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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Influência do lançamento de esgotos na qualidade das águas do aquífero aluvial do rio Sucurú, no município de Sumé – PB.

SALGADO, Jaqueline Pereira. 30 July 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-07-30T13:37:45Z No. of bitstreams: 1 JAQUELINE PEREIRA SALGADO -DISSERTAÇÃO (PPGECA) 2016.pdf: 4613492 bytes, checksum: e2106196261e0c2eb71ee8147c208d65 (MD5) / Made available in DSpace on 2018-07-30T13:37:45Z (GMT). No. of bitstreams: 1 JAQUELINE PEREIRA SALGADO -DISSERTAÇÃO (PPGECA) 2016.pdf: 4613492 bytes, checksum: e2106196261e0c2eb71ee8147c208d65 (MD5) Previous issue date: 2016-12-02 / Na Paraíba a utilização das águas subterrâneas tem crescido consideravelmente, de forma que essas águas estão cada vez mais suscetíveis a contaminações, tanto pelo lançamento de esgotos sem tratamento quanto por outras ações antropogênicas, especialmente atividades agropastoris. Este trabalho tem por objetivo avaliar a influência causada pelo lançamento de esgotos na qualidade das águas subterrâneas e a viabilidade destas em usos diversos. Para realização desta pesquisa foram escolhidos 9 poços ao longo do aquífero aluvial do Rio Sucurú, no município de Sumé-PB. Os indicadores de qualidade selecionados foram: físico-químicos - alcalinidade bicarbonato, alcalinidade carbonato, cálcio, cloretos, condutividade elétrica, DBO, DQO, ferro, magnésio, nitrato, nitrito, nitrogênio amoniacal, OD, pH, potássio, salinidade, sódio, sólidos totais dissolvidos, temperatura, turbidez; e microbiológicos - coliformes termotolerantes e E. coli. Ao longo do aluvião foram identificadas diversas fontes de poluição antrópica, que exercem influência na qualidade da água do aquífero. Através da metodologia GOD, o aquífero foi classificado com nível de vulnerabilidade médio. Os indicadores relacionados à salinidade mostraram altos níveis de sais ao longo do aluvião, o que restringe o uso para irrigação. Os parâmetros mínimos para classificação das águas subterrâneas de acordo com a Resolução CONAMA 396/2008, estiveram, na maioria dos poços, acima do VMP, exceto para nitrato, qualificando, dessa forma, as águas do aquífero como Classe 4. Assim foi concluído que as águas do aquífero aluvial do rio Sucurú somente podem ser utilizadas sem tratamento, para usos menos restritivos. / In Paraíba, the usage of groundwater has increased considerably, therefore, these water resources are more susceptibles to contamination, either by the discharge of untreated wastewater, or by other anthropogenic activities, above all, agropastoral activities. The main objective of this study is to evaluate the influence of the sewage discharge on the groundwater quality and the viability of these resources for various uses. For this research 9 wells along the alluvial aquifer of Sucuru River in Sumé-PB were chosen. The water quality indicators selected were: physico-chemical - bicarbonate and carbonate alkalinity, calcium, chloride, conductivity, BOD, COD, iron, magnesium, nitrate, nitrite, ammoniacal nitrogen, DO, pH, potassium, salinity, sodium, total dissolved solids, temperature, turbidity; microbiological - thermotolerant coliforms and E-Coli. Along the alluvium were indentified various fonts of anthropogenic pollution, which have influence on the aquifer water quality. Through the GOD method, the aquifer was classified with medium vulnerability level. The indicators related to salinity presented high salt levels along the alluvion, which restricts the water use to irrigation. The minimal parameters for the classification of groundwater according to the CONAMA Resolution 396/2008, have been, on most the wells, above the MVA, except for nitrate, thus qualifying the aquifer water as Class 4. Therefore it was concluded that the water from the alluvial aquifer of the Sucuru River can only be used, untreated, for least restrictive uses.
82

Vliv hospodaření v lužních lesích jižní Moravy: rekonstrukce obmýtních cyklů a dendroklimatologická analýza růstu dřevin / Effect of management in alluvial forests of South Moravia: reconstruction of harvest cycles and dendroklimatological analysis of tree growth

JANSKÁ, Eliška January 2014 (has links)
This thesis deals with management history of floodplain forests in south Moravia. Using dendrochronological and dendroclimatological analyses, we revealed past disturbances and inferred former forestry practices, and we demonstrated the effect of climate and decrease of water table on the growth of oak (Quercus robur).
83

