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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.
1

Estimación de la erosión y transporte potencial de sedimentos hasta el eje de la futura represa Callazas en sub-cuenca del río Callazas en la región Tacna-Perú / Estimation of erosion and potential sediment transport to the axis of the future Callazas dam in sub-basin of the Callazas river in Tacna – Peru region

Laqui Calizaya, Fernando Ramiro 04 September 2019 (has links)
La investigación consiste en la estimación de la tasa potencial media de erosión hídrica (ton/ha. año) y el volumen promedio del transporte potencial de sedimentos en millones de metros cúbicos (MMC) en proyección a 50 años hasta el eje de la futura represa Callazas. La delimitación del área de estudio se ubica desde aguas abajo de la laguna Suches hasta el eje de la futura represa Callazas denominada subcuenca Callazas Zona 1. Se estima que la tasa de erosión hídrica promedio con la metodología de USLE a nivel conceptual es 108.9 (ton/ha. Año) y con herramienta GIS un valor de 64.3 (ton/ha. año), el cual se considera una erosión ligera/moderada. Asimismo, se estima el volumen de sedimentos del vaso proyectado de la represa Callazas con el valor de 0.372 MMC del registro histórico de 50 años con USLE y con la fórmula de transporte total de sedimentos de Englund-Hansen la estimación de 0.485 MMC en proyección a 50 años de operación. Por tanto, por un factor de seguridad de resultados se complementan las 2 metodologías con un volumen muerto de 0.857 MMC. El resultado preliminar se podría considerar aceptable ya que el estudio de factibilidad de la represa Callazas estima 11.5 MMC de volumen de almacenamiento y 1 MMC de volumen muerto, el cual resulta menor al volumen muerto proyectado. / The research consists in estimating the average potential rate of water erosion (ton / ha. Year) and the average volume of potential sediment transport in millions of cubic meters (MMC) in projection at 50 years to the axis of the future dam Callazas. The delimitation of the study area is located from downstream of the Suches lagoon to the axis of the future Callazas dam called Callazas sub-basin Zone 1. It is estimated that the average water erosion rate with the USLE methodology at the average conceptual level is 108.9 (ton / ha. year) and with GIS tool an average of 64.3 (ton / ha. year), which is considered a light / moderate erosion. Likewise, the volume of sediments of the projected vessel of the Callazas dam is estimated with the value of 0.372 MMC of the historical record of 50 years with USLE and with the formula of total transport of sediments of Englund-Hansen the estimate of 0.485 MMC in projection to 50 years of operation. Therefore, the 2 methodologies area complemented by a safety factor of results with a dead volume of 0.857 MMC. The preliminary result could be considered acceptable since the feasibility study of the Callazas dam estimates 11.5 MMC of storage volume and 1 MMC of dead volume, which is less than the projected dead volume. / Tesis
2

Geochemical evaluation of source rocks within the upper Ecca, main Karoo

Mowzer, Zainab January 2012 (has links)
>Magister Scientiae - MSc / The Karoo in South Africa is an area in which petroleum studies are being reviewed with particular interest, especially within the Tanqua and Laingsburg subbasins of the Karoo. The particular formations of interest comprises of the Laingsburg, Fort Brown, Kookfontein and Vischkuil of the Upper Ecca group, located within the Laingsburg subbasin as well as the Kookfontein formation found within the Tanqua subbasin. The present work dealt with interpreting and distinguishing the different types of source rock lithologies, to identify the source rock zones and organic matter within the Laingsburg, Fort Brown, Kookfontein and Vischkuil formations. This was achieved by utilising different geochemical analyses (such as rock eval pyrolysis and TOC) and organic chemistry (XRD) to assess the maturity, mineralogy and the quality of the source rocks.
3

Geophysical constraints on the stratigraphy, structure and tectonic evolution of the Late Devonian/Carboniferous Moncton Subbasin, New Brunswick /

Nickerson, William A. January 1994 (has links)
Thesis (Ph.D.)--Memorial University of Newfoundland. / Typescript. Restricted until November 1995. Bibliography: leaves [306]-329. Also available online.
4

Propagation des flux de sédiments en suspension sur l'Amazone de Tamshiyacu (Pérou) à Obidos (Brésil) : variabilité spatio-temporelle / Propagation of suspended sediment flux in the Amazon river from Tamshiyacu gauging station in Peru to Obidos gauging in Brazil : spatio-temporal variability

