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1
Rice, Stephanie Kimberly. "Suspended sediment transport in the Ganges-Brahmaputra River System, Bangladesh." [College Station, Tex. : Texas A&M University, 2007. http://hdl.handle.net/1969.1/ETD-TAMU-1588.
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Islam, Muhammod Nazrul. "Braiding and channel morphodynamics : the Brahmaputra-Jamuna river, Bangladesh." Thesis, University of Hull, 2000. http://hydra.hull.ac.uk/resources/hull:11252.
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This study investigates the bar morphology, sediment properties and amount of sediment yield in relation to channel dynamics of the Brahmaputra-Jamuna River over a decadal timescale (1987-1997) using digital satellite images and field observations. Two typical reaches were chosen for study, representing the upper widest reach (Bahadurabad Ghat Reach) and the lower narrowest reach (Jamuna Bridge Reach) of the Brahmaputra-Jamuna River. Erosion and accretion of channel banks appears to be the root of all the processes of braiding. Channel banks of both the study reaches are more severely affected by erosion than accretion and both banks are retreating each year. An increased amount of sediment load in excess of transport competence immediately downstream node of a flow convergence seems to initiate the process of development of a braid bar. The process of braiding and channel expansion appears to be interdependent which reveals 'chicken and egg' relationships between them. Bars are usually diamond or triangular-shaped in plan view and their long axes are oriented parallel to the channel. The bars of the Brahmaputra-Jamuna River are grouped into two types, island and attached according to their morphological characteristics, this classification provides increased functional capability with less ambiguity. Between these two types, island bars are prominent features relative to attached bars. Both forms of bars are characterised by three level successions of topographic features although they constantly change their position with few localities left to be permanently stable. Most of the bars are submerged during high flow and erosion tends to occur at the upstream end of a bar and deposition on its downstream, while during falling stage the upstream end and lateral margins of bars receive sediment deposits and the downstream faces occasional erosion. There are considerable mutual adjustments in bar erosion and deposition between the two forms of bars. During the decadal timescale both the study reaches are accreted by bar deposition and the Brahmaputra-Jamuna River is in a condition of active aggradation. Sediment size characteristics at both banks and bars are dominated by very fine sand to fine sand particles. Very little discernible variability of particle size parameters and mineralogical compositions between the banks and bars indicate channel bank material as the potential source of bar sediments. There is no evidence of downstream diminution of sediment particle size, indeed the study results reveal a slight trend of downstream coarsening. Estimation of reach-scale sediment balance using cross-sections and satellite images provides information of quality comparable to that of measured cross-sections or a sediment continuity approach, and demonstrates a preferred method for sediment balance estimations in the Brahmaputra-Jamuna River. These findings suggest that analysis of digital satellite images has an advantage over the traditional field-based studies while a very intensive field work program supplements ground truth information that fills in the drawbacks of satellite imagery. Combination of both methods and relevant computer analysis is useful as a means of mapping and quantifying spatial and temporal change of channel morphology, and as a means of measuring some of the variables which promote, sustain and control channel braiding over annual-decadal timescales.
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Asada, Haruhisa. "Climate and Rice Cropping Systems in the Brahmaputra Basin." 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/147382.
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Islam, Md Nurul. "Sedimentation, vegetation and land use dynamics on the Brahmaputra-Jamuna floodplain, Bangladesh." Thesis, University of Nottingham, 2011. http://eprints.nottingham.ac.uk/13280/.
