cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6084/m9.figshare.7507052
title: Uncertainty assessment in hydrodynamic modeling of floods generated by dam break

description: ABSTRACT The objective of the present work was to evaluate sources of uncertainty in dam break simulations for areas with contrasting characteristics: one in a narrow valley with high slopes, and another an open valley with low slopes. A sensitivity analysis of the hydrodynamic model Hec-Ras 5.03 was performed, varying the input data of the model (Manning coefficient, breach configurations, reservoir volume, type of valley topography and equation considered). These variations cause different changes in peak flow, peak time, maximum depth and a maximum speed for different sections of the downstream watercourse. It was concluded that there are uncertainties in determining the input data that impacts in many ways at the generated flood wave, considering both a hydraulic variable of interest, the distance of the section from the dam and the mean geomorphological characteristic of the downstream valley. Topography is not always the most important input data, which allows the possibility of use of low resolution topographies to estimate the peak time in some sections, depending on the valley. Finally, safety coefficients for dam break studies are suggested, aiming to represent uncertainties of the input data in the generated results.
DOI: 10.6084/m9.figshare.7507052.v1
title: Uncertainty assessment in hydrodynamic modeling of floods generated by dam break

description: ABSTRACT The objective of the present work was to evaluate sources of uncertainty in dam break simulations for areas with contrasting characteristics: one in a narrow valley with high slopes, and another an open valley with low slopes. A sensitivity analysis of the hydrodynamic model Hec-Ras 5.03 was performed, varying the input data of the model (Manning coefficient, breach configurations, reservoir volume, type of valley topography and equation considered). These variations cause different changes in peak flow, peak time, maximum depth and a maximum speed for different sections of the downstream watercourse. It was concluded that there are uncertainties in determining the input data that impacts in many ways at the generated flood wave, considering both a hydraulic variable of interest, the distance of the section from the dam and the mean geomorphological characteristic of the downstream valley. Topography is not always the most important input data, which allows the possibility of use of low resolution topographies to estimate the peak time in some sections, depending on the valley. Finally, safety coefficients for dam break studies are suggested, aiming to represent uncertainties of the input data in the generated results.
DOI: 10.6084/m9.figshare.7185587
title: Study of the flow around cofferdams constructed in running water through computational model

description: ABSTRACT River closure to provide a dry area for the construction of the works in the river bed must be carefully performed because a failure can lead to serious and costly delays. By means of a computational approach, using the FLOW 3D® software, this paper studies the hydraulic behavior of the flow around a cofferdam constructed in running water. The computational model was validated using results of an experimental investigation. Then the effect of changing the cofferdam configuration on the flow characteristics in this region was analyzed. This study showed that the computational model adequately reproduces this type of flow and that changing the configuration of the cofferdam: increasing the width of the crest or decreasing the embankment slope affects the flow curvature and positively affects the river closure process.
DOI: 10.6084/m9.figshare.7185587.v1
title: Study of the flow around cofferdams constructed in running water through computational model

description: ABSTRACT River closure to provide a dry area for the construction of the works in the river bed must be carefully performed because a failure can lead to serious and costly delays. By means of a computational approach, using the FLOW 3D® software, this paper studies the hydraulic behavior of the flow around a cofferdam constructed in running water. The computational model was validated using results of an experimental investigation. Then the effect of changing the cofferdam configuration on the flow characteristics in this region was analyzed. This study showed that the computational model adequately reproduces this type of flow and that changing the configuration of the cofferdam: increasing the width of the crest or decreasing the embankment slope affects the flow curvature and positively affects the river closure process.
DOI: 10.6084/m9.figshare.7215812
title: Influence of the rain gauge network on the performance of a hydrological lumped model applied at different basin scales

