Modern sedimentation in the Lower Negro River, Amazonas State, Brazil
Geomorphology on large rivers. Special issue
Amazonas ; Brésil ; Capacité de charge ; Charge en solution ; Cours d'eau ; Dynamique fluviale ; Néotectonique ; Plaine d'inondation ; Profil transversal ; Qualité de l'eau ; Sédimentologie ; Zone intertropicale
The aim of this paper is to discuss the sedimentation that currently occurs in the Negro River, and to demonstrate how the modern deposition and water quality in this river system are controlled by regional neotectonism.
AmazonasRiver ; Exploration ; Peru ; Prague ; Scientific expedition ; Springs ; Stream ; University
Amazonas rio ; Cours d'eau ; Exploration ; Expédition scientifique ; Praha ; Pérou ; Source ; Université
The expedition Hatun Mayu (Big River in Quecha) of the Faculty of Science of Charles University, Prague, measured the lenght of the main source of Apurimac River considered as the longest source segment of Amazon. In addition the expedition measured
This study examines the chemical properties of fluvial deposits (Entisols) of eight different rivers in the Peruvian Amazon. Factors affecting sediment geochemistry are surveyed, and comparisons are made with published statistics concerning Peruvian
The fluvial belt of the Amazon River is a complex of Quaternary sedimentary units of different ages and formation conditions. Present position of the channel and the morphology and size of the alluvial plain are related to neo-tectonic lineaments
. The river may be considered anastomosed, albeit with few islands and anabranches. The main Holocene units are the impeded floodplain and the channel-dominated floodplain. This very large river system had a complex and delayed response to variations
, focusing on the history of one of the largest Amazonian tributaries, The Tocantins River, and on the origin of the Marajó Island, throughout the Quaternary. It is also discussed how tectonic reactivations have contributed to the geological evolution
How does floodplain width affect floodplain river ecology? A preliminary exploration using simulations
AmazonasRiver ; America ; Biodiversity ; Brazil ; Discharge ; Ecosystem ; Fauna ; Floodplain ; Fluvial hydrology ; Fluvial processes ; Mississippi ; Model ; Papua New Guinea ; River bed ; Seasonal variability ; United States of America ; Vegetation
The AA. explore this question with a simple simulation model of the dynamics of a food web in a river with seasonally fluctuating discharge. Components of this river food web spread across a floodplain when it is inundated at high water
Using semivariance statistics, the AA. analyze the spatial relationship between the hydrogeomorphology and the pattern of vegetation cover of the Amazon River floodplain in Brazil during high water. Classified Landsat images for three reaches
of the river that represent the geomorphology of thhe channel-floodplain system were analysed to show the upstream to downstream variation in the spatial heterogeneity of the floodplain environments. In addition to hydrogeomorphic inluence, vegetation
The AA. investigate the hydrological and geochemical characteristics of the Jamari and Jiparana river basins (Amazonia), during the period 1978-1984. In order to detect the long term influence of the large scale deforestation on the ecosystem
they first characterize the hydrological behavior of the drainage basins and its relationship with the particulate and dissolved river loads in this region.
Amazonas rio ; Amérique du Sud ; Bassin-versant ; Charge en suspension ; Crue ; Delta ; Débit ; Ecosystème ; Hydrodynamique ; Orinoco rio ; Plaine côtière ; Sédimentologie ; Tectonique ; Venezuela ; Zone intertropicale
image and historical aerial photograph analyses, and a series of delta expeditions. The AA. briefly describe the geomorphic features and associated water and sediment dynamics of the Orinoco drainage basin and river system. Finally, they summarize major
Amazonas rio ; Brésil ; Diagramme pollinique ; Dynamique de la végétation ; Estuaire ; Holocène ; Mangrove ; Milieu humide ; Palynologie ; Pará ; Salinité
This paper complements the research on wetland dynamics, providing pollen data and radiocarbon dates from sediment cores sampled from Lake Arari and herbaceous flat, located in Marajó Island at the mouth of the Amazon River. It proposes
The aim of this study is to compare the modern Amazon River pollen discharge and terrestrial fossil pollen records with high-resolution fossil pollen and stable isotope records from the Amazon Fan so as to reconstruct the vegetation of the Amazon