Sándor Baranya

Sándor Baranya
Budapest University of Technology and Economics · Hydraulic and Water Resources Engineering

PhD

About

63
Publications
17,770
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441
Citations
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August 2009 - present
Budapest University of Technology and Economics
Position
  • Professor (Assistant)

Publications

Publications (63)
Article
A three-dimensional numerical model that computes hydrodynamics and morphodynamics is applied to the problem of calculating local scour around cylinders. A nested grid approach is implemented in the numerical scheme in order to decrease the overall computational demand but at the same time allow for high spatial resolution around the cylinder to in...
Article
Full-text available
An estimation procedure for suspended sediment concentrations based on the intensity of backscattered sound of acoustic Doppler current profilers (ADCP) is introduced in this paper. Based on detailed moving and fixed boat ADCP measurements with concurrent sediment sampling, we have successfully calibrated the estimation method for a reach of River...
Article
Full-text available
The paper introduces a three-dimensional numerical model that solves the Reynolds Averaged Navier-Stokes (RANS) equations on a curvilinear grid system using a novel nested grid approach. The main benefit of the model is the possibility to model locally complex hydraulic features in large rivers like the flow field at hydraulic structures. The entir...
Article
A comprehensive flow analysis for a confluence of two medium-sized (Qmean ≈ 30–50 m3/s) Hungarian rivers was carried out by means of a three-dimensional Reynolds-averaged Navier–Stokes modelling. The model was validated against detailed fixed and moving Acoustic Doppler Current Profiler velocity profiling. Unsteady simulations with steady-state bou...
Article
Full-text available
Spatial complexity of turbulent flow conditions has been investigated by means of ADCP measure-ments and CFD modelling in river Danube. The study area was a meandering river reach, characterized by shallows and strongly influenced by various river training works. High resolution bed survey and freezing plate sampling provided input river bed data f...
Article
Establishing and operating a harmonized sediment monitoring system along large rivers such as the Danube River is a challenging international task. As an element of such a system, a new monitoring site with state-of-the-art instrumentation is currently under development in the Upper-Hungarian section of the Danube River. The monitoring station will...
Article
Full-text available
Bedload transport is an important factor to describe the hydromorphological processes of fluvial systems. However, conven- tional bedload sampling methods have large uncertainty, making it harder to understand this notoriously complex phenom- enon. In this study, a novel, image-based approach, the Video-based Bedload Tracker (VBT), is implemented t...
Article
Full-text available
Non-intrusive technologies for the in-situ measurement of river morphological features are increasingly popular in the scientific and practice communities due to their efficient and productive data acquisition. While the measurement of suspended load with optical and acoustic technologies is currently an active area of research, the measurement of...
Article
This paper presents a proof of concept that acoustic velocity and backscatter intensity measurements can provide essential information on ship wave-induced sediment transport processes in the littoral zone of a large river. Through a case study in the Hungarian section of Danube River, a combined application of an acoustic Doppler velocimeter (ADV)...
Article
The effects of inland navigation on the aquatic ecosystem are numerous. One of the most relevant impacts from the ecohydraulic point of view is ship-induced waves, resulting in the local and temporary alteration of the hydrodynamic regime, especially in shallow water areas. In this paper, a novel hydrodynamic modeling-based evaluation framework is...
Conference Paper
Full-text available
SAŽETAK Ušće rijeke Drave u Dunav karakteriziraju specifični morfodinamički procesi znatne sedimentacije nanosa i posljedično problema vezanih uz osiguravanje gabarita plovnog puta. Analiza morfodinamičkih promjena zahtijeva dugoročno praćenje režima voda i nanosa kako bi se odredilo ravnotežno stanje u odnosu na referentne uvjete (nulto stanje utv...
Article
Full-text available
Computational Fluid Dynamics (CFD) modeling has become a widely used research tool in the hydraulic engineering community, however, for many problems the numerical model setup and even the selection of the suitable hydrodynamic solver is still a challenging task. This is the case for fine scale analysis of flow features around hydraulic structures...
