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Andrade,Eunice Maia de; Silva,Bernardo Barbosa da; Rodrigues,Meilla Marielle Araújo; Mendonça,Marcos Amauri Bezerra; Chaves,Luiz Carlos Guerreiro. |
Despite uncertainties as to the real causes, there is a large amount of evidence of climatic change on Earth. With the objective of investigating changes in extreme air temperatures, as well as the local effects of these changes, eight data sets, collected throughout the State of Ceará in Brazil, were analyzed. Four series of data were obtained from the semi-arid region, three from the coastal zone, and one from a mountainous region. To quantify the changes that occurred during the study period, variations in maximum and minimum temperatures were calculated in relation to the mean of each data series. The annual rates of temperature increase were estimated from the angular coefficients of the best-fit lines. The results showed that although there are... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Climatic changes; Global warming; Air temperature. |
Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902012000200008 |
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Chaves,Luiz Carlos Guerreiro; Lopes,Fernando Bezerra; Maia,Anthony Rafael Soares; Meireles,Ana Célia Maia; Andrade,Eunice Maia de. |
ABSTRACT The semi-arid region of Brazil is characterised by the irregular temporal and spatial distribution of the rainfall, which together with anthropogenic action causes degradation of the water quality. The aim of this study was to evaluate water quality in surface reservoirs in the Brazilian semi-arid region due to rainfall variability and the degree of anthropisation of the watersheds. Water samples were collected at the Orós, Trussu and Muquém reservoirs during August and December of 2012, April, October and December of 2013, and March and June of 2014 (dry and rainy periods). The following limnological attributes were analysed: electrical conductivity, pH, turbidity, transparency and chlorophyll-a, with the results evaluated using box plots, and... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anthropised area; Surface water; Spatial and temporal variability of precipitation. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902019000200223 |
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Meireles,Ana Célia Maia; Andrade,Eunice Maia de; Chaves,Luiz Carlos Guerreiro; Frischkorn,Horst; Crisostomo,Lindbergue Araujo. |
A study on surface water quality in the Acaraú Basin, in the North of the state of Ceará, Brazil was performed. Qualitative dynamics of water flowing to the Acaraú River that supplies water to the irrigation project in the area was evaluated. Multivariate Factor Analysis/Principal Component Analysis was used for evaluation of water quality in order to develop a water quality index (WQI) that reflects soil salinity and sodicity risks and water toxicity to plants. From April/2003 to September/2005 water were sampled from ten sampling sites covering the basin, where physical and chemical parameters that contribute to the WQI were evaluated. The results showed that the use of water for irrigation in the Acaraú basin, according to the proposed WQI, are... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water Irrigation; Soils/salinity; Soils/sodium content; Acaraú Basin (Brazil). |
Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902010000300005 |
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