parapuã, Mariápolis e Ribeirão dos Índios, durante os meses de estiagem, assim como realizado em 1906. Os resultados apontam aumento na largura, profundidade, velocidade de fluxo e vazão e diminuição nos índices de declividade e sinuosidade. A análise geográfica do comportamento fluvial perpassa pela evolução do uso das terras em série histórica e levantamento do regime de chuvas e hidrológico da bacia hidrográfica. Constatou-se que a partir de 1920 a cobertura vegetal natural é paulatinamente retirada, causando efeitos no equilíbrio do canal fluvial. Concluiu-se que o aumento nas variáveis de geometria hidráulica se devem ao aumento do escoamento superficial e carga sedimentar gerado pelo desmatamento, uso agrícola e urbana, assim como o incremento no sistema de águas subterrâneas por meio de exploração de poços tubulares dos sistemas aquíferos sedimentar e basáltico / Abstract: This research analyzes hydraulic geometry changes of the Peixe river occurred in a period of 106 years. The historical reference data are from the extinct Geographical and Geological Commission of the State of São Paulo. This 1906 expedition occour when the basin river system was still free of urban occupation and intensive farming. The explorers carried descriptions of the landscape surrounding the river (vegetation, topography, soil and the indigenous population) as well as cross sections on fluvial channel to check width, depth and discharge, which are remade by this research. Field data were obtained from five profiles, distributed between the middle and lower course, located in the municipalities of Tupa, Bastos, Parapuã, Mariápolis and Ribeirão dos Indios during the winter months, as done in 1906. The results accuse increase in width, depth flow velocity and flow and reduce the rates of slope and sinuosity. The geographical analysis of behavior river goes through the evolution of land use in time series and survey of rainfall and hydrological regime in the basin. It is known that in 1906 there was a natural dynamics in the watershed and after 1920 the vegetation is gradually withdrawn, increasing runoff and erosion development / Mestrado / Análise Ambiental e Dinâmica Territorial / Mestre em Geografia

Le Paraná argentin, le cinquième plus grand fleuve du monde par la taille de son bassin versant et le dixième par son débit, est également un fleuve de paradoxes : axe essentiel pourtant délaissé ; immense mais inconnu en dehors des pays qu’il traverse ; richesse environnementale qui n’est cependant pas protégée ; au potentiel naturel gigantesque mais très peu utilisé. Avec les 3.2 millions de km² de son bassin versant et un débit moyen de 18 000 m3/s à son embouchure il peut être considéré comme un mégafleuve. La séparation des thématiques de recherche entre géographie physique et humaine implique que le thème des grands fleuves ne soit pas abordés de manière concertée. En 2008, E. Latrubesse propose la notion de « mégafleuve », faisant franchir un saut épistémologique à certains très grands fleuves. Le concept trouve son équivalent dans les réflexions propres à la géographie humaine. L’objectif de cette thèse est donc de proposer un élargissement du concept de mégafleuve à la géographie humaine. Les grands projets tels que l’Hidrovia Paraná-Paraguay ou encore les grands barrages hydroélectriques permettent de mettre en place des ponts entre les domaines de compétence et de croiser la vision des acteurs de différents secteurs. Le Paraná est un fleuve en mutation, porteur d’enjeux socio-économiques de plus en plus importants : c’est pourquoi il est un objet idéal pour promouvoir un aménagement intégré porteur de valeurs environnementales. L’enjeu se situe principalement dans la mise en place des relations entre les échelles locales et supranationales induisant des recompositions territoriales. Ces dernières se fondent sur la mise en réseau de tout ou partie des territoires nationaux permettant de construire de nouvelles architectures régionales grâce à la convergence d’intérêts entre les différents acteurs. L’objectif visé est celui d’aboutir à des coopérations ouvertes permettant de diminuer l’approche verticale-sectorielle qui prédomine de nos jours. / The argentinian Paraná is the fifth river of the world by the size of its watershed, its tenth and its flow. It also is a river of paradoxes: it is an essential axis but has been abandoned; it is immense but unknown outside the countries which it crosses; it represents an environmental wealth which isn’t protected; and finaly is gigantic but very poorely used. With the 3.2 million km ² of its watershed , and an average flow which reaches 18 000 m3/s at its mouth it can be considered as a megariver.The theme of big rivers is nowadays quite fashionable in the scientific literature, but the research is separated between physical and human geography. It then seems necessary to reconcile both approaches around new concepts. In 2008, E. Latrubesse proposed the concept of megariver. This concept finds its equivalent in the reflections found in the human geography. The objective of this thesis is to propose an extension of the concept of megariver to the human geography. Few transversal approaches are led on the Paraná river and links between sectors, services and actors are fragile. The big projects such as the fluvial higway called Hidrovia Paraná-Paraguay or the big hydroelectric dams, allow to link different fields of expertise and to cross the vision of diferent actors. As a fact, the river carries more and more socio-economic issues which can only be approached with an integrated vision, joining social, environmental and economical questions. The issue is aslo situated in the relations between local, national and supranational scales, which leads to territorial reorganizations. These networks of geographical scales allow to build new cooperations inbetween all the actors and lead to an integrated managment of the Parana river.