description: ABSTRACT In this study was evaluated the influence of the rainfall monitoring network density and distribution on the result of rainfall-runoff daily simulations of a lumped model (IPH II) considering basins with different drainage scales: Turvo River (1,540 km2), Ijuí River (9,462 km2), Jacuí River (38,700 km2) and Upper Uruguay (61,900 km2). For this purpose, four rain gauge coverage scenarios were developed: (I) 100%; (II) 75%; (III) 50% and (IV) 25% of the rain gauges of the basin. Additionally, a scenario considering the absence of monitoring was evaluated, in which the rainfall used in the modeling was estimated based on the TRMM satellite. Was verified that, in some situations, the modeling produced better results for scenarios with a lower rain gauges density if the available gauges presented better spatial distribution. Comparatively to the simulations performed with the rainfall estimated by the TRMM, the results obtained using rain gauges’ data were better, even in scenarios with low rain gauges density. However, when the poor spatial distribution of the rain gauges was associated with low density, the satellite’s estimation provided better results. Thus, was conclude that spatial distribution of the rain gauge network is important in the rainfall representation and that estimates obtained by the TRMM can be presented as alternatives for basins with a deficient monitoring network.
DOI: 10.6084/m9.figshare.7215812.v1
title: Influence of the rain gauge network on the performance of a hydrological lumped model applied at different basin scales

description: ABSTRACT In this study was evaluated the influence of the rainfall monitoring network density and distribution on the result of rainfall-runoff daily simulations of a lumped model (IPH II) considering basins with different drainage scales: Turvo River (1,540 km2), Ijuí River (9,462 km2), Jacuí River (38,700 km2) and Upper Uruguay (61,900 km2). For this purpose, four rain gauge coverage scenarios were developed: (I) 100%; (II) 75%; (III) 50% and (IV) 25% of the rain gauges of the basin. Additionally, a scenario considering the absence of monitoring was evaluated, in which the rainfall used in the modeling was estimated based on the TRMM satellite. Was verified that, in some situations, the modeling produced better results for scenarios with a lower rain gauges density if the available gauges presented better spatial distribution. Comparatively to the simulations performed with the rainfall estimated by the TRMM, the results obtained using rain gauges’ data were better, even in scenarios with low rain gauges density. However, when the poor spatial distribution of the rain gauges was associated with low density, the satellite’s estimation provided better results. Thus, was conclude that spatial distribution of the rain gauge network is important in the rainfall representation and that estimates obtained by the TRMM can be presented as alternatives for basins with a deficient monitoring network.
DOI: 10.6084/m9.figshare.7215821
title: Microbial contamination of groundwater in a swine fertigation area

description: ABSTRACT The use of swine effluents as a biofertilizer is an alternative to chemical fertilizers and to water demand in dry season. Nevertheless, fertigation studies usually focus on the plant demand and the soil nutrition parameters, mainly physic-chemical ones. This work aimed to evaluate the impacts of fertigation with swine effluents treated in the microbial quality of groundwater from the phreatic aquifer in two lots on Campanário settlement, on the city of São Gabriel do Oeste, MS, Brazil. Microbial analyses were carried out on groundwater samples from four piezometer and two supply wells using the Colilert system to quantify total coliform and Escherichia coli. Samples were collected during twelve months. The results indicate groundwater contamination by bacteria of the coliform group, according to the drinking water Brazilian standards and its spatial distribution from the point sources to a spreading area in accordance with groundwater flow. Therefore, water disinfection is strongly recommended for drinking purposes. Despite having a strong correlation with groundwater microbial contamination, especially in rainy season, fertigation with swine effluents seem not to be the only source of pathogens in the phreatic aquifer. However, high total coliform values in dry season samples could be assigned to the fertigation.
DOI: 10.6084/m9.figshare.7215821.v1
title: Microbial contamination of groundwater in a swine fertigation area

