Tobias Bleninger

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Verified

Tobias verified their affiliation via an institutional email.

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• Dr.-Ing.
• Professor at Federal University of Paraná

Floating photovoltaic (FPV) systems are designed for free water surface installations to provide a feasible solution for places with no availability of land areas and to avoid land-use conflicts caused by conventional solar energy farms. However, lakes and reservoirs are essential for ecosystem services like water supply and biodiversity support. I...

Floating photovoltaic (FPV) systems are increasingly deployed on gravel pit lakes to generate renewable energy and mitigate land-use conflicts. However, their environmental impacts on hydrological and ecological processes remain insufficiently studied. This study investigates the effects of a 1.5-MWp FPV system covering 8% of a 19-ha gravel pit lak...

An analysis of the effects of waves on the transport and fate of sediments from submerged outfalls in relatively shallow waters is presented. Five sewage outfalls in the coastal area of Baixada Santista, Brazil, were selected as a case study. A hydrodynamic model both with and without wave effects was implemented, and sediment discharges from the f...

RESUMEN La presente investigación evalúa el efecto de la turbulencia 2D−3D de chorros de alta velocidad; provenientes de conductos laterales en usinas hidroeléctricas de baja caída (UHE), en la eyección efectiva disponible para las turbinas. Se emplearon 352 conjuntos de datos en 3D de variables hidrodinámicas y de turbulencia en la llamada Región...

Solar photovoltaic installations are growing fast worldwide as a renewable alternative for power generation, although, there are some disadvantages of the conventional land-based solar power plants, such as the need of a large land area. Thus, floating photovoltaic power plants (FPV) have emerged as a new solution in solar energy; however, the envi...

Reservoirs present different and intrinsic characteristics from the point of view of physical, chemical, and biological nature from other environmental systems. They therefore should be characterized differently for a better representation aiming for proper planning and management strategies. This paper analyzes eleven reservoirs and develops a cla...

A estimativa da evaporação de lagos e reservatórios é essencial para quantificar as perdas de volume de água disponível, sendo um processo crucial no ciclo hidrológico e indispensável para a gestão eficaz dos recursos hídricos. Embora muitos estudos tenham realizado estimativas de evaporação de lagos com diferentes modelos, um número pequeno de est...

O impacto das atividades humanas tem contribuído para o aumento da frequência e intensidade de eventos climáticos extremos, como a grande enchente que assolou o estado do Rio Grande do Sul em maio de 2024. O monitoramento automático do nível de corpos d'água pode auxiliar em uma melhor gestão envolvendo os riscos de inundação, além de servir como f...

This study addresses the diurnal variation in water quality and phytoplankton and zooplankton communities in a reservoir influenced by a floating photovoltaic system (FPS). Two daily campaigns were conducted in 2023, one in february and another in august, to monitor the physico-chemical parameters of the water, such as temperature, dissolved oxygen...

The objective of this study is to investigate how hydraulic variables can indicate the condition of the physical habitat and how these habitat conditions are related to the diversity of macroinvertebrates' community by applying a 3D numerical simulation. The 2D and 3D flow modeling provides key information of physical variables to complement ecolog...

Regardless of the specific technology adopted, the use of desalination to produce fresh water from seawater results in a discharge of brine effluent containing a high concentration of salts and other desalination by-products that must be dealt with appropriately. Until now, this effluent has most commonly been discharged into the sea through a subm...

The transport of methane from sediments to the atmosphere by rising gas bubbles (ebullition) can be the dominant, yet highly variable emission pathway from shallow aquatic ecosystems. Ebullition fluxes have been reported to vary in space and time, as methane production, accumulation, and bubble release from the sediment matrix is affected by severa...

The Madeira River is characterized by large amount of woody material transported, especially during floods, which interferes with the operation of the Jirau Hydroelectric Power Plant. There are many logs and the log boom structures inserted to retain them do not always present the desired efficiency. This work involves the hydrodynamic simulation o...

Biogeochemical fluxes and water masses transport in thermally stratified lakes are often dominated by internal waves. These phenomena are triggered by baroclinic forces generated by the interaction of wind-driven flows and temperature variation along the water column. Although this mechanism is well documented, the complexity of the mathematical to...

Ensuring compliance with the minimum Water Quality Standards stipulated by law demands the implementation of strategic measures within the watershed. Water pollution modeling serves as a tool to guide the formulations of effective pollution control strategies. However, the inherent complexity of calibration, spatial-temporal variability, and uncert...

Despite jellyfish’s ecological and socioeconomic impacts, they are still an understudied component of marine ecosystems. Even with its conspicuous size, reaching ~ 1 m in bell diameter, Drymonema gorgo has been rarely observed, with only a few occurrences in the literature, suggesting that it is not a common species. Here, we gathered historical re...

