Showing papers in "Revista Brasileira de Recursos Hídricos in 2016"
TL;DR: In this paper, the authors analyzed time series of 212 rain gauges and TRMM data within a spatial grid of 198 pixels, for a 14-year period (1998-2011).
Abstract: The spatio-temporal rainfall variability, the low-density of rain gauges and operational problems are complexity factors for hydrologic studies in developing countries such as Brazil. This research evaluates rainfall estimates derived from Tropical Rainfall Measuring Mission (TRMM) 3B42 product, version 7, over Paraiba state, in Northeast of Brazil. This study analyzed time series of 212 rain gauges) and TRMM data within a spatial grid of 198 pixels, for a 14-years period (1998-2011). Analyses were carried out punctually for each pluviometer as well as spatially aggregated for the mesoregions Mata, Agreste, Borborema and Sertao, considering daily, 3-days, 7-days and monthly rainfall. Largest agreement between TRMM estimates and observed rainfall was obtained for Sertao region (correlation coefficient r daily = 0,89 and absolute average error EMA monthly = 16mm) and smallest agreement for seaside region (r daily = 0,75 and EMA monthly = 31 mm), i.e., the best agreement was obtained for regions with low rainfall rates. TRMM data underestimated observed rainfall in sites with large rainfall amount (monthly bias of -24 mm in Mata region) and overestimated in sites with low rainfall (monthly bias of +13 in Sertao and of +11 mm in Borborema). The spatially detailed characterization over Paraiba of the quality of the TRMM estimates showed in this work illustrates the potential of using such rainfall estimates for this state, because knowing its errors, their types and quantification tends to raise the trust in using them and also allows applying correction methods.
31 citations
TL;DR: The IPH-Hydro Tools is presented, an open source tool coupled to MapWindow GIS software designed for watershed topology acquisition, including preprocessing steps in hydrological models such as MGB-IPH, allowing for better drainage network and less processing time for catchment delineation.
Abstract: Watershed delineation, drainage network generation and determination of river hydraulic characteristics are important issues in hydrological sciences. In general, this information can be obtained from Digital Elevation Models (DEM) processing within GIS commercial softwares, such as ArcGIS and IDRISI. On the other hand, the use of open source GIS tools has increased significantly, and their advantages include free distribution, continuous development by user communities and full customization for specific requirements. Herein, we present the IPH-Hydro Tools, an open source tool coupled to MapWindow GIS software designed for watershed topology acquisition, including preprocessing steps in hydrological models such as MGB-IPH. In addition, several tests were carried out assessing the performance and applicability of the developed tool, given by a comparison with available GIS packages (ArcGIS, IDRISI, WhiteBox) for similar purposes. The IPH-Hydro Tools provided satisfactory results on tested applications, allowing for better drainage network and less processing time for catchment delineation. Regarding its limitations, the developed tool was incompatible with huge terrain data and showed some difficulties to represent drainage networks in extensive flat areas, which can occur in reservoirs and large rivers.
31 citations
TL;DR: In this article, the authors evaluated the precipitation and temperature projections from global models, made available through the Coupled Model Intercomparison Project Phase 5 (CMIP5), and actually used in the AR5 by Intergovernmental Panel on Climate Change - IPCC-AR5, for the Sao Francisco River Basin.
Abstract: Precipitation and temperature projections from global models, made available through the Coupled Model Intercomparison Project Phase 5 (CMIP5), and actually used in the AR5 by Intergovernmental Panel on Climate Change - IPCC-AR5), are assessed here for Sao Francisco River Basin. RCP 4.5 and RCP 8.5 are considered througout the period 2011 to 2100. Incidentally, global models are evaluated concerning their representativity related to 1961-2000 climatology from Brazilian National Meteorological Institute (INMET) data. Two indexes were evaluated: correlation and square mean error. The analisys of projections was performed through the assessment of yearly average values of 30 years period (2011-2040, 2041-2070 e 2071-2100). Additionally to evaluate trends and variability it was considered 10 year moving averages, linear regression and Mann-Kendall-Sen method. Approximately 28% analyzed models do not capture the seasonal precipitation reliably. All models present positive trend for temperature, and despite of divergence on precipitation, the models projected anomalies between -20 and 20 for each time-slice for this variable.
28 citations
TL;DR: In this paper, a hierarchical calibration scheme for the Soil and Water Assessment Tool (SWAT) model by considering land use and climate changes was used to test the performance of the SWAT model.
Abstract: One of the main challenges of hydrological modeling is the effective calibration of model parameters. The aim of this study was to test a hierarchical calibration scheme for the Soil and Water Assessment Tool (SWAT) model by considering land use and climate changes. The study area was the Rio Negrinho watershed, located in Santa Catarina State, Brazil. Model calibration was performed with the Sequential Uncertainty Fitting (SUFI2) Algorithm through increasing complexity tests. The observed discharge data were first divided into calibration and validation periods(Split Sample Test) wherein the predicted monthly flow matched the measured values, with a Nash–Sutcliffe coefficient (NSE) ≥0.5 and Pbias<±25%. When wet and dry periods were considered separately (Differential Split-Sample Test) the NSE values of wet years (2008 a 2012) were higher than dry year values (2003 to 2007). In the SWAT validation for a watershed with similar land use (Proxy-Catchment Test), the model could not capture the flow peaks well (NSE of 0.0), however, the water balance volumes were compensated (Pbias of 0.1%). The case study demonstrates that SWAT performance varies greatly, depending on the spatial scale and calibration period. The SWAT model can be used in further studies to simulate land use and climate change scenarios however it must be calibrated and validated using spatially well distributed data and recorded series segment including dry and wet periods.
