cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.5720290
title: Hydrological regionalization of maximum stream flows using an approach based on L-moments

description: ABSTRACT The proper design of hydraulic structures depends on estimates of maximum stream flows. The scarce stream flow monitoring in Brazil has led to the use of regionalization methods. The main objective of this study was to develop a tool via regional function to estimate maximum stream flows and their corresponding return periods (RP) with the aid of techniques based on the L-moments method, seeking for adequate hydrologic engineering applications and flood risk management. Annual maximum stream flow historical series were adjusted to traditional 2-parameter probability density functions (PDFs) (Normal, 2-parameter Log-Normal, Gumbel, Gamma) and multiparameter PDFs (GEV and Kappa), based on the L-moments method, which were used in the development of the regional function employing the dimensionless curve method. The regional function’s predictive capability was determined by cross-validation for different RPs. It can be concluded that the approach based on L-moments was successfully used to adjust the regional function. In addition, the regional function: i) was improved when using the aforementioned multiparameter PDFs and ii) was framed as optimum for RP of up to 100 years and considered useful for practical engineering projects and flood risk management.
DOI: 10.6084/m9.figshare.5720290.v1
title: Hydrological regionalization of maximum stream flows using an approach based on L-moments

description: ABSTRACT The proper design of hydraulic structures depends on estimates of maximum stream flows. The scarce stream flow monitoring in Brazil has led to the use of regionalization methods. The main objective of this study was to develop a tool via regional function to estimate maximum stream flows and their corresponding return periods (RP) with the aid of techniques based on the L-moments method, seeking for adequate hydrologic engineering applications and flood risk management. Annual maximum stream flow historical series were adjusted to traditional 2-parameter probability density functions (PDFs) (Normal, 2-parameter Log-Normal, Gumbel, Gamma) and multiparameter PDFs (GEV and Kappa), based on the L-moments method, which were used in the development of the regional function employing the dimensionless curve method. The regional function’s predictive capability was determined by cross-validation for different RPs. It can be concluded that the approach based on L-moments was successfully used to adjust the regional function. In addition, the regional function: i) was improved when using the aforementioned multiparameter PDFs and ii) was framed as optimum for RP of up to 100 years and considered useful for practical engineering projects and flood risk management.
DOI: 10.6084/m9.figshare.7515716
title: Principle of maximum entropy in the estimation of suspended sediment concentration

description: ABSTRACT The concern with water quality has been promoting development of better monitoring and control techniques every day. As sediments transport most of water contaminants, their study is fundamental. Given the large number of variables for estimating sediment concentration and high costs of monitoring campaigns, it becomes necessary to develop more accessible methods which bring satisfactory practical results. Therefore, this work deals with application of the principle of maximum entropy, a probabilistic method to determine concentration of sediments in river channels with various concentrations and particle sizes. For this purpose, it was proposed a relationship between the theory of entropy parameters in order to reduce the computational effort. The results were satisfactory at concentrations above 10 g/L with R2 greater than 0.88. The calculated squared errors in this study were lower than those found when using the theory of entropy by Tsallis and the equation of Rouse, classic models for determining the sediment concentration profile. The applicability of the proposed model and the ease of using the probabilistic method, since it reduces the amount of data needed to perform the estimate, makes it feasible on a global scale.
DOI: 10.6084/m9.figshare.7515716.v1
title: Principle of maximum entropy in the estimation of suspended sediment concentration

description: ABSTRACT The concern with water quality has been promoting development of better monitoring and control techniques every day. As sediments transport most of water contaminants, their study is fundamental. Given the large number of variables for estimating sediment concentration and high costs of monitoring campaigns, it becomes necessary to develop more accessible methods which bring satisfactory practical results. Therefore, this work deals with application of the principle of maximum entropy, a probabilistic method to determine concentration of sediments in river channels with various concentrations and particle sizes. For this purpose, it was proposed a relationship between the theory of entropy parameters in order to reduce the computational effort. The results were satisfactory at concentrations above 10 g/L with R2 greater than 0.88. The calculated squared errors in this study were lower than those found when using the theory of entropy by Tsallis and the equation of Rouse, classic models for determining the sediment concentration profile. The applicability of the proposed model and the ease of using the probabilistic method, since it reduces the amount of data needed to perform the estimate, makes it feasible on a global scale.
DOI: 10.6084/m9.figshare.7515725
title: Impact of filamentous cyanobacteria on the water quality of two tropical reservoirs