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This study investigated contemporary floodplain sedimentation, interactions between sediment, vegetation, and agricultural land use, and the potential utility for a Bayesian Network Decision Support System (BNDSS) to assist farmers in making better decisions concerning agricultural land use. The research was performed around Bara Bania Mouza (village) under Daulotpur Uazila in Manikgong district of the Brahmaputra-Jamuna floodplain in Bangladesh. This area was selected because it is representative of the young and active floodplain, where the land is flooded and receives overbank sediment deposition every year. The research employed exploratory data analysis and Bayesian approaches to identify and investigate causal relationships among the variables and so support probabilistic inferences. The study investigated two distinctly different types of monsoonal flood: a bonna (an abnormally large flood that occurred in 2007) and a barsho (a normal flood that occurred in 2008). Data on landforms, flood hydraulics, sediment dynamics (suspended sediment concentrations and sediment accumulation rates), and vegetation, rain-fed flooding, land use and farmers knowledge on soil suitability and cropping were collected through field surveys. The results establish how flow and sediment dynamics contrast as a function of landform and demonstrate that the thickness and calibre of deposited sediment strongly influence farmers' decisions on which and how many crops to cultivate on a given plot. Natural vegetation (e.g. sun grass) and certain agricultural crops were shown to have huge potential for use in slowing floodwater and trapping coarse grain sediment particles in buffer stripes. Marked contrasts were also observed between the characteristics of sediment deposited by rain-fed and river water flooding. Questionnaires and semi-structured interviews revealed that although farmers have profound knowledge on soil types and crop associations their methods are crude and little or no science is involved in the investigation of soil and sediment properties. Despite this, farmers' estimates of soil properties proved to be reasonably accurate with the estimate of particle size differing by only <15% from the results of laboratory particle size analysis. This suggests that the farmers' methods do give reliable indications of key soil attributes, but that they could be improved if scientific information was integrated with their local knowledge. A Bayesian approach provides a means of achieving this and the BNDSS developed in this study was found to produce good results when compared to field observations and backward propagation indicated that for better decision making it is crucial to consider both physical and socioeconomic variables. The findings of the research reported in this thesis show that sedimentation has major impacts on agricultural land use dynamics in the Brahmaputra-Jamuna floodplain and that both natural vegetation and agricultural crops significantly influence sediment movement and the way that deposition is distributed over the floodplain. In a wider context, flood, sediment, vegetation and agricultural land use dynamics are controlled by complex set of both physical and human phenomena that are challenging to describe, integrate, analyse and interpret in a single study. In light of this, it is not surprising that the findings presented in this thesis highlight important gaps in knowledge that need to be addressed through further research.
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Govin, Gwladys. "Tectonic-erosion interactions : insights from the paleo-drainage of the Brahmaputra River." Thesis, Lancaster University, 2017. http://eprints.lancs.ac.uk/88206/.
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This thesis investigates the interactions between tectonics and erosion in the eastern Himalaya through the study of paleo-Brahmaputra deposits in the foreland basin. Sediment depositional dating of two sedimentary sections is performed using magnetostratigraphy, apatite fission-track and luminescence dating. Provenance analysis using zircon and apatite U-Pb dating allows the reconstruction of the Miocene-Quaternary paleo-drainage of the Brahmaputra River and the documentation of the tectonic evolution of two poorly understood Himalayan features: the Shillong Plateau and the Namche Barwa Syntaxis. The Shillong Plateau is the only elevated topography in the Himalayan foreland and the timing of its surface uplift is debated. Decoupling between of the time of rock exhumation and surface uplift has been explained by differences in rock erodibilities of the plateau between the Shillong Precambrian basement and the overlying Cenozoic sedimentary rock. New detrital zircon U-Pb data and lithospheric stress field modelling presented here date the rise of the Plateau between 5.2 Ma and 4.4 Ma leading to the redirection of the Brahmaputra River at that time, and the role of tectonics in the rise of the plateau is invoked. The Namche Barwa syntaxis is located at the eastern Himalayan termination and its development is widely debated. It has been subjected to anomalously young (< 10 Ma) peak metamorphism, and unusually high exhumation rates (up to 10 mm/yr), in comparison with the Himalayan main arc of the orogen. However, the timing of the onset of rapid exhumation of the Namche Barwa syntaxis is poorly constrained (between 10 and 3 Ma). Focusing on the proximal detrital record of material eroded from the syntaxis, new rutile U-Pb, white-mica 40Ar/39Ar and zircon fission-track data, together with published data are incorporated in a thermokinematic model which suggests an older onset ( > 10 Ma) of rapid exhumation, and at high but not extreme rates (< 5 mm/yr).
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Mahmood, Abu Rushed Jamil. "Forest change in the mangroves of the Ganges-Brahmaputra delta 1906-2014." Thesis, Durham University, 2015. http://etheses.dur.ac.uk/11238/.