25 citations
TL;DR: In this article, the authors proposed a mapping of areas liable to flooding in the township of Rio Largo (Alagoas) in the Rio Mundau watershed by means of an “off-line” coupling of the hydrological/hydraulic models (MGB-IPH/HEC-RAS), through consideration of extreme floods with different return periods for discharge.
Abstract: Overbank flooding caused by historically high flows, such as that in the Rio Mundau watershed (lying between the states of Alagoas and Pernambuco) in 2010, has been the cause of widespread damage. The purpose of work described in this paper was to propose a mapping of areas liable to flooding in the township of Rio Largo (Alagoas) in the Rio Mundau watershed by means of an “off-line” coupling of the hydrological/hydraulic models (MGB-IPH/HEC-RAS), through consideration of extreme floods with different return periods for discharge. The hydrological model had a parameterization appropriate for extreme floods, using as input rainfall data with different return periods. Calibration and validation of the hydrological model were adequate in drainage areas larger than 1500 km2, but were less acceptable in headwater drainage areas where different geology and soil cover gave rise to surface runoff. The hydraulic model showed good agreement with point observations of flood levels in 2010 in both rural and urban areas along the water-course (R2 = 0.99; RMSE = 1.41 m and CV (RMSE) = 0.04). In urban areas distant from the river, however, flood levels were over-estimated, indicating a need to use more detailed Digital Elevation Models. Flood events with return period greater than 50 years have the potential to cause great damage (floods exceeding 0.46 km2 in the urban area). The study showed that the use of coupled models was a viable approach for mapping areas liable to flooding, when it is not possible to analyse local flow frequencies in support of a hydraulic model.
20 citations
TL;DR: In this article, the authors describe the development of a methodology for hazard mapping of river floods and to map areas susceptible to inundation on a municipal scale using the hydrologic-hydraulic simulation for the lower course of the Ipojuca River.
Abstract: Studies focusing on urban vulnerabilities due to river floods need the construction of hazard maps and definition of potential flood areas The objective of this article is to describe the development of a methodology for hazard mapping of river floods and to map areas susceptible to inundation on a municipal scale The study area is the municipality of Ipojuca – Pernambuco State with area of 52711 km2 and population of 80,637 inhabitants The first methodology uses the hydrologic-hydraulic simulation for the lower course of the Ipojuca River using the HEC-HMS and HEC-RAS models The streamflow calculated in the rainfall-runoff model is used as input for the hydraulic model, to simulate the water surface profile in the river This makes it possible to calculate the water depth and flow velocity, the key elements for the definition of hazard indicators The results of the hydraulic model were used to generate the hazard indicators: water depth, flow velocity, combination of depth and velocity, energy head, flow force and intensity (flow velocity x water depth) The other methodology seeks to identify areas with potential for inundation considering the entire territory of the municipality Topographic index of the region and a distance cost matrix (which uses slope and drainage) are the auxiliary variables for determination of this map Both variables use the digital terrain model Analysis of risk is essential for planning and intervention in areas susceptible to inundation Both characterizations of hazard and vulnerability are needed to evaluate risk The results of the study in Ipojuca can be used for hazard characterization
16 citations
TL;DR: In this article, the authors analyzed the rainfall interception in two forests with native vegetation belonging to the Atlantic Forest biome (MA1 and MA2 plots), and a eucalyptus forest (RE plot); located in southern Brazil.
Abstract: Rainfall interception by vegetation (I) can affect the hydrological behavior of a watershed, influencing the hydrological modeling processes. The limitations of monitoring and the wide variety of Brazilian climate and vegetation make it difficult to estimate the interception process. Therefore interception is often overlooked or underestimated in hydrological modeling. This study analyzed the rainfall interception in two forests with native vegetation belonging to the Atlantic Forest biome (MA1 and MA2 plots), and a eucalyptus forest (RE plot); located in southern Brazil. The throughfall (Pi) and stemflow (Et) were monitored for low cost collectors. Forty Pi collectors were used in MA1 plot and 20 collectors in MA2 and RE plots, and three Et collectors in each plot. In total 40, 34 and 22 collections of Pi and 17, 18 and 6 Et collections in MA1, MA2 and RE plots, respectively were analyzed. The total precipitation (P) observed was equal to 2046.50; 1726.23 and 957.96 mm; and total Pi found was 75.97; 82.40 and 78.07% of P, for the plots MA1, MA2 and RE, respectively. The Et was equal to 5.69; 2.91 and 11.09% P; and the estimated I was 17.76; 16.90 and 14.56% P, for MA1, MA2 and RE plots, respectively. Observed values of Pi and I are within the range reported by other authors for similar vegetation, however monitored Et was well above the reported results. The adjustment ratios presented limitations due to the number of Et collectors used and the number of Pi and Et collections monitored, especially in the RE plot; and also because of the large spatial and temporal variability of the processes analyzed, that make the monitoring process difficult.
15 citations
TL;DR: In this paper, the authors proposed a methodology to support the establishment of Brazilian CONAMA 357/2005 rivers water quality classes based on quality parameters Flow-Duration Curves and self-purification analysis.