Submarine outfalls have been employed to convey urban effluents to their fate in the open ocean due to their dilution capacity and organic matter decay. This work analysed Escherichia coli concentrations in the Barra da Tijuca (Rio de Janeiro, Brazil) submarine outfall plume, considering an hourly variable bacterial die-off due to environmental par...

Gravity and intrusion currents occur when there is a variation of fluid density under a gravitational field. In the gravity current case, the differences in the hydrostatic pressure result in an underflow of the dense fluid while the less dense fluid has a counter flow on the top. In the case of intrusion currents, the fluid flows horizontally on i...

The present paper shows the state of the art on this topic, within the framework of a research project in a 1:70 physical type-model implemented at the Center of Hydraulics and Hydrology Prof. Parigot de Souza (CEHPAR/LACTEC); located in the Campus III of the Federal University of Parana (UFPR). The aim of the study is to study and identify combina...

In the present research work, a theoretical and experimental assessment of the specific variables playing a key-role on the dispersion of a submerged jet in a tank have been made. Bernoulli and continuity equations were applied with the aim of evaluating the outlet velocities and discharges. Results were assessed by using the Absolute Percentage Er...

Droughts can impact ecosystem services provided by reservoirs. Quantifying the intensity of droughts and evaluating their potential effects on the thermal stability of reservoirs are subjects that demand greater attention, due to both the importance of temperature on aquatic metabolism and the climate change scenarios that predict an increase in th...

The dynamics of vertical mixing and the occurrence of basin-scale internal waves (internal seiches) in lakes and reservoirs are often classified and described based on the force balance of wind shear and horizontal pressure gradients resulting from wind-generated currents (the Wedderburn number). The classification schemes consider specific time sc...

Every dam or barrage construction affects the watercourse and the retention of sediment that previously was carried by the river, which can lead to siltation of the reservoir and obstruction of water intakes over time, reducing their capacities. However, the information available regarding the effect of sediment and drawdown parameters, sediment ma...

The aim of this research is to complement and improve the results about ejection effect in a low-head hydropower plant from a previous study in physical models and to evaluate the effect of ejection on the turbine power and efficiency, in the model alternative with the best performance. The study covers four additional geometric alternatives, aside...

Water quality models are often applied to support the definitions for water resources planning and management. This process requires appropriate data to calibrate and make the required verification process for validation analysis. However, in some case studies, there is not enough data to run a complex water quality model whatever is the water syst...

The dynamics of vertical mixing and the occurrence of basin-scale internal waves (internal seiches) in lakes and reservoirs are often classified and described based on the force balance of wind shear and horizontal pressure gradients resulting from wind-generated currents (the Wedderburn number). The classification schemes consider specific time sc...

Bedload sediment transport in rivers can cause impacts, such as bed erosion/deposition, sandbank formation and changes in flow capacity. Bedload sampling techniques have limitations related to spatial and temporal resolution. These constraints are more relevant in rivers with dunes and high sediment transport. This paper presents a comparison betwe...

The presence of large amounts of aquatic macrophytes in reservoirs can trigger several impacts on the local ecosystem and conventional methodologies used for their monitoring only returns information from the present moment. With that in mind, this study aimed to map spatio-temporal variation of macrophyte cover using Landsat 5, 7 and 8 images betw...

Em termos de regulamentação de qualidade da água, apesar de haver diferenciação entre reservatórios e corpos hídricos fluviais, os primeiros recebem uma classificação única para toda sua extensão, mesmo podendo apresentar características distintas tanto temporal como espacialmente. Este trabalho buscou avaliar a necessidade e indicar uma estratégia...

An application of a large-scale PIV technique on a scaled hydraulic model of a hydroelectric powerplant was performed. A detailed study regarding the relationship between the tracer size (paper confetti) and the spatial resolution settings of the statistical correlation program was carried out. The validated parameters and operational procedures we...

Chlorophyll-a (chla) is an important parameter to assess water quality in lakes and reservoirs, since it is a proxy for phytoplankton biomass and primary production. The increasing availability of data with high spatial and temporal resolution allows assessing short-term dynamics and small-scale variations of chla within larger water bodies. In fre...

Bubble-mediated transport is the predominant pathway of methane emissions from inland waters, which are a globally significant sources of the potent greenhouse gas to the atmosphere. High uncertainties exist in emission estimates due to high spatial and temporal variability. Acoustic methods have been applied for the spatial mapping of ebullition r...

Numerical models are an important tool for simulating temperature, hydrodynamics, and water quality in lakes and reservoirs. Existing models differ in dimensionality by considering spatial variations of simulated parameters (e.g., flow velocity and water temperature) in one (1D), two (2D) or three (3D) spatial dimensions. The different approaches a...