Armijos Cardenas, Elisa Natalia 10 November 2015 (has links)
Le bassin amazonien est considéré au niveau mondial comme l'un des principaux apports de sédiments à l'Océan Atlantique. Comprendre la distribution spatiale et temporelle des flux sédimentaires est l'objectif de cette étude pour laquelle on a choisi quatre stations hydrométriques de suivi réparties tout au long de l'Amazone depuis sa formation au Pérou jusqu'à environ 800 km de son embouchure au Brésil (Óbidos). Pour atteindre cet objectif, on a mis en place pour chaque station un échantillonnage décadaire en surface et une exploration totale de leur section à différentes périodes de l'année. Des profils de turbidité et des échantillons pour la granulométrie sur toute la section faisaient également partie de ce suivi. Sur les stations andines et sub-andines, la turbulence de l'écoulement jointe aux faibles profondeurs permet l'ascension de sédiments grossiers vers la surface. Par conséquent, on observe une relation directe entre la concentration de sédiments en suspension de surface et la concentration moyenne dans la section, ce qui permet un calcul simple des flux sédimentaires et d'arriver à une valeur de 540 Mt/an pour qui concerne l'apport du basin péruvien de l'Amazone. Dans la plaine brésilienne, le contexte change, les profondeurs moyennes se situent entre 40 et 100 m de telle sorte que la présence de sable en surface est quasi nulle. Cependant, l'analyse des résultats à la station d'Óbidos montre qu'il existe une relation directe entre la concentration de sédiments de surface et la concentration moyenne de sédiments fins dans la section alors que la concentration moyenne de sédiments grossiers dans la section est, elle, em relation directe avec le débit liquide. En différenciant ainsi le calcul suivant ces deux types de sédiments, on arrive à une valeur de flux de 1100 Mt/an transitant par Óbidos, dont 60% correspond au flux des sédiments fins et 40% aux grossiers. On a utilisé la turbidité pour par courbes de calibration em funtion da granulometrie parvenir aux valeurs de concentration. On a utilisé le modèle de Rouse pour différencier le signal de concentration obtenu avec la turbidité résultat du signal de le deux types de sediment. On a constaté que les granulométries en présence sont les mêmes tout au long du régime hydrologique mais que ce sont les proportions de chacune d'entre elles qui varient. Aussi a-t-on abouti à des profils de concentration pour sédiments fins et des profils pour sédiments grossiers. En montée de crue, les profils de concentration présentent un gradient bien marqué pour les sédiments fins, alors qu'en période de crue ce gradient est contrôlé par les sables et les profils de fines sont alors verticaux et constants sur toute la section. Ces résultats montrent qu'il est possible de prédire, en Amazonie, les profils de concentration à partir de la turbidité. / The sediments flux in Amazon Basin have an important role on the aquatic biodiversity and richness in the floodplains because the nutrients and organic matter attached on suspended sediments are deposited in these zones. The aim of this study is to understand the spatial and temporal distribution of sediments flux in the Amazon River, therefore were select four gauging station located along of Amazon Riven from Peru to Brazil. In each gauging station was make superficial samples each ten days and samples in the section in different times of hydrological period. Turbidity profiles and granulometry measuring were made too in each gauging station. In the Andean region, it is observed a relationship between the suspended sediments concentration and discharge, however, this relationship become a hysteresis in the plain especially in the Óbidos gauging station located at 870 km before of mouth. This result can be by the contribution of influx poor in suspended sediments from Guyanese and Brazilian shields. In 3000 km of long from Peru to Brazil plain, the suspended sediments is composed by two well-defined types of suspended sediments: fine sediments (10-20 µm) and coarse sediments (100-250 µm). The percentage of each type of sediments in the main river is different during the hydrologic regime. Peak of fine sediments is observed in the same period of peak of rainfall (December to March) and peak of coarse sediments is observed in flood period (May to July). The Andean and sub-Andean basin gauging station show the coarse sediments in surface due to great turbulence and low depths. Therefore, this gauging station show a relationship between the suspended sediments concentration in surface and average suspended sediments concentration in section, with this relation is possible to calculate the suspended sediments flux. Hence the Peruvian basin provide 540 Mt year -1. However in the Brazilian plain the context is different, the depth is from 40 to 100 m, becoming almost null the presence of coarse sediments in the surface. Therefore, cannot use the relationship between suspended sediments concentration in surface and average suspended sediments concentration in section. When the Óbidos gauging station is analysed, it found there is a relationship between suspended sediments concentration in surface and average of fine suspended sediments concentration. It is observed too, that there is the relationship between coarse suspended sediments concentration and discharge. Therefore, it is possible to calculate of suspended sediments flux using these two relationships. The Amazon River export 1100 Mt year-1 of suspended sediments at Óbidos gauging station, of which 60% correspond at fine sediments flux and 40% to coarse sediments flux. It is observed that the suspended sediments are sensitivity of climate variability, generally El Niño events is associate with increase of fine suspended sediments and La Niña events increase a percentage of coarse sediments in Amazon River. It is using the turbidity for determinate of suspended sediments concentration, we use this technique due the high frequency in acquisition of data. However for use the turbidity is necessary the previous calibration. It was observed that the turbidity signal is an addition to the signal emitted by the particles in one sample and with this assumption the Rose model was used to separate the concentration signal obtained by the turbidity of the two types of sediments present in the Amazon River, fine particles and sand. Therefore, it was obtained the concentration profiles to fine sediments and the concentration profiles to the sand. It is observed during the rising period that the fine sediments profiles show a strong gradient, however in the flood periods this gradient reduce come a constant in all section. These results show that turbidity and Rouse model can be used for prediction of suspended concentration in Amazon River.
5