Conference Paper
Full-text available
Drava River confluence is characterized by specific morphodynamic processes under which significant sediment deposition is occurring at the Drava River mouth, impeding fairway conditions. Morphodynamic analysis requires long-term hydraulic and sediment transport regime data as input for estimation of equilibrium conditions, taking into account base...
Article
Full-text available
The composition or bed material plays a crucial role in the physical hydromorphological processes of fluvial systems. However, conventional bed material sampling methods provide only pointwise information, which can be inadequate when investigating large rivers of inhomogeneous bed material characteristics. In this study, novel, image-based approac...
Article
Full-text available
The monitoring of fluvial suspended sediment transport plays an important role in the assessment of morphological processes, river habitats, or many social activities associated with river management. However, establishing and operating a well-functioning sediment monitoring system requires the involvement of advanced indirect methods. This study i...
Article
Full-text available
In this study, the field measurement-based validation of a novel sediment transport calculation method is presented. River sections with complex bed topography and inhomogeneous bed material composition highlight the need for an improved sediment transport calculation method. The complexity of the morphodynamic features (spatially and temporally va...
Article
Full-text available
The temporal alteration of the hydrodynamic regime in rivers due to navigation has significant effects on riverine ecosystems. Most of the key mechanisms and interactions between hydrodynamic and ecological variables have already been revealed; however, the quantitative evaluation of biotic and abiotic variables still stands a challenge. This paper...
Article
This study proposes a spatiotemporally Adaptive Search Area (SA) size selecting algorithm for Particle image velocimetry (PIV), ASAPiv. The presented method releases the constraint of conventionally used static SAs, offering a significant computational performance increase through optimizing the dimensions of the SA according to the local flow cond...
Poster
Full-text available
Theanalysisofbed-loadmovementisessentialtounderstandmorphologicalprocessesinalluvialrivers.Betterunderstanding of these mechanisms may help predict changes occurring in the riverbed during flood events, estimate the effect of these events on riverbank ecosystems, and forecast the amount of sediment deposited in reservoirs. Mostly physical based samp...
Conference Paper
The physical interaction of aquatic vegetation with flow and sediment has long been investigated as it affects ecological conditions around submerged macrophytes, determines the effectiveness of shore protection by vegetation, and governs the natural evolution of vegetation patches through enhanced sedimentation. Tower-based imaging techniques such...
Article
Full-text available
The aim of this study is to introduce a novel method which can separate sand- or gravel-dominated bed load transport in rivers with mixed-size bed material. When dealing with large rivers with complex hydrodynamics and morphodynamics, the bed load transport modes can indicate strong variation even locally, which requires a suitable approach to esti...
Article
Many pharmaceuticals inevitably end up in surface waters, exerting unwanted biological activity in nontarget organisms. This effect is confined by the compound's environmental persistence. Regulatory laboratory simulation tests are used in persistence assessment and exposure modeling. While doubt has been expressed about the usefulness of laborator...
Conference Paper
Full-text available
Three-dimensional numerical modelling with nested grid approach is tested in this paper to simulate hy-drodynamics and sediment transport in a large sand bed river with large bedforms.
Conference Paper
Full-text available
This paper introduces a methodology to prepare digital maps of bed material composition in rivers with inhomogeneous bed material, which can be used in riverine habitat assessment studies. The method combines information from physical bed material samplings and results from three-dimensional computational flow modeling. The main idea is to set up a...
Preprint
The aim of this study is to introduce a novel method which can separate sand or gravel dominated bed load transport in rivers with mixed-size bed material. In engineering practice, the Shields-Parker diagram could be used for such purposes, however, the method has certain applicability limits, due to the fact that it is based on uniform bed materia...
Conference Paper
Full-text available
Riverine ship traffic results in the temporal alteration of the flow regime in the close proximity of the vessels, but waves propagating in the direction of banks may also have significant hydrodynamic effects. Ecohydraulic problems related to vessel induced wave wash (e.g. bank erosion; drift of larval fish or macroinvertebrates) are getting incre...