description: ABSTRACT Artificial lakes play an important role in water availability in tropical semi-arid Northeastern Brazil. However, in addition to the negative effects that dams have on the water quality of rivers, other practices such as discharge of untreated wastewater, intensive crop fertilization and fish farming have been contributing to water quality deterioration. Climate change may be another driver of water quality decrease. Increases in precipitation and drought intensities as well as temperature increase may redefine the dynamics of planktonic communities and favour species more adapted to the new environment. Water samples were collected in two reservoirs selected based on the recurrence of positive results for saxitoxins, Acarape do Meio (AM) and Sitios Novos (SN). In general, diversity in SN (1.08) was higher than in the AM (0.60). Phytoplankton dynamics in these reservoirs differ from other reservoirs in the same region of Brazil, in the sense that filamentous cyanobacteria are dominant. Furthermore, lower diversity, concentration and richness of chlorophyceae and bacillariophyceae were found in both reservoirs. Increase in diversity was observed during the intense rainy season of 2011, suggesting a slight improvement of water quality. A close inverse correlation between Cylindrospermopsis sp and other cyanobacteria was found in SN (R2= –0.862) and in AM (R2= –0.997) and the data collected demonstrates that a season with intensive rainfall may lead to lower cyanobacteria concentrations probably due to water dilution and higher flushing rates.
DOI: 10.6084/m9.figshare.7515725.v1
title: Impact of filamentous cyanobacteria on the water quality of two tropical reservoirs

description: ABSTRACT Artificial lakes play an important role in water availability in tropical semi-arid Northeastern Brazil. However, in addition to the negative effects that dams have on the water quality of rivers, other practices such as discharge of untreated wastewater, intensive crop fertilization and fish farming have been contributing to water quality deterioration. Climate change may be another driver of water quality decrease. Increases in precipitation and drought intensities as well as temperature increase may redefine the dynamics of planktonic communities and favour species more adapted to the new environment. Water samples were collected in two reservoirs selected based on the recurrence of positive results for saxitoxins, Acarape do Meio (AM) and Sitios Novos (SN). In general, diversity in SN (1.08) was higher than in the AM (0.60). Phytoplankton dynamics in these reservoirs differ from other reservoirs in the same region of Brazil, in the sense that filamentous cyanobacteria are dominant. Furthermore, lower diversity, concentration and richness of chlorophyceae and bacillariophyceae were found in both reservoirs. Increase in diversity was observed during the intense rainy season of 2011, suggesting a slight improvement of water quality. A close inverse correlation between Cylindrospermopsis sp and other cyanobacteria was found in SN (R2= –0.862) and in AM (R2= –0.997) and the data collected demonstrates that a season with intensive rainfall may lead to lower cyanobacteria concentrations probably due to water dilution and higher flushing rates.
DOI: 10.6084/m9.figshare.7515731
title: Circulation and salt balance in the São Francisco river Estuary (NE/Brazil)

description: ABSTRACT In order to evaluate how river discharge and tidal currents forcing influence the circulation and salt transport within the São Francisco River-Estuary, a two 25 hour surveys campaigns and along-channel profiles were performed in the estuary main channel (18/19 and 25/26 February 2014). The current intensity showed higher asymmetry between flood (v&lt;0) and ebb (v&gt;0) currents in spring tide (-0.6 and 1.1 m/s), as compared to neap tide (-0.4 and 1.0 m/s), which was attributed to the intense buoyancy energy enhanced by the stronger discharge in spring. Overall, salinity presented high stratified conditions and varied between 0.0
DOI: 10.6084/m9.figshare.7515731.v1
title: Circulation and salt balance in the São Francisco river Estuary (NE/Brazil)