Indicadores de avaliação ambiental em Áreas de Preservação Permanente (APPs) na sub-bacia do Rio Saracuruna RJ / Indicators for environmental valuation of Permanent Preservation Areas (PPAs) in the subbasin of river Saracuruna, RJ

Rodrigo Silva da Conceição 27 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Áreas de Preservação Permanente (APPs) configuram áreas protegidas, cobertas ou não por vegetação nativa, legalmente estabelecidas em lei. Estas possuem funções ambientais que se integram entre si e se associam às suas diferentes categorias. O trabalho objetivou a adaptação do sistema de indicadores PEIR (pressão, estado, impacto, resposta) para avaliação ambiental integrada de APPs, com aplicação na sub-bacia do rio Saracuruna, RJ. Especificamente visou: a) Levantamento da legislação pertinente às APPs inseridas no contexto do uso e ocupação do solo e gestão ambiental integrada; b) Delimitação das faixas de APP, segundo os parâmetros definidos pelo Código Florestal para cada categoria existente na área; c) Seleção de indicadores ambientais relacionados às APPs delimitadas considerando suas diversas categorias e funções ambientais associadas; d) Avaliação do potencial e limitações da aplicação de indicadores de avaliação integrada em APPs, envolvendo a espacialização das informações com suporte de geotecnologias, com enfoque para a legitimação/intervenções nas faixas inseridas na sub-bacia em estudo. Metodologicamente envolveu a pesquisa bibliográfica, compreendendo o levantamento de todo o arcabouço jurídico ambiental pertinente às APPs e das referências de cartas de indicadores; a caracterização física e humana da sub-bacia, subsidiando a delimitação e pré-avaliação de APPs; a seleção de indicadores ambientais voltados à avaliação integrada de APPs, a aplicação, com o suporte de geotecnologias, de parte destes indicadores estruturados em ciclos PEIR frente à hierarquização, exemplificativa, das funções ambientais por grupo de categorias de APPs; e, por fim, a elaboração de mapas-síntese da situação das faixas de APP ligadas à drenagem e ao relevo de altitude, com enfoque na legitimação das mesmas. A revisão das políticas específicas e transversais às APPs e de seus planos incidentes atestou uma ampla base para a gestão local ou compartilhada destas faixas, no entanto, a delimitação de APPs em função da realidade local ainda não ocorre. A Carta-síntese de indicadores de avaliação integrada de APPs na sub-bacia contemplou um conjunto de quarenta indicadores, dentre os quais vinte e seis compuseram dois ciclos aplicados e seis ciclos parcialmente aplicados. Para as APPs ligadas à drenagem e ao relevo de altitude foram aplicados, respectivamente, os indicadores de: a) pressão: Alteração de áreas naturais por áreas antrópicas e Evolução da área urbana em encostas; b) estado: Impermeabilização do solo e Qualidade ambiental das terras; c) impacto: Áreas críticas de inundação e Áreas de risco de escorregamentos ou desmoronamentos; e d) resposta: Plano de bacia hidrográfica e Áreas de risco recuperadas. Tais ciclos atestaram a precisão dos indicadores de pressão e estado quando da avaliação sobre a preservação em APPs, porém não foram capazes de explicar isoladamente a causa de impactos, os quais não ocorrem de maneira exclusiva nestas faixas. Demonstraram ainda um nível maior de antropização em APPs localizadas na porção de baixada da sub-bacia, principalmente em margens de rios. Sendo assim, cabem ações voltadas à fiscalização de APPs legitimadas, à recuperação de