Article
Hydromorphological features of rivers, such as flow depth, flow velocity, and the composition of bed material play a crucial role in the habitat selection of fish. Although these basic hydromorphological parameters can be determined with high spatial and temporal resolution using state‐of‐the‐art investigation methods, only few studies deal with th...
Conference Paper
Full-text available
Vessel generated waves are investigated with video based methods in the littoral zone of a river. LSPIV is used for the assessment of wave runup dynamics, while basic photogrammetric methods are used for the temporal analysis of small frequency waves.
Article
Full-text available
An experimental study was conducted to explore sediment particle motion in an open channel and its relationship to bedform characteristics. High-definition submersed video cameras were utilized to record images of particle motion over a dune’s length scale. Image processing was conducted to account for illumination heterogeneity due to bedform geom...
Article
An experimental study was conducted to clarify sediment particle motion and its relation to the dune migration. High-definition action video cameras were utilized to record the images of particle motion in a domain covering dune scale. Image processing was conducted to homogenize the illumination heterogeneity due to bed form and light reflection a...
Article
Full-text available
Accurate estimation of discharge capacity and local hydrodynamics are essential when designing hydraulic structures. Instead of the application of conventionally used empirical relationships, this study introduces a 3D numerical modeling technique which is capable to adequately predict both the discharge-upstream water level relationship and the fl...
Conference Paper
Full-text available
The metadata of the Norwegian historical topographic maps are given, in order to make its georeference possible, using just their corners points as control points. The earliest systematic topographic map product is the square mile-maps (kvadratmil kart). They cover the southern leg of the Swedish border region of Norway as it was in the end of 18 t...
Conference Paper
Full-text available
The 1:50,000 and 1:100,000 scale historical sheets of the Norwegian topographic 'Rektangelkart' map series were georeferenced, in order to obtain the original hydrography of the Gaula River, at a ca 50 kilometer long section between Støren and the estuary to the Gulosen Bay. The 1:50,000 scale sheets are the earliest systematic topographic works of...
Poster
Full-text available
The poster presents the numerical modelling of the hydromorphological evolution of a 10-km reach of the Po River close to Ostiglia in Italy, affected by the presence of two bridges.
Conference Paper
Full-text available
The paper presents the numerical modelling of the hydromorphological evolution of a 10-km reach of the Po River close to Ostiglia in Italy, affected by the presence of a railway bridge. The 3D simulation is performed using the freely available code SSIIM, developed at the University of Science and Technology in Trondheim in Norway. The domain consi...
Poster
Full-text available
The reliable prediction of morphological changes of rivers is of major need in the field of river engineering. Besides the conventionally used empirical procedures or hydraulic scale models, the numerical modeling is a progressively developing, but still not a widespreadly used tool. Moreover, the sediment transport modeling at non-uniform river be...
Article
Full-text available
The aim of this study is to analyze the current morphological changes and to predict the potential future trends of a critical reach of the upper Hungarian Danube River. In this section of the river the morphological features have undergone significant changes, mainly due to human impacts, such as the construction of the Gabcikovo hydropower plant...
Article
The use of acoustic and optic devices has become more and more common for estimating suspended sediment loads in rivers. The echo intensity levels (EIL) recorded by means of an Acoustic Doppler Current Profiler (ADCP) have been applied in different methods, which provided relationships between scattering particles features derived from samples (i.e...
Article
Full-text available
3D numerical models are increasingly used to simulate flow, sediment transport and morphological changes of rivers. For the simulation of bedload transport, the numerical flow model is generally coupled with an empirical sediment transport model. The application range of the most widely used empirical models is, however, often limited in terms of h...
Article
Full-text available
Waves induced by ship movement might be harmful for the habitat in the littoral zone of rivers due to the temporally increasing bed shear stress, the high-energy breaking waves and the consequently related detachment of benthic animals. In order to understand the complex hydrodynamic phenomena resulting from littoral waves, we present the testing o...