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For the first time in the history of mangroves, the Ganges-Brahmaputra delta in particular, this doctoral research aims to quantify forest change with an unprecedented period spanning from 1906 to 2014. The world’s largest mangroves – the Sundarbans of the Ganges-Brahmaputra delta accounts for 4.5% of the world’s mangrove forests, has been used as the test site. The research quantified the forest change into two distinct strands: (a) an assessment of vegetation dynamics over 106-years (1906-2012) in the Bangladesh Sundarbans and (b) a 42-years long (1973-2014) satellite imagery-based assessment of spatial change patterns of the Sundarbans. To address those objectives, this study used three different datasets: (1) a three month long extensive ground survey in 2011-12; (2) synthesis of six epochs of vegetation estimates: 1906-10, 1923-26, 1957-59, 1982-84, 1996-97 and 2011-12; and (3) mapping forest and forest types from six epochs of Landsat time-series: 1973 (MSS1), 1979 (MSS3), 1989 (ETM+ 7), 2010 (TM5), and 2014 (OLI8) using ground-based training samples and high (5m-RapidEye) to very high (<5m-GeoEye, IKONOS, QuickBird, OrbView) spatial resolution optical imagery spanning from 1967 to 2014. Ground survey of 164 sample plots, 400 m2 per plot, has recorded 21 tree species from 33 recorded plant species having median values of stem diameter and total height estimated to 3 cm and 5.4 m, respectively. Out of 47,293 stems, gewa was found dominating (42%) which together with sundri constitute about 80% of the stems. Sundri stems were found to be taller than gewa but opposite in the case of stem median diameter and are significant in both cases. Stocking has declined to 50 stems.ha-1 from 650 stems.ha-1 from ≥20 cm to ≥10 cm diameter. Tree richness, diameter and total height has found declining with increasing salinity. The southeast region of the Bangladesh Sundarbans has recorded the highest diameter and taller stems. Overall, total height of stems has declined while tree mortality from top-dying has increased 4.5 times. Over the last 106-years (1906-2012), a 58% decline of ≥15 cm diameter sundri has been estimated. From 1923-2012, the sundri-dominated forest has declined by 34% while gewa and other-dominated forests have increased by 11% and 24% respectively. Decline in larger diameter stems (≥ 5cm) has provided space for younger stems to grow and dominate which showed an overall increase in stocking of sundri, gewa and other-dominated forest types. These long-term forest change estimates will benefit in understanding ecology and carbon dynamics of mangroves that eventually contribute in UN-led reduced emission from deforestation and forest degradation (REDD+) programmes for mangroves of the Ganges-Brahmaputra delta.
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Jian, Jun. "Relationship between the Pacific Ocean SST Variability and the Ganges-Brahmaputra River Discharge." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6994.
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A simple correlation analysis was used to investigate the linear relationships between sea surface temperature (SST) and monthly flow of Ganges and Brahmaputra at the borders of Bangladesh and India using approximately 50 years of river discharge data. Strong correlations were found between the equatorial Pacific SST and boreal summer Ganges discharge from three-month lag to two-month lead times. The El Nio-Southern Oscillation (ENSO) explains Ganges flow variance exceeding 0.95 significance level using both the Nino 3.4 SST correlation and the composites made for El Nio (La Nina) periods.
The May SST of the southwest Pacific Ocean to the east of Australia continent has a strong correlation (>0.6) with early summer Ganges discharges. Using a lag correlation analysis of Ganges discharge and SST, we found a steady and continuous development in the Nino 3.4 SST relationship, and a strong correlation with the southwest Pacific SST which is most pronounced three-four months prior to the onset of Asian summer monsoon. These relationships mean that at least 25% of the interannual summer Ganges River discharge variability can be explained by antecedent equatorial and southwest Pacific SST. It provides a possible statistical method for linear forecasting two or three months in advance.
The Brahmaputra River discharge, on the other hand, shows weak relationships with tropical SST variability except for the Bay of Bengal and the higher northern latitudes of the Pacific.
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Fischer, Sandra. "Sensitivity of sediment transport on river characteristics in the large, braided Brahmaputra River." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-118443.