faixas com baixa interferência humana, e às intervenções urbanísticas ou prioritárias em áreas degradadas ou impactadas / Permanent Preservation Areas (PPAs) configure protected areas, covered or not by native vegetation, legally established by law. These areas have environmental functions that integrate with each other and are associated with their different categories. The study aimed the adaptation of the system of PSIR indicators (pressure, state, impact, and response) for integrated environmental evaluation of PPAs, with application in the sub basin of river Saracuruna, RJ. Specifically aimed: a) Survey of relevant legislation about PPAs, inserted in the context of the use and occupation of land and integrated environmental management; b) Delimitation of strip of PPAs, according to parameters defined by Brazilian Forest Code for each categorie in the area; c) Selection of environmental indicators related to the delimited PPAs considering its various categories and associated environmental functions; d) Evaluation of the potential and limitations of application of indicators of integrated evaluation in PPAs, involving the spatialisation of the information supported by Geotechnology, with a focus in the legitimization/interventions of the strips of PPAs on the subbasin under study. Methodologically involved the bibliographical research, including the survey of all the relevant environmental and legal framework about PPAs and the collect of the reference of letters of indicators, the physical and human characteristics of the subbasin, supporting the delimitation and pre-assessment of its PPAs; the selection of environmental indicators focused on integrated assessment of PPAs; the application, supported by geotechnology, of part of these indicators structured in PSIR cycles in view of the, exemplary, hierarchization of environmental functions by category group of PPAs; and, finally, the development of mapssynthesis of the situation of the bands of PPAs connected to the drainage and the relief of altitude, with a focus on legitimizing this bands. The review of specific and cross-cutting policies to PPAs and their incident plans testified a broad base for local or shared management of these bands, however, the delimitation of the PPAs depending on the local conditions does not exist yet. The letter-synthesis of indicators of integrated evaluation of PPAs in the subbasin included a set of 40 (forty) indicators, of which 26 (twenty-six) composed 2 (two) applied cycles and 6 (six) partially applied cycles. For the APPs related to drainage and relief of altitude were applied, respectively, indicators: a) pressure: Change of natural areas to disturbed areas and Evolution of urban area on slopes b) state: Waterproofing of soil and Environmental quality of the land; c) impact: Critical areas of flooding and Areas of risk of landslides or mudslides; and d) response: Basin plan and Risk areas recovered. Such cycles have attested to the accuracy of indicators of pressure and state in the evaluation of the preservation in PPAs, but were not able to explain alone the cause of impacts, which do not occur exclusively in these bands. Also showed a higher level of human disturbance in PPAs located in the lowland portion of the subbasin, especially on river banks. Therefore, actions that aim the supervision of legitimized PPAs are appropiate, as well as action that aimed the recovery of tracks with low human interference and the urban or priority interventions in degraded or impacted areas
6

