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| Palácio,Helba Araújo de Queiroz; Andrade,Eunice Maia de; Lopes,Fernando Bezerra; Alexandre,Deborah Mithya Barros; Arraes,Francisco Dirceu Duarte. |
| Com a demanda de água crescendo a cada ano, é necessária uma maior atenção aos fatores responsáveis da qualidade das águas. Esta pesquisa teve como objetivo identificar a similaridade de variáveis determinantes da qualidade das águas do trecho perenizado da bacia do Curu, Ceará, durante a estação seca e chuvosa, pelo emprego de análise multivariada. As amostras de água foram coletadas em sete pontos (georreferenciados), nos meses de janeiro, março, maio e agosto de 2005, totalizando 28 amostras. Nas águas, foram analisados os seguintes atributos: pH, CE, Ca2+, Mg2+, Na+, K+, Cl-, CO3-, HCO3-, SO4-, PO4(3-), NH4- e NO3-. Quatro grupos homogêneos foram identificados, sendo estes independentes da posição geográfica dos pontos de coleta, demonstrando a maior... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Qualidade de água; Sazonalidade; Análise de agrupamento; Análise multivariada. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782009000900017 |
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| Andrade,Eunice Maia de; Rodrigues,Rafael do Nascimento; Palácio,Helba Araújo de Queiroz; Brasil,José Bandeira; Guerreiro,Maria João Simas. |
| ABSTRACT The greater probability of small rainfall events occurring in semi-arid regions, and the little understanding of their role in hydrological processes, has led to this investigation of surface runoff generated during these events in two adjacent micro basins in the Brazilian semi-arid region. The types of plant cover to be investigated were the Phytogeographical Caatinga Domain under regeneration for 35 years (CPDReg) and thinned CPD (CPDThin), which consisted of the elimination of trees with a diameter of <10 cm. Two historical series were considered, one of 40 years (1974-2013) with 2,259 events and the other consisting of 247 rainfall events of <30 mm from 2009 to 2013. The cumulative frequency distribution showed that the series of 247... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Eco-hydrological processes; Seasonally Dry Tropical Forest; Thinning; Surface runoff; Rainfall patterns. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902020000200408 |
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| Santos,Julio Cesar Neves dos; Andrade,Eunice Maia de; Medeiros,Pedro Henrique Augusto; Palácio,Helba Araújo de Queiroz; Araújo Neto,José Ribeiro de. |
| ABSTRACT The semi-arid region in the northeast of Brazil is characterised by rains of high intensity and short duration, with the processes of erosion being aggravated by an inappropriate land-use model. In this region, the lack of measured data for runoff and sediment yield increases the need to apply hydro-sedimentological models in estimating erosion, requiring knowledge of the actual sediment delivery ratio for the region. The aim of this study therefore, was to map soil erosion, making use of the Universal Soil Loss Equation (USLE), in the Iguatu Experimental Watershed (IEW). The mean annual sediment delivery ratio (SDR), and the SDR for individual events, was calculated from hydro-sedimentological measurements, contributing to an understanding of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sediment yield; Soil erosion; USLE; SDR. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902017000100049 |
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| Santos,Júlio César Neves dos; Andrade,Eunice Maia de; Araújo Neto,José Ribeiro de; Meireles,Ana Célia Maia; Palácio,Helba Araújo de Queiroz. |
| Water body eutrophication process has been a serious problem around the world, especially in semiarid and arid region where main approach to storage water is reservoir. The aim of this work was to investigate the spatial and seasonal variability in water quality of a reservoir in a semi-arid tropical region with regards to its trophic state, and to identify the sources of nutrient input to the reservoir. Essa pesquisa foi realizada no reservatório Orós, segundo maior do estado do Ceará-Brasil. This research was developed in the Orós reservoir, the second one most important reservoir in Ceará State, Brazil. Samples were collected bimonthly during the period April 2008 to April 2010, from sex sampling points representing the outlet of tributaries, and one... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water resources; Reservoirs; Water quality. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902014000100005 |
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| Pereira Júnior,Lécio Resende; Andrade,Eunice Maia de; Palácio,Helba Araújo de Queiroz; Raymer,Poliana Costa Lemos; Ribeiro Filho,Jacques Carvalho; Pereira,Francisco Jairo Soares. |
| ABSTRACT The dry forests are the type most widely distributed vegetation in the tropics, and studies aimed at quantifying the carbon stock in these forests are important for it to be quantified their participation as mitigating the effects of climate change. With that in mind, the aim of this research was to quantify the carbon stocks in the woody, herbaceous, litter and root components of a patch of dry tropical forest, with 30 years of regeneration in Iguatu-CE, Brazil. Initially the vegetation was inventoried by means of a floristic and phytosociological survey of the woody component in a 1 ha area which had been under conservation. The biomass was then estimated employing allometric equations, and the stored carbon was quantified. Stocks of carbon in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Semi-arid; Caatinga; Biomass. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902016000100032 |
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| Santos,Julio Cesar Neves dos; Palácio,Helba Araújo de Queiroz; Andrade,Eunice Maia de; Meireles,Ana Célia Maia; Araújo Neto,José Ribeiro de. |
| Although water erosion is the principle agent responsible for soil degradation, field data on the impacts of erosion, due to high operational costs and measurement difficulties, are scarce, especially in semiarid regions. In this context, the aim of this study was to evaluate runoff and soil and nutrient losses in uncultivated areas in the semiarid region of the state of Ceará in Brazil. The experiment was conducted in a 20 m² erosion plot that was uncultivated and populated with herbaceous plants. Data were collected during the rainy season from January to May 2009. Monthly water losses from overland flow ranged from 3.4 to 168.9 mm, representing 1.8 to 42.3% of the total monthly rainfall for January and April, respectively. Soil loss from erosion totaled... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil-erosion; Sediments (Geology); Arid regions. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902011000300030 |
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| Neto,José Ribeiro de Araújo; Andrade,Eunice Maia de; Palácio,Helba Araújo de Queiroz; Sales,Maria Monaliza de; Maia,Anthony Rafael Soares. |
| ABSTRACT The growing pressure on water resources has reduced its availability as regards quality. Data was investigated for two different periods, with the aim of evaluating the influence of the use and occupation of space on the temporal dynamics of the quality of surface and groundwater in the perennialised valley of the Trussu River in the State of Ceará, Brazil. The first period was from September 2002 to February 2004 and the second from April 2013 to April 2014. Twenty-two water samples were taken from nine sampling stations, five on the surface and four underground. The same stations were considered, monitoring 12 attributes of water quality for a total of 2,376 analyses. Temporal dynamics were characterised employing a technique of multivariate... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water contamination; Multivariate analysis; Semi-arid region. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902017000100059 |
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