The use of echo-levels from Acoustic Doppler Current Profiler (ADCP) recordings has become more and common for estimating suspended bed-material wash loads in rivers over the last decade. Empirical, semi-empirical physical-based acoustic methods have been applied different case studies, which provided relationships between scattering particles features derived samples (i.e., concentration grain size) corresponding backscattering strength sound attenuation. These entail assumptions regarding...

Abstract Since the ingestion of both natural and anthropogenic microfibers produces a deleterious effect on aquatic organisms, it is crucial to explore emission these pollutants by WWTPs into receiving water bodies, such as rivers. Cellulose- petroleum-based microfibers, well microplastic particles, were collected from effluent municipal WWTP operating with activated sludge technology in Budapest, Hungary. During two sampling campaigns organized February April 2023 different working days at...

A comprehensive flow analysis for a confluence of two medium-sized (Qmean ≈ 30–50 m3/s) Hungarian rivers was carried out by means three-dimensional Reynolds-averaged Navier–Stokes modelling. The model validated against detailed fixed and moving Acoustic Doppler Current Profiler velocity profiling. Unsteady simulations with steady-state boundary conditions were performed on structured grid in order to reveal the characteristic large-scale spatial behaviour flow, such as strong secondary...

Abstract Knowledge of sediment dynamics in rivers is great importance for various practical purposes. Despite its high relevance riverine environment processes, the monitoring rates remains a major and challenging task both suspended bed load estimation. While measurement currently an active area testing with nonintrusive technologies (optical acoustic), does not mark similar progress. This paper describes innovative combination techniques analysis protocols that establishes proof‐of‐concept...

Zusammenfassung Buhnen werden im Wasserbau vielfach angewendet und sind aufgrund der komplexen Strömungsverhältnisse in Abhängigkeit von Wasserstand Buhnengeometrie herausfordernd bezüglich Wirksamkeit Eignung als flussbauliche Maßnahme. Physikalische Modellierungen seit etwa 130 Jahren angewendet, bei Bedarf mit Feldmessungen mittlerweile auch numerischen Modellen kombiniert, wodurch unter anderem die Bewertung profitiert. Aufgrund Skalierung physikalischen kann es jedoch zu...

3D numerical models are increasingly used to simulate flow, sediment transport and morphological changes of rivers. For the simulation bedload transport, flow model is generally coupled with an empirical model. The application range most widely is, however, often limited in terms hydraulic sedimentological features therefore can hardly be applied complex situations where different kinds processes take place at same time, such as local scouring, bed armoring aggradation finer particles. As a...

The paper introduces a three-dimensional numerical model that solves the Reynolds Averaged Navier-Stokes (RANS) equations on curvilinear grid system using novel nested approach. main benefit of is possibility to locally complex hydraulic features in large rivers like flow field at structures. entire study domain such case can be discretized with coarser resolution, whereas much finer resolution applied defined zone obstructions, where detailed description needed. tested laboratory experiment...

Abstract An estimation procedure for suspended sediment concentrations based on the intensity of backscattered sound acoustic Doppler current profilers (ADCP) is introduced in this paper. Based detailed moving and fixed boat ADCP measurements with concurrent sampling, we have successfully calibrated method a reach River Danube Hungary, characterized by significant transport. The effect measurement uncertainty various data filtering load determination also analyzed quantified. Some physical...

Waves induced by ship movement might be harmful for the habitat in littoral zone of rivers due to temporally increasing bed shear stress, high-energy breaking waves and consequently related detachment benthic animals. In order understand complex hydrodynamic phenomena resulting from waves, we present testing a novel methodology that incorporates field observations numerical tools. The study is performed at section Danube River Hungary analyzes influence different types. methods consist...

The monitoring of fluvial suspended sediment transport plays an important role in the assessment morphological processes, river habitats, or many social activities associated with management. However, establishing and operating a well-functioning system requires involvement advanced indirect methods. This study investigates advantages limitations optical acoustic devices, to quantify uncertainties provide comprehensive comparative investigated novelty this study, compared previous ones, is...