Indicadores de avaliação ambiental em Áreas de Preservação Permanente (APPs) na sub-bacia do Rio Saracuruna RJ / Indicators for environmental valuation of Permanent Preservation Areas (PPAs) in the subbasin of river Saracuruna, RJ

Rodrigo Silva da Conceição 27 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Áreas de Preservação Permanente (APPs) configuram áreas protegidas, cobertas ou não por vegetação nativa, legalmente estabelecidas em lei. Estas possuem funções ambientais que se integram entre si e se associam às suas diferentes categorias. O trabalho objetivou a adaptação do sistema de indicadores PEIR (pressão, estado, impacto, resposta) para avaliação ambiental integrada de APPs, com aplicação na sub-bacia do rio Saracuruna, RJ. Especificamente visou: a) Levantamento da legislação pertinente às APPs inseridas no contexto do uso e ocupação do solo e gestão ambiental integrada; b) Delimitação das faixas de APP, segundo os parâmetros definidos pelo Código Florestal para cada categoria existente na área; c) Seleção de indicadores ambientais relacionados às APPs delimitadas considerando suas diversas categorias e funções ambientais associadas; d) Avaliação do potencial e limitações da aplicação de indicadores de avaliação integrada em APPs, envolvendo a espacialização das informações com suporte de geotecnologias, com enfoque para a legitimação/intervenções nas faixas inseridas na sub-bacia em estudo. Metodologicamente envolveu a pesquisa bibliográfica, compreendendo o levantamento de todo o arcabouço jurídico ambiental pertinente às APPs e das referências de cartas de indicadores; a caracterização física e humana da sub-bacia, subsidiando a delimitação e pré-avaliação de APPs; a seleção de indicadores ambientais voltados à avaliação integrada de APPs, a aplicação, com o suporte de geotecnologias, de parte destes indicadores estruturados em ciclos PEIR frente à hierarquização, exemplificativa, das funções ambientais por grupo de categorias de APPs; e, por fim, a elaboração de mapas-síntese da situação das faixas de APP ligadas à drenagem e ao relevo de altitude, com enfoque na legitimação das mesmas. A revisão das políticas específicas e transversais às APPs e de seus planos incidentes atestou uma ampla base para a gestão local ou compartilhada destas faixas, no entanto, a delimitação de APPs em função da realidade local ainda não ocorre. A Carta-síntese de indicadores de avaliação integrada de APPs na sub-bacia contemplou um conjunto de quarenta indicadores, dentre os quais vinte e seis compuseram dois ciclos aplicados e seis ciclos parcialmente aplicados. Para as APPs ligadas à drenagem e ao relevo de altitude foram aplicados, respectivamente, os indicadores de: a) pressão: Alteração de áreas naturais por áreas antrópicas e Evolução da área urbana em encostas; b) estado: Impermeabilização do solo e Qualidade ambiental das terras; c) impacto: Áreas críticas de inundação e Áreas de risco de escorregamentos ou desmoronamentos; e d) resposta: Plano de bacia hidrográfica e Áreas de risco recuperadas. Tais ciclos atestaram a precisão dos indicadores de pressão e estado quando da avaliação sobre a preservação em APPs, porém não foram capazes de explicar isoladamente a causa de impactos, os quais não ocorrem de maneira exclusiva nestas faixas. Demonstraram ainda um nível maior de antropização em APPs localizadas na porção de baixada da sub-bacia, principalmente em margens de rios. Sendo assim, cabem ações voltadas à fiscalização de APPs legitimadas, à recuperação de faixas com baixa interferência humana, e às intervenções urbanísticas ou prioritárias em áreas degradadas ou impactadas / Permanent Preservation Areas (PPAs) configure protected areas, covered or not by native vegetation, legally established by law. These areas have environmental functions that integrate with each other and are associated with their different categories. The study aimed the adaptation of the system of PSIR indicators (pressure, state, impact, and response) for integrated environmental evaluation of PPAs, with application in the sub basin of river Saracuruna, RJ. Specifically aimed: a) Survey of relevant legislation about PPAs, inserted in the context of the use and occupation of land and integrated environmental management; b) Delimitation of strip of PPAs, according to parameters defined by Brazilian Forest Code for each categorie in the area; c) Selection of environmental indicators related to the delimited PPAs considering its various categories and associated environmental functions; d) Evaluation of the potential and limitations of application of indicators of integrated evaluation in PPAs, involving the spatialisation of the information supported by Geotechnology, with a focus in the legitimization/interventions of the strips of PPAs on the subbasin under study. Methodologically involved the bibliographical research, including the survey of all the relevant environmental and legal framework about PPAs and the collect of the reference of letters of indicators, the physical and human characteristics of the subbasin, supporting the delimitation and pre-assessment of its PPAs; the selection of environmental indicators focused on integrated assessment of PPAs; the application, supported by geotechnology, of part of these indicators structured in PSIR cycles in view of the, exemplary, hierarchization of environmental functions by category group of PPAs; and, finally, the development of mapssynthesis of the situation of the bands of PPAs connected to the drainage and the relief of altitude, with a focus on legitimizing this bands. The review of specific and cross-cutting policies to PPAs and their incident plans testified a broad base for local or shared management of these bands, however, the delimitation of the PPAs depending on the local conditions does not exist yet. The letter-synthesis of indicators of integrated evaluation of PPAs in the subbasin included a set of 40 (forty) indicators, of which 26 (twenty-six) composed 2 (two) applied cycles and 6 (six) partially applied cycles. For the APPs related to drainage and relief of altitude were applied, respectively, indicators: a) pressure: Change of natural areas to disturbed areas and Evolution of urban area on slopes b) state: Waterproofing of soil and Environmental quality of the land; c) impact: Critical areas of flooding and Areas of risk of landslides or mudslides; and d) response: Basin plan and Risk areas recovered. Such cycles have attested to the accuracy of indicators of pressure and state in the evaluation of the preservation in PPAs, but were not able to explain alone the cause of impacts, which do not occur exclusively in these bands. Also showed a higher level of human disturbance in PPAs located in the lowland portion of the subbasin, especially on river banks. Therefore, actions that aim the supervision of legitimized PPAs are appropiate, as well as action that aimed the recovery of tracks with low human interference and the urban or priority interventions in degraded or impacted areas

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