Vliv hospodaření v lužních lesích jižní Moravy: rekonstrukce obmýtních cyklů a dendroklimatologická analýza růstu dřevin / Effect of management in alluvial forests of South Moravia: reconstruction of harvest cycles and dendroklimatological analysis of tree growth

JANSKÁ, Eliška January 2014 (has links)
This thesis deals with management history of floodplain forests in south Moravia. Using dendrochronological and dendroclimatological analyses, we revealed past disturbances and inferred former forestry practices, and we demonstrated the effect of climate and decrease of water table on the growth of oak (Quercus robur).
84

Paleoekologická studie prameniště v centru starosídelní oblasti. / Palaeoecological study of mire in the centre of an old-settlement area.

BERNARDOVÁ, Alexandra January 2009 (has links)
The palaeoecological development of alum mire since early Eneolithic on the basis of the results of macro-remains, pollen, and chemical analysis. The developement of local vegetation and nearest surrounding area was studied.
85

GÃnese e classificaÃÃo de solos em ambientes de planÃcies da regiÃo Nordeste do Brasil / Genesis and classification of soils from lowland environments in the Northeast region, Brazil

Rafael Cipriano da Silva 16 July 2012 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Solos formados por sedimentos em ambientes de planÃcie apresentam caracterÃsticas genÃticas distintas quanto ao material de origem, podendo ser compostos basicamente por sedimentos minerais e orgÃnicos. O primeiro à formado a partir do intemperismo das rochas, e as propriedades quÃmicas, fÃsicas e mineralÃgicas sÃo herdadas do material que lhe deram origem. Jà os sedimentos orgÃnicos sÃo influenciados pelo tipo de vegetaÃÃo predominante na paisagem, e o aporte de material orgÃnico em condiÃÃo de saturaÃÃo de Ãgua, que favorece o acÃmulo e o espessamento das camadas de sedimentos orgÃnicos, podendo levar à gÃnese dos solos orgÃnicos. Este estudo teve por objetivo avaliar as caracterÃsticas morfolÃgicas, fÃsicas e quÃmicas de seis perfis de solos orgÃnicos desenvolvidos na regiÃo litorÃnea dos Estados do CearÃ, Rio Grande do Norte e ParaÃba; e avaliar os mesmos atributos e as caracterÃsticas mineralÃgicas e micromorfolÃgicas de quatro perfis de solos originados de sedimentos aluviais do baixo curso da Bacia do rio Acaraà - CE. Foram avaliadas propriedades tais como: cor, densidade, textura, teores de fibras, grau de decomposiÃÃo da matÃria orgÃnica, teores de C, matÃria orgÃnica, N, P e micronutrientes, soma de bases, valor T e V, fraÃÃes hÃmicas, grau de repelÃncia à Ãgua, condutividade elÃtrica, sais solÃveis, difratometria de raio-X, dentre outras. Para os Organossolos, foi verificado que os teores de C estabeleceram correlaÃÃes positivas com a densidade do solo, com a subsidÃncia, acidez potencial, com os teores de N e com a hidrofobicidade, alÃm de influenciar na CTC e no teor de H+ proveniente dos Ãcidos orgÃnicos. Os diferentes mÃtodos para a determinaÃÃo dos teores de carbono orgÃnico apresentaram correlaÃÃo positiva entre si. Os teores de C da fraÃÃo humina foram mais elevados devido à presenÃa de fibras nesta fraÃÃo, enquanto que os teores de Ãcidos fÃlvicos foram os menores em relaÃÃo aos teores de Ãcidos hÃmicos, indicando maior estabilidade dos compostos orgÃnicos presentes nestes solos. Com relaÃÃo aos solos de sedimentos aluviais, foram observados elevados teores de sais solÃveis, conferindo-lhes carÃter salino e sÃdico. Isso se deve à influÃncia marinha e do lenÃol freÃtico elevado, alÃm da presenÃa de minerais intemperizÃveis. Na descriÃÃo micromorfolÃgica foram verificados alguns aspectos relacionados à gÃnese desses solos, tais como a iluviaÃÃo de argila em profundidade, a origem alÃctone do material de origem e a alteraÃÃo in situ desses sedimentos aluviais. A geomorfologia foi o principal fator na maior expressÃo dos processos pedogenÃticos na paisagem, e a posiÃÃo em que os solos se encontram à um forte indicativo de sua fragilidade ambiental. / Soils formed by sediments in lowland environments have distinct genetic characteristics according to the parent material, which can be basically composed of mineral and organic sediments. The first is formed from the weathering of rocks, and the chemical, physical and mineralogical properties are inherited from the source material. The organic sediments are influenced by the type of vegetation dominant in the landscape, and the addition of organic material under water saturation conditions, that favors the accumulation and thickening of organic sediment layers, which can lead to the genesis of organic soils. This study aimed to evaluate the morphological, physical and chemical properties of six organic soil profiles developed in the coastal region of the States of CearÃ, Rio Grande do Norte and ParaÃba; besides these attributes and the mineralogical and micromorphological characteristics of four soil profiles from alluvial sediments in the lower course of Acaraà river Basin - CE. The properties evaluated were: color, density, texture, fiber content, degree of decomposition of organic matter, C content, organic matter, N, P and micronutrients, sum of bases, T and V value, humic fractions, degree of water repellency, electrical conductivity, soluble salts, X-ray diffraction, among others. For the Histosols, it was found a positive correlation of the C levels with the soil density, with subsidence, potential acidity, N content and hydrophobicity; as well as influencing the CTC and the content of H+ from the organic acids. The different methods for measuring organic carbon were positively correlated with each other. The C content of humin fraction were higher due to the presence of fibers in this fraction, while the fulvic acid contents were lower compared to the humic acids, indicating increased stability of organic compounds present in these soils. With respect to the soils from alluvial sediments, there were observed high levels of soluble salts, conferring them the saline and sodic characters. This is due to the marine influence and the high water table, besides the presence of weatherable minerals. The micromorphological description showed some aspects related to the soil genesis, such as clay illuviation in depth, the allochthonous origin of the parent material and in situ alteration of the alluvial sediments. The geomorphology was the main factor in the greatest expression of pedogenetic processes in the landscape, and the position where the soils are located is a strong indicator of their environmental fragility.
86

Avaliação de lavagem incompleta de sais em neossolo flúvico utilizando modelagem computacional

MONTEIRO, Adriano Luiz Normandia 31 May 2007 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-06-30T12:04:31Z No. of bitstreams: 1 Adriano Luiz Normandia Monteiro.pdf: 2165253 bytes, checksum: a56a08a2a876133289d03517e9c8d77a (MD5) / Made available in DSpace on 2016-06-30T12:04:31Z (GMT). No. of bitstreams: 1 Adriano Luiz Normandia Monteiro.pdf: 2165253 bytes, checksum: a56a08a2a876133289d03517e9c8d77a (MD5) Previous issue date: 2007-05-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study has been developed in two locations which are typical of communal agriculture in the Northeast semi-arid, in alluvial valleys: Nossa Senhora do Rosário Farm, municipal district of Pesqueira, in the “agreste” area of Pernambuco State and another in the municipal district of Belo Jardim-PE. The objective was to evaluate a computational model to simulate scenarios involving salinization in alluvial soils in the semi-arid Northeast and to simulate the reduction effect on soil salinity in drainage leaching lisimeters and the precipitation as an element to reduce salt content. Based on numeric simulations with finite elements, using the model HYDRUS-1D, it was evaluated flow and transport of salts. For model calibration, of the model field data of water content and soil water pressure head, electric conductivity of soil solution, in adition to soil water characteristic parameters. Using measured actual evapotranspiration of the crop separated: potential evaporation (Ep) and potential transpiration (Tp), and precipitation, besides irrigation with different leaching depths, it was verified that the model is a satisfactory tool to simulate flow and transport in the studied situations. The leach should be used as handling for reduction of the salinity in the root zone since effective precipitations can drain in the winter periods. Incomplete leaching can be an effective alternative to reduce salinity in the root zone, when rainfall might occur. / O presente estudo foi desenvolvido em duas localidades que são modelos típicos de pequena agricultura familiar no semi-árido do Nordeste, em vales aluviais: a Fazenda Nossa Senhora do Rosário, localizada do município de Pesqueira-PE, região Agreste do Estado de Pernambuco, e em lotes irrigados na zona de rural do município de Belo Jardim, região Agreste do Estado de Pernambuco. O objetivo foi calibrar e validar modelo computacional para simular cenários que envolvam o transporte de sais em solos aluviais no semi-árido nordestino, e prever o efeito de lâminas de lixiviação e da precipitação no controle da salinidade do solo em lisímetros de drenagem. Com base em simulações numéricas, utilizando o modelo HYDRUS-1D, avaliou-se o fluxo e o transporte de sais. Para calibração do modelo foram utilizados dados do potencial matricial da água no solo, condutividade elétrica da solução do solo, além de dados da curva característica de retenção de água no solo. Usando medidas de campo de evapotranspiração potencial, e precipitação, foi possível inferir que o modelo apresentou-se como ferramenta adequada nas simulações realizadas, para diferentes cenários de lâminas de lixiviação. Verificou-se experimentalmente e numericamente que a lixiviação incompleta pode ser utilizada como alternativa de manejo para redução da salinidade na zona radicular, desde que precipitações efetivas possam complementar as lavagens.
87