The cross-sectional form of semi-alluvial bedrock channels was investigated. Channel geometry data were collected from a variety of streams in Ontario and Québec, Canada to develop empirical downstream scaling relationships. The relationships revealed that bedrock, mixed, and alluvial channels scale at similar rates with respect to discharge. The widest channels were formed in low-relief sedimentary bedrock with minimal alluvial cover. Channels influenced by resistant igneous/metamorphic bedrock produced a strong scaling relationship, whereas channels influenced by weak sedimentary bedrock produced a weak scaling relationship. Alluvial cover appeared to exhibit more control on channel width in low-relief settings in comparison to high-relief settings, with increased alluvial cover promoting channel narrowing. Channels influenced by igneous/metamorphic bedrock produced identifiable thalwegs, presumably due to well-defined bedload transport pathways. Channels influenced by sedimentary bedrock tended to have planar beds. Additionally, fish habitat was investigated at one semi-alluvial bedrock stream in Ontario, Canada. Fish sampling was conducted at proximate bedrock and alluvial sections followed by a survey of physical habitat parameters to evaluate habitat preferences. Adult logperch (Percina caprodes), juvenile white sucker (Catostomus commersonii), adult round goby (Neogobius melanostomus), and adult longnose dace (Rhinichthys cataractae) demonstrated preference toward alluvial substrate, whereas juvenile logperch and adult banded killifish (Fundulus diaphanus) demonstrated preference toward bedrock. Juvenile silver shiner (Notropis photogenis) and juvenile yellow perch (Perca flavescens) were indifferent to substrate type. Empirical depth and flow velocity habitat suitability indices (HSIs) were developed for each fish species. This study presents the first fish habitat suitability criteria developed from a small semi-alluvial bedrock stream and may provide valuable information for fisheries management endeavours in such environments.

The October 2007 removal of Marmot Dam, a 14.3-m-tall dam on the Sandy River in northwestern Oregon storing approximately 730,000 m3 of impounded sediment, provided an opportunity to study short- and long-term geomorphic effects of dam removal. Monitoring reservoir morphology during the two years following dam decommissioning yields a timeline of reservoir channel change. Comparison of a pre-dam survey in 1911 with post-removal surveys provides a basis from which to gage the Reservoir Reach evolution in the context of pre-dam conditions. Analyses of time-lapse photography, topographic surveys, and repeat LiDAR data sets provide detailed spatial and temporal documentation of a release of sediment from the reservoir following dam removal. The majority of morphologic changes to the reservoir largely took place during the first few days and weeks following removal. Channel incision and widening, along with gradient changes through the Reservoir Reach, exhibit diminishing changes with time. Channel incision rates of up to 13 m/hr and widening rates of up to 26 m/hr occurred within the first 24 hours following breaching of the coffer dam. Although channel position through the Reservoir Reach has remained relatively stable due to valley confinement, its width increased substantially. The channel reached an average width of 45 m within two weeks of breaching, but then erosion rates slowed and the channel width reached about 70 to 80 m after one and two years, respectively. Diminishing volumes of evacuated sediment were measured over time through quantitative analysis of survey datasets. About 15 percent of the initial impounded sediment was eroded from the Reservoir Reach within 60 hours of breaching; after one and two years, 50 and 58 percent was eroded, respectively. Grain-size analysis of terraces cut into reservoir fill following dam removal show that bed material coarsened over time at fixed elevations and vertically downward as the channel incised. Overall, these findings indicate valley morphology and local in-channel bedrock topography controlled the spatial distribution of sediment within the reservoir reach while variability in river discharge determined the timing of episodic sediment release. Changes within the Reservoir Reach shortly after dam removal and subsequent evolution over the two years following removal are likely attributable to 1) the timing and intensity of flow events, 2) the longitudinal and stratigraphic spatial variations in deposit grain-size distributions initially and over time, and 3) the pre-dam topography and existing valley morphology.

No description available.

The complex and non-linear fluvial river dynamics are characterized by repeated periods of fluvial erosion and re-deposition in different parts of the floodplain. Understanding the fluvial architecture (i.e. the three-dimensional arrangement and genetic interconnectedness of different sediment types) is therefore fundamental to obtain well-based information about controlling factors. However, investigating the fluvial architecture in buried floodplain deposits without natural exposures is challenging. We studied the fluvial architecture of the middle Weiße Elster floodplain in Central Germany, an extraordinary long-standing archive of Holocene flooding and landscape changes in sensitive loess-covered Central European landscapes. We applied a novel systematic approach by coupling two-dimensional transects of electrical resistivity tomography (ERT) measurements and closely spaced core drillings with spatially resolved measurements of electromagnetic induction (EMI) of larger floodplain areas at three study sites. This allowed for (i) time and cost-efficient core drillings based on preceding ERT measurements and (ii) spatially scaling up the main elements of the fluvial architecture, such as the distribution of thick silt-clay overbank deposits and paleochannel patterns from the floodplain transects to larger surrounding areas. We found that fine-grained sand and silt-clay overbank deposits overlying basal gravels were deposited during several periods of intensive flooding. Those were separated from each other by periods of reduced flooding, allowing soil formation. However, the overbank deposits were severely laterally eroded before and during each sedimentation period. This was probably linked with pronounced meandering or even braiding of the river. Our preliminary chronological classification suggests that first fine-grained sedimentation must have occurred during the Early to Middle Holocene, and the last phase of lateral erosion and sedimentation during the Little Ice Age. Our study demonstrates the high archive potential of the buried fluvial sediments of the middle Weiße Elster floodplain and provides a promising time and cost-effective approach for future studies of buried floodplain sediments.