scholarly journals Ecohydromorphology of river environments of the das Velhas River upstream of Rio de Pedras hydroelectric reservoir, MG, Brazil

2016 ◽  
Vol 4 (1) ◽  
pp. 41
Author(s):  
Helena Lúcia Menezes Ferreira ◽  
Paulo de Tarso Amorim Castro ◽  
Márcia Couto Melo ◽  
Pedro Fialho Cordeiro ◽  
Aylton Carlos Soares ◽  
...  

<p>This paper presents the applicability of ecohydromorphology assessment in differentiating ecophysical structure of river habitats of Rio das Velhas river basin upward of Rio de Pedras reservoir, Minas Gerais,Brazil. It also presents the identification of the factors conditioning the ecophysical structure of river habitats. This review associated with biological and physico-chemical conditions of the waters aims to assess the ecological integrity of the river system and also validate the characterization of water bodies identified on a large scale in the Rio das Velhas basin.</p>

1985 ◽  
Vol 75 (4) ◽  
pp. 549-594 ◽  
Author(s):  
J. F. Walsh

AbstractThe control of Simulium has always relied largely on the use of insecticides against the larvae, and this is the case in the current large-scale Onchocerciasis Control Programme against the vector S. damnosum Theobald in West Africa. Resistance to temephos has occurred in some vector species, and it is necessary to find alternatives to this preferred larvicide. In order to provide a frame of reference for the development of new larvicides or formulations, the literature relating to larval filter-feeding behaviour is first reviewed in detail. Then the physico-chemical conditions in larval habitats are outlined. The types of formulations and classes of insecticide used in Simulium control are considered, with particular attention being given to emulsifiable concentrate formulations and the reasons for their effectiveness. Particulate formulations, which have been recommended on environmental grounds, are also discussed. Techniques used in the screening of larvicides are considered, and it is concluded that flow-through systems are necessary; mini-gutter tests conducted using water and fauna from rivers to be treated are to be strongly preferred, followed by stream trials. Knowledge of Bacillus thuringiensis var. israelensis as a Simulium larvicide is reviewed in detail. The environmental impact of control of Simulium larvae, both in the tropics and the temperate zone, is extensively reviewed. Throughout, key features which might lead to improved larvicide formulations and testing procedures, together with serious gaps in our knowledge are emphasized.


1995 ◽  
Vol 59 (396) ◽  
pp. 455-463 ◽  
Author(s):  
Gema Ribeiro Olivo ◽  
Michel Gauthier

AbstractPalladium-bearing minerals from the Cauê iron mine, Itabira District, Minas Gerais, Brazil, are found in gold-rich jacutinga, a hydrothermally-altered Lake Superior-type carbonate-bearing oxide facies iron-formation. Palladium occurs as: native palladium with trace contents of Au, Fe and Cu; palladseite ((Pd,Cu,Hg)17Se15), which was found in the core of a grain of palladium; palladium–copper oxide ((Pd,Cu)O); and arsenopalladinite (Pd8(As,Sb)3), with inclusions of palladium–copper oxide. The palladium and palladium–copper oxide grains are coated with films of gold and commonly do not exceed 100 µm in width. These palladium minerals occur in hematite bands and in boudinaged bands of quartz and white phyllosilicate parallel to the S1 mylonitic foliation. Palladium-copper oxide also occurs as inclusions in gold grains which are strongly to weakly stretched parallel to S1.Palladium mineralization is interpreted as synchronous with intense D1 shearing and contemporaneous with the peak of thermal metamorphism. At high oxygen fugacities and high temperatures (up to 600°C), Pd may have been transported as chloride complexes and deposited following changes in pH caused by mineralizing fluids reacting with jacutinga. Deposition may also have been prompted by the formation of insoluble selenide and arsenide–antimonide minerals and by the dilution of C1 concentrations in the mineralizing fluid. Textural studies, and the zonation observed in palladium and other hydrothermal minerals, suggest that oscillations in the physico-chemical conditions of hydrothermal fluids occurred during the mineralizing event.


Author(s):  
Monica Marian ◽  
◽  
Thomas Dippong ◽  
Oana Mare Rosca ◽  
◽  
...  

This paper presents a physico-chemical and ecological characterization of some ponds of anthropogenic origin, resulted from the drilling and extraction of lithological substrate. These artificial water bodies located in a Natura 2000 protected area are the result of some environmental pressures and replaced a potential meadow vegetation. The study aims to characterize the ponds in the perspective of their evaluation as support habitats for fauna and vegetation. For this, some typical physico-chemical parameters of water bodies, important to aquatic life, were analyzed: conductivity, pH, dissolved oxygen, oxygen saturation, turbidity, temperature, ammonium concentrations, nitrate, nitrites, free ammonia, total ammonia, free residual chlorine, total chlorine, phosphates, iron, copper, total alkalinity and water hardness. Also, the types of vegetation and natural habitats were identified and mapped. The analysis of the water quality in the studied area is very important for the conservation and improvement of the natural ecological system.


2016 ◽  
Vol 8 (2) ◽  
pp. 651-661 ◽  
Author(s):  
Eduardo Venticinque ◽  
Bruce Forsberg ◽  
Ronaldo Barthem ◽  
Paulo Petry ◽  
Laura Hess ◽  
...  