Gelatinous animals have been historically viewed as trophic dead-ends. However, there are increasing data showing these organisms being consumed by diverse predators and demonstrate they play an important role in ecosystem functioning. Here we document the Ocypode quadrata (Fabricius, 1787) scavenging on stranded Physalia physalis (Linnaeus, 1758)...

This study presents some applications of Dyenamic, an automatic dye tracing software which has is designed to analyze gravity currents from laboratory experiments and numerical models. Dyenamic tracks flow features of dye-coloured experimental setups. Through video observations obtained with standard cameras (e.g. professional cameras or cell phone...

A Mecânica dos Fluidos refere-se ao estudo sistemático e unificado da transferência de quantidade de movimento, energia e matéria de fluidos (i.e. líquidos e gases) e de substâncias dissolvidas. O objetivo principal desta obra é destacar demandas específicas de conceitos da Mecânica dos Fluidos para o setor de Engenharia e de Ciências Ambientais, f...

Water reservoirs have the function to control the temporal variability of the water availability, thus bringing greater security over these resources. The water quality of these systems must be adequate for their multiple uses, and one of the main tools to understand it, is mathematical modelling. Given the importance of the water quality, the goal...

Numerical models are an important tool for simulating temperature, hydrodynamics and water quality in lakes and reservoirs. Existing models differ in dimensionality by considering spatial variations of simulated parameters (e.g., flow velocity and water temperature) in one (1D), two (2D) or three (3D) spatial dimensions. The different approaches ar...

With the aim to improve current knowledge on physical processes in tropical and subtropical reservoirs, we explored the dynamics of prevailing hydrodynamic processes in a small-to medium-sized reservoir based on 1-year continuous measurements of temperature, flow velocity, and turbulence. The mixing regime of the reservoir is characterized as warm...

Generally, fluvial systems are used for different objectives including energy production, water supply, recreation, and navigation. Thus, many impacts must be considered with their use. An understanding of sediment dynamics in fluvial systems is often of value for a variety of objectives, given that erosion and depositional processes can change the...

Siltation has significant economic and social impacts as it directly reduces the useable amount of water in reservoirs. Giving a solution to the issue of sedimentation is a complicated task and maybe one of the most important engineering and environmental challenges of the 21 st century. The deposited volume and the distribution pattern of the sedi...

This research aims to improve data post-processing from an acoustic Doppler current profiler (ADCP) to obtain additional depth information with a high-quality bathymetric result. To validate the depth, dataset in a control area was used a scaled rod, the RTK (Real-Time Kinematic) positioning technique, and a single beam echo sounder (SBES). The dev...

Hydrodynamic modelling is an important tool for several studies, such as flood forecasting and analysis of energy and mass transport. In rivers, the most common calibration parameter is the roughness coefficient, that accounts for the friction term. However, while uncertainties are associated to this parameter definition, it is often defined as con...

An internal wave is a propagating disturbance within a stable density-stratified fluid. The internal seiche amplitude is often estimated through theories that describe the amplitude growth based on the Bulk Richardson number (Ri). However, most theoretical formulations neglect secondary effects that may influence the evolution of internal seiches....

Interwave Analyzer is an open source software that provides detailed characterization of the dynamics of internal waves in lakes and reservoirs. It is based on well-established theories and empirical knowledge on internal waves and lake mixing and facilitates a general physical classification of lakes and reservoirs. As input data, the program requ...

In this paper we synthesize the special sessions of the XXIII Brazilian Water Resources Symposium 2019 in order to understand the major advances and challenges in the water sciences in Brazil. We analyzed more than 250 papers and presentations of 16 special sessions covering topics of Climate Variability and Change, Disasters, Modeling, Large Scale...

Observations have shown that gravity currents, a horizontal buoyancy driven flow generated by density differences commonly observed in lakes and reservoirs, may be an important agent of sediment resuspension, playing an important role for water quality of these ecosystems. We ran laboratory experiments in a rectangular tank to characterize the sedi...

As desalination develops, the impacts of brine ocean disposal rise increasing concerns. Here we present a screening of the hurdles to brine disposal through pressurized submerged outfalls in the broader Mediterranean region. Using first-tier dilution models, we analyze how different environmental quality standards reflect in terms of initial outfal...

While we increasingly turn to desalination as a secure water supply, it is still perceived as an expensive and environmentally damaging solution, affordable only for affluent societies. In this contribution, we recast desalination from one of a last resort to a far-reaching, climate change mitigating, water security solution. First, we argue that t...

In recent decades, several lake models of varying complexity have been developed and incorporated into numerical weather prediction systems and climate models. To foster enhanced forecasting ability and verification, improvement of these lake models remains essential. This especially applies to the limited simulation capabilities of biogeochemical...

O reservatório Passaúna localizado na região metropolitana de Curitiba abastece cerca de 650.000 pessoas. Com o intuito de avaliar a taxa de sedimentação e os nutrientes do sedimento, pela importância do reservatório para esta região, foram utilizadas cinco armadilhas de sedimento ao longo do reservatório. Foram instaladas duas armadilhas na superf...

