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Análise temporal da relação entre uso e ocupação do solo e situação das Áreas de Preservação Permanente (APPs) marginais, na bacia hidrográfica do rio São José dos Dourados, SP; Temporal analysis of the relationship between land use and land cover and status of Legal Permanent Preservation Areas (PPAs), in the São José dos Dourados river basin, SP

Anselmo, Marcelo Ferreira
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/05/2014 PT
Relevância na Pesquisa
46.3%
As faixas que margeiam os cursos d'água são áreas protegidas por lei, com a função ambiental de preservar os recursos hídricos, a paisagem, a estabilidade geológica e a biodiversidade, facilitar o fluxo gênico de fauna e flora, proteger o solo e assegurar o bem estar das populações humanas. Atividades antrópicas, principalmente agricultura e pecuária, alteram o uso e ocupação do solo com o consequente desflorestamento de áreas de interesse ambiental. O uso do sensoriamento remoto e do geoprocessamento permite uma analise multitemporal das alterações ocorridas em uma determinada região, possibilitando o monitoramento de áreas legalmente protegidas, em um determinado período. O trabalho em questão procurou realizar um diagnostico da evolução da relação do uso e ocupação do solo com a situação das Áreas de Preservação Permanente (APPs) marginais em um período de 20 anos, da bacia hidrográfica do rio São Jose dos Dourados - SJD (UGRHI-18), no noroeste paulista, utilizando imagens do satélite Landsat-5 sensor TM (Thematic Mapper) de 1990, 2000 e 2010. Para o desenvolvimento do trabalho foi utilizado o SPRING (versão 5.2), que consiste em um software livre de Sistema de Informações Geográficas (SIG) desenvolvido pelo Instituto Nacional de Pesquisas Espaciais (INPE) / Divisão de Processamento de Imagens (DPI). Os resultados obtidos demonstram que a bacia do SJD possui área total de 5.161...

Tectonics and paleogeography of the Marajó Basin, northern Brazil

COSTA, JOÃO B. S.; HASUI, YOCITERU; BEMERGUY, RUTH L.; SOARES-JÚNIOR, ADILSON V.; VILLEGAS, JAVIER M. C.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: 519-531
ENG
Relevância na Pesquisa
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A área da Bacia do Marajó apresenta feições geológicas e geomorfológicas devidas principamente à distensão Mesozóica e à neotectônica pós-miocênica. O evento de distensão, com fases do Cretáceo Inferior e Superior, originou quatro sub-bacias que contituem a Bacia do Marajó, com uma espessa seqüência clástica continental mostrando influência marinha. Falhas normais NW e NNW e direcionais NE e ENE controlaram a geometria da bacia. A distensão, relacionada com a abertura do Atlântico Equatorial, propagou-se continente adentro ao longo de zonas de fraqueza crustal dos cinturões orogênicos pré-cambrianos Tumucumaque, Amapá e Araguaia. O evento neotectônico é um regime transcorrente que desenvolveu bacias transtensivas preenchidas por sedimentos marinhos rasos (Formação Pirabas) e seqüências transicionais (Grupo Barreiras) do Terciário Superior, seguidos por depósitos fluviais e seqüências transicionais do Quaternário, derivadas dos rios Amazoans e Tocantins e do estuário do Marajó. A paisagem atual tem morfologia tipicamente estuarina. A morfologia costeira apresenta escarpas em seqüências transicionais do Terciário Superior, enquanto no interior dominam elevações sustentadas por crosta laterítica do Pleistoceno Médio...

Urbanização e fragilidade ambiental na Bacia do Corrego Proença, Municipio de Campinas (SP); Urbanization and environmental fragility in the basin drainage, Proença Municipality of Campinas (SP)

Luis Ribeiro Vilela Filho
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 21/08/2006 PT
Relevância na Pesquisa
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o acelerado processo de expansão urbana verificado nas últimas décadas, particularmente nas grandes cidades brasileiras, fez com que os chamados problemas ambientais urbanos se avolumassem de forma generalizada. Dentre esses problemas, a questão das enchentes tem se constituído em um dos mais relevantes por acarretar danos socioambientais por vezes irremediáveis. Em sua gênese, a incidência de enchentes em áreas urbanas está associada às circunstâncias em que se consolida a apropriação do espaço urbano, que em geral são baseadas em posturas pouco abrangentes da gestão pública, na medida em que essas intervenções são regidas por interesses particulares em detrimento das características e propriedades do espaço natural. Essas intervenções alteram e desestabilizam o sistema natural, fazendo com que sua dinâmica passe a responder a novos estímulos e processos, podendo resultar na ftagilidade do sistema, uma vez que, no meio fisico a fragilidade está associada à suscetibilidade desse meio sofrer alterações. Nesse contexto, o objeto de estudo deste trabalho é a bacia de drenagem do córrego Proença, situada nas imediações da área central da cidade de Campinas (SP) que, em função de um modelo de planejamento associado a uma lógica especulativa imobiliária...

Tectonics and paleogeography of the Marajó Basin, northern Brazil

COSTA,JOÃO B. S.; HASUI,YOCITERU; BEMERGUY,RUTH L.; SOARES-JÚNIOR,ADILSON V.; VILLEGAS,JAVIER M. C.
Fonte: Academia Brasileira de Ciências Publicador: Academia Brasileira de Ciências
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2002 EN
Relevância na Pesquisa
46.05%
The Marajó Basin area presents geologic and geomorphologic features chiefly due to the Mesozoic extension and post-Miocene neotectonics. The extension event with an Early and a Late Cretaceous phases originated four sub-basins that constitutes the Marajó Basin, with a thick continental clastic sequence showing marine influence. NW and NNW normal faults and NE and ENE strike-slip faults controlled the basin geometry. The extension, related to the Equatorial Atlantic opening, propagated into the continent along crustal weakness zones of the Precambrian Tumucumaque, Amapá and Araguaia orogenic belts. The neotectonic event is a strike-slip regime which developed transtensional basins filled in by Upper Tertiary shallow marine (Pirabas Formation) and transitional sequences (Barreiras Group), followed by Quaternary fluvial deposits and transitional sequences derived from the Amazon and Tocantins rivers and the Marajoara estuary. The current landscape has a typical estuarine morphology. The coast morphology presents sea-cliffs on transitional Upper Tertiary sequences, while inwards dominate hills sustained by Mid-Pleistocene lateritic crust, with a flat erosive surface at 70 m. In the eastern Marajó Island several generations of paleochannels associated with fluvial-estuarine sequences are recognized...

A force-of-infection model for onchocerciasis and its applications in the epidemiological evaluation of the Onchocerciasis Control Programme in the Volta River basin area

Remme, J.; Ba, O.; Dadzie, K. Y.; Karam, M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em //1986 EN
Relevância na Pesquisa
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A simple force-of-infection model for onchocerciasis has been developed for a study of the age-specific epidemiological trends during a period of vector control in the Onchocerciasis Control Programme in the Volta River basin area (OCP). The most important factors included in the model are the longevity of an infection, the aspect of super-infection, age-specific exposure, and the intensity of transmission during the pre-control period. The aim of the study was to determine the most appropriate statistics for the epidemiological evaluation in the OCP. There was generally good agreement between the epidemiological trends, predicted by the model, and the observed trends in the prevalence and mean load of microfilariae in skin snips taken from a cohort population from 23 villages in an area with 8 years of successful vector control in the OCP. It is concluded that the epidemiological trends during the control period are not uniform but depend on the initial age and the initial endemicity level of the population. The epidemiological indices for cohorts of children, born before the start of control, will not show a decrease during the first 8 years of interruption of transmission. The prevalence is too insensitive to be useful for the evaluation in hyperendemic villages during most of the control period. The most sensitive and meaningful statistic for a comparative analysis and for the assessment of epidemiological changes is the geometric mean microfilarial load in a cohort of adults. This index...

Use of Landsat Land Surface Temperature and Vegetation Indices for Monitoring Drought in the Salt Lake Basin Area, Turkey

Orhan, Osman; Ekercin, Semih; Dadaser-Celik, Filiz
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 21/01/2014 EN
Relevância na Pesquisa
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The main purpose of this paper is to investigate multitemporal land surface temperature (LST) changes by using satellite remote sensing data. The study included a real-time field work performed during the overpass of Landsat-5 satellite on 21/08/2011 over Salt Lake, Turkey. Normalized vegetation index (NDVI), vegetation condition index (VCI), and temperature vegetation index (TVX) were used for evaluating drought impact over the region between 1984 and 2011. In the image processing step, geometric and radiometric correction procedures were conducted to make satellite remote sensing data comparable with in situ measurements carried out using thermal infrared thermometer supported by hand-held GPS. The results showed that real-time ground and satellite remote sensing data were in good agreement with correlation coefficient (R2) values of 0.90. The remotely sensed and treated satellite images and resulting thematic indices maps showed that dramatic land surface temperature changes occurred (about 2°C) in the Salt Lake Basin area during the 28-year period (1984–2011). Analysis of air temperature data also showed increases at a rate of 1.5–2°C during the same period. Intensification of irrigated agriculture particularly in the southern basin was also detected. The use of water supplies...

The Impact of Water Supply Variability on Treaty Cooperation between International Bilateral River Basin Riparian States

Dinar, Ariel; Blankespoor, Brian; Dinar, Shlomi; Kurukulasuriya, Pradeep
Fonte: Banco Mundial Publicador: Banco Mundial
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This paper assesses the impact of water supply variability on treaty cooperation between international bilateral river basin riparian states. Climate change is anticipated to change the variability of water supply, as well as its expected magnitude. Previous studies have focused mainly on water scarcity, measured in terms of mean precipitation or per capita water availability in the country, as a trigger for conflict or cooperation. The water variability measure used here captures both annual runoff variability and precipitation variability over periods of 30 and 100 years. The analysis used economic and international relations data to identify incentives for international cooperation in addressing water supply variability. The authors find that small-to-moderate increases in variability create an impetus for cooperation, although large increases in variability would reduce incentives for treaty cooperation. Stronger diplomatic and trade relations support cooperation, while uneven economic power inhibits cooperation. Various measures of democracy/governance suggest different impacts on cooperation across the basin riparians. The findings have policy implications in the context of preparedness for impacts of climate change on the water sector.

The Niger River Basin: A Vision for Sustainable Management

George Golitzen, Katherin; Andersen, Inger; Dione, Ousmane; Jarosewich-Holder, Martha
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
EN_US
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This book comprises two distinct elements. The first, and major, part of the book (chapters 1-3) is a unique and essential compilation of technical information and data on the entire Niger River system. It presents a comprehensive overview of the physical environment and hydrological functions of the watershed, thus providing the necessary background for examination of the challenges of resource management and development potential. The second part of the book (chapter 4) presents the fundamental challenges that the nine countries1 of the Basin face and are now addressing.

Decentralization of River Basin Management : A Global Analysis

Dinar, Ariel; Kemper, Karin; Blomquist, William; Diez, Michele; Sine, Gisèle; Fru, William
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
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Decentralization and increased stakeholder involvement have been major elements of water sector reform as ways to promote sustainable and integrated resource management particularly of river basins. Based on an analytical framework for relating decentralization and stakeholder involvement to improved river basin management, this paper infers several hypotheses about factors associated with greater or lesser likelihood of success of the decentralization process using data from 83 river basins worldwide. The results suggest that physical, political, economic, financial, and institutional characteristics of the basin do affect the process and the level of performance of the decentralization. In particular, the presence of water scarcity may be a stimulus to reform, uniting the stakeholders in the basin and leading to better performance; organized user groups push for the initiation of decentralization reforms but may be associated with costs to the process and difficulty of achieving decentralization; the existence of dispute resolution mechanisms supports stakeholder involvement and improves decentralization performance; where stakeholders accepted greater financial responsibility, complying with tariffs and contributing to the budget for basin management...

Water Resource Development in Northern Afghanistan and Its Implications for Amu Darya Basin

Ahmad, Masood; Wasiq, Mahwash
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
EN_US
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This study attempts to provide an overview of (a) the amount of Amu Darya flows generated in the northern Afghanistan; (b) the amount of water presently used in northern Afghanistan, prospective use in the near future, and possible impact of the increased use on the riparian states and the Aral Sea; (c) existing agreements between Afghanistan and the neighboring Central Asian States regarding the use waters in the Amu Darya Basin, their relevance and applicability in the present and in the future; and (d) future directions for water resources development and improved water management in the basin. Scarcity of data and information has been a key constraint in carrying out this study and the main reason for somewhat indefinite answers to the above questions. Adequate data is not available to provide assessment of non-agricultural water uses, such as the supply and potential for hydropower production and domestic water use, as well as future trends. Non-agricultural water uses should be addressed in future studies as the information becomes available.

Water and Climate Adaptation Plan for the Sava River Basin; Annex 1. Development of the Hydrologic Model for the Sava River Basin

World Bank Group
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Report; Economic & Sector Work; Economic & Sector Work :: Other Environmental Study
ENGLISH; EN_US
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This report presents the water and climate adaptation plan (WATCAP) developed for the Sava river basin (SRB) as result of a study undertaken by the World Bank. The WATCAP is intended to help to bridge the gap between the climate change predictions for the SRB and the decision makers in current and planned water management investment projects that will be affected by changing climate trends. The purpose of the report is to: (i) assist stakeholders and decision makers in assessing and planning for the risks generated by climate change impacts on water resources; (ii) provide a basis for future plans and studies of adaptation to climate change impacts in the SRB; and (iii) stimulate cooperation and debate across the basin toward additional and more detailed studies on climate change impacts at the regional and basin scale. The SRB is projected to experience small increases in water use by the public water supply, industry, energy, and agricultural and irrigation sectors. However, it is widely expected that new hydropower plants (HPPs) will be constructed in the near future...

Water and Climate Adaptation Plan for the Sava River Basin; Annex 3. Guidance Note on Adaptation to Climate Change for Hydropower

World Bank Group
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Report; Economic & Sector Work; Economic & Sector Work :: Other Environmental Study
ENGLISH; EN_US
Relevância na Pesquisa
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This report presents the water and climate adaptation plan (WATCAP) developed for the Sava river basin (SRB) as result of a study undertaken by the World Bank. The WATCAP is intended to help to bridge the gap between the climate change predictions for the SRB and the decision makers in current and planned water management investment projects that will be affected by changing climate trends. The purpose of the report is to: (i) assist stakeholders and decision makers in assessing and planning for the risks generated by climate change impacts on water resources; (ii) provide a basis for future plans and studies of adaptation to climate change impacts in the SRB; and (iii) stimulate cooperation and debate across the basin toward additional and more detailed studies on climate change impacts at the regional and basin scale. The SRB is projected to experience small increases in water use by the public water supply, industry, energy, and agricultural and irrigation sectors. However, it is widely expected that new hydropower plants (HPPs) will be constructed in the near future...

Institutional and Policy Analysis of River Basin Management : The Tárcoles River Basin, Costa Rica

Blomquist, William; Ballestero, Maureen; Bhat, Anjali; Kemper, Karin
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH
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This paper describes and analyzes the effort to institute river basin management in the Tárcoles basin of Costa Rica. Located in west-central Costa Rica, the Tárcoles basin represents 4.2 percent of the nation's total land area, but is home to half the nation's population and the metropolitan area of San José, the nation's capital and largest city. Water management issues include severe water pollution resulting from sewage, industrial waste discharges, agricultural runoff, and deforestation. In the early 1990s a locally-initiated effort established a river basin commission for the Río Grande de Tárcoles (CRGT), which was supported by the central government's environment ministry. Since the late 1990s, however, the DRGT has struggled through changes of leadership, inconsistent support from the central government, and waning participation from basin stakeholders. Despite several programs to arrest deforestation and encourage better industrial and agricultural practices, the basin's water problems continue largely unabated. The Tárcoles case is instructive about both the possibilities and the fragility of efforts to establish integrated water resource management at the river basin level.

Institutional and Policy Analysis of River Basin Management : The Alto-Tietê River Basin, São Paulo, Brazil

Johnsson, Rosa Maria Formiga; Kemper, Karin Erika
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH
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The authors describe and analyze river basin management in the most intensely urbanized and industrialized region of Brazil. The area covered by the Alto Tiete basin is almost coterminous with the Metropolitan Region of Sao Paulo. With a drainage area of 5,985 square kilometers (2.4 percent of the state's territory), the basin encompasses 35 of the 39 municipalities and 99.5 percent of the population of Greater Sao Paulo. Population growth and urban sprawl in Greater Sao Paulo have been rapid and uncontrolled in recent decades. In 2000, 17.8 million people lived in the basin and by 2010 the population is estimated to reach 20 million. This massive human occupation was accompanied by the large-scale construction of water infrastructure, including dams, pumping stations, canals, tunnels, and inter-basin transfers to and from neighboring basins. Today, the Alto-Tiete basin is served by a complex hydraulic and hydrological system. Despite this extensive water infrastructure, the water availability of the region is still very low (201

Institutional and Policy Analysis of River Basin Management : The Jaguaribe River Basin, Ceará, Brazil