Abstract. Despite large-scale infrastructure development, deforestation, mining and petroleum exploration in the Amazon Basin, relatively little attention has been paid to the management scale required for the protection of wetlands, fisheries and other aspects of aquatic ecosystems. This is due, in part, to the enormous size, multinational composition and interconnected nature of the Amazon River system, as well as to the absence of an adequate spatial model for integrating data across the entire Amazon Basin. In this data article we present a spatially uniform multi-scale GIS framework that was developed especially for the analysis, management and monitoring of various aspects of aquatic systems in the Amazon Basin. The Amazon GIS-Based River Basin Framework is accessible as an ESRI geodatabase at doi:10.5063/F1BG2KX8.


2017 ◽  
Vol 43 (4) ◽  
pp. 1953 ◽  
Author(s):  
G. Vargemezis ◽  
I. Fikos

In Anthemountas river basin a number of studies have taken place mainly because of the significant drop of underground water level observed in the beginning of the last decade. Data from existing hydrowells show the existence of a complex aquifer with the two main underground water bodies situated east and west of the region of Vasilika and Galarinos villages respectively. A large scale geophysical survey took place consisting of Vertical Electrical Soundings (VES) and Electrical Resistivity Tomography (ERT). The main area of interest is in the central region of the basin between Vasilika and Galarinos villages where eighty five (85) VES (Schlumberger array), located on a regular grid revealed a three dimensional model for the sedimentary formations while mapping the bedrock down to a depth of more than 600m has been achieved. In the same area, ERT measurements and geological information derived from borehole data are used to obtain a more detailed geological model for the area of interest. From surface to bedrock depth, the hydraulic communication between these two water bodies is examined. Furthermore significant geological features are observed and discussed.


2016 ◽  
Author(s):  
Eduardo Venticinque ◽  
Bruce Forsberg ◽  
B. Ronaldo Barthen ◽  
Paulo Petry ◽  
Laura Hess ◽  
...  

Abstract. Despite large-scale infrastructure development, deforestation, mining and petroleum exploration in the Amazon Basin, relatively little attention has been given to the management scale required for the protection of wetlands, fisheries and other aspects of aquatic ecosystems. This is due, in part, to the enormous size, multinational composition and interconnected nature of the Amazon River system, but also to the absence of an adequate spatial model for integrating data across the entire Amazon Basin. In this data article we present a spatially uniform multi-scale GIS framework that was developed especially for the analysis, management and monitoring of various aspects of aquatic systems in the Amazon Basin. The Amazon GIS-Based River Basin Framework is accessible as an ESRI geodatabase at https://knb.ecoinformatics.org/#view/doi:10.5063/F1BG2KX8.


2020 ◽  
Vol 13 (5) ◽  
pp. 2491
Author(s):  
Fernanda Mourão Fonseca Carneiro ◽  
Micael De Souza Fraga ◽  
Guilherme Barbosa Reis ◽  
Tiago Tozi ◽  
Demetrius David da Silva

O enquadramento dos corpos d’água em classes de uso consiste em uma importante ferramenta para a gestão dos recursos hídricos, pois permite a conexão entre os seus aspectos qualitativos e quantitativos. Sendo assim, o presente trabalho teve como objetivo elaborar uma proposta de enquadramento dos corpos hídricos em classes de uso na bacia do rio Piranga, estado de Minas Gerais. A metodologia foi aplicada em função de critérios considerados relevantes ao enquadramento e da meta de qualidade da água a ser alcançada na bacia, sendo executada com o auxílio do geoprocessamento. Os critérios utilizados para a elaboração do enquadramento foram: finalidade das outorgas, volume outorgado, uso e a ocupação do solo, vazão mínima de referência e densidade populacional. Para cada critério foi atribuído um peso e o mapa de enquadramento foi gerado a partir da sobreposição dos mapas dos critérios adotados. Para definição das áreas prioritárias de intervenção, o Índice de Conformidade ao Enquadramento (ICE) foi calculado com base no enquadramento obtido para os trechos de rio. Como resultado, os rios Piranga, Xopotó, Turvo Limpo e Ribeirão dos Oratórios foram enquadrados nas classes 1 e 2, sendo as zonas de cabeceira enquadradas prioritariamente como classe 1 com exceção para o rio Turvo Limpo, que foi classificado como classe 2 em toda sua extensão. Os resultados mostraram que a metodologia se mostrou adequada, entretanto alguns ajustes foram fundamentais para a obtenção do mapa final de enquadramento dos corpos hídricos na bacia. Proposed framing of water bodies in use classes in the Piranga river watershed using geoprocessingA B S T R A C TThe framing of water bodies in classes of use is an important tool for the management of water resources, as it allows the connection between their qualitative and quantitative aspects. Thus, the present work had as objective to elaborate a proposal of framing the water bodies in classes of use in the Piranga river basin, state of Minas Gerais. The methodology was applied according to criteria considered relevant to the framework and the water quality target to be obtained in the basin, being carried out with the aid of geoprocessing. The criteria used to elaborate the proposal were the purposes of the grants, volumes granted, usage and occupation of the soil, minimum reference flow and population density. For each criterion, a weight was attributed, and the framing map was generated from the overlay of the adopted criteria maps. Framing Conformity Index (FCI) was also calculated in order to define priority areas for intervention purposes. As a result, Piranga, Xopotó, Turvo Limpo e Oratórios rivers were classified in classes 1 and 2, and the headwaters classified as class 1, except for the Turvo Limpo river, which was classified as class 2 throughout extension. The results showed that the methodology proved to be adequate, however some adjustments were essential to obtain the final map of the water bodies in the basin.Keywords: geoprocessing, hydrology, Minas Gerais, water quality.


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