Showing papers in "Revista Brasileira de Recursos Hídricos in 2014"
TL;DR: In this paper, a coupling between the MapWindow GIS platform and the MGB-IPH hydrological model is presented for the modeling of the Ijuí River basin (Southern Brazil).
Abstract: Problems involving efficient use of water resources are major challenges to be faced by humanity in the coming decades. In this context, hydrological modeling application is an extremely useful tool to develop assessments and to support decision-making. The distributed type hydrologicalal models can represent the behavior of a watershed in a complex manner, allowing detailed analysis and studies based on their results. One of the essential requirements for the use of distributed models is the detailed physiographic description of the studied basin, obtained by using Geographic Information Systems (GIS) platforms. Aiming to enhance the use of hydrological simulation and to develop solutions for proper water resources management, this paper presents the design of a coupling between the MapWindow GIS® platform and the MGB-IPH hydrological model. The developed integration can be considered a close coupling, due to the internal data transfer characteristics developed. The designed tool was successfully tested for the modeling of the Ijuí River basin (Southern Brazil). The application showed that a high degree of integration was obtained between the GIS and the hydrological model. Useful tools were created for input data handling and representation in the GIS environment, and for post-processing and analysis of the hydrological model results. Key-words: hydrological model, geographic information
29 citations
26 citations
TL;DR: In this paper, the authors present applicability tests of the inertial model numerical solution by an explicit scheme, aiming at future integration as a module of flow routing in hydrologic rainfall-runoff models.
Abstract: River flow routing calculations are typically performed using numerical solutions of the Saint-Venant equation. However, in rainfall -runoff hydrological models that besides streamflow in rivers represents the other water cycle processes, it is common to use simplified methods to represent the spread of floods. Among the most used methods are the kinematic wave and the Muskingum-Cunge methods. These simplified methods, however, do not allow representing low slope streams, rivers subject to the backwater effects, and estuaries in which the flow is subject to the effect of tides, because they do not use, among other things, the pressure gradient term of the Saint-Venant equations. An alternative in this case is the use of non-inertial models, which include the pressure gradient term. Recent publications suggest that simplified routing methods should include the local inertia term. This article presents some applicability tests of the inertial model numerical solution by an explicit scheme, aiming at future integration as a module of flow routing in hydrologic rainfall-runoff models. The Inertial model is also compared with other simplified models and with the complete solution of Saint-Venant equations. The set of tests evaluates the models in situations of different slopes, backwater reservoir effect, and the effect of the tide. Results show that for a variety of cases the inertial model has results similar to those of a full hydrodynamic model, and equal or better results than simplified models (Muskingum-Cunge Linear and Muskingum-Cunge-Todini non-linear). We conclude that the inertial model solution with an explicit numerical scheme is applicable to the simulation of the propagation of flow in river reaches, and promising as a module for flow routing in hydrological models.
20 citations
TL;DR: In this article, a quantitative and spatial assessment of precipitation occurring in the Brazilian Amazon over a period of 30 years (1978 to 2007) was performed based on a nonparametric Mann-Kendall test, considering data consistency, density of spatial distribution for the stations, the historical series and climatic phenomena.
Abstract: Encompassing 9 countries in South America the Amazon region has the largest hydric potential in the world. The region is vitally important for the global climate, as well as having rich biodiversity, and relevant economic, social and environmental aspects. It covers an area of approximately 7.5 million square kilometers, which corresponds to around 7% of the planet’s solid surface. This study performs a quantitative and spatial assessment of precipitation occurring in the Brazilian Amazon over a period of 30 years (1978 to 2007). The treatment was based on a non-parametric Mann-Kendall test, considering data consistency, density of spatial distribution for the stations, the historical series and climatic phenomena. The results show that in terms of precipitation in the Brazilian Amazon, over the 30-year period there was a trend towards the decreasing rainfall in the southwest quadrants of the region where the arc of deforestation is found, while in the northern quadrants there was a slight increase that was not significant.
19 citations
13 citations
TL;DR: In this paper, the authors used a series of rainfall data from nine stations in a 78 km2 basin, located in the northwestern region of Rio Grande do Sul, which has a temperate climate with four clearly defined annual seasons.