Conference Paper
Despite the importance of sediment transport processes in large rivers, the measurement of sed-iment transport rate in the in-situ, especially bedload, is difficult, costly and time consuming using conven-tional methods. In this paper, a novel indirect bedload estimation methodology is presented that is based on the Acoustic Mapping Velocimetry (AM...
Article
The qualitative and quantitative assessment of bedform dynamics has been a continuous challenge for conventional river monitoring methods due to the vexing problems associated with the limited capabilities to observe the bedforms in-situ and the intrusive nature of the instruments used for quantification of their movement. The advent of the new gen...
Conference Paper
Full-text available
The complexity of fluvial hydromorphological monitoring and the man ever-increasing data needs make an essential point of involving faster and modern measurement techniques as a common practice among engineers. In particular, suspended sediment real-time measurement remains challenging and prone to physical sampling difficulties encountered in the...
Article
Knowledge of sediment dynamics in rivers is of great importance for various practical purposes. Despite its high relevance in riverine environment processes, the monitoring of sediment rates remains a major and challenging task for both suspended and bed load estimation. While the measurement of suspended load is currently an active area of testing...
Poster
Full-text available
The spatial and temporal variability of the flow field, the sediment transport and the morphology of rivers directly influence navigation, habitat and flood risk. Therefore, the prediction of bed geometry changes is essential for rivers that are exposed to multiple use, such as the Danube River. Nowadays, the computational models are increasingly u...
Article
Full-text available
The use of echo-levels from Acoustic Doppler Current Profiler (ADCP) recordings has become more and more common for estimating suspended bed-material and wash loads in rivers over the last decade. Empirical, semi-empirical and physical-based acoustic methods have been applied in different case studies, which provided relationships between scatterin...
Article
Suspended sediment and particle size measurements were in this study performed with two instruments based on laser diffraction. The measurements were conducted in the river Danube during a 1-year flood, which enabled measurements in a large scale and under conditions with high sediment load. The aim of this study was to compare LISST-SL stationary...
Article
Full-text available
A Duna hidromorfológiai állapotát nagymértékben befolyásolják a hajózási, energiatermelési, vízhasználati és egyéb célú emberi beavatkozások. A szabályozások okozta mederszűkítések, valamint a hordalékháztartás módosításai, mint pl. a vízgyűjtő területen való hordalék visszatartás és a hordaléktranszport folytonosságának megszakítása, a természetes...
Article
Die unterschiedlichen Nutzungen der Donau für die Schifffahrt, zur Energiegewinnung und zur Trinkwasserversorgung beeinflussen die ökologische Qualität des Flusses. Einengung durch Regulierungen sowie Modifikationen des Sedimenthaushaltes wie Rückhalt im Einzugsgebiet und Unterbrechung des Sedimentkontinuums ergeben Veränderungen der flussmorpholog...
Conference Paper
Full-text available
In this study the local scour development around a single groin was investigated in the laboratory flume of the Norwegian University of Science and Technology (NTNU). The main goal of the experiments was to carry out a comprehensive data analysis on bed morphology, sediment transport, bed composition as well as hydrodynamics at conditions where bed...
Article
Full-text available
A three-dimensional numerical model is introduced which is capable of reproducing the bed armoring process in rivers resulted by nonuniform bed material. The numerical flow model solves the 3D Reynolds Averaged Navier-Stokes equations with a k-ɛ turbulence model. The bed shear stress field is calculated over the study domain which serves as input d...
Article
The main goal of this paper is to introduce a suitable procedure for the assessment of reach-scale hydro-morphological conditions of rivers. For this purpose a 4 km long reach of River Tisza in Hungary was chosen and investigated by means of comprehensive field measurements and three-dimensional numerical modelling. The river can be characterized w...