description: ABSTRACT The use of swine effluents as a biofertilizer is an alternative to chemical fertilizers and to water demand in dry season. Nevertheless, fertigation studies usually focus on the plant demand and the soil nutrition parameters, mainly physic-chemical ones. This work aimed to evaluate the impacts of fertigation with swine effluents treated in the microbial quality of groundwater from the phreatic aquifer in two lots on Campanário settlement, on the city of São Gabriel do Oeste, MS, Brazil. Microbial analyses were carried out on groundwater samples from four piezometer and two supply wells using the Colilert system to quantify total coliform and Escherichia coli. Samples were collected during twelve months. The results indicate groundwater contamination by bacteria of the coliform group, according to the drinking water Brazilian standards and its spatial distribution from the point sources to a spreading area in accordance with groundwater flow. Therefore, water disinfection is strongly recommended for drinking purposes. Despite having a strong correlation with groundwater microbial contamination, especially in rainy season, fertigation with swine effluents seem not to be the only source of pathogens in the phreatic aquifer. However, high total coliform values in dry season samples could be assigned to the fertigation.
DOI: 10.6084/m9.figshare.7215797
title: Sub-hourly rainfall patterns by hyetograph type under distinct climate conditions in Northeast of Brazil: a comparative inference of their key properties

description: ABSTRACT The lack of process-based classification procedures may lead to unrealistic hyetograph design due to complex oscillation of rainfall depths when assimilated at high temporal resolutions. Four consecutive years of sub-hourly rainfall data were assimilated in three study areas (Guaraíra, GEB, São João do Cariri, CEB, and Aiuaba, AEB) under distinct climates (very hot semi-arid and tropical wet). This study aimed to define rainfall events (for Minimum Inter-event Time, MIT, and Minimum Rainfall Depth, MRD, equal to 30 min and 1.016 mm, respectively), classify their hyetograph types (rectangular, R, unimodal with left-skewed, UL, right-skewed, UR, and centred peaks, UC, bimodal, B, and shapeless, SL), and compare their key rainfall properties (frequency, duration, depth, rate and peak). A rain pulse aggregation process allowed for reshaping SL-events for six different time spans varying from 2 to 30 min. The results revealed that the coastal area held predominantly R-events (64% events and 49% rainfall depth), in western semi-arid prevailed UL-events (57% events and 63% rainfall depth), whereas in eastern semi-arid mostly were R-events (61% events and 30% rainfall depth) similar to coastal area. It is concluded that each cloud formation type had important effects on hyetograph properties, differentiating them even within the same climate.
DOI: 10.6084/m9.figshare.7215797.v1
title: Sub-hourly rainfall patterns by hyetograph type under distinct climate conditions in Northeast of Brazil: a comparative inference of their key properties

description: ABSTRACT The lack of process-based classification procedures may lead to unrealistic hyetograph design due to complex oscillation of rainfall depths when assimilated at high temporal resolutions. Four consecutive years of sub-hourly rainfall data were assimilated in three study areas (Guaraíra, GEB, São João do Cariri, CEB, and Aiuaba, AEB) under distinct climates (very hot semi-arid and tropical wet). This study aimed to define rainfall events (for Minimum Inter-event Time, MIT, and Minimum Rainfall Depth, MRD, equal to 30 min and 1.016 mm, respectively), classify their hyetograph types (rectangular, R, unimodal with left-skewed, UL, right-skewed, UR, and centred peaks, UC, bimodal, B, and shapeless, SL), and compare their key rainfall properties (frequency, duration, depth, rate and peak). A rain pulse aggregation process allowed for reshaping SL-events for six different time spans varying from 2 to 30 min. The results revealed that the coastal area held predominantly R-events (64% events and 49% rainfall depth), in western semi-arid prevailed UL-events (57% events and 63% rainfall depth), whereas in eastern semi-arid mostly were R-events (61% events and 30% rainfall depth) similar to coastal area. It is concluded that each cloud formation type had important effects on hyetograph properties, differentiating them even within the same climate.
DOI: 10.6084/m9.figshare.7215785.v1
title: Different approaches to estimate the sediment yield in a tropical watershed