Abstract: The availability of continuous rainfall time series can enable the execution of many studies that were not possible using series with gaps, but these are usually part of the reality of the data available due to technical, operational and budget difficulties. The objective of this research is to test a methodology with artificial neural networks (ANN) to fill gaps in hourly series of rainfall data. We used a series of rainfall data from nine stations in a 78 km2 basin, located in the northwestern region of Rio Grande do Sul, which has a temperate climate with four clearly defined annual seasons. Three different alternatives have been tried with regard to the length and the arrangement of the time series used: 1. Long series, with approximately 365 days, for training and verification; 2. Short training series, with approximately 12 to 30 days, and also several verification series, each one independent of the weather station; 3. Short series (also 12-30 days), similarly to the previous alternative, except that the verification is done only in periods close to training. The best results were obtained with the third alternative, whose Nash-Sutcliffe (NS) coefficients were higher than 0.9, with both the training and verification series. This demonstrates that even in basins where rainfall is considered homogeneous, relations between rain gauges are not constant, requiring training for each specific atmospheric process to fill the gaps in short, successive periods. Key-words: continuous time series; rain hourly data; neural network, seasonal training.
12 citations
12 citations
11 citations
TL;DR: In this article, the authors discuss the Brazilian program based on the contributions of the international experiences, and also present a review of literature on the subject, and present an agenda for future research taking into account the gaps identified.
Abstract: Rainfall water intake is an important alternative to supply the water demands worldwide. However, differences are found in the perspectives of using this water source. The most notable differences in this sense involve the models of programs adopted in the rural areas and the concepts of urban areas. Brazil is outstanding in this scenario, since currently, in this country, one of the largest programs worldwide to build cysterns for rainwater storage is being developed. Water is taken from these cisterns for human consumption, and by August 2013, 476,040 of the 1,186,602 structures foreseen to be built in the Brazilian Semiarid had been built. In this context, the present work discusses the Brazilian program based on the contributions of the international experiences, and also presents a review of literature on the subject. Finally, the article presents an agenda for future research taking into account the gaps identified
11 citations
TL;DR: In this article, a streamflow regionalization model for water rights in the State of São Paulo has been proposed and evaluated using a new methodology and the accuracy of the models with regard to the prediction of flows used as criteria for water right concession.
Abstract: Streamflow regionalization is a technique that allows transferring information between similar watersheds in order to calculate the hydrological variables of interest at sites for which there are no data. This technique is a useful tool to ensure the rights to water resources use, an instrument provided by Law 9433/97. The Department of Water and Electric Power (DAEE) is the agency responsible for the management of water resources in the State of São Paulo and uses a streamflow regionalization model formulated in the 80s. Since the model used by DAEE presents some limitations, this study aims to formulate a model, through a new methodology and so test the accuracy of the models, with regard to the prediction of flows used as criteria for water rights concession. The models were evaluated
11 citations
TL;DR: In this article, a balanco de massa de Fosforo durante um ciclo hidrologico and compreender a relacao with o estado trofico in dois reservatorios tropicais localizados in the semiarido do Rio Grande do Norte.
Abstract: O aumento do impacto antropico sobre os ecossistemas aquaticos vem acelerando o processo de eutrofizacao,
comprometendo os usos multiplos de agua dos lagos e reservatorios no Brasil e no mundo. Este fato faz parte da realidade dos
reservatorios do semiarido do Estado do Rio Grande do Norte. O objetivo deste trabalho foi realizar o balanco de massa de
fosforo durante um ciclo hidrologico e compreender a relacao com o estado trofico em dois reservatorios tropicais localizados
na regiao do semiarido do Rio Grande do Norte. Foram realizadas amostragens mensais, durante o periodo de seca (de junho
a dezembro de 2010) e o periodo chuvoso (de janeiro a marco de 2011). Em cada reservatorio foram amostrados 3 pontos ao
longo do eixo longitudinal, alem dos rios contribuintes e da agua de chuva durante o periodo chuvoso. As cargas de fosforo
total e solidos suspensos, recebidas pelos reservatorios atraves dos rios afluentes foram elevadas. Os afluentes podem estar
atuando na manutencao do estado trofico dos reservatorios, e estes, como acumuladores de solidos e nutrientes da bacia de
drenagem, o que se relaciona com o uso e ocupacao na area da bacia e com a qualidade da agua
TL;DR: An alternative method is presented for modeling streamflow series based on the CARMA formulation and a hybrid technique of classification and non-equiprobable stratification is proposed in order to reduce the number of synthetic series generated by the stochastic model.
Abstract: Modeling large water systems proves to be challenging as the complexity and the number of variables involved increase. It is common to employ simplifications as, for example, aggregation of reservoirs that operate in the same region. However, these simplifications may omit important system features, making them inflexible and jeopardizing the reliability of results. In this paper, an alternative method is presented for modeling streamflow series based on the CARMA formulation. The model is successfully applied to monthly streamflow from 146 hydroelectric plants that comprise the Brazilian Electric System, and is able to reproduce short and long term statistics and preserve the spatial correlations among the plants. Furthermore, a hybrid technique of classification and non-equiprobable stratification is proposed in order to reduce the number of synthetic series generated by the stochastic model. The intention is to make it possible to apply the generated series in studies requiring greater computer processing. It is shown that it is possible to reduce the number of scenarios without distorting the probability distribution obtained with the stochastic model. Key-words: contemporary model, monthly synthetic series, large water systems, sampling.
TL;DR: In this paper, the authors analyzed the performance of the direct runoff from baseflow separation methods and developed an algorithm for application of automated separation methods, and the results indicated that the three separation methods analyzed have similar results in estimating daily direct runoff and annual total direct runoff.
Abstract: The separation of direct runoff from baseflow shows the magnitude and dynamics of groundwater and direct runoff in basins. Given the importance of studies on direct runoff and baseflow, the purpose of this paper was: to analyze the performance of the direct runoff from baseflow separation methods; and to develop an algorithm for application of automated separation methods. The performance analysis was carried out comparing the direct runoff considering daily and total annual volumes estimated by the separation methods: fixed interval, sliding interval and local minimum. The algorithm was developed in VBA code, to permit the application of the automated separation methods considering the standard format of the databases available in the HidroWeb system, of ANA. The results indicate that the three separation methods analyzed have similar results in estimating daily direct runoff and annual total direct runoff. The computer system developed allows the application of the three separation methods — fixed interval, sliding interval and local minimum — for HidroWeb system databases. Key-words: streamflow, hydrogram, water resources, river basin, statistical analysis
TL;DR: In this paper, a study aimed to determine the rainfall intensity to be used in designing building facilities for rainfall in the state of Santa Catarina, Brazil, where daily rainfall data from 147 raingaging stations in Brazil were used.
Abstract: The design rainfall for storm water facilities may be established based on the analysis of rainfall series observed at the project site. In places without this information NBR 10844 indicates the value of 150 mm.h-1. This study aimed to determine the rainfall intensity to be used in designing building facilities for rainfall in the state of Santa Catarina. Daily rainfall data from 147 raingaging stations in Santa Catarina were used. For each station the IDF equation was adjusted and a 5-minute rainfall intensity was estimated with a return period of 1, 5 and 25 years. Rainfall intensity with a 5-minute duration and return period of 5 years ranged from 127.7 mm.h-1to 266.5 mm.h-1. The average intensity of the stations was 163.2 mm.h-1with a confidence interval of 95% for a variation from 158.9 to 167.4 mm.h-1. It was also observed that the intensity at 82.8% of the stations was greater than 150 mm.h-1. The results show the need to use local data in drainage projects and the importance of updating studies of heavy rainfall.
TL;DR: In this article, the authors presented the simulation of scenarios, with regard to the adoption of technological measures for urban water demand (water-sparing devices and individualized water metering), aiming to subsidize the development of a possible rational water use program for residential consumers in Campina Grande.
Abstract: In order to cope with the pressures exerted by urban areas on the available water resources, there is increasing emphasis on urban water demand management, mainly in arid and semi-arid areas. In the State of Paraíba, Brazil, the case of Campina Grande city deserves promiAlternativas de Gerenciamento da Demanda de Água na Escala de uma Cidade 134 nence, especially due to the last crisis in its water supply system (1997-2003) and the perspective of a new crisis (2012-2014). Considering that the city’s main water demand is for domestic supply, this article presents the simulation of scenarios, with regard to the adoption of technological measures for urban water demand (water-sparing devices and individualized water metering), aiming to subsidize the development of a possible rational water use program for residential consumers in Campina Grande. The analysis of results indicates the environmental feasibility of employing these measures (reduction of water consumption by up to 33.64%). Regarding economic feasibility, there are attractive scenarios and others presenting a longer investment return period. In this context, the role of the public authority is emphasized in the sense of offering financial incentives to the population, inducing it to the rational use of water and avoiding new crises in the city water supply. Key-words: Water-sparing devices, individualized water metering, rational use of water.
TL;DR: In this paper, the authors developed a decision support system AQUATOOL in the Uberabinha River Basin for water planning and management including water quantity and quality modeling, which consists of hydrological rain-flow modeling and a subsequent water management model developed with the SIMGES module for the period from October 2006 to September 2011.
Abstract: Water supply and quality is becoming a common problem in many river basins located in rapidly developing countries. Dealing with the human water supply of cities located in these basins requires sophisticated water planning processes. The increase in population and industry in the city of Uberlandia (Minas Gerais) has generated private and collective conflicts of interest in the multiple use of water in the Uberabinha River, thus requiring integrated management of quantity and quality. This paper explains the development of decision support system AQUATOOL in the Uberabinha River Basin for water planning and management including water quantity and quality modeling. The quantitative part consists of hydrological rain-flow modeling and a subsequent water management model developed with the SIMGES module for the period from October 2006 to September 2011. The water quality model was performed using the GESCAL module that is connected with the SIMGES module. The parameters studied were dissolved oxygen, biochemical oxygen demand, organic nitrogen, ammonia, nitrate and total phosphorus. The future scenarios simulated show the need to choose new locations, outside the Uberabinha river basin, for the abstraction of water used in public water supply in Uberlândia. The disagreement with the DN COPAMCERH 01:2008 regarding biochemical oxygen demand and total phosphorus, in the months with less rain also shows the need to choose new locations to discharge additional pollution loads coming from the main wastewater treatment plant of the city. Key-words: Water quantity and quality modeling, Decision support system AQUATOOL, SIMGES module, GESCAL module, Uberabinha river.
TL;DR: In this paper, the authors present a monitoring strategy considering the combination of different water quality parameters and spectroscopic analysis to characterize the organic matter content in urban basins and analyse its main sources, composition, transport and degradation mechanism.
Abstract: The main goal of this paper is to present a monitoring strategy considering the combination of different water quality parameters and spectroscopic analysis to characterize the organic matter content in urban basins and analyse its main sources, composition, transport and degradation mechanism. The reason for this approach is to find a parameter that will best represent the different fractions of organic matter and overcome some limitations and the subjectivity of the results of current monitoring strategies. The case study was developed at Iguassu River, located in a highly urbanized basin in Curitiba-PR, a 3,000 km2 basin with approximately 3 million people. Samples were collected at six monitoring points from 2005 to 2013, over a 100 km reach of the main river. BOD, COD, DOC, absorbance and fluorescence spectroscopy were used to characterize the organic content of the river. The results confirmed the high discharges of sewage into the river. DOC seems to be the most appropriate parameter for continuous monitoring due to its stability and representativeness, indicating that it is necessary to learn more about the other parameters commonly used and the relation to the other parameters used in water quality planning and management.
TL;DR: Universidade Estadual Paulista, Departamento de Planejamento Territorial e Geoprocessamento, Instituto de Geociencias e Ciencias Exatas de Rio Claro
Abstract: Universidade Estadual Paulista, Departamento de Planejamento Territorial e Geoprocessamento, Instituto de Geociencias e Ciencias Exatas de Rio Claro
TL;DR: In this article, a methodology was applied that allows to estimate suspended particulate matter (SPM) concentrations from the acoustic backscattering data from a 1.5Mhz frequency bottom track SONTEK ADCP (AcousticDoppler current profiler) in the estuarine area of the Patos Lagoon, a very large lagoon located in the south of Brazil.