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Erosional issues in the Brahmaputra River in the eastern Himalayas pose increasing pressure on the nearby societies and ecosystems. With a proceeding climate change and increasing anthropogenic disturbance, predictive models are needed to evaluate the effect on sediment transport. Especially in braided rivers, like the Brahmaputra, sediment transport processes imply high demands on numerical models. The objective is therefore to assess the sensitivity of sediment transport on changed river characteristics in the Brahmaputra River, in order to qualitatively evaluate future possible dynamics. Through the one-dimensional steady state model, HEC-RAS 4.1, the braided river was simplified into a single straight channel to enable an extensive reach (700 km) to be modelled. Since little comparative data were at hand, a literature review gathered independent estimates of each parameter. Their natural variability was applied in the sensitivity analysis, and the model produced a suspended sediment load representing approximately 35% of observed data. The sensitivity analysis showed that the channel bathymetry form had a large impact on the model results, whereas the amount of lateral inflow (both surface and subsurface waters) to the main channel flow had a very small impact. Overall, the suspended sediment load were interpreted to be increasing from a future climate change, while further river regulation could counteract such elevation. Further studies are required concerning the river bathymetry in large scale modelling and to address transport of finer cohesive sediments. This methodology proposes a novel approach on how to analyze sediment transport at a large scale that could be used as a tool to interpret future possible changes and ultimately contribute to a better understanding of sediment transport modelling in the area.
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Shamsudduha, Mohammad. "Mineralogical and geochemical profiling of arsenic-contaminated alluvial aquifers in the Ganges-Brahmaputra floodplain, Minikganj, Bangladesh." Auburn, Ala., 2007. http://repo.lib.auburn.edu/2007%20Spring%20Theses/SHAMSUDDUHA_MOHAMMAD_47.pdf.
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Sarker, Maminul Haque. "Morphological response of the Brahmaputra-Padma-Lower Meghna river system to the Assam earthquake of 1950." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/14566/.
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The channels of the great rivers of Bangladesh are highly dynamic and their banklines change continuously, consuming large areas of floodplain and making thousands of people landless. As a result, bank erosion is a serious cause of poverty in Bangladesh. Severe bank retreat associated with net widening of the Jamuna, Padma and Lower Meghna Rivers during the last 50 years has greatly increased the suffering of the people. Changes in the width and planform patterns of these rivers indicate that they have not been operating in dynamic equilibrium. However, the causes of instability and planform metamorphosis remain contested. This is significant as identifying the causes of the observed channel adjustments would be of great interest not only to river scientists and engineers, but also to planners attempting better to manage the nation's natural and human resources. In this context, the research reported in this thesis proposes a working hypothesis that morphological changes in the Jamuna-Padma-Lower Meghna system have occurred in response to disturbance of the fluvial system by the Assam earthquake of 1950. Contemporary documents report that landslides triggered by the earthquake generated about 4.5* 1010 m3 sediment, much of which entered the Brahmaputra River in Assam either directly or via its tributaries. It is proposed that the fine fraction of this sediment (silt and clay) travelled quickly through the system, without disturbing the morphology of the channels, before settling in the Meghna Estuary and Bay of Bengal. In contrast, it is hypothesised that the coarser fraction (sand) took half a century to progress through the system, moving as a wave of bed material load, with a celerity between 10 and 32 kmy-1. Preliminary analyses of historical maps and satellite images, together with records of discharge, water level, sediment transport and cross-sectional form reveals a sequence of morphological changes in the Jamuna-Padma-Lower Meghna system with a downstream phase lag that is commensurate with the celerity of the coarse sediment wave. A conceptual process-response model has been developed to elucidate the relationship between downstream propagation of the sand wave and morphological responses, based on models previously reported in the literature and the sequence of changes observed in the Jamuna River. The model has been validated using morphological responses observed in the Padma and Lower Meghna rivers, which appear to have acted as a downstream continuation of the Jamuna River. Based on the conceptual model, a scheme has also been developed to explain and predict planform responses to changes in sediment supply to a braided river. This scheme is shown to be consistent with earlier models, the responses to increased sediment supply in the great rivers of Bangladesh and those of some very large rivers in China. Once fully validated, the conceptual model and the scheme may be used not only to explain the past behaviour of braided rivers, but also to predict the morphological responses of the large rivers of Bangladesh to future disturbance by, for example, climate change, seismic events or interventions in the fluvial system upstream in India. The capability to make such predictions would be immensely helpful in planning how to manage future channel instability and mitigate its socioeconomic impacts for the benefit of floodplain dwellers and the Nation.
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Jian, Jun. "Predictability of Current and Future Multi-River discharges: Ganges, Brahmaputra, Yangtze, Blue Nile, and Murray-Darling Rivers." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19777.
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Thesis (Ph.D)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2008.Committee Chair: Judith Curry; Committee Chair: Peter J Webster; Committee Member: Marc Stieglitz; Committee Member: Robert Black; Committee Member: Rong Fu.