Article
Full-text available
A confluence zone of two rivers of different sizes was chosen to study the complex flow and morphological features with up-to-date measurement techniques. The main stream is River Danube with a mean flow of 2000m 3/s, an average depth of 6m and an average width of 500 m, which approaches the junction zone in a sharp bend. The second river is a trib...
Article
Full-text available
Detailed hydrodynamic survey of two critical river reaches has been performed from hydro- and sediment dynamics points of view, in order to explore the main features, moreover, provide calibration and verification data to related 3D flow and sediment transport modelling. Special attention has been paid to compare moving and fix boat measurement mod...
Article
Full-text available
The paper deals with the hydrodynamic investigation of the junction of two rivers in north-west Hungary in an urban area. The goal of the investigation was to study the flow conditions by means of a 3D k-" turbulence CFD model and hydraulic scale model. The project gave the opportunity to compare the outcome of the distorted scale model with the on...
Conference Paper
Turbulence features in an operating vertical slot fish pass were explored by means of analyzing 3D ADV data as well as 3D k-ε CFD modelling. Beside turbulent kinetic energy, the Eulerian integral time- and space-scale were quantified, which are expected to provide valuable information on the dominant eddy size in the flow thus contributing to the a...
Conference Paper
Turbulence features in a operating vertical slot fish pass were explored first by means of analyzing in situ ADV data. The mean velocity field, its vorticity and important turbulence parameters were quantified. The swirling character of the flow was made visible, and the vertical velocity component proved to play an important role at places. As to...

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Projects (3)
Project
Complex hydro-morphological processes, such as sediment erosion, transport, deposition, or fan development, affect open water environments, including rivers, estuaries as well as lakes and reservoirs. Consequently, many research tasks as well as practical applications rely on the correct prediction of these processes. During the last decades, numerical models have become a powerful tool in the research fields of hydraulic engineering and geosciences to simulate these hydro-morphological processes. With improved algorithms as well as an ever-growing computational power, it became feasible to simulate the interaction of water, sediments, and air with high resolution in space and time. In addition, with an increasing quantity and quality of validation data from laboratory experiments and field studies, numerical models are continuously enhanced so that many good examples of sediment transport modelling offer new insights in multiphase processes, e.g., dune development, river bed armouring or density-driven transport. Hence, new generations of numerical techniques open the possibility to explore numerous outstanding research questions related to hydro-morphologic processes. Artificial Intelligence procedures offer an additional alternative to hydro-morphological studies, e.g., determining particle size or floodplain vegetation cover. The main goal of this session is to bring together scientists and engineers, who develop, improve, and apply numerical models of multiphase flows for sediment transport in open water environments. We invite contributions that deal with numerical modelling from small-scale, such as bed structure development, to large-scale interactions, such as long-term development of hydro-morphological processes in rivers, lakes, reservoirs, and estuaries. Contributions may refer, but are not restricted, to: • Entrainment processes of sediments (from cohesive sediments to armoured river beds) • Bed load and suspended sediment transport processes (including flocculation processes) • Simulation of sediment management including planning, operation and maintenance of hydro power plants • Design and evaluation of restoration measures to revitalize rivers • Navigation issues, such as sediment replenishment, dredging and erosion induced by ship generated waves • Flood related issues of long term effects of morphological bed changes on flood security • Eco-hydraulics such as flow – sediment – vegetation interaction • Density driven transport https://meetingorganizer.copernicus.org/EGU22/session/43395 Convener: Gergely T. Török | Co-conveners: Bernhard Vowinckel, Katharina Baumgartner, Sándor Baranya, Gabriele Harb
Project
Setting up and calibrating a new sediment monitoring station in the Danube River. Thorough hydromorphological field measurements and 3D numerical modeling of hydordynamics and sediment transport.
Archived project
Elaboration of a tuition/technical program and base dataset for a complex fieldwork for students of hydro-engineering and geophysics, based on field measurements on test sites in Norway and Hungary. After the end of the project, the Hungarian training site would be the BME training center at Göd (Central Hungary)