Carlo Gualtieri

• Doctor of Engineering
• Professor at University of Naples Federico II

Confluences are key features in river networks and serve as critical nodes for ecological patterns, often exhibiting rich biodiversity. However, our current understanding of how hydrodynamics influences these patterns remains limited, as most previous studies have focused on ecological factors alone. This study applied a Particle Image Velocimetry...

Confluences are common components of all riverine systems and are characterized by converging streamlines and potential mixing of separate flows. The fluid dynamics of confluences is characterized by a highly complex structure with several common types of flow features observed. Many theoretical, field, laboratory and numerical studies tried to ide...

Fallen trees enter the adjacent stream and are carried away downstream by the current. As the stream joins another one, the complex hydrodynamics near their confluence make the movement of wood hard to predict. These woods may accumulate near the confluence resulting in backwater and subsequent potential flooding. A laboratory study was conducted t...

In this synthesis, we assess present research and anticipate future development needs in modeling water quality in watersheds. We first discuss areas of potential improvement in the representation of freshwater systems pertaining to water quality, including representation of environmental interfaces, in-stream water quality and process interactions...

In lakes, the vertical distribution of phytoplankton is strongly influenced by turbulence mixing in the near-surface layer, driven by atmospheric forces. In large channel-type reservoirs, it additionally influenced by inflows and reservoir regulation. However, the surface turbulent mixing and its impact on phytoplankton dynamics in these channel ty...

Study region: The middle and lower reaches of the Yangtze River basin, China. Study focus: The overlapping of main and tributary river flood processes often leads to multi-source flood coincidence events, which involve complex spatiotemporal relationships and coincidence risks between different flood processes. This study analyzed flood spatial-te...

This study reported and discussed turbulence characteristics, such as turbulence intensity, correlation time scales, and advective length scales. The characteristic airewater time scale, including the particle chord time and length and their probability density functions (PDFs), was investigated. The results demonstrated that turbulence intensity w...

The amount of sediment bed load being carried by rivers significantly impacts the inherent development of the riverine systems in terms of hydrodynamic and morphodynamic changes. In this direction, acoustic Doppler current profiler velocity literature data collected at the Óbidos station in the Amazon River were applied to investigate bed-load tran...

Fish migration patterns are driven by hydrodynamic factors, which are essential in aquatic ecology. This study investigated the hydrodynamic drivers of Gymnocypris przewalskii fish migration in two distinct river reaches—a straight reach (SR) and a confluence reach (CR)— in the area of Qinghai Lake, China, using a 3D numerical model, fish density f...

The characteristics of environmental vortices significantly influence the behavioral strategies of fish. This study investigated how wake vortices from obstacles affected propulsion and stability disturbances in fish behavior by numerically quantifying hydrodynamic effects related to different scales of semi-cylinders. The strong reverse flow in th...

Confluences between a pipeline and a channel are commonly found in urban drainage networks. The mechanisms of sediment transport and the coherent structure within the confluence zone remain ambiguous. The hydro-morpho-sedimentary processes at pipe and channel confluences, which are influenced by discharge ratios, are investigated using a laboratory...

Confluences are marked by converging streamlines, complex hydrodynamics features and mixing processes. Understanding such intricate flow patterns and their effects on the mixing at natural river junctions is difficult, particularly for large confluences with a compound channel tributary, due to the scarcity of field data. This research aims to asse...

Upon entering the environment, Microplastics (MPs) experience aging processes that modify their properties and integrity. Previous methods for predicting the incipient motion of MPs have been validated using pristine plastics, which do not account for the effects of aging. This can lead to uncertainties in both quantification and characterization....

River confluences with a compound‐channel tributary are common in large river networks, for example, the Yangtze River basin and the Amazon basin. They affect the confluence hydrodynamics, nutrient depletion and fish migration in the network, due to the seasonal exposure and submergence of the tributary floodplain. The corresponding influencing mec...

Natural channels often take the form of compound channels during flooding events. The unsteadiness of floods is crucial for flood management and river-floodplain ecosystems. However, the impact of unsteady flow on three-dimensional hydrodynamic processes within compound channels remains poorly understood. This study employed a validated two-dimensi...

Flooding propagation is a crucial aspect of hydrological monitoring and forecasting. Previous studies have focused on hysteresis in the rating curve, caused by energy loss during flood propagation. However, the impact of tributary inflow on hysteresis downstream remains unclear, leading to inconsistent field observations on whether it strengthens o...

The recent tragic events in Sikkim and other Himalayan regions highlight the urgent need for research on flash floods in steep channels. Catastrophic floods like those at Lhonak Lake in Sikkim, caused by heavy rainfall and a glacial lake burst, resulted in loss of life and extensive damage. Similar incidents in Solan and Shimla underscore the vulne...