Para o estudo proposto, utilizou-se a técnica de velocimetria por processamento de imagens de partícula para grandes escalas (LS-PIV) aplicada às obras hidráulicas do modelo reduzido da Usina Hidrelétrica de Sinop. Foram ajustados parâmetros e procedimentos operacionais para a caracterização do escoamento na área de aproximação do vertedouro. Como...

The dynamic/online coupling of the Distributed Entrainment Sink Approach with the model CORMIX for the near field and Delft3D-FLOW for the far field of outfall discharges is analysed in terms of hydrodynamic results. Six test cases have been performed, considering a straight channel with a steady state flow with a submerged positively buoyant disch...

Environmental monitoring is an important issue to guarantee continuous preservation of the natural resources. Lakes and reservoirs are closed water bodies that often have an inherent dynamic, in which modify spatially and temporally many environmental parameters. One of the most important parameters to evaluate the water quality is the turbidity, w...

Gravity currents are a common phenomenon that occurs in ocean, lakes, and atmosphere. Many studies have explored the propagation of gravity currents in ideal situations, thus avoiding the comparison between the well-known theory and specific situations, such as when the gravity current flows in a roughness bottom or in a stratified ambient. This pa...

Greenhouse gas fluxes from the sediment to the atmosphere are a common byproduct of the anthropogenic disruption of rivers by damming. Recent studies have reported that reservoir surfaces contribute to around 1.5% of the global anthropogenic GHG emissions in a CO2-equivalent base and over a 100-year time span. However, quantifying the influence of...

The aim of the present research is to assess the ejection effect in a low-head hydropower plant with lateral conduits. The study includes six geometrical variants, under submerged downstream condition using 1:70 scale model tests. The model test results are compared to theoretical equations from the scientific literature, and new equations are prop...

One and three-dimensional heat transport models are compared in a dendritic reservoir in Brazil. We estimate the periods of temperature stratification for both models using physical indices and temperature gradients. The three-dimensional model reproduces more accurately the water column temperature profiles, however with focus on the physical indi...

The original version of this article unfortunately did not contain all information in Figure 3.

Water bodies, either natural or constructed im-poundments, are sources of methane to the atmosphere, in which ebullition is frequently mentioned to be the dominant pathway. Ebullition is a complex process that is spatially dependent on factors acting over large distances (atmospheric pressure changes, wind) and factors acting locally (sediment char...

In recent decades, several lake models of varying complexity have been developed and incorporated in numerical weather prediction systems and climate models. To foster enhanced forecasting ability and verification, improvement of these lake models remains essential. This especially applies to the limited simulation capabilities of biogeochemical pr...

Excess sediment is one of the main agents of water pollution, affects the aquatic ecosystem and causes siltation problems in reservoirs and rivers. Bottom sediments are coarse and easily deposited, being the major responsible for morphological alterations in rivers. Therefore, is important to estimate the amount of sediment transported in other to...

This study presents a computational tool for the analysis of commercial navigation capacity of rivers by a fast-time two- dimensional vessel–current interaction model. Different scenarios of rivers and vessels can be simulated, and the model can be used during early-stage design and overall management of inland fairways. The mathematical descriptio...

Thermal stratification in lakes, hydropower or drinking water reservoirs occurs mainly by the effect of temperature on water density. One-dimensional heat transport models are widely used to simulate vertical temperature profiles since vertical temperature gradients are dominant in reservoirs. Many applications have been made using one-dimensional...

The vertical movements caused by internal waves in lakes and reservoirs have chemical and biological consequences for these ecosystems. The vast majority of studies that investigate internal waves are conducted on large lakes. There are just few researches that investigate this phenomenon on dendritic reservoirs. The purpose of this research was to...

Validation and scaling of sophisticated physical and numerical fluvial hydraulic models to real field conditions are limited by temporal and spatial constraints of field measurement technologies. These limitations increase when analyzing hydraulic properties of complex river forms such as submerged bedrock canyons. The analysis of flow under these...

Resumo: Correntes de gravidade e de intrusão ocorrem quando há variações na massa específica em um fluido sob a ação de um campo gravitacional. Para o caso de correntes de gravidade em um experimento lock-eschange, as diferenças na pressão hidrostática fazem com que o fluido mais denso flua numa direção ao longo do fundo, enquanto o fluido mais lev...

Resumo: O transporte vertical de nutrientes, compostos químicos e microrganismos causado pela presença de ondas internas causam um grande efeito no estado trófico de reservatórios e, consequentemente, afetam de forma significativa a qualidade da água destes ecossistemas. Poucas pesquisas no cenário nacional e internacional buscam verificar a ocorrê...