description: ABSTRACT Several Sediment Delivery Ratio (SDR) models have been used to estimate Sediment Yield (SY), mainly in data-scarce and ungauged basins, such as in many regions of Brazil. However, it is difficult to choose the most suitable SDR model, mainly because of the lack of investigations of this approach using observed data. Here, we investigated the performance of five widely used SDR models (SDREST) to estimate sediment yield values (SYEST ) based on observed data in a tropical watershed. We used observed sediment yield values (SY OBS) during September 2011 to July 2017 in three sub-basins of the Guariroba Basin, Midwestern Brazil. To estimate the average annual soil loss, we used the Revised Universal Soil Loss Equation. The SDROBS and SYOBS ranged from 5.56 to 10.54% and 940.76 to 5,400.32 t yr-1, respectively. The Williams and Berndt (1972) method presented the best performance, with a percent bias ranging from -2.34 to 3.30% in SRD estimation. Therefore, this model provided suitable SDR and SY estimates, and may be useful to estimate SY in other tropical data-scarce and ungauged basins.
DOI: 10.6084/m9.figshare.7215785
title: Different approaches to estimate the sediment yield in a tropical watershed

description: ABSTRACT Several Sediment Delivery Ratio (SDR) models have been used to estimate Sediment Yield (SY), mainly in data-scarce and ungauged basins, such as in many regions of Brazil. However, it is difficult to choose the most suitable SDR model, mainly because of the lack of investigations of this approach using observed data. Here, we investigated the performance of five widely used SDR models (SDREST) to estimate sediment yield values (SYEST ) based on observed data in a tropical watershed. We used observed sediment yield values (SY OBS) during September 2011 to July 2017 in three sub-basins of the Guariroba Basin, Midwestern Brazil. To estimate the average annual soil loss, we used the Revised Universal Soil Loss Equation. The SDROBS and SYOBS ranged from 5.56 to 10.54% and 940.76 to 5,400.32 t yr-1, respectively. The Williams and Berndt (1972) method presented the best performance, with a percent bias ranging from -2.34 to 3.30% in SRD estimation. Therefore, this model provided suitable SDR and SY estimates, and may be useful to estimate SY in other tropical data-scarce and ungauged basins.
DOI: 10.6084/m9.figshare.7244387
title: Manning’s roughness coefficient for the Doce River

description: ABSTRACT The Manning’s roughness coefficient is used for various hydraulic modeling. However, the decision on what value to adopt is a complex task, especially when dealing with natural water courses due to the various factors that affect this coefficient. For this reason, most of the studies carried out on the subject adopt a local approach, such as this proposal for the Doce River. Due to the regional importance of this river in Brazil, the objective of this article was to estimate the roughness coefficient of Manning along the river, in order to aid in hydraulic simulations, as well as to discuss the uncertainties and variations associated with this value. For this purpose, information on flow rates and water depths were collected at river flow stations along the river. With this information, the coefficients were calculated using the Manning equation, using the software Canal, and their space-time variations were observed. In addition, it was observed that the uncertainties in flow and depth measurements affect the value of the Manning coefficient in the case studied.
DOI: 10.6084/m9.figshare.7244387.v1
title: Manning’s roughness coefficient for the Doce River

description: ABSTRACT The Manning’s roughness coefficient is used for various hydraulic modeling. However, the decision on what value to adopt is a complex task, especially when dealing with natural water courses due to the various factors that affect this coefficient. For this reason, most of the studies carried out on the subject adopt a local approach, such as this proposal for the Doce River. Due to the regional importance of this river in Brazil, the objective of this article was to estimate the roughness coefficient of Manning along the river, in order to aid in hydraulic simulations, as well as to discuss the uncertainties and variations associated with this value. For this purpose, information on flow rates and water depths were collected at river flow stations along the river. With this information, the coefficients were calculated using the Manning equation, using the software Canal, and their space-time variations were observed. In addition, it was observed that the uncertainties in flow and depth measurements affect the value of the Manning coefficient in the case studied.
DOI: 10.6084/m9.figshare.7304702
title: Managed aquifer recharge: study of undisturbed soil column tests on the infiltration and treatment capacity using effluent of wastewater stabilization pond