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Levy, Beth Michele. "High-Resolution Seismic Stratigraphy of the Ganges-Brahmaputra River System: Subaqueous Deltaic Progradation on the Bengal Shelf." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539617696.
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Goodbred, Steven Lee Jr. "Sediment dispersal and sequence development along a tectonically active margin: Late Quaternary evolution of the Ganges-Brahmaputra River delta." W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539623939.
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Situated in the Bengal Basin, the Ganges-Brahmaputra river delta comprises one of the largest fluviodeltaic systems in the world, comprising ∼ 100,000 km2 of floodplain and delta plain and a 40,000 km2 subaqueous delta on the shelf. Sediment load of the Ganges-Brahmaputra river is 109 t/yr, and seasonal flooding may inundate >70% of the delta during large events. Active tectonic processes have resulted in both uplift and subsidence in this structurally complex region. These general characteristics suggest that the Ganges-Brahmaputra delta represents a heretofore undescribed delta end-member, forming along a high-yield, high-energy, tectonically active margin. to investigate this view, stratigraphic, sedimentologic, and geochronologic data are used to evaluate processes, controls, and development of the system over different spatial and temporal scales in the Late Quaternary.;Results of a century-scale sediment accretion study using radioisotope geochronology indicate that ∼ 30% of fluvial sediment load is sequestered to the delta and not reaching the coastal ocean as previously assumed. A Holocene-scale sediment budget generated from radiocarbon-dated stratigraphy also reveals ∼ 30% of sediment discharge was sequestered to the delta during this time. Considered with offshore data, these sediment budgets indicate contemporaneous highstand strata formation across floodplain, shelf, and deep-sea depocenters. Radiocarbon-dated stratigraphy was used to reconstruct the Late Quaternary history of delta formation. Growth of the Ganges-Brahmaputra delta began ∼ 10,000--11,000 cal yr BP, notably 2000--3000 years prior to most of the world's deltas. During subsequent rapid sea-level rise, the immense sediment discharge was sufficient to maintain relative shoreline stability while most margin systems experienced major transgression. offset of radiocarbon dates from eustatic sea level indicate 2--4 mm/yr of subsidence in several areas of the delta, suggesting tectonic control on deltaic sediment trapping and sequence formation. Shallow vibracore stratigraphy from the delta reveals a cap of muddy sediments overlying largely sandy material, reflecting differences in preservation between floodplain and channel deposits. Over longer time frames, floodplain sediments are eroded through channel migration and avulsion, thus preferentially preserving channel sands. Overall, the role of tectonics in controlling deltaic processes and product in the Ganges-Brahmaputra river delta implies a fundamental distinction for deltas forming along active margins.
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Lexén, Tove. "A Gendered Analysis of the Brahmaputra Dialogue : A study of the relation between transboundary water management and gender norms." Thesis, Uppsala universitet, Statsvetenskapliga institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-345328.
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Transboundary water management (TWM) regards how internationally shared waters are managed. Recently, TWM processes have been researched from the perspective of gender inclusivity. In line with this trend, this thesis is investigating to what extent the Transboundary Policy Dialogue for Improved Water Governance in Brahmaputra River (the Brahmaputra Dialogue) about the Brahmaputra River is gender sensitive. The Brahmaputra River is shared by China, India, Bhutan and Bangladesh. The management of the river is severely conflicted both intra- and interstate wise. Therefore, the Brahmaputra Dialogue, facilitated by the South Asia Consortium for Interdisciplinary Water Resources Study (SaciWATERs), aims at creating understanding between the different stakeholders. To measure the gender sensitivity, the Gender Sensitivity Framework is created. The framework is a toolkit that, through a set of indicators, measure gender inclusivity from both a structural and a substantive perspective. Using a descriptive text analysis method of the reports from the third and current phase of the Brahmaputra Dialogue, the investigation reveals that the Brahmaputra Dialogue is only 45% gender sensitive. While the work ways of the Brahmaputra Dialogue generally are gender inclusive, the Brahmaputra Dialogue content wise lacks some key aspects of gender awareness. One such aspect is that the concept of “gender” is broader than women’s vulnerabilities to masculine decision-making.
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Heroy, David Carlson. "Sand- and Clay-Size Mineralogy of the Ganges and Brahmaputra Rivers: Records of River Switching and Late-Quaternary Climate Change." W&M ScholarWorks, 2000. https://scholarworks.wm.edu/etd/1539617766.