Abstract: Estuaries are, by definition, very complex coastal systems. The connection with the sea and all the effects of this feature highlight the importance of studying and acRBRH – Revista Brasileira de Recursos Hídricos Volume 19 n.2 –Abr/Jun 2014, 299‐309 309 quiring knowledge on estuarine systems. Suspended particulate matter (SPM) is a very important property of the estuarine circulation which results from the drainage of rivers located in the system. The dynamics of SPM varies greatly, due to estuary hydrodynamics, major forcings and morphology, given that estuaries tend to imprison elements from continental drainage. Also, the SPM distribution can be related to several aspects in the estuarine circulation. In this paper a methodology was applied that allows to estimate SPM concentrations from the acoustic backscattering data from a 1.5Mhz frequency bottom track SONTEK ADCP (AcousticDoppler current profiler) in the estuarine area of the Patos Lagoon, a very large lagoon located in the south of Brazil. The data were collected during seven cruises carried out in the study area from February to October 2012. The results showed a good correlation obtained in the calibration process (r = 0.75) and a good concordance between the in situ data and the estimated data. However, a better fit was shown for small concentrations, which was reflected in the comparison of both series. This problem was due to the calibration procedure (lack of an optical instrument for calibration) and the dynamics and distribution of the SPM in the study area, especially during the sampling period. In addition, the conversion equation was applied to acoustic data obtained in a short term survey carried out in 2010 in the study area with the same ADCP, in order to estimate SPM exportation. The results demonstrated good concordance with the velocity profiles from the ADCP, but the low fit for the higher concentrations produced some bad data (very high SPM concentrations). In conclusion, for a first attempt, this study produced good results for the study area, but a more a detailed survey must be performed in order to improve the results, especially regarding the calibration procedure. Key-words: Suspended particulate matter, Acoustic Doppler current profiler, Patos Lagoon estuary
TL;DR: In this article, the authors proposed a methodology for analyzing river basin water sustainability through the use of indicators, considering the basin at macro (basin) and micro (subbasin, municipality, reservoir) planning levels.
Abstract: This article proposes a methodology for analyzing river basin water sustainability, through the use of indicators. Considering the basin at macro (basin) and micro (sub-basin, municipality, reservoir) planning levels, the analysis is based on three indicators — Indicator of Potentiality, Availability and Demand; Indicator of Water Resources Management System Performance; and Indicator of Water Use Efficiency — and their respective indexes. Indicators and their indexes are classified based on global and partial scales which are composed by five sustainability degrees: very high, high, medium, low and very low. The A Gestão de Recursos Hídricos Subsidiada pelo Uso de Indicadores de Sustentabilidade 222 proposed methodology is applied to the Taperoá River basin which is located in the State of Paraíba semi-arid portion. The outcomes show that: (i) different results may be achieved depending on the planning level considered; and (ii) the river basin in the case study presents a low degree of water sustainability; besides they allow water management actions to be suggested in order to support decision-making of the entities responsible for this management. Key-words: Indicators, water sustainability, river basin.
TL;DR: In this article, the authors used precipitation from global models of the CMIP3 (in the fourth report of the Intergovernmental Panel on Climate Change IPCC-AR4) for the period of 2010 to 2099 for the A1B, B1 and A2 scenarios.
Abstract: The flow projections for Brazilian basins with hydroelectric power plants were obtained using THE precipitation from global models of the CMIP3 (in the fourth report of the Intergovernmental Panel on Climate Change IPCC-AR4) for the period of 2010 to 2099 for the A1B, B1 and A2 scenarios. Flows were generated for the rain with the Soil Moisture Account Procedure (SMAP) hydrological model, which was initialized with statistically corrected precipitation from the monthly rain data of the Climatic Research Unit (CRU) and by the estimated evaporation according to the Penman-Monteith Method. The percentage impacts on average annual flows were analyzed for the periods from 2010 to 2039, 2040 to 2069 and 2070 to 2099 in comparison with the period from 1931 to 1999. The IPCC-AR4 models agree in terms of the impact on the electrical sector in the Southeast/Midwest and South regions, showing that the flows may be reduced up to 5% in each 30-year period in Furnas and approximately 4% by the end of the century in Itaipú. Regarding the North and Northeast sectors, the divergence of the models suggests great uncertainty in these regions; however, they suggest a range within which the planning of infrastructure must occur. The divergence of the IPCC-AR4 models regarding the projections indicates great uncertainty. However, this information defines the bounds for potential future flow scenarios and can be used for the adoption of management policies.