Abstract: This study aimed to propose a methodology to support the establishment of Brazilian CONAMA 357/2005 rivers water quality classes based on quality parameters Flow-Duration Curves and self-purification analysis. To establish the different simulation water quality scenarios three sewage treatment conditions associated with distinct biochemical oxygen demand (BOD) removal efficiencies, two organic loads conditions and three time horizons (2014, 2020 and 2030) were considered. The QUAL-UFMG model for assessment of the self-purification capacity of the Pardo river, located in the south of Espirito Santo state, Brazil, was applied considering the BOD and dissolved oxygen (DO) parameters. In the simulations only river watershed sewage discharges were considered. BOD Flow-Duration Curves associated with environmental standards established by CONAMA Resolution 357/2005 for classes 1, 2 and 3 rivers were drawn. The results indicate the great importance of using river self-purification modeling for assessment of surface water body quality to establish river water classes. The results also indicate that a non-deterministic approach to water quality Flow-Duration Curves facilitates the decision-making process for the establishment of progressive water quality objectives.
14 citations
TL;DR: In this article, the role of the Water Basin Committee as the first instance to deal with conflicts and the consideration of the Regulatory Framework in the new water basin plan was analyzed, verifying aspects which led to its creation and contribution in resolving/mitigating conflicts.
Abstract: Water resources conflicts have their roots not only in water shortage but also in water resources management failures. There are many shared water basins around the world and agreements may help solve, minimize or avoid water conflicts. In Brazil, the Paraiba and Rio Grande do Norte states share the Piranhas-Acu Water Basin. Considering this, a Regulatory Framework was defined between them designed by the Brazilian Water Agency (ANA), Brazilian Department Against Droughts (DNOCS) and both states. This Regulatory Framework was established by ANA Resolution no 687/2004 and defined the discharge that must flow through the border of those states. In this article, the Regulatory Framework during its ten years of existence (2004 to 2014) is analyzed, verifying aspects which led to its creation and contribution in resolving/mitigating conflicts. This research also analyzed the role of the Water Basin Committee as the first instance to deal with conflicts and the consideration of the Regulatory Framework in the new water basin plan (which is in elaboration). It is concluded that the Regulatory Framework allowed a reasonable discussion about the problems of the basin but that the lack of sufficient monitoring and water uses control actions made it difficult to solve conflicts during water shortage periods. However, the ongoing negotiations to define a “new” Regulatory Framework are considered positive
13 citations
TL;DR: In this article, the authors evaluated the performance of the HAND contour method in mapping areas susceptible to flooding, based on topographic surveys available for the municipalities of Blumenau and Brusque.
Abstract: Mapping areas susceptible to flooding is an important step to minimize the damage caused by floods, especially in urban areas. This mapping is used to establish guidelines for use and occupation of the soil and in the formulation of civil defense plans. In the municipalities of Blumenau and Brusque, flood stricken areas were mapped, from surveys carried out after the events. From the topography represented in digital terrain models (DTM), the HAND model had been preliminarily applied to predict potential flood areas. Recently a new concept was introduced in contours above the nearest drainage (HAND contours), demonstrating the specific ability of this method for use in hydrological risk area assessment. This study aimed to evaluate more widely the performance of the HAND contour method in mapping areas susceptible to flooding, based on topographic surveys available for the municipalities of Blumenau and Brusque. The evaluation used the variables accuracy, omission and commission, and the parameters F statistic, overall accuracy, Fit (%), false alarm rate (FAR) and the trend rate (BIAS). The results showed that for floods of small magnitude, the HAND model overestimates the area susceptible to flooding. As the flood level increases, the HAND model performance improves. For the largest simulated flood of Brusque and Blumenau, the omission (missing area) was of 7.5 and 4.7%, respectively. The commission (surplus area) was 35.3 and 42.2%, respectively. Comparison with other studies shows that the performance of the HAND model is similar to those obtained by other authors with hydrodynamic models, which have a high demand for data input.
12 citations
TL;DR: A primeira etapa foi realizar analise de tendencia temporal das variaveis hidrologicas, sendo identificadas tendencias de aumento significativas em alguns postos pluviometric, nao refletidas nos dados fluviometricos na bacia de estudo as mentioned in this paper.
Abstract: O possivel impacto das mudancas climaticas sobre os usos multiplos que envolvem a UHE de Furnas foi um dos objetivos deste trabalho, sendo apresentado uma abordagem metodologica para mitigacao destes conflitos. A primeira etapa foi realizar analise de tendencia temporal das variaveis hidrologicas, sendo identificadas tendencias de aumento significativas em alguns postos pluviometricos, nao refletidas nos dados fluviometricos na bacia de estudo. Para representacao do clima futuro, foi utilizado o modelo hidrologico (MGB-IPH), alimentado pelo modelo global HadCM3 e regional Eta por meio do cenario A1B do IPCC. Caso os cenarios de mudancas do climas se verifiquem, o reservatorio pode esvaziar-se intensamente; contudo pelo aprimoramento de uma metodologia que considera a fixacao da duracao e frequencia de transgressao de niveis, os conflitos pelo uso da agua podem ser minimizados, sem prejuizos a geracao de energia.
TL;DR: In this article, an experimental basin in the western portion of the federal district of Brazil was used to study the groundwater recharge process in the Cerrado biome, and the results obtained were considered valid as a starting point for further implementations studies in the area.