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AlSamra, Jana. "Der Einfluss des Monsuns als bedeutender Klimafaktor auf dem Indischen Subkontinent und seine Beziehung zur geomorphologischen Exposition der Flüsse insbesondere im Bereich des Brahmaputra." Doctoral thesis, Universitätsbibliothek Leipzig, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-154638.
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Geprägt wird das Klima auf dem Indischen Subkontinent ganz erheblich durch den Einfluss des Monsuns, der ein Teilelement des gesamten asiatischen Monsunsystems ist. Der Monsun hat als wesentlicher Klimafaktor einen wichtigen Einfluss auf die geomorphologische Entwicklung der Flüsse und Flusstäler des Indischen Subkontinents in Verbindung mit den Überschwemmungen, die durch die Niederschläge des Monsuns verursacht werden.
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AlSamra, Jana [Verfasser], and Werner [Gutachter] Kirstein. "Der Einfluss des Monsuns als bedeutender Klimafaktor auf dem Indischen Subkontinent und seine Beziehung zur geomorphologischen Exposition der Flüsse insbesondere im Bereich des Brahmaputra. / Jana AlSamra ; Gutachter: Werner Kirstein." Leipzig : Universitätsbibliothek Leipzig, 2014. http://d-nb.info/1238789897/34.
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Palamenghi, Luisa [Verfasser], Volkhard [Akademischer Betreuer] Spiess, and Till [Akademischer Betreuer] Hanebuth. "Tectonic and Sea Level Control on the Transport and Depositional Processes in a Siliciclastic Sedimentary Basin. Insights from the Ganges-Brahmaputra Delta, Bengal Basin, Bangladesh / Luisa Palamenghi. Gutachter: Volkhard Spiess ; Till Hanebuth. Betreuer: Volkhard Spiess." Bremen : Staats- und Universitätsbibliothek Bremen, 2012. http://d-nb.info/1072046326/34.
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Blaes, Estelle. "Détermination des constantes de temps des processus d'altération et de transfert sédimentaire par les nucléides des séries de l'U : étude d'un bassin versant de Porto Rico et du système himalayen." Thesis, Strasbourg, 2013. http://www.theses.fr/2013STRAH007.
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Cette thèse se propose de définir les temps caractéristiques des processus d’altération à l'échelle de profil d'altération (bassin versant de Rio Icacos à Porto Rico) et de transfert sédimentaire subséquent dans les plaines alluviales (bassins du Gange et du Brahmapoutre). Cette problématique est abordée par l’analyse des nucléides des séries de désintégration radioactives de l’uranium-238. L’étude du système d’altération sphéroïdale développée sur le site de Porto Rico a permis de développer une méthode numérique de type quasi-Newton afin de résoudre le système d'équations qui rend compte du comportement des nucléides et du taux de formation de la saprolite et des couronnes d’altération.Pour les bassins du Gange et du Brahmapoutre, les sédiments ont été collectés sur différents affluents et à son exutoire. La variation des déséquilibres 238U-234U-230Th dans les sédiments, différente pour les sédiments en suspension et les sédiments à grains grossiers d’amont en aval, semble être une caractéristique générale des rivières himalayennes coulant dans la plaine Indo-gangétique. Par ce travail de thèse, nous avons montré l’utilité d’inclure l’analyse du 226Ra à l’analyse des autres nucléides de la chaîne de décroissance radioactive de l’238U (l’238U -234U-230Th 230Th) pour déterminer un taux d’altération dans un système bien défini. Néanmoins, l’étude du système du Brahmapoutre montre que la méthode proposée demande à être affinée car le transfert sédimentaire est un processus plus complexe dû à la variabilité minéralogique, granulométrique et à la dynamique sédimentaire (locale) des échantillons récoltésThis thesis proposes to define the time-scales of weathering processes on a spheroidal weathering profile, (Rio Icacos watershed, Puerto Rico ) and the transfer time of sediments within alluvial plains (Ganges and Brahmaputra basins). This issue is addressed through the analysis of the nuclides of the 238U decay chain. The study of a spheroidal weathering system developed on the site of Puerto Rico permit to develop a limited memory quasi-Newton algorithm in order to solve the system of equations that reflects the behavior of nuclides and the rate of formation of the saprolite and the rindlet zone. For the Ganges and Brahmaputra basins, sediments were collected from different tributaries and their outlets. The variation of 238U - 234U - 230Th disequilibria in the sediments, with different variation trends for suspended and coarse-grained sediments, is probably a general feature of all Himalayan rivers flowing across the Indo-Gangetic plain. For this work, we have shown the usefulness of including the analysis of 226Ra analysis of other nuclides in the chain of radioactive decay of 238U (238U - 234U - 230Th) to determine the weathering rate in a well-defined system. Nevertheless, the study of the Brahmaputra system shows that proposed method needs to be refined as the sediment transfer is a complex process due to the mineralogical variability, size and (local) dynamics of sediments samples collected
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Lénard, Sébastien. "Évolution de l'Himalaya de la fin du Miocène à nos jours à partir de l'histoire de son érosion." Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0161.