River confluences contribute to the outflux of saturated dissolved gases in the water resulting from high dam discharges. This process is related to gas transfer across the water–air interface, which is primarily controlled by turbulent dissipation near the water surface. However, the near-surface turbulence dissipation is rarely reported in conflu...

Large-Eddy Simulations (LES) were used to investigate the hydrodynamics and mass transfer between the flow in the main channel and a vegetated lateral cavity. Fourteen vegetation densities (0 to 10.65 %) were tested, revealing two distinct hydrodynamic patterns. For cavities with low vegetation density (a < 3.99 %), one primary gyre in contact with...

There is an urgent need to predict the bed-load transport rate in vegetated river ecosystems to support restoration efforts. In response, we have developed a novel model for estimating the effective shear stress acting on the riverbed. This model is based on the energy equation and considers the intrinsic relationship between energy loss in the mea...

The entropy model has been successfully used to calculate the flow velocity profile of rivers according to the measured surface-flow velocity. However, it has limitations in the large river where the obvious secondary flow and flow dip (i.e., the location of maximum flow velocity moves down from the surface) occur. The confluence of rivers is usual...

The loss of fish swimming capacity induced by those energetic vortical structures is detrimental, and limited research on the mechanism of fish entrainment in the vortex has been reported. The present study investigated the entrainment of a fish in vortices generated in wake of a semi-cylinder. The swimming fish was modeled using an undulatory NACA...

As floodplains are inundated during floods in a compound channel, solutes in the surface water column reach the hyporheic zone and react with solutes upwelled from the groundwater. These biogeochemical reactive processes, such as aerobic respiration, nitrification, and denitrification, need more clarification. In this study, a 3D hydrodynamic model...

A survey on bubble clustering in air–water flow processes may provide significant insights into turbulent two-phase flow. These processes have been studied in plunging jets, dropshafts, and hydraulic jumps on a smooth bed. As a first attempt, this study examined the bubble clustering process in hydraulic jumps on a pebbled rough bed using experimenta...

This study reported and discussed turbulence characteristics, such as turbulence intensity, correlation time scales, and advective length scales. The characteristic air–water time scale, including the particle chord time and length and their probability density functions (PDFs), was investigated. The results demonstrated that turbulence intensity w...

River confluences are nodes where the unique hydrological processes of two rivers meet, resulting in complex flow structure and water quality mixing processes. Thus, greater food availability and habitat complexity can occur at a confluence, making it a hotspot for fish productivity and diversity. Nonetheless, studies that relate fish community tr...

The ecology of the aquatic environment in Poyang Lake, the largest fresh lake in China, is notably impacted by the backflow from the Yangtze River, which conveys a high flux of sediments. This study employs a widely recognized numerical model to replicate the backflow in 2007 (the strongest backflow after the operation initiation of the Three Gorge...

Natural or human-induced intra-annual variation of river discharge alters estuarine hydrological regimes and further affects habitat conditions for saltmarsh vegetation, particularly at the river mouth bar. In this study, numerical experiments were performed in Delft3D to simulate the evolution of a schematized river mouth bar under prototypical un...

Lateral cavities, in the context of rivers, are regions connected to the main channel by a single interface. The presence of vegetation in lateral cavities modifies the flow, mass and sediment transport. Similarly, the shape of the lateral cavity also impacts on these metrics. In this study, the impact of both shape and vegetation density on the hy...

In river engineering, lateral cavities are regions outside of the main flow connected by a single interface. Their occurrence in rivers influences the local biota due to the capture of sediments and, consequently, nutrients. The capture of the nutrients favors vegetation growth inside its volume, which alters the flow and function as habitat for th...

Natural rivers are often shaped as compound channels during flooding. Unsteady properties of floods are critical for flood management and river floodplain ecosystems. However, the effect of unsteady flow on the hydrodynamic processes in a compound channel remains poorly understood. In this study, an experimental study and a sequentially coupled 2D/...

The flow over a step in an open channel can create complex flow patterns and recirculation zones. In this study, the impact of a cylinder located downstream of a step in a three-dimensional channel was numerically investigated using computational fluid dynamics (CFD). Such a cylinder placed at different locations downstream of the step can signific...

Extreme earthquake disturbances to the vegetation of local and regional landscapes could swiftly impair the former hydrologic function, significantly increasing the challenge of predicting threshold behaviors of rainfall–runoff processes as well as the hydrologic system's complexity over time. It is still unclear how alternating catchment hydrologi...

Confluences are common components of river networks and are characterized by a highly complex flow structure. Two confluence geometries, without and with the floodplain in the tributary, were comparatively investigated to highlight the effects of floodplain on confluence hydrodynamics. The three-dimensional velocity field and the spatial distributi...