Abstract: Natural groundwater recharge is a key information to the integrated water resources management (IWRM), but still not well researched in Cerrado Biome – being as an important continental recharge zone, responsible for tzhe base flow in some stretches in major Brazilian rivers. In this context, the purpose of this study was to research and understand key aspects of this process in this important biome: (i) rates; (i) spatial distribution; and (iii) determining factors. The studied area encompasses an experimental basin located in the western portion of the Federal District and the methodology consisted in the application of Numerical Modeling Flow of Saturated Zone. In the method proposed, the spatial distribution of groundwater recharge was previously mapped, and the rates of the recharge zones were estimated by numerical model calibration. In spite of model limitations, simulated rates were close to that provided by literature. The hydraulic properties of the porous media were overriding in the study process, however, land cover/use was considered as an important regulatory factor in the groundwater recharge process in the area. The results obtained were considered valid as a starting point for further implementations studies in Cerrado biome, showing a better porous medium characterization and a better methodology alternative to characterize the spatial variability of recharge zones.
TL;DR: The analysis of the results showed that through the expansion of online communication and the creation of open forums through websites and social networks, the discussions among the watershed committee members may extend beyond the plenary meetings that occur not very often throughout the year.
Abstract: According to the National Water Resources Council 91/2008, the approval of the action plan of the framework of water bodies should be carried out through a decision-making process along the participation of the Watershed Committee (CBH). However, decision-making processes involving multiple stakeholders are vulnerable to flaws that can lead to mistrust among members and lack of commitment with the decisions taken. Some of these failures refer to the absence of information, transparency and lack of knowledge of the object of decision. In this context, the use of technological tools as a means to expand social participation has increased considerably. Among these, it is possible to mention the Information and Communication Technologies (ICTs). This paper presents a study about the use of Information and Communication Technologies (ICTs) to aid watershed committee members on deciding about the set of actions for the execution of the framing of water bodies, having the Salitre River Watershed as a study case. To support the decision on selecting the best action plan the Analytic Hierarchy Process (AHP) multi-criteria analysis method was used, for which a Distance Learning course (DL) within the free platform of “facebook” was developed. The analysis of the results showed that through the expansion of online communication and the creation of open forums through websites and social networks, the discussions among the watershed committee members may extend beyond the plenary meetings that occur not very often throughout the year. The application of ICTs presented some advantages regarding to the decision-making process within the CBH, such as: more time to discuss and obtain consensus; increasing access and exchange of information and experiences; transferring of technical information more clearly; and solving problems like inability to travel by the CBH members.
TL;DR: In this article, the authors evaluated the use of water saving equipment in vertical buildings, in order to minimize the impact of water demand increasing over five years, and concluded that it is possible to minimize water scarcity problem using management tools that can contribute to rational use and also improve society awareness of natural resources in urban areas.
Abstract: This research evaluates the use of water saving equipment in vertical buildings, in order to minimize the impact of water demand increasing over five years. The area studied is a district of Campina Grande city (PB) named Catole. A survey was developed of some reducing devices that could contribute to the water demand decrease in the studied buildings. Water Demand Management recommends the use of water saving devices in buildings to decrease water consumption. The main goal was to evaluate the reduction of the water use caused by water savers in residential buildings and to try to establish parameters for the new buildings. Those parameters can be used for urban planning guidelines and laws to minimize water consumption. Therefore, four different types of water saving devices were selected and the economic and efficiency aspects of implementation were analyzed. Some scenarios were simulated for unfinished buildings (under construction) to evaluate the future water consumption. The results obtained show that the use of water saving devices can reduce water consumption in vertical buildings by 83.26%. Therefore, it has been concluded that it is possible to minimize the water scarcity problem using management tools that can contribute to rational use and also improve society’s awareness of natural resources in urban areas.
TL;DR: In this paper, the authors presented an exploratory analysis of well data extracted from the Groundwater Information System (SIAGAS), which refer to parameters such as degree of confining, lithology and static level.
Abstract: The aim of this study is to perform a geostatistical estimation of hydrogeological parameters to compose the intrinsic vulnerability map for an aquifer. The study presents an exploratory analysis of well data extracted from the Groundwater Information System (SIAGAS), which refer to parameters such as degree of confining, lithology and static level. Therefore, initially, among other procedures, we look for inconsistent data, we produce descriptive statistics and we also apply a normality test to the dataset. The following steps were to make up the primary space description of the respective parameters based on the corresponding identified patterns, randomness and grouping of well data in addition to exploring the existence of a tendency along certain directions. After the preliminary steps, the geostatistical methodology is then applied divided into three phases. The first refers to the variogram study, characterized by the construction of the experimental variograms. In the second phase, automatic adjustment is made to these variograms for three mathematical models: spherical, exponential and gaussian. Then, by cross validation, the performance is estimated for the different models adjusted using statistical indicators. After validation of these models, the last phase takes place, in which we perform the geostatistical estimation by kriging. The estimated values of hydrogeological parameters, when jointly multiplied, composes the estimation of the intrinsic vulnerability index illustrated in the form of a map. This proposal was applied in an area partially covering the city of Belem. The results showed that the methodological approach represents an excellent planning and management tool for the protection of groundwater aquifers.
TL;DR: In this paper, the authors aimed to determine the dissolved inorganic nutrient flows and calculate a budget for N and P in the Itajai-Acu River Estuary, SC, Brazil.
Abstract: This work aimed to determine the dissolved inorganic nutrient flows and calculate a budget for N and P in the Itajai-Acu River Estuary, SC, Brazil. Flows were calculated according to the method developed by LOICZ (Land Ocean Interactions in the Coastal Zone), based on the balance of water, salt and N and P in the estuary. Data were collected weekly at seven sampling sites between 2003 and 2004 and the balances were calculated for the lowest and highest period of the river discharge (97 and 228 m3.s-1). The results showed a hydraulic residence time ranging between 12.4 h and 23 h for the surface layer of the system and between 58 h and 65 h for the bottom layer. The estuary was a sink for phosphate, removing 50% of the computed entries and this was attributed to adsorption to suspended particulate material, since the primary productivity is low. The estuary showed no conservative increase of ammonia and nitrite, related to mineralization and nitrification of organic matter, and low variation for nitrate. The sewage was shown to be an important component of the flows, accounting for 28-42% of P inputs and 23-30% of N inputs to the estuary.
TL;DR: In this paper, a hydrodynamic study of the Santos Estuarine System (Sao Paulo State, Brazil) focused on aspects related to the transport of constituents from inland water discharges is presented.
Abstract: In order to optimize action strategies for environmental management plans and environmental projects in coastal areas, the investigation of processes related to an estuarine system contributes to a better inference of the complex dynamics of constituents present in its water. This paper reports a hydrodynamic study of the Santos Estuarine System (Sao Paulo State, Brazil) focused on aspects related to the transport of constituents from inland water discharges. A computational model was implemented using SisBaHiA (Base System for Environmental Hydrodynamics) in order to reproduce the hydrodynamic patterns of the system. Based on the Lagrangian Transport Model the most significant tributary river discharges were represented: Boturoca River, Cubatao River, Quilombo River and Itapanhau River. Results were probabilistically analyzed based on the lifetime of tributary discharges flowing into the estuarine system and their position during the simulation period. Such simulation results were presented on contour maps of occurrence percentage separated by lifetime limits, supporting a trajectory analysis of the inland water discharges. Map results indicated that water from Cubatao River reaches the Santos Bay preferably through the mouth of the Sao Vicente Estuary and water from Quilombo River preferably flows through the Port of Santos Channel instead. Water from Cubatao River remained in a mangrove area during most of the simulation period. Considering 3 days of lifetime limit only 1% reached the main channels.
TL;DR: In this paper, the authors describe the planning of a water quality monitoring network for the Muriae River Basin, so that based on the technical criteria adopted, the positioning of the stations meets the monitoring needs.
Abstract: Among the premises for planning a water quality monitoring network is understanding of the regional geographic, hydrological and economic conditions. In this context, this article describes the planning of a water quality monitoring network for the Muriae River Basin, so that based on the technical criteria adopted, the positioning of the stations meets the monitoring needs. The Muriae River, a tributary on the left bank of the Paraiba do Sul River, has a watershed of 8,161 km2. The leading economic activities in this area are manufacturing, concentrated in two industrial clusters in the municipalities of Muriae (Minas Gerais state) and Itaperuna (Rio de Janeiro state), and agriculture, mainly along the Gaviao River and near the discharge of the basin. Regarding hydropower generation, there are no power plants with inundated areas greater than 3 km2, the lower threshold for required monitoring according to Resolution 003/2010 issued jointly by the National Water Agency and National Electric Energy Agency. Finally, monitoring points were projected following the criteria for control or strategic points, reference points, impact points and potential power generation points. A Water Quality Index (WQI) was calculated to identify the points with water stress in the basin. The scales defined were hydrography of 1:250,000, Otto codification at level 6 and distribution of discharge of organic waste by urban districts. The results indicate that the location of the stations tends to approximate the potential points of pollution in the basin.
TL;DR: In this article, the authors evaluated statistically the impact of the Taquaracu watershed on water quality in the Rio das Velhas basin and concluded that the inflow from the Rio Taquara is insufficient to mitigate the poor water quality of the basin.
Abstract: Southeastern Brazil is experiencing severe water scarcity because of low rainfall and inefficient water resource management. As a consequence, water supply companies have begun discussing potential solutions to this problem. One proposed solution is creation of new public water supply reservoirs. Recently, managers from municipalities in the metropolitan region of Belo Horizonte, along with sanitation companies, have begun to focus their attention on the Rio Taquaracu. The Taquaracu lies in the Rio das Velhas Basin and displays both good water quantity and quality within the Belo Horizonte metropolitan area. The Taquaracu is a tributary of the Rio das Velhas, and it was proposed that the Taquaracu waters dilute pollutant concentrations entering the Rio das Velhas, thereby improving downstream water quality. This study evaluated statistically the impact of the Rio Taquaracu on water quality in the Rio das Velhas. For this analysis, we used data collected between 1997 and 2015 from sampling points established by the Minas Gerais Estate Institute of Water Management(IGAM) in the Rio Vermelho, in the Rio Taquaracu, and in upstream and downstream sites (the Rio Taquaracu input) of the Rio das Velhas. Box-plots were created for water quality variables and a Principal Component Analysis (PCA) was run for periods referred to as “dry” and “wet.” Despite receiving sewage releases from cities in its watershed, the Rio Taquaracu maintains good water quality. Nevertheless, our results indicate that inflow from the Rio Taquaracu is insufficient to mitigate the poor water quality of the Rio das Velhas.
TL;DR: In this paper, double porosity aquifers with flow controlled simultaneously by intergranular and planar porosity are popularly known as double-porosity aquifer.
Abstract: Groundwater reservoirs with flow controlled simultaneously by intergranular and planar porosity are popularly known as double porosity aquifers. Research studies on these aquifers are important to understand the hydraulic behavior of reservoirs with this type of flow. The Raizama and Diamantino aquifers consist of deformed, low grade metamorphic sediments, distributed along a northeast-southwest belt with southeast concavity. Saturated zones flow is controlled by anisotropy, with low permeability, and the storage is conditioned by fracture and intergranular porosity. In double porosity aquifers the predominance of one or another type of porosity can be observed. When compared to fractured aquifers, double porosity systems present lower drawdown and higher specific capacity values. The transmissivity and hydraulic conductivity hydrodynamic parameters are respectively on the order of 10-5 m2/s and 10-7 m/s for the the Raizama Aquifer, and 10-6 m2/s and 10-7 m/s for the Diamantino Aquifer.
TL;DR: In this paper, the authors evaluated the global accuracy of the Hydrus 1-D model (version 3.0) to predict nitrate leaching within the soil profile, and the mean relative error between the observed (experiment) and calculated (model) values was -1.97%, and the R2 was 0.96.
Abstract: Due to its organic matter and nutrient content, sewage sludge presents a good potential for use in reforestation and reclamation of degraded lands. However, its application poses water contamination risks, due to the high mobility of compounds such as nitrate (carcinogenic). On the other hand, mathematical modeling is becoming an important tool for the evaluation of risks of water contamination by nutrients and pesticides. The aim of the present study was to evaluate the global accuracy of the Hydrus 1-D model (version 3.0) to predict nitrate leaching within the soil profile. For this purpose, experimental data from a laboratory leaching study, considering three different soils and submitted to four doses of sewage sludge, were fed into the Hydrus model, after calibrating the parameters of the Van Genuchten-Mualen equation, using the percolated volumes from the experiment as the objective function. Mean nitrate concentrations in the leachate, collected at the bottom of the experimental columns, were then compared with nitrate concentrations predicted by the Hydrus model. The mean relative error between the observed (experiment) and calculated (model) values was -1.97%, and the R2 was 0.96. The Nash-Sutcliffe coefficient was E=0.95, indicating a very high model accuracy in the prediction of nitrate leaching, under the studied conditions
TL;DR: In this article, o presente trabalho avalia os possiveis efeitos dessa condicao na disponibilidade hidrica for outorga de uso dos recursos hidricos em seis postos hidrometricos brasileiros, considerando como referencia a Q95%.
Abstract: Atividades antropicas nas bacias hidrograficas sao responsaveis por causar mudancas no uso do solo, de modo a ocasionar reflexos nas vazoes afluentes de seus rios. Dentre essas consequencias esta a alteracao dos primeiros momentos estatisticos das series hidrologicas, condicao conhecida por nao estacionariedade. O emprego de uma serie nao estacionaria pode repercutir em erros relevantes e conclusoes tendenciosas nas analises propostas. Dessa maneira, o presente trabalho avalia os possiveis efeitos dessa condicao na disponibilidade hidrica para outorga de uso dos recursos hidricos em seis postos hidrometricos brasileiros, considerando como referencia a Q95%. Opta-se pelo uso da curva de permanencia mediana anual e de curvas de permanencia sazonais, determinadas em dois momentos distintos das series historicas, antes e depois do ano de 1969. Os resultados sugerem aumento da Q95% em quatro postos e reducao nos outros dois. Alem disso, alteracoes importantes foram tambem identificadas em permanencias intermediarias, sugerindo que as variacoes nas series nao estao limitadas a valores extremos.
TL;DR: In this article, a performance index of a sanitary sewage service for the city of Campina Grande (IDSES-CG), Paraiba, Brazil was determined based on existing methodologies, and taking into account criteria such as coherence with regional characteristics, data accessibility and reliability of the source.
Abstract: The contamination of water resources by wastewater is a major concern of water protection. The use of tools to assist the water management process is of utmost importance to improve the sanitation service. This study aims to determine a performance index of a sanitary sewage service for the city of Campina Grande (IDSES-CG), Paraiba. A number of indicators on sewer service quality, operation and maintenance were selected based on existing methodologies, and taking into account criteria such as coherence with regional characteristics, data accessibility and reliability of the source. The selected indicators were calculated, standardized and weighted so that the IDSES-CG could be determined. Based on a nominal scale, the situation involving the sewage service in the city was evaluated and then classified as fair. This study also discussed some of the quality indicators in order to identify the most problematic areas regarding the sewage system.
TL;DR: In this article, a modelo de simulacao de OD and DBO, combinando rios and reservatorios, foi desenvolvido no aplicativo Microsoft Office Excel and aplicaado no rio Tiete, trecho entre Pirapora do Bom Jesus e Salto, conhecido por ser poluido devido to recebimento do aporte de carga orgânica remanescente da Regiao Metropolitana de Sao Paulo.