Abstract Many pharmaceuticals inevitably end up in surface waters, exerting unwanted biological activity nontarget organisms. This effect is confined by the compound's environmental persistence. Regulatory laboratory simulation tests are used persistence assessment and exposure modeling. While doubt has been expressed about usefulness of laboratory‐derived indicators under field conditions, these remain only inputs for chemical fate models due to difficulties measuring situ, especially at...

Abstract The temporal alteration of the hydrodynamic regime in rivers due to navigation has significant effects on riverine ecosystems. Most key mechanisms and interactions between ecological variables have already been revealed; however, quantitative evaluation biotic abiotic still stands a challenge. This paper aims present thorough, spatiotemporal framework, involving field computational tools, for assessment wave hydrodynamics littoral zone rivers, where its relevance is most...

This paper describes the in-situ implementation of a recently developed bedload transport estimation method, called Acoustic Mapping Velocimetry (AMV). The method combines components and processing protocols from acoustic image-based methods to provide velocity maps bedforms migrating in riverbed. AMV is illustrated with repeated Multibeam Echo Sounder (MBES) mappings that are acquired along longitudinal swaths over entire transect study river sections. exemplifies case studies leading rates...

A three-dimensional numerical model that computes hydrodynamics and morphodynamics is applied to the problem of calculating local scour around cylinders. nested grid approach implemented in scheme order decrease overall computational demand but at same time allow for high spatial resolution cylinder increase accuracy there. The consists two structured blocks – a coarse block discretises entire domain fine only area novel interpolation technique accomplishes communication between blocks....

Abstract Hydromorphological features of rivers, such as flow depth, velocity, and the composition bed material play a crucial role in habitat selection fish. Although these basic hydromorphological parameters can be determined with high spatial temporal resolution using state‐of‐the‐art investigation methods, only few studies deal connection abundance fishes (i.e., modelling) large rivers. The aim this study is to fill gap by introducing so‐called maps connecting results 3D hydrodynamic...

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 material. When dealing large complex hydrodynamics and morphodynamics, the modes indicate strong variation even locally, requires suitable approach estimate locally unique behavior sediment transport. However, literature offers only few studies regarding issue, they are concerned uniform load. In order partly fill gap, we suggest here decision...

Abstract Bedload transport is an important factor to describe the hydromorphological processes of fluvial systems. However, conventional bedload sampling methods have large uncertainty, making it harder understand this notoriously complex phenomenon. In study, a novel, image-based approach, Video-based Tracker (VBT), implemented quantify gravel by combining two different techniques: Statistical Background Model and Large-Scale Particle Image Velocimetry. For testing purposes, we use...

The composition or bed material plays a crucial role in the physical hydromorphological processes of fluvial systems. However, conventional sampling methods provide only pointwise information, which can be inadequate when investigating large rivers inhomogeneous characteristics. In this study, novel, image-based approaches are implemented to gain areal information surface using two different techniques: monocular and stereo computer vision. Using underwater videos, captured shorter reaches...

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 large river. Through case study Hungarian section Danube River, combined application an Doppler velocimeter (ADV) formerly calibrated sensor (ABS) is introduced for parallel 3D flow velocities suspended concentration (SSC) characteristic point near-bank zone. SSC times series detected by...

The aim of this study is to analyze the current morphological changes and predict potential future trends a critical reach upper Hungarian Danube River. In section river features have undergone significant changes, mainly due human impacts, such as construction Gabcikovo hydropower plant close Slovakian border, or regulation measures with groin fields along reach. inherently led management issues, e.g. developed gravel bars caused problems for inland navigation. order reveal understand...

Abstract Establishing and operating a harmonized sediment monitoring system along large rivers such as the Danube River is challenging international task. As an element of system, new site with state-of-the-art instrumentation currently under development in Upper-Hungarian section River. The station will consist near-bank optical backscatter sensor horizontal acoustic Doppler current profiler (H-ADCP). previous studies showed, suspended concentration (SSC) that continuously measured sensors...