The Congo River is the second largest river in the world in terms of basin area and discharge. Several field studies were carried out from 2010 to 2019 under different flow conditions due to the cooperation among SCVNGIE, the ECHOBACO Project and HYBAM to characterize hydrodynamics and sediment transport in the reach close to the city of Brazzavill...

Data of paper "Large wood transport and accumulation near the separation zone of a confluence channel"

Local scour at a pile or pier in current or wave environments threats the safety of the upper structure all over the world. The application of a net-like matt as a scour protection cover at the pile or pier was proposed. The matt weakens and diffuses the flow in the local scour pit and thus reduces local scour while enhances sediment deposition. Nu...

In this study, divided into two parts, the effect on a two-dimensional backward-facing step flow (BFSF) of a cylinder placed downstream of the step was numerically investigated. While in Part 1, the numerical simulations carried out without the cylinder were validated using the available literature data, in Part 2 the effect of the cylinder was inv...

The backward-facing step flow (BFSF) is a classical problem in fluid mechanics, hydraulic engineering, and environmental hydraulics. The nature of this flow, consisting of separation and reattachment, makes it a problem worthy of investigation. In this study, divided into two parts, the effect of a cylinder placed downstream of the step on the 2D f...

Mixing processes downstream of river confluences impacts the ecology and the related environmental management of river networks. A clear understanding of such processes is challenging, especially for confluences having width-to-depth ratios larger than 100, due to the limited available field data. In this study, four field surveys based on hydro-ac...

The random walk path method (RWP) is a stochastic model that transforms the solution of the unsteady open channel flow equations into a probability problem. In this paper, this method is introduced to solve the discretized Saint-Venant equations, with probabilistic representation of the water levels at junctions. Different boundary conditions, whic...

During ‘Lake Flood’ scenarios (flood with high lake level) the water level was larger than that during ‘River Flood’ (flood with normal lake level), inundating a broader area, decreasing flow velocity, increasing residence time, and decreasing particle travel distance. Due to the increased discharge, the NWRPG will reduce the residence time and re...

With the rapid development of commercial aquaculture in recent decades, large numbers of submerged cages or pens are clustered in fish farms that are commonly located within inland lakes, reservoirs, and coastal embayments around the world. The submerged structures have significant influence on both the flow fields and mass transport processes in s...

The hyporheic zone is the volume within streambed where stream water and surface water mix. In a compound channel, as floodplains are submerged, solutes in the water column enter the hyporheic zone and react with the solutes upwelling from the groundwater. Those reactive processes, such as aerobic respiration, nitrification, and denitrification, st...

Extreme earthquake disturbances to local and regional landscape vegetation could rapidly impair original hydrologic functioning, significantly increasing the hydrologic nonstationarity and complexity in threshold behaviors of rainfall-runoff processes. It is unclear how alternating catchment behaviors under an ongoing large earthquake disruption ar...

Transverse hyporheic transport and biogeochemical reactions in a compound channel remain poorly understood. As floodplains are submerged, solutes in the surface water enter the hyporheic zone of the compound channel and react with the solutes upwelling below the floodplain. Aerobic respiration (AR) and denitrification (DN) processes in the hyporhei...

Aquaculture cages constructed from rigid material have become increasingly popular in recent years due in part to the continuous expansion of the aquaculture industry offshore, where cages need to withstand much harsher ocean conditions. Most previous studies of hydrodynamic interactions with aquaculture cages have explored the impacts of more trad...

A common phenomenon associated with alluvial rivers is their meander evolution, eventually forming cutoffs. Point bar deposits and ox-bow lakes are the products of lateral bend migration and meander cutoff. The present study focuses on identifying the meanders of River Manu and their cutoffs. Moreover, this study compares the temporal evolution and...

A common phenomenon associated with alluvial rivers is their meander evolution, eventually forming cutoffs. Point bar deposits and ox-bow lakes are the products of lateral bend migration and meander cutoff. The present study focuses on identifying the meanders of River Manu and their cutoffs. Moreover, this study compares the temporal evolution and...

A common phenomenon associated with alluvial rivers is their meander evolution, eventually forming cutoffs. Point bar deposits and ox-bow lakes are the products of lateral bend migration and meander cutoff. The present study focuses on identifying the meanders of River Manu and their cutoffs. Moreover, this study compares the temporal evolution and...

The hydrodynamic of a river confluence generates significant vertical, lateral, and stream-wise gradients in velocity, forming highly complex three-dimensional flow structure, including the development of large scale turbulence structures. The above features affect the ecologically important underlying hyporheic zone, where surface and subsurface w...