Abstract: Um modelo de simulacao de OD e DBO, combinando rios e reservatorios, foi desenvolvido no aplicativo Microsoft Office Excel e aplicado no rio Tiete, trecho entre Pirapora do Bom Jesus e Salto, conhecido por ser poluido devido ao recebimento do aporte de carga orgânica remanescente da Regiao Metropolitana de Sao Paulo. Na calibracao utilizaram-se dados monitorados e ferramentas de otimizacao. Foram simulados 12 cenarios caracterizados pela combinacao das seguintes variaveis: vazao descarregada (700, 411 e 130 m3/s), nivel do reservatorio (691 e 688 m) e concentracao de DBO afluente ao reservatorio de Pirapora (37 e 56 mgO2/L). A analise destes cenarios permitiu avaliar os possiveis impactos da operacao do reservatorio na qualidade da agua do rio Tiete a jusante deste barramento. Os resultados indicaram que a qualidade da agua afluente ao reservatorio sobressai perante os aspectos operacionais do mesmo. Diminuir o aporte dessa carga orgânica remete a um planejamento de longo prazo. Uma alternativa de curto prazo para minimizar os impactos e operar o reservatorio com descarga baixa (130 m3/s), mantendo o nivel normal (691 m). Desta maneira, quando a concentracao de DBO afluente e alta (56 mgO2/L), o trecho entre Pirapora do Bom Jesus e Cabreuva fica anoxico e a regiao de Salto apresenta concentracoes de OD e DBO de 3 e 20 mgO2/L, respectivamente. Quando e normal (37mg/L), nao e encontrada condicoes de anaerobiose em todo o trecho simulado e a regiao de Salto apresenta concentracoes de 6 mgO2/L e DBO igual a 17 mgO2/L.
TL;DR: In this article, o rendimento operacional conjunto e individual, of um barco removedor e a escavadeira hidraulica de braco longo, for the retirada de macrofitas aquaticas flutuantes do corpo hidrico do Reservatorio Piraquara II (Piraquera II) in Costa Rica, was avaliado.
Abstract: A eutrofizacao de corpos d’agua tem causado desiquilibrios ambientais, alterando dinâmicas populacionais, como o crescimento excessivo de macrofitas aquaticas. Havendo necessidade de controle dessas comunidades, os metodos mecânicos sao os mais empregados. O presente trabalho teve o objetivo de avaliar o rendimento operacional conjunto e individual, de um barco removedor e de uma escavadeira hidraulica de braco longo, na retirada de plantas aquaticas flutuantes (e seus conteudos de Nt e Pt) do Reservatorio Piraquara II (Piraquara – PR). Os tempos gastos em 100 ciclos operacionais, no trabalho conjunto dos equipamentos (carregamento, transporte e descarregamento de caminhoes), entre outras atividades complementares, foram medidos por cronometragem. A escavadeira hidraulica de braco longo apresentou rendimentos satisfatorios na retirada de macrofitas aquaticas do corpo hidrico, quando comparados com outros trabalhos reportados na literatura. No entanto, o apoio do referido barco aumentou consideravelmente o rendimento (ordem de 115%). O rendimento medio foi de 35,57 ± 0,27 m3/h ou 284,67 m3/dia. Aplicando-se relacoes de area, massa e volume para o caso avaliado, isto equivale a 3273,7 m2/dia (considerando 11,5 m2/m3) ou a 142,28 t umidas/dia (considerando a densidade umida do material = 0,5 ± 0,08; n = 30). Foi constatado que, para situacoes similares, ambos os equipamentos sao recomendados para o controle de infestacoes de plantas aquaticas em corpos hidricos.
TL;DR: In this paper, the size of a stable inlet is discussed considering an analysis based on well established criteria of stability of tidal inlets and with 1D computational modeling, through 2DH hydro-sedimentological modeling, the morphodynamic evolution of the lagoon, its tidal inlet and adjacent maritime region, are analyzed considering the projected situation, and the inlet considered changed very little in the Lagoon bathymetry and remained unobstructed during the 365 days of simulation.
Abstract: The Araruama Lagoon, Brazil’s largest hypersaline lagoon, is an important estuarine system located in the southeast of the state of Rio de Janeiro. This lagoon is oblong-shaped and extends for circa 40 km from west to east at its longest axis. Since it has a negative water balance and only one connection with the open sea, through the long Itajuru Channel, there is very little water renewal, which causes a natural tendency to eutrophication. Creating a new maritime connection on the western side of the Lagoon would take advantage of the very frequent ENE winds, generating a drift from east to west that would increase water renewal and, consequently, enhance the quality of the environment. This paper analyses the hydro-sedimentological viability of this tidal inlet using computer models. Initially the sizing of a stable inlet is discussed considering an analysis based on well established criteria of stability of tidal inlets and with 1D computational modeling. Afterward, through 2DH hydro-sedimentological modeling, the morphodynamic evolution of the lagoon, its tidal inlets and adjacent maritime region, are analyzed considering the projected situation. The inlet considered changed very little in the lagoon’s bathymetry and remained unobstructed during the 365 days of simulation.
TL;DR: In this paper, the authors evaluate the impacts of structural and management alterations proposed for the water treatment plant on water quality in the network, based on the simulation of the behavior of free residual chlorine (FRC), as well as evaluate the reduction the risks to the health of consumers, through the application of risk analysis method Failure Mode and Effect Analysis (FMEA), aiming a safe supply for the population of a medium-sized city.