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La communauté des sciences de la Terre est animée d'un intense débat sur l'impact des Glaciations sur les chaînes de montagnes. Les montagnes forment leur relief à partir des interactions entre la tectonique, le climat et l'érosion. L'érosion détruit les roches en altitude et les rivières et les écoulements gravitaires sous-marins (turbidites) en transfèrent les débris vers les bassins sédimentaires. L'érosion résulte de l'action des précipitations, des rivières ou des glaciers. Des études suggèrent que les changements dans l'amplitude ou la saisonnalité des précipitations et les changements dans l'étendue des glaciers ont provoqué une augmentation mondiale et considérable des taux d'érosion sur les derniers millions d'années. Cependant, cette hypothèse est débattue car les taux d'érosion passés sont estimés avec des approches indirectes. Ici, je me concentre sur l'Himalaya, la chaîne de montagne par excellence située à la convergence des plaques indiennes et eurasiennes. C'est là que se développent les plus hauts sommets et les vallées les plus profondes de la Terre. Les glissements de terrain et l'érosion glaciaire fournissent l'un des flux sédimentaires les plus élevés aux océans. Pour déterminer les taux d'érosion passés, j'ai mesuré la quantité d'isotope cosmogénique 10Be accumulée dans le sédiment de quartz. Ces isotopes sont produits à la surface de la Terre par l'interaction des rayons cosmiques avec la matière. Les isotopes s'accumulent progressivement dans les roches proches de la surface, en fonction de l'altitude et des taux d'érosion. La concentration isotopique du sédiment donne accès au taux d'érosion moyen du bassin versant à la source de celui-ci. Pour déterminer la source des sédiments et le paléoenvironnement de dépôt, j'ai effectué des mesures complémentaires sur les isotopes Sr-Nd et C-O. J'ai réalisé mes mesures sur deux sites. Le site A est constitué de turbidites sableuses sédimentées dans les fonds marins de la baie du Bengale et recueillies par les expéditions 353 et 354 du programme scientifique IODP. Le site B est constitué de molasses déposées au front de l'Himalaya, dans les collines des Siwaliks, au sein du sanctuaire animalier de Valmiki en Inde. Le site A intègre l'érosion des bassins versants du Gange et du Brahmapoutre, couvrant l'Himalaya central et oriental. Le site B intègre l'érosion du bassin Narayani-Gandak, qui couvre le centre du Népal. Mes résultats donnent un aperçu sans précédent de la variation de l'érosion dans une chaîne de montagnes au cours des sept derniers millions d'années. Ils impliquent que les taux d'érosion moyens sont stables depuis au moins trois millions d'années dans l'Himalaya, malgré les variations dans le transfert sédimentaire ou sur le lieu de l'érosion, et malgré les glaciations intenses de la fin du CénozoïqueAn intense debate animates the Earth Sciences community about the impact of the Glaciations on mountain ranges. Mountains develop their relief from the interaction of tectonics with climate through erosion. Erosion breaks rocks in the highland, and rivers and submarine gravity flows (turbidites) transfer the waste material to sedimentary basins. Erosion results from the action of rainfall, rivers or glaciers. Studies suggest that changes in the rainfall amplitude or seasonality, and changes in the extent of glaciers have triggered a worldwide and considerable increase of erosion rates for the last millions of years. However, this hypothesis is debated because past erosion rates are estimated with indirect approaches. Here, I focus on the Himalaya, the iconic mountain range at the convergence of the Indian and Eurasian plates. There, the highests summits and the deepest valleys on Earth grow. Landslides and glacial erosion supply one of the highest sedimentary fluxes to the oceans. To determine the past erosion rates, I measured the amount of the 10Be cosmogenic isotope accumulated in the quartz sediment. These isotopes are produced at Earth's surface by the interaction of cosmic rays with matter. Isotopes gradually accumulate in rocks close to the surface, depending on the elevation and the erosion rates. The isotopic concentration in sediment gives access to the average erosion rate of the source drainage basin. To determine the source of sediment and the deposition paleoenvironment, I performed supplementary measurements on Sr-Nd and C-O isotopes. I conducted my measurements on two sites. Site A consists in sandy turbidites sedimented on the deep sea floor of the Bengal Bay and collected by Expeditions 353 and 354 of the International Ocean Discovery Program. Site B consists in molasse sediment deposited at the front of the Himalaya, in the Siwalik Hills, within the Valmiki Wildlife Sanctuary in India. Site A integrates the erosion of the Ganga and Brahmaputra drainage basins, covering Central and Eastern Himalaya. Site B integrates the erosion of the Narayani-Gandak basin, covering Central Nepal. My results yield an unprecedented insight in the variation of erosion in a mountain range over the last seven million years. They imply that average erosion rates have been steady since at least three million years in the Himalaya, despite the variations in sediment transfer or the locus of erosion, and despite intense late Cenozoic Glaciations
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Khan, Md Abu Obaida Ansari. "Predicting bank movement of the Brahmaputra River in Bangladesh." 1995. http://hdl.handle.net/1993/18852.
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Khan, Md Abu Obaida Ansari. "Statistical analysis of bank erosion of the Brahmaputra River in Bangladesh." 1988. http://hdl.handle.net/1993/16613.
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Neog, Promod Chandra. "Strategic farm production decisions in the upper Brahmaputra valley zone of Assam." Thesis, 1991. http://hdl.handle.net/2009/3799.
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Chen, Yueh-Wen, and 陳玥妏. "The influence of Brahmaputra River governance on the trilateral relationship between China, India, and Bangladesh." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/s6h53y.
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Mipun, B. S. "Immigrants and the agricultural changes in the lower Brahmaputra valley A case study of Darrang District." Thesis, 1988. http://hdl.handle.net/2009/3876.
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Lin, Sheng-Che, and 林聖哲. "The analysis and annotation of original version Yang Qin concertos《Brahmaputra Edge》、《Spring Night Light Rain》." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/20021159655086427160.
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碩士中國文化大學
音樂學系碩士班中國音樂組
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Nowadays, Original works of Yang Qin concertos are less than Erhu, Dizi and Pipa. The author assumes the following reasons for that: The composers are not familiar with the instrumental characteristics of Yang Qin. And the composers also think the sound of Yang Qin which is not suitable in the concerto. This thesis discusses and analyzes the interpretation of two Yang Qin concertos,"Brahmaputra edge" by Qu Chun-Quan and "Spring Night Light Rain" by Xu Jing-Xin. The research explains and analyzes the characteristics of the Yang Qin instrumental music, the special playing skills and unique sound. Furthermore, the research will provide clear information for contemporary composers making the concertos and music for Yang Qin. This work will discuss the motivation and background of the concerto. The original concept of composition and performance skills will be presented by interview with the composers and the first night performers. In addition, the emphasis of playing Yang Qin concertos will be summarized by the analysis and interpretation these concertos. Finally, the author will propose innovative comment and the interpretations techniques for the two concertos.
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Rahman, Md Matiur. "Peasants' adjustment to natural hazards in Bangladesh : a case study of two upazillas in the Brahmaputra floodplain." 1992. http://hdl.handle.net/1993/18682.
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Haque, Chowdhury Emdadul. "Impacts of river-bank erosion hazard in the Brahmaputra-Jamuna floodplain : a study of population displacement and response strategies." 1988. http://hdl.handle.net/1993/16656.
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Zaman, Mohammad Q. "The socioeconomic and political dynamics of adjustment to riverbank erosion hazard and population resettlement in the Brahmaputra-Jamuna floodplain." 1988. http://hdl.handle.net/1993/16710.
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Suharyanto. "Analyzing movement of centroid of conveyance of a braided river : an attempt to identify the channel migration of the Brahmaputra River in Bangladesh." 1992. http://hdl.handle.net/1993/18705.
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