description: ABSTRACT In order to evaluate how river discharge and tidal currents forcing influence the circulation and salt transport within the São Francisco River-Estuary, a two 25 hour surveys campaigns and along-channel profiles were performed in the estuary main channel (18/19 and 25/26 February 2014). The current intensity showed higher asymmetry between flood (v&lt;0) and ebb (v&gt;0) currents in spring tide (-0.6 and 1.1 m/s), as compared to neap tide (-0.4 and 1.0 m/s), which was attributed to the intense buoyancy energy enhanced by the stronger discharge in spring. Overall, salinity presented high stratified conditions and varied between 0.0
DOI: 10.6084/m9.figshare.7515749
title: Reservoir yield intercomparison of large dams in Jaguaribe Basin-CE in climate change scenarios

description: ABSTRACT Climate changes can have different impacts on water resources. Strategies to adapt to climate changes depend on impact studies. In this context, this study aimed to estimate the impact that changes in precipitation, projected by Global Circulation Models (GCMs) in the fifth report by the Intergovernmental Panel on Climate Change (IPCC-AR5) may cause on reservoir yield (Q90) of large reservoirs (Castanhão and Banabuiú), located in the Jaguaribe River Basin, Ceará. The rainfall data are from 20 GCMs using two greenhouse gas scenarios (RCP4.5 and RCP8.5). The precipitation projections were used as input data for the rainfall-runoff model (SMAP) and, after the reservoirs’ inflow generation, the reservoir yields were simulated in the AcquaNet model, for the time periods of 2040-2069 and 2070-2099. The results were analyzed and presented a great divergence, in sign (increase or decrease) and in the magnitude of change of Q90. However, most Q90 projections indicated reduction in both reservoirs, for the two periods, especially at the end of the 21th century.
DOI: 10.6084/m9.figshare.7518203
title: PAHs diagnostic ratios for the distinction of petrogenic and pirogenic sources: applicability in the Upper Iguassu Watershed - Parana, Brazil

description: ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are considered persistent organic pollutants and can cause serious damage in some organisms, including mutagenic and carcinogenic properties. The aim of this study was to evaluate the PAH concentrations in an urban basin and use diagnostic ratios to possible distinguish sources of contamination. The surface water analysis showed predominance of compounds containing 3 to 4 aromatic rings while in suspended particulate matter and sediment there was a predominance of compounds containing 4, 5 and 6 rings. Although present in low concentrations in the sediment, assessment of toxicity equivalent factor (TEF) showed values higher than 3 ng g–1 pellet to 50% of the samples with values of up to 125.35 ng g-1. The use of diagnostic ratios allowed verifying that the main source of PAHs in these aquatic environments, are pyrogenic sources. Still, the use of such relations should be done with caution, trying to assess possible interference of degradation factors
DOI: 10.6084/m9.figshare.7518203.v1
title: PAHs diagnostic ratios for the distinction of petrogenic and pirogenic sources: applicability in the Upper Iguassu Watershed - Parana, Brazil

description: ABSTRACT Polycyclic aromatic hydrocarbons (PAHs) are considered persistent organic pollutants and can cause serious damage in some organisms, including mutagenic and carcinogenic properties. The aim of this study was to evaluate the PAH concentrations in an urban basin and use diagnostic ratios to possible distinguish sources of contamination. The surface water analysis showed predominance of compounds containing 3 to 4 aromatic rings while in suspended particulate matter and sediment there was a predominance of compounds containing 4, 5 and 6 rings. Although present in low concentrations in the sediment, assessment of toxicity equivalent factor (TEF) showed values higher than 3 ng g–1 pellet to 50% of the samples with values of up to 125.35 ng g-1. The use of diagnostic ratios allowed verifying that the main source of PAHs in these aquatic environments, are pyrogenic sources. Still, the use of such relations should be done with caution, trying to assess possible interference of degradation factors
DOI: 10.6084/m9.figshare.7515740
title: Temperature Surface of Guaíba Lake, RS, from time series of MODIS images