Mares et plaines alluviales du Niger supérieur et de ses affluents (Guinée, Mali). Hydrodynamique et ressources associées / Small lakes and alluvial floodplains of the Upper Niger River and its tributaries (Guinea, Mali) - Hydrodynamic and associated resources

Renard-Toumi, Agnès 15 November 2013 (has links)
L’étude des mares et des plaines alluviales du Niger supérieur et de ses affluents révèle la grande variété des modes de mise en valeur des ressources de ces milieux. Les pratiques hydro-agricoles recensées sont classées selon leur degré de maîtrise de l’eau, depuis les pratiques de submersion libre (Baro) ou partiellement contrôlée (Office Riz Ségou) jusqu’à l’irrigation gravitaire manuelle, motorisée (moto-pompage de la basse vallée du Sankarani) ou encore grâce à un barrage (périmètre irrigué de Baguinéda). La plupart des mares recensées fait par ailleurs l’objet de pêches collectives spectaculaires. Au-delà des apports nutritionnels issus de la pêche des poissons retenus prisonniers dans les points bas des plaines suite à la décrue du fleuve, ces rassemblements véhiculent des valeurs sociales, culturelles et symboliques fortes et emblématiques du Haut Niger.Les entretiens, les mesures hydrométriques ainsi que l’étude approfondie du cas de la plaine alluviale du Niandan à Baro, ont permis d’identifier les pratiques tributaires du régime fluvial. La réalisation future du barrage de Fomi sur le Niandan en Guinée pose la question du maintien de l’accessibilité des ressources – agricoles et de pêche – des plaines alluviales pour les populations riveraines. Les connaissances apportées sur la mise en valeur actuelle des plaines alluviales du Niger supérieur doivent par ailleurs permettre d’anticiper les impacts d’un tel ouvrage. L’étude des scenarii de gestion proposés jusque-là incite, à la lumière des retours d’expérience des grands barrages déjà existants en Afrique de l’Ouest, à notamment réexaminer l’intérêt de produire une crue artificielle. / The study of small lakes and alluvial floodplains of the Upper Niger River and its tributaries reveals the large variety of ways of developing the resources of these areas. The listed hydro-agricultural practices are classified according to their degree of water control, such as the practices of free flooding (Baro) or partially controlled flooding (Office Riz Ségou) as well as the ”gravity irrigation / surface irrigation”, which could be either manual or motorized (motorcycle-pumping of the low valley of Sankarani) or else thanks to a dam (irrigated perimeter of Baguinéda). Most of the listed small lakes are besides the object of spectacular collective peaches. Beyond the nutritional contributions stemming from the fishing of trapped fishes in the low points of the alluvial plains subsequent to the flood recession, these gatherings convey strong and symbolic social, cultural and symbolic values. Interviews and hydrometric measures as well as the depth study of the case of the alluvial floodplain of the Niandan River at Baro, allowed to identify the practices dependent on the river regime. The future realization of the dam of Fomi across the Niandan River in Guinea raises the question of the preservation of the accessibility of the resources - agricultural and fishing – of alluvial floodplains for local communities. The knowledge brought on the current development of the Upper Niger River besides have to allow to anticipate the impacts of such a work. In the light of the experience feedback of the already existing dams in West Africa, the study of the current river management leads to revise the interest of artificial flooding.
88

Developing a form-process framework to describe the functioning of semi-arid alluvial fans in the Baviaanskloof Valley, South Africa

Bobbins, Kerry Leigh January 2012 (has links)
The Baviaanskloof catchment is a semi-arid catchment located in the Cape Fold Mountains of South Africa. Little is known about the functioning of the complicated Baviaanskloof fluvial system and the role alluvial fans in the fluvial landscape. This thesis will contribute to field of geomorphology and, more specifically, to the field of fan morphometry by producing a standalone fan framework outlining methods to investigate the influence of external and internal control variables on alluvial fans. In this thesis, outcomes of the applied framework and case study are used to develop fan restoration guidelines for the Baviaanskloof Valley. The framework incorporates external and internal fan control variables at a valley-wide and local fan scale. External control variables include accommodation space, base-level change, and drainage basin inputs. Internal control variables include fan style, morphometry and fan channels. In order to apply the framework, fan morphometry data was required. This data was collected by creating a spatial plan of fans and basins in the valley. Outcomes of the applied framework include; an understanding of baselevel change on fans, relationships between fan basin characteristics and the fan surface and insight into fan channel processes. Results of the applied framework are investigated further using bivariate (correlation matrix) and multivariate (principle component analysis and regression analysis) analysis techniques. Significant relationships identified are: drainage basin area versus fan area, fan area and fan slope and drainage basin ruggedness and basin size. The primary outcomes of this thesis include an alluvial fan form-process framework, key considerations to be included in alluvial fan restoration projects and fan restoration guidelines. Contributions of this thesis to broader alluvial fan morphology science includes new insights into general fan literature by compiling a form-process alluvial fan classification framework to identify external and internal fan control variables and identify fan form. Additions have been made to Clarke’s (2010) evolutionary stages to describe stages 4 and 5 of fan evolution that has been adapted to describe fan evolution and differentiate between stages of mature fan evolution. This thesis has also contributed to the study of alluvial fans in South Africa, particularly in the Baviaanskloof Valley. The layout of the procedural guidelines and key considerations for an alluvial fan project provides a guide for rapid fan assessment for maximum cost and time benefits for stakeholders.
89

Effects Of Seepage On Incipient Motion, Resistance, Stability And Mobility Of Sand Bed Channels

Sitaram, Nagaraj 08 1900 (has links) (PDF)
No description available.
90

River Analysis and Climate Change: Continuous Prediction of Clay-Bed Erosion in Watts Creek

Brennan, Colin January 2017 (has links)
Predicted future precipitation is downscaled and used to drive a hydrologic model to assess future erosion potential in a semi-alluvial clay-bed watercourse, Watts Creek. The 21 km2 watershed is predominantly urban, with overall impervious cover of 22%, and the remaining land use split between agricultural and forested areas. Continuous simulations for the open water year, excluding spring freshet (April 1st to October 31st) were performed using the SWMHYMO (Stormwater Management Hydrologic Model) lumped hydrologic modelling platform. A shear stress exceedance and stream power erosion routine was added to the platform to calculate erosion potential. To account for uncertainty in the collected data, nine different observed discharge data sets were used to calibrate the model, each leading to a distinct set of calibrated parameter values. The difference between the observed data sets lies in the choice of rating curves and the collection period. The 2041-2080 precipitation outputs of the fourth version of the Canadian Regional Climate Model (CanRCM4) ran under Representative Concentration Pathways (RCPs) 4.5 and 8.5 at the MacDonald Cartier International Airport were downscaled using quantile matching and then used as input to the hydrologic model. For each set of calibrated parameters, a cumulative effective work index (CWI) based on the reach-averaged shear stress was calculated for Watts Creek during the open water year using both the historic (1968 2007) and projected future (2041-2080) flows, using a bed material critical shear stress for entrainment of 3.7 Pa. Results suggest an increase of 75% (resp. 139%) under RCP4.5 (resp. RCP8.5) in CWI compared to historic conditions for the average measured bed strength. The work index increase is driven by an increased occurrence of above-threshold events, and more importantly by the increased frequency of large events. The predicted flow regime under climate change would significantly alter the erosion potential and stability of Watts Creek. A channel adjustment sensitivity analysis, which balances future erosion potential with historic potential, was implemented and indicated that the channel could widen in the future from the current bankfull width of 6.1 m to 8.2 m for RCP4.5 and 10.2 m for RCP8.5. Specific morphological behaviour should be investigated in more detail, particularly to assess if the governing erosion mechanism is seasonally dependent, perhaps incising during spring freshet and widening when the bed is vegetated in the summer.

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