Abstract: This work involving the analysis of scenarios based on the proposition of operational and structural changes in water supply systems and their impacts on the quality of water supplied to the population. The aim of this study is to evaluate the impacts of structural and management alterations proposed for the water treatment plant on water quality in the network, based on the simulation of the behavior of free residual chlorine (FRC), as well as to evaluate the reduction the risks to the health of consumers, through the application of risk analysis method Failure Mode and Effect Analysis (FMEA), aiming a safe supply for the population of a medium-sized city. The simulation of water quality behavior was developed in the software EPANET 2.0, being the network map constructed from the network tracing of water supply network of two places of Campina Grande City, Paraiba state, Brazil. In the current scenario (C1) one of the places presented, on all nodes, FRC below the minimum recommended by the Ordinance of Brazilian Health Ministry; after the changes, simulated in scenario 2 (C2) an improvement of 60% was observed in the disinfectant concentration compliance with the minimumrecommended value. The risk assessment for C2 showed that the changes provided a reduction of about 66% of the risks in relation to C1. The simulation indicated that there is an improvement in the quality of water but it was concluded, however, that only promoting changes in the water treatment plant is not sufficient to ensure the same or higher concentrations of FRC equal or superior to 0.2mgCl2 /L, throughout the network.
TL;DR: In this paper, a physical criterion used is the propagation of tidal wave in the estuary, which is simulated by the non-permanent flow module of HEC-RAS model.
Abstract: The land use in the basin directly affects the coastal zone as both are connected and must be managed in an integrated manner. However, in Brazil the management policies of both environments are fragmented and there is no effective consideration that the coastal zone is part of the basin. This study aims to test whether the use of a zone of coastal influence (ZCI) based on physical criteria is useful for integrated coastal management. The physical criterion used is the propagation of tidal wave in the estuary, which is simulated by the non-permanent flow module of HEC-RAS model. The case study is the basins of Mampituba, Ararangua, Tubarao and Tijucas rivers, Santa Catarina state, Brazil. The ZCI was set using the minimum affluent flow, which leads to: up to 29 km upstream in the Mampituba River, 34.4 km in Itoupava River and 28.8 km in Mae Luzia River (both Ararangua River affluents), 20.7 km in Tubarao River and 21,25 km in Tijucas river. The model showed good results for the penetration of the astronomical tide, although the ZCI was small due to low tidal range in the analyzed estuaries. The ZCI based on physical criteria proves to be a useful tool, but the criteria used need adaptations, such as the inclusion of 50 km line from the coast or the propagation of meteorological tide. The ZCI is important to include the cause and effect relationships between land and water use and coastal zone management, especially for the grant of water rights and environmental licensing.
TL;DR: In this paper, the authors evaluated the occurrence of antimicrobials and hormones in soil profile in an experimental agricultural area by applying different doses of swine slurry over a period of 60 days.
Abstract: The use of swine slurry as fertilizer in agriculture is a common practice in areas where thematerialis available. However, the presence of chemicals known as emerging organic pollutants in these wastes can contaminatewater bodies through runoff or leaching. In this work,we evaluate the occurrence of antimicrobials and hormones in soil profile in an experimental agricultural area by applying different doses of swine slurry. The work was performed in the twelfth year of an experiment involving two annual applications of swine slurry in an oxisol at doses of 0, 50, 100, and 200 m3ha-1 and a control, to restore the amounts of P and K exported by grain crops. Soil solution samples were collected using suction lysimeters installed in soil layers at average depths of 20, 40, and 80 cm to determine the concentrations of antibiotics and hormones over a period of 60 days.The concentrations were measured by high-efficiency liquid chromatography. The results showed the occurrence of sulfadimidine antimicrobials, chlortetracycline, oxytetracycline, doxycycline, and the hormones estrone, 17β-estradiol, and 17α-ethinylestradiolat depths of up to 80 cm during the collection period. The concentrations of antimicrobials and hormones in the soil solutions varied over the sampling period and were not affected by the doses of swine slurry applied. An analysis of the concentrations observed in different layers showed that the application of swine slurry in an oxisolcan potentially cause groundwater contamination.
TL;DR: In this paper, an optimization technique was applied to a precipitation-flow model for the purpose of developing an automatic calibration tool, which was tested in the estimation of some parameters required for modeling the water level in drainage systems, which were evaluated in a case study, involving the simulation of flood waves in the main course that drains the watershed of D'Antas Stream located in Nova Friburgo-RJ.
Abstract: This work couples an optimization technique to a precipitation-flow model, for the purpose, among others, of developing an automatic calibration tool. The strategy was tested in the estimation of some parameters required for modeling the water level in drainage systems, which were evaluated in a case study, involving the simulation of flood waves in the main course that drains the watershed of D’Antas Stream located in Nova Friburgo-RJ. Here, the direct problem consisted in calculating the water level variation at a given position on that course, implemented on the MOHID-Land platform. On the other hand, the inverse problem focused on the estimation of three hydraulic parameters, which are characteristic of both the basin and the course itself. By applying the method of Luus-Jaakola (LJ) values were estimated for these parameters, resulting in the best fit between simulation and observation. The assessment of the adopted methodology was based on results achieved for three different rainfall scenarios, including the one that led to the reported tragedy in the mountain region of Rio de Janeiro in January 2011. Generally speaking, the results were very satisfactory, both regarding the computational efficiency in the estimates and the ability of the model to fit the observed data.