Showing papers in "Revista Brasileira de Recursos Hídricos in 2015"

Determinação de anti-inflamatórios na água e sedimento e suas relações com a qualidade da água na bacia do Alto Iguaçu, Curitiba-PR

Abstract: Environmental contamination by emerging pollutants has been explored in different studies in the environmental area. This is due, in the most part, by the low efficiency of municipal wastewater treatment and the high chemical consumption. The watershed of the Alto Iguacu located in the Metropolitan Region of Curitiba has a high population density in your surroundings and, consequently, has some problems in water quality of its rivers. Considering this aspect, this study comprehended the evaluation of emerging contaminants in five rivers inside this watershed. Contamination by anti-inflammatory ibuprofen, paracetamol and diclofenac in surface water and sediment was evaluated for a year, a total of four sampling campaigns. Ibuprofen was found only in the first sampling, but in high concentrations in the Belemriver(729 ng.L-1). Diclofenac had been widely detected in water and it reached concentrations of 285 ng.L-1 in the third sampling in the Iguacu river. Unlike the rest, paracetamol was often quantified in the water, being the Iguacu and Belem rivers with more presence of this drug. It was also determined in sediments, especially in Bariguiriver, being founded 6,896 µg g-1. The presence of these compounds in the sampled rivers confirms an anthropogenic interference with the Alto Iguacu watershed, which suffers from unplanned urbanization

Avaliação do potencial de redução do consumo de água potável por meio da implantação de sistemas de aproveitamento de água de chuva em edificações unifamiliares

Abstract: In a scenario of relative water scarcity, it is advisable to implement public policies aiming at maintaining adequate potable water supply. A relevant alternative regarding water supply policies is the use of rainwater harvesting systems in residential buildings in order to meet the households non-potable water demands. This paper suggests a methodology to evaluate the potential for drinking water savings in urban area using rainwater for non-potable purposes in single-family dwellings. Hydraulic and financial assessments were performed, taking as case study Belo Horizonte, 2.4 million-inhabitant city that is the capital of the state of Minas Gerais. Results suggest that, in a scenario of widespread use of domestic rainwater harvesting systems, one can get the equivalent of two months of drinking water supply as drinking water annual savings. On the other hand, for the adopted scenario, results suggest economic feasibility of the systems, although with a high payback and internal rate of return very close to the attractive interest rates. These results suggest that the dissemination of these systems may require funding models and other economic tools to promote them for large scale use

Caracterização da formação de cheias na bacia do rio Una em Pernambuco: simulação hidrológica-hidrodinâmica

Abstract: In June 2010, a hydrological event caused severe damage to cities located along the banks of the main rivers in Zona da Mata in the States of Pernambuco and Alagoas. The Una River basin was one of the most affected by the flood. The Una River basin covers 6,704.0 km2 and is situated in the Zona da Mata and Agreste of Pernambuco State. To represent the event of June 2010, the rainfall-runoff model HEC-HMS and the hydrodynamic model HEC-RAS were used. The geometry of the minor and major riverbed of the Una River and its tributary Pirangi River was determined by mean of surveying using the LiDAR technique (Light Detection and Ranging), which employs laser beams emitted from an aircraft to scan the river area and its proximities. The objective of the paper is to simulate the flood events that occurred in the Una river basin, verifying the main aspects that influence the formation of the flood in the river and how this influences the calibration of the models. Continuous and event-based manual calibration was tested. The results showed that it is not possible to get a single set of parameters for wet and dry periods. The best option was to calibrate the models using two flood events and validate them with six other events. After the calibration, the 2010 event was simulated to estimate the peak flow. The 2010 flood can be considered the most severe event that has ever occurred despite the lack of streamflow records. The result could be compared only to the spatialized water depth at Palmares city. There was an overestimation of the water depth calculated by the HEC-RAS model, but there was also a good agreement with the extent of the flooded area.

Variação temporal de parâmetros limnológicos em manancial de abastecimento em Juiz de Fora, MG

Abstract: The availability of temporal data bases of limnological parameters of a catchment can be treated statistically to understand the quality status. The Municipal Sanitation Company of Juiz de Fora monitors the water catchment of Sao Pedro Reservoir monthly, providing data from 1998 to 2012, which were statistically treated using Student’s t test and Factor Analysis / Principal Components Analysis (FA/PCA). The first test determined the seasonal influence on the color, biochemical oxygen demand, iron, oxygen consumed and conductivity parameters. The AF / ACP excluded the last three mentioned variables and pH, resulting in the extraction of three major components that together explained 73 % of the total variation in the data. The first component reflected the contribution of allochthonous material carried by runoff and erosion; the second and third components are associated with the organic contribution such as the discharge of sewage, animal excrement and fertilizers, respectively, increased mostly by land use and by the absence or fragmentation of riparian forests. These factors suggest negative human interference in the water of the studied catchment

Fragilidade ambiental e escassez hídrica em bacias hidrográficas: Manancial do Rio das Araras - Araras, SP./ Environmental Fragility and water scarcity in catchment basins: Headwaters of Araras River - Araras, SP.

Abstract: Estudos envolvendo bacias hidrográficas raramente abordam os impactos gerados pelas atividades humanas em bacias utilizadas como mananciais de abastecimento. As ações humanas relacionadas à urbanização, industrialização e agropecuária, sem o planejamento adequado, são as que mais comprometem os serviços ambientais em tais bacias. No município de Araras (SP), assim como ocorreu para todo o Estado de São Paulo, foi constatada importante escassez hídrica no ano de 2014 com a redução das principais fontes de captação superficiais. A área estudada abrange 352,77 km2, está delimitada pelas coordenadas geográficas 47°29’2,4” W; 22°13’52,7” S e 47°12’32,4” W; 22°26’42” S e pertence à UGRHI do Rio Mogi Guaçu Alto Mogi. O presente trabalho analisou a fragilidade ambiental na Bacia Hidrográfica do Rio das Araras (BHRA), no intervalo de 15 anos (1999 2014), envolvendo cinco classes de fragilidade (Muito Fraca, Fraca, Média, Forte e Muito Forte) e sua relação com o cenário de escassez hídrica. As parcelas dessa bacia, que apresentaram fragilidade Forte e Muito Forte, e que tem como principal uso o plantio de cana de açúcar, correspondem às áreas de nascentes dos principais mananciais superficiais de abastecimento. Tal situação tem contribuído para a redução da disponibilidade hídrica, como consequência da combinação entre os atributos do meio físico e as atividades humanas.

Twenty-six years of uneven changes in low flows due to different uses and operation of a large dam in a semiarid river

Abstract: Little is known about the hydrological impact of the dams in Brazil, despite the rising energy demand and untapped potential. The Paraguaçu River’s discharge has been greatly impacted since 1986 by a large dam built in the lower course of the river. In the 26 years of the history of the dam, the minimum discharges have followed different operational guidelines: 1) there was no established discharge minimum between 1987 and 1996; 2) the discharge minimum was 11 m3s-1 between 1997 and 2004; and 3) hydropower generation began in 2005, when local wet season discharges were either 80 m3s-1 or 160 m3s-1, and dry-season pulses of 10 m3s-1, which were adopted as minimum stream flow. The mean annual dam discharge between 1987 and 2012 was 17.4% less than the incoming river flow. While rare events of daily null flow exist in the historic records, hundreds of occurrences of daily null flow have been observed in the outgoing discharge since 1987. Other important hydrologic alterations (IHAs) have included: the one-day minimum, the 3-day minimum and the number of low-discharge pulses. Ecochange analysis indicates an overall discharge loss (ecodeficit) in the system. The period of dam operation has coincided with a noticeable drop in the natural river discharge, when the mean discharge was 32% lower than in the pre-dam period (1947-1986)

Desenvolvimento e validação de um simulador de chuvas portátil

Abstract: The validation of the rainfall simulator should produce average drop diameter with impact velocity and kinetic energy of impact similar to drops in natural rainfall. The objective of this work is develop, build, calibrate and test a small portable rainfall simulator. The rainfall intensity is controlled with a solenoid valve and a cyclic digital timer. Close-open relation range of the solenoid valve can produce rainfalls between 63 and 106 mm/h. The Christiansen, Statistical and Uniformity coefficients were considered appropriate and with a good uniformity of water distribution. The agreement between simulated and natural rainfall kinetic energy was a good relationship. Thus, the rainfall simulator developed meets the technical requirements established in the literature and can be used in many agricultural and environmental sciences tasks

Avaliação do tipo de distribuição de probabilidades das vazões máximas diárias anuais no Brasil

Abstract: The frequency analysis of hydrologic and climate data has been the main tool used by engineers to estimate the environmental risk of civil works. One of the steps necessary for frequency analysis consists of choosing a probabilistic model to estimate flows for certain return periods based on observed data. However, this step has been performed subjectively in Brazil, which may compromise the use of this method. In this paper, several probabilistic models were evaluated to indicate which one was the best fit to Brazilian runoff data in order to stimulate discussion about the standardization of the methods used in the frequency analysis. The data were collected automatically from the Web Service of the National Water Agency (ANA). The adequacy of the 1943 samples was ensured through the application of criteria to eliminate stations with a large number of missing data and the Mann –Whitney, Spearman and Pettit tests, to test the homogeneity, stationarity and shifts in the mean and variance, respectively. The Akaike information criterion (AIC), Bayesian information criterion (BIC) and a goodness-of-fit measure based on the Anderson Darling test, the diagram of L-moments ratios, the method of Beard and the SEAF software were used to assess which probabilistic models are the most suitable to Brazilian data. The results obtained with the application of such procedures show that the most appropriate probability distributions for the Brazilian data are the two and three parameter log-normal distributions and that the only distribution among those tested that did not prove adequate to the Brazilian data was the generalized Pareto

Seleção de eficiências de tratamento de esgotos a partir da manutenção de equidade entre sistemas de tratamento - uma abordagem para o gerenciamento de bacias /Selection of sewage treatment efficiencies to maintain equity between systems - an approach to

Abstract: Rivers are usually the destination of treated sewage. Thus, planning and designing wastewater treatment systems must take the water depuration capacity of the rivers into account. Within a watershed the evaluation of depuration capacities becomes more complex due to the multiple effluent discharges presenting different loads and the variability of different water body self-depuration capacities. In this context, the aim of this study is to define wastewater treatment plants efficiencies within a watershed, by combined application of an optimization technique and mathematical modeling of water quality, considering a restriction related to equity among wastewater treatment plants. The study was developed considering possible effluent disposal in the upper part of the Santa Maria da Vitoria river watershed. This watercourse, located in the Espirito Santo state, Brazil, is one of the most important water sources for the Grande Vitoria Metropolitan Region. The results indicate that the incorporation of equity reduces the variability associated with organic waste loads at different disposal points by requiring higher treatment levels for stations which receive larger organic loads

Monitoramento e modelagem hidrológica de plano de infiltração construído em escala real

Abstract: The purpose of this study was to monitor and later model the flow along an infiltration plane, built in real scale, for rain water management area of 3001 m2. Rainfall, inflow and water depth of flow over the inclined plane were monitored. The equipment employed for measurement was calibrated in triplicate through field measurements under conditions of controlled drainage of 9.3 m3 volume of water poured over the plane. 32 events were monitored of which only seven produced measurable water depth. The inclined plane was calibrated by PULS’ method considering constant and variable hydraulic conductivity obtaining mean R2 of 0.75 and 0.72. In the validation process, R2 of 0.71 was obtained for both cases. The drainage times of around 25 minutes were explained by the high rates of infiltration and the area of the plane. Observed average lag times was 5,9 min; times to peak 28,3min and flow time over the plane from 12,2 min. It was observed that the initial calculated water levels were superior to those observed, because there were flooded area, but the depth-area-volume ratio calculated by PULS did not adhere with observed data

Análise de fragilidade ambiental na bacia do rio Pardo - RS, frente à instalação de pe- quenas centrais hidrelétricas (PCHs)

Abstract: Fragility of the natural environment can be understood as susceptibility to damage and should be evaluated when it is to be applied to environmental land planning. Therefore the Integrated Environmental Assessment (IEA) aims to assess synergistic and cumulative effects resulting from environmental impacts caused by the set of hydroelectric developments. The present study applied the assessment method for vulnerable environments considering changes caused to the environment and society, due to the possible installation of five small hydroelectric projects (SHPs) in cascade in the Pardo River Basin, RS. With the help of the Geographic Information Systems (GIS) the algebra method of maps was used to analyze the environment as a whole and the study area was divided into three environments: physical (remnant vegetation and soil resistance variables), biotic (Phytosociological vegetation and Biodiversity variables) and anthropic (soil use and HDI variables) in order to have a perspective of different scenarios covering the entire environment. Hence, the results show that in all final maps of fragilities for the of the physical, anthropic and biotic environments the sites chosen to construct the five hydroelectric plants present a classification of between medium and high fragility

Estudo de propagação de ondas para auxiliar a elaboração do plano de ação emergencial externo – PAE

Abstract: This study meets the guidelines of the Act 12.334/2010 of the National Dam Safety and aims to assess the flood waves caused by full flow operation and flow induced by hypothetical dam rupture, for the preparation of an Emergency Action Plan. The study was developed in HPP Tres Irmaos, in Rio Tiete, CESP - Companhia Energetica de Sao Paulo. The flood waves were propagated along a 30 km reach, using the HEC-RAS model, calibrated from the reproduction of historical water levels. The methodology seeks to determine the peak arrival times, period of submersion, water levels and velocities at different points of interest along the river for different scenarios. Flood maps were made to serve as the basis for defining a plan for evacuation of the affected population. The outflow hydrographs generated resulted in peak flows between 20.915 and 40.507 m³/s, with breach opening times between 1 and 14 h. The results showed little influence of the breach opening time in the extent and time of submersion of the affected areas, with only appreciable difference in arrival time of the peak. The simulations in steady and unsteady flow regimes showed no large variations of the maximum water depth. It was observed small attenuation of the max flow rate along the river reach due to the large reservoir storage and the long depletion time. The risk of cascade rupture was not identified, because the downs tream Jupia dam can control flow rates up to 50.000 m³/s