Johnsson, Rosa Maria Formiga; Kemper, Karin Erika
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH
Relevância na Pesquisa
46.29%
The authors describe and analyze water resources reform and decentralization of river basin management in the state of Ceara, Northeast Brazil, the poorest part of the country. The Jaguaribe river basin is located entirely within the state of Ceara. With a drainage area of 72,560 square kilometers, it covers almost half of the state's territory. The basin has 80 municipalities and more than 2 million people, about half rural and half urban, in primarily small towns, representing about a third of Ceara's population. Precipitation in the basin is highly variable, ranging from 400 mm in the hinterland to 1,200 mm along the coast. Rivers in the basin are ephemeral and only flow during the rainy season. The key water management challenge is to capture the water in reservoirs in rainy years and to manage it such that it will last for several years, in case the following years are drought years. The other important challenge is the increasing dependence of the state capital Fortaleza, located in a different basin, on water from the Jaguaribe basin. Decentralization of decisionmaking has taken place at two levels. Devolution from the federal to the state level in the past 15 years was highly successful. The state has created its own Water Resources Management Company (COGERH) which is responsible for water resources management throughout the state. Decentralization from state to local level has been more partial. Although COGERH has decentralized the allocation of strategic reservoir waters to local institutions...

Qualidade da água do rio Vieira sob a influência da área urbana de Montes Claros MG; Vieira river quality under Montes Claros/MG urban area influence

Borges, Luciene
Fonte: Universidade Federal de Uberlândia Publicador: Universidade Federal de Uberlândia
Tipo: Dissertação
POR
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O Rio Vieira, localizado no município de Montes Claros – MG é o objeto de estudo da presente pesquisa. A cidade de Montes Claros, com cerca de 348.996 habitantes, de acordo com dados do IBGE de julho de 2006, ocupa uma significativa porção da bacia do Rio Vieira e, por essa razão, exerce grande influência na qualidade de suas águas. No presente trabalho de Dissertação de Mestrado, buscou-se compreender a relação causa-efeito da urbanização sobre a qualidade do recurso hídrico superficial. Para tanto, adotaram-se os parâmetros norteadores de qualidade da água definidos na Resolução CONAMA nº 357, de 17/03/2005. Foram adotados, também, os preceitos da abordagem integrada de bacia hidrográfica e de ecossistema, conforme apresentados na Lei nº 9.433, de 08 de janeiro de 1997, que estabelece a Política Nacional de Recursos Hídricos, o Sistema Nacional de Gerenciamento de Recursos Hídricos. Para a consecução do objetivo do estudo, realizaram-se análises de metais, análises físico-químicas e bacteriológicas de amostras de água coletadas em estações chuvosa e seca de 2005/2006. Foram determinados oito pontos de amostragens ao longo do curso do Vieira. A definição desses pontos de amostragem levou em consideração as características da ocupação urbana e biofísica da bacia e da região. Como resultado do estudo...

ESTUDO DE TENDÊNCIAS DO RITMO PLUVIOMÉTRICO DA BACIA HIDROGRÁFICA DO RIO PARDO-MS; STUDY OF TENDENCIES OF PLUVIOMETRIC RHYTHM OF THE HYDROGRAPHIC BASIN OF RIO PARDO-MS

BEREZUK, André Geraldo; Laboratório de Geografia Física/UFGD; GARCIA, Márcio Ribeiro; Laboratório de Geografia Física/UFGD
Fonte: UFPR Publicador: UFPR
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 20/06/2012 POR
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Compreender o ritmo pluviométrico de uma bacia hidrográfica é algo relevante para o conhecimento das tendências climáticas de uma determinada região. Além disso, serve para proteger e procurar mitigar uma área na qual as atividades humanas possam provocar possíveis impactos negativos, principalmente quando estes impactos se refletem sobre os setores vinculados à agricultura ou ao saneamento básico. Dessa forma, um estudo sobre tendências do ritmo pluviométrico da Bacia Hidrográfica do Rio Pardo-MS é de significativa importância para o Estado do Mato Grosso do Sul, seja porque é a bacia hidrográfica no qual está localizada a capital Campo Grande, seja porque o próprio Estado encontra-se em uma expansão dos níveis de produtividade agrícola, cuja bacia está inserida. Os dados climáticos, organizados e tabulados no presente artigo, fazem parte da monografia de Garcia (2010), correspondendo esta, ainda, a um dos poucos trabalhos realizados nessa área territorial. Estes dados, por sua vez, indicam uma tendência à maior sazonalização dos períodos secos e chuvosos...