description: ABSTRACT Managed Aquifer Recharge (MAR) is a useful tool for the treatment and use of sewage effluent because it complements conventional treatment, recovers the aquifer and minimizes risk of saltwater intrusion. This study aims to investigate technical data to determine the treatment of wastewater stabilization pond effluent using undisturbed soil columns collected from a coastal watershed study area within the BRAMAR (BRAzil Managed Aquifer Recharge) project. The treatment efficiency was monitored by measuring physico-chemical parameters (BOD 5, COD, DOC, TSS, NH3 and NO3) in two columns filled with undisturbed sandy soil in which sewage effluent was infiltrated under unsaturated condition for 72 days with an average input flow of 10 mm h-1. Results indicated reduction greater than 60% of organic matter, suspended solids and ammoniacal nitrogen. However, high concentrations of nitrate in the outflow were detected originating from nitrification of ammoniacal nitrogen. Moreover, difficulties in relation to soil clogging were observed. Furthermore, this study brought relevant contributions to understanding the influence of the infiltration rate and ability to treat effluent from wastewater stabilization ponds using undisturbed soil columns. Future research should be undertaken to improve the pretreatment methods and the operation of a MAR system in the study area.
DOI: 10.6084/m9.figshare.7304702.v1
title: Managed aquifer recharge: study of undisturbed soil column tests on the infiltration and treatment capacity using effluent of wastewater stabilization pond

description: ABSTRACT Managed Aquifer Recharge (MAR) is a useful tool for the treatment and use of sewage effluent because it complements conventional treatment, recovers the aquifer and minimizes risk of saltwater intrusion. This study aims to investigate technical data to determine the treatment of wastewater stabilization pond effluent using undisturbed soil columns collected from a coastal watershed study area within the BRAMAR (BRAzil Managed Aquifer Recharge) project. The treatment efficiency was monitored by measuring physico-chemical parameters (BOD 5, COD, DOC, TSS, NH3 and NO3) in two columns filled with undisturbed sandy soil in which sewage effluent was infiltrated under unsaturated condition for 72 days with an average input flow of 10 mm h-1. Results indicated reduction greater than 60% of organic matter, suspended solids and ammoniacal nitrogen. However, high concentrations of nitrate in the outflow were detected originating from nitrification of ammoniacal nitrogen. Moreover, difficulties in relation to soil clogging were observed. Furthermore, this study brought relevant contributions to understanding the influence of the infiltration rate and ability to treat effluent from wastewater stabilization ponds using undisturbed soil columns. Future research should be undertaken to improve the pretreatment methods and the operation of a MAR system in the study area.
DOI: 10.6084/m9.figshare.7336550
title: Hydrological simulation uncertainties in small basins through the SWAT model

description: RESUMO A modelagem hidrológica é uma das principais ferramentas de apoio à gestão dos recursos hídricos. Entretanto, vários fatores dificultam a extrapolação dos parâmetros estimados em bacias com grandes áreas de contribuição para bacias de pequena dimensão. O objetivo deste trabalho foi analisar as incertezas na simulação de vazões em bacias de pequena dimensão. O processo metodológico envolveu a aplicação do modelo de simulação hidrológica Soil and Water Assesssment Tool (SWAT) à bacia representativa do ribeirão Concórdia (30,74 km 2) e à bacia do rio Itajaí (15.000 km2). Primeiramente, comparou-se 6 cenários distintos de discretização das unidades de respostas hidrológicas (HRUs) na calibração e validação da bacia hidrográfica do ribeirão Concórdia, avaliando-se a influência do número de HRU na simulação de pequena bacia hidrográfica. Em seguida, calibrou-se os parâmetros do modelo para a bacia do rio Itajaí, em 12 estações fluviométricas. Posteriormente, determinou-se uma tendência de variação dos parâmetros calibrados através da formulação de equações de regressão. Estas equações foram elaboradas a partir da correlação entre os índices físicos de cada estação fluviométrica considerada e seus valores. No presente estudo, a discretização das HRUs indicou que não há necessidade de aumentar o número de HRU quando o objetivo a ser alcançado é representar os picos do fluxo de água na pequena bacia hidrográfica. Os resultados obtidos com a aplicação das equações de regressão demonstraram que o coeficiente de compacidade (kC) pode gerar até 42,1% de variação na vazão média e 82,7% na Q95 das sub-bacias. Portanto, a utilização das equações de regressão pode auxiliar na redução das incertezas geradas durante a calibração dos parâmetros.