description: ABSTRACT The Guaíba lake is located in an area of complex weather variation and is influenced by many atmospheric circulation systems, bringing about violent occluded fronts, and, sometimes, intense precipitation. In Rio Grande do Sul, during El Niño, air temperatures and the precipitation index are higher, contrary to La Niña. Moreover, the Guaíba Lake receives water from the Guaíba's Hydrographical Region, which corresponds to 1/3 of Rio Grande do Sul State, and is thus an important water body to the metropolitan region of Porto Alegre. Methods that seek to understand the behavior of Guaíba lake surface water temperature (LSWT) may lead to relevant information to identify periods of more or less water warming, as well as the relations between LSWT, water quality deterioration and risks to human health. This paper aims to comprehend the behavior of Guaíba LSWT during periods of climatic anomalies (El Niño/La Niña). Therefore, 418 sea surface temperature (SST) images from the MODIS sensor were processed with SeaDas 7.2 software. The quarterly averages of LSWT were obtained and compared to the climatological anomalies in Equatorial Pacific Ocean. LSWT behavior is more complex in El Niño/La Niña periods. The results show that during climatic abnormality periods there are no direct relationship between the warming/cooling of Guaíba LSWT and the warming/cooling of Equatorial Pacific Ocean’s SST. The precipitation indices were more significant to the behavior of LSWT during El Niño periods, but for all periods (of climatic normality and abnormality), air temperature is what most influences LSWT. This relation occurs with climatic factors of water retention time, water entry and precipitation, and air temperature. There is a major correspondence during La Niña periods with the cooling of Guaíba LSWT only for some years. On the other hand, during El Niño periods there are no correspondences of this phenomenon with the warming of Guaíba LSWT. There are only more intense oscillations in surface temperatures than during regular and La Niña periods, but with a tendency to LSWT warming.
DOI: 10.6084/m9.figshare.7515740.v1
title: Temperature Surface of Guaíba Lake, RS, from time series of MODIS images

description: ABSTRACT The Guaíba lake is located in an area of complex weather variation and is influenced by many atmospheric circulation systems, bringing about violent occluded fronts, and, sometimes, intense precipitation. In Rio Grande do Sul, during El Niño, air temperatures and the precipitation index are higher, contrary to La Niña. Moreover, the Guaíba Lake receives water from the Guaíba's Hydrographical Region, which corresponds to 1/3 of Rio Grande do Sul State, and is thus an important water body to the metropolitan region of Porto Alegre. Methods that seek to understand the behavior of Guaíba lake surface water temperature (LSWT) may lead to relevant information to identify periods of more or less water warming, as well as the relations between LSWT, water quality deterioration and risks to human health. This paper aims to comprehend the behavior of Guaíba LSWT during periods of climatic anomalies (El Niño/La Niña). Therefore, 418 sea surface temperature (SST) images from the MODIS sensor were processed with SeaDas 7.2 software. The quarterly averages of LSWT were obtained and compared to the climatological anomalies in Equatorial Pacific Ocean. LSWT behavior is more complex in El Niño/La Niña periods. The results show that during climatic abnormality periods there are no direct relationship between the warming/cooling of Guaíba LSWT and the warming/cooling of Equatorial Pacific Ocean’s SST. The precipitation indices were more significant to the behavior of LSWT during El Niño periods, but for all periods (of climatic normality and abnormality), air temperature is what most influences LSWT. This relation occurs with climatic factors of water retention time, water entry and precipitation, and air temperature. There is a major correspondence during La Niña periods with the cooling of Guaíba LSWT only for some years. On the other hand, during El Niño periods there are no correspondences of this phenomenon with the warming of Guaíba LSWT. There are only more intense oscillations in surface temperatures than during regular and La Niña periods, but with a tendency to LSWT warming.
DOI: 10.6084/m9.figshare.7515752
title: Development of management Tool for Water Risk Assessment (FARH): application in the mineral metalurgical segment in Brazil