Inorganic composition of suspended sediments in the Acre River, Amazon Basin, Brazil

Fonseca Duarte,Alejandro; Gioda,Adriana
Fonte: Latin American journal of sedimentology and basin analysis Publicador: Latin American journal of sedimentology and basin analysis
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
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The purpose of this study was to determine the chemical and mineralogical composition of suspended sediments from the Acre River, located in the Purus Basin, upper Amazon basin, a region associated with the Fitzcarrald Arch. The elemental and mineralogical compositions of the sediments were assessed by using mass and atomic spectroscopy, and X-ray diffraction. A total of 46 samples were collected between 2008 and 2011 from four sites in the study area during wet and dry seasons. The suspended sediments contained feldspar, kaolinite, illite and quartz as well as the elements Hg, Zn, V, Ti, Si, Pb, Ni, Na, Mn, Mg, K, Fe, Cu, Cr, Cd, Ca, Al, S, and P in different proportions that were associated with the various weathering reactions linked to physical, chemical and biological processes in the region. The obtained results represent the first set of values and relationships regarding the mineralogy and chemical identification of the suspended sediments in the Acre River and can be used as a reference for the geochemical characteristics of the Purus Basin. Such regional studies will become increasingly necessary to observe the impacts of climate change and human activities on the suspended sediment load and composition of the Amazon River.

Seismic sequence stratigraphy of a foreland unit inthe Magallanes-Austral Basin, Dorado Riquelme Block, Chile: Implications for deep-marine reservoirs

Gallardo,Rocío E
Fonte: Latin American journal of sedimentology and basin analysis Publicador: Latin American journal of sedimentology and basin analysis
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2014 EN
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This contribution presents geological data that provides a sequence-stratigraphic-based exploration model for Oligocene units in the central Magallanes-Austral Foreland Basin, and identifies the related sedimentary deposits that constitute basin-floor fan reservoirs. The study area is located in the Magallanes Region, Chile, and it was discovered in 2009-2010 by the joint venture of the National Oil Company of Chile and Methanex group at Dorado Riquelme Block. Seismic stratigraphic analysis of the Magallanes-Austral Foreland Basin enabled the definition of four evolutionary stages using 3D seismic information from a 91.6 km long section, as well as lithostratigraphic and biostratigraphic records and wireline logs. The clinoforms observed in the Foreland III stage of the Magallanes-Austral Foreland Basin are the focus of this study. Six seismic units (SU-1 to SU-6) and twenty-five depositional sequences were identified there, based on temporal affinity and genetic mechanisms. The youngest four seismic units comprise alternating forestepping and downstepping prograding patterns, while the fifth seismic unit is characterized by a backstepping pattern, which is followed by a sixth seismic unit in which forestepping patterns are again developed. The most important reservoirs were identified in seismic unit SU-2...

Variability of continental depositional systems during lowstand sedimentation: an example from the Kimmeridgian of the Neuquen Basin, Argentina

Spalletti,Luis A.; Veiga,Gonzalo D.
Fonte: Latin American journal of sedimentology and basin analysis Publicador: Latin American journal of sedimentology and basin analysis
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2007 EN
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Several second order lowstand wedges are recognized in the Jurassic-Early Cretaceous sedimentary record of the backarc Neuquén Basin (central-west Argentina). They are distinguished by sharp based continental and marginal marine siliciclastic deposits encased in offshore shales. The Kimmeridgian lowstand wedge was developed slightly after the emergence of the Andean magmatic arc and the tectonic inversion of previous intrabasinal extensional structures. As a result, the Neuquén Basin was compartmentalized into three main depocentres characterised by widespread continental sedimentation under arid to semiarid climatic conditions. A fluvial-dominated system characterised by systematic downstream changes in architectural style is recognized in the Northwestern Depocentre. A gravely and sandy bedload fluvial system was developed in the southern upstream sector, while ticker beds of finer-grained sediments formed in a distal ephemeral fluvial system prevail in the downstream part of the system. The overall fining upward stacking pattern of the sedimentary record in the Northwestern Depocentre accompanied by frequent development of soil horizons and darker deposits suggests a change towards higher accommodation and high water table emplacement. In the Southwestern and Eastern Depocentres...