DEGEO - Departamento de Geologia

URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/8

Navegar

Resultados da Pesquisa

Agora exibindo 1 - 3 de 3
  • Item
    Aplicação do método AHP para confecção de modelo de favorabilidade hídrica subterrânea de aquíferos fraturados.
    (2020) Olivieira, Nilcileia Cristina de Magalhães; Bacellar, Luis de Almeida Prado; Fiume, Bruna; Barella, Cesar Falcão; Nola, Iraydes Tálita de Sena
    A locação de poços tubulares em aquíferos fraturados é complexa devido à dificuldade de se encontrar água nestes meios, de alta heterogeneidade e anisotropia. Há várias propostas metodológicas que têm como objetivo encontrar áreas mais favoráveis para a produção de água nestes aquíferos, que normalmente envolvem condicionantes geológicos e geomorfológicos. No presente trabalho, pretende-se definir um mapa de favorabilidade hídrica subterrânea para uma área a norte do Quadrilátero Ferrífero (MG) por meio da integração dos mapas litológico, de declividade, HAND (Height Above the Nearest Drainage) e densidade de lineamentos morfoestruturais, magnetométricos e radiométricos. Para tal, adotou-se o método AHP (Analytic Hierarchy Process), que possibilita a integração de vários planos de informação de forma menos subjetiva. O mapa de favorabilidade, validado com dados de capacidade específica de 361 poços tubulares, mostrou que os fatores condicionantes mais relevantes são em ordem decrescente, o HAND, declividade, densidade de lineamentos e litologia. Com os resultados, criou-se um modelo de favorabilidade hídrica subterrânea para a área de estudo, que poderá ser utilizado em outras regiões similares.
  • Item
    Assessment of the groundwater favorability of fractured aquifers from the southeastern Brazil crystalline basement.
    (2019) Brito, Thaís Palma de; Bacellar, Luis de Almeida Prado; Barbosa, Maria Sílvia Carvalho; Barella, Cesar Falcão
    Groundwater favorability maps can aid groundwater exploitation in fractured aquifers, such as those of the Bação and Northern Bonfim complexes (Quadrilátero Ferrífero) southeastern Brazil, bringing alternatives for water supply in regions where water availability is at risk. These maps were obtained by means of the analytic hierarchy process (AHP), using six information levels: the height above the nearest drainage (HAND) model, the declivity map, three lineament maps (morphostructural, radiometric and magnetometric), and the lithological map. The E–W strike of the lineaments was emphasized for the integration, because it is the most frequent and subparallel to the present strike of the maximum principal stress σ1. The favorability maps were validated by varying the input parameters and comparing the maps with 82 specific capacity values obtained from well tests. Although more data should be necessary to confirm this method, the results are promising and can be tested in other crystalline basement areas.
  • Item
    Influence of the natural oxidation of the leachate organic fraction from a landfill on groundwater quality, Belo Horizonte: Minas Gerais, south-eastern Brazil.
    (2013) Barella, Cesar Falcão; Bacellar, Luis de Almeida Prado; Nalini Júnior, Hermínio Arias
    The objective of this work was to evaluate the influence of the natural degradation of the leachate organic fraction from the Belo Horizonte landfill on groundwater chemical evolution. The work focused on the modifications introduced by redox reactions in the presence of terminal electron acceptors. Twenty-one sampling points distributed along 13 monitoring wells were selected for the analysis of the chemical indicators of interest (TDS, SO4 -2, Fe?2, Ba, pH and Eh). The behaviour of the variables involved in the alteration of the water quality was assessed by the spatial distribution of target parameters, elaboration of redox diagrams and chemical modelling that focused on the determination of mineral saturation indexes. The study showed a trend toward pyrite precipitation, which leads to the removal of chemical species such as divalent iron and sulphur as sulphide from the system. This removal disturbs the chemical equilibrium, typically by moving the reactions to replenish the sulphate concentration present in the groundwater. This process occurs primarily through the dissolution of compounds that have sulphate in their chemical composition, such as barite, suggesting that part of the barium concentration in the subsurface can be of geogenic origin. This study demonstrated the importance of knowing the nature of the geochemical processes in groundwater contaminated by urban solid waste.