description: ABSTRACT Although water governance in the industrial sector has evolved in recent years, water risk management is still considered a challenge in the country. In this way, the present article had the objective of developing a Management Tool for Water Risk Assessment (FARH) in the mining-metallurgical segment. The structural format of the FARH was based on input blocks, processing and data output with the purpose of elaborating a risk matrix (dashboard). The dashboard based on the characterization of the situation of the river basin in relation to the degree of water stress (Y axis), characterization of the water management status of the enterprise (X axis) and the definition of the level of dependence in relation to the water resource. The tool was applied on a pilot scale in 09 (nine) mining-metallurgical enterprises located in the States of Minas Gerais, Goiás and São Paulo (Zn, Ni, Al). With the validation of the FARH criteria, the data platforms were inserted in “macro excel” to computerize their application. The risk matrix allowed the consolidated visualization of the data and provided a technical basis for the prioritization of actions, allocation of resources within an organization and preparation of a guide for the development of the water management plan of these enterprises.
DOI: 10.6084/m9.figshare.7515752.v1
title: Development of management Tool for Water Risk Assessment (FARH): application in the mineral metalurgical segment in Brazil

description: ABSTRACT Although water governance in the industrial sector has evolved in recent years, water risk management is still considered a challenge in the country. In this way, the present article had the objective of developing a Management Tool for Water Risk Assessment (FARH) in the mining-metallurgical segment. The structural format of the FARH was based on input blocks, processing and data output with the purpose of elaborating a risk matrix (dashboard). The dashboard based on the characterization of the situation of the river basin in relation to the degree of water stress (Y axis), characterization of the water management status of the enterprise (X axis) and the definition of the level of dependence in relation to the water resource. The tool was applied on a pilot scale in 09 (nine) mining-metallurgical enterprises located in the States of Minas Gerais, Goiás and São Paulo (Zn, Ni, Al). With the validation of the FARH criteria, the data platforms were inserted in “macro excel” to computerize their application. The risk matrix allowed the consolidated visualization of the data and provided a technical basis for the prioritization of actions, allocation of resources within an organization and preparation of a guide for the development of the water management plan of these enterprises.
DOI: 10.6084/m9.figshare.7515776
title: Coupling the atmospheric model RAMS 6.0 /ECHAM 4.1 to hydrologic model SMA/HMS for operating a reservoir in Brazil’s semiarid

description: ABSTRACT The planning and the efficiency of water resources are subject to the uncertainties of the input data of climate and hydrological models. Prediction of water inflow to reservoirs that would help decision making for the various water uses, contain uncertainties fundamentally the initial conditions assumed in the modeled processes. This paper evaluates the coupling of a regional atmospheric model with a hydrological model to make streamflow forecast for seasonal operation of Orós reservoir, Ceará State, Brazil. RAMS model, version 6.0, was forced by the ECHAM 4.5 atmospheric general circulation model over Alto Jaguaribe basin to obtain the rainfall data. To remove biases in the simulated precipitation fields was applied the probability density function (PDF) correction on them. Then the corrected precipitation data were inserted in the hydrologic Soil Moisture Account (SMA) model from the Hydrologic Modeling System (HEC-HMS). For SMA calibration, it was used the Nash-Sutcliffe objective function. Finally, decisions to water release from the Orós were evaluated using the Heidke Skill Score (HSS). The SMA model showed a satisfactory performance with Nash-Sutcliffe values of 0.92 (0.87) in the calibration (validation) phase, indicating that it is a rainfall runoff model alternative. For decisions in releasing water from the Orós reservoir, using climate predictions, obtained HSS = 0.43. The results show that the simulated rainfall coupled with a hydrological model is able to represent the hydrological operation of Brazilian semiarid reservoir.