This study investigates the effect on the flow structure in a backward-facing step (BFSF) due to a cylinder placed downstream of the step. Numerical simulations were carried out using OpenFOAM with several turbulence models (standard k-ɛ, RNG k-ɛ, standard k-ω, and SST k-ω). The recirculating flow, the skin friction coefficient (Cf), and the pressu...

In rivers and canals, lateral cavities are regions of low velocities and recirculation, which have ecological importance, such as sediment retention. The presence of vegetation in cavities has the potential to modify the flow and alter the retention of sediments inside the cavity. In this study, the impact of vegetation on hydrodynamics and sedimen...

In the present study, laminar and turbulent flow over a backward-facing step (BFSF) where a cylinder was placed immediately downstream of the step was investigated through numerical simulation using OpenFOAM. In laminar flow mean errors between numerical and literature experimental data for velocity profiles and reattachment lengths were lower than...

In riverine systems, lateral cavities are semi-enclosed volumes adjacent to the main channel flowing through its only opened side. These volumes play an important role in the mass transport processes, due to their higher residence time. The shape of the lateral cavity seems to influence the flow structure, although its effect on sediment transport...

The Orinoco River has the third largest discharge in the world, with an annual mean flow of 37600 m 3 /s at the outlet to the Atlantic Ocean. Several field studies were carried out within the HYBAM Program to characterize hydrodynamics and sediment transport in the reach of the Orinoco River close to the city of Ciudad Bolivar (Venezuela). The stud...

A positive surge is associated with a sudden change in flow that increases the water depth and modifies flow structure in a channel. Positive surges are frequently observed in artificial channels, rivers, and estuaries. This paper presents the application of Kolmogorov complexity and its spectrum to the velocity data collected during the laboratory...

In open channel flows, a hydraulic jump is a rapid shift from a supercritical flow to a subcritical flow with a sharp rise in the elevation of the free surface, which is associated with strong energy dissipation, air entrainment, and spray. The present research aims to investigate the air–water flow properties in a hydraulic jump on rough pebbled b...

A field investigation was carried out in March 2019 at the large river confluence between the Yangtze River and the outflow channel with a large inner-side floodplain of Poyang Lake using acoustic Doppler current profiling (ADCP) and water quality sampling. The study was intended to complement previous field studies carried out under different flow...

The large confluence between the Yangtze River and the outflow channel of Poyang Lake is receiving attention due to its importance in flood control and ecological protection in the Yangtze River basin. There is a large floodplain along the outflow channel of Poyang Lake, which is submerged during high flow and dry during low flow. The effects of th...

River confluences are key nodes in fluvial systems. Past studies on large river confluences were focused on the Paranà, Amazon, and Yangtze rivers, while the Yarlung Zangbo River (YZR), the longest plateau river in China, has not been investigated yet. This paper investigates a large multi-channel confluence between the YZR and one of its major tri...

Hydrodynamic features of the confluence zone of large rivers are complicated because of their three-dimensional flow structure. The confluence between the Rio Negro and the Rio Solimões, characterised by black and white waters, respectively, ranks among the largest river junctions on Earth. An Entropy-based investigation was carried out to assess t...

Confluences act as critical nodes in a river system. They affect hydrodynamics, sediment transport, bed morphology, and eco-hydraulics of the river system. Convergence of streams produces the complex mechanism of flow momentum and mass mixing which may affect the aquatic environment locally and even lasting for a long distance downstream. The conf...

A comprehensive experimental study was conducted to evaluate the effects of soil properties and the rip-rap as well as cohesive and non-cohesive soil material and the riprap particle size on the breaching process and the failure mechanism of the levee. The results showed the crucial role of the riprap coverage and the soil properties in the breachi...

Understanding the meanings and identifying the controls for the stormflow generation with complex and nonlinear behaviors is essential for the development of threshold-based hydrological theory, as well as accurate assessment and prediction for flash flood risks. However, the study of catchment emergent patterns with three-linear threshold behavior...

Lateral cavities are a type of transient storage zones that occur in riverine systems. They play an important role in mass transport processes, especially due to a higher residence time. In this study, a numerical simulation of flow past a lateral cavity with vegetation was performed to assess the impact of the vegetation on the cavity hydrodynamic...

In free-surface turbulent flows, large amount of air may be entrapped and advected in the water current. The resulting air-water flows are frequently observed in natural water systems, where they are also relevant to water quality, ecological sustainability and integrated assessment within such systems. Herein, a review of physical and numerical mo...

Environmental Hydraulics (EH) is the scientific study of environmental water flows and their related transport and transformation processes affecting the environmental quality of natural water systems, such as rivers, lakes, and aquifers, on our planet Earth [...]

When two mega rivers merge the mixing of two flows results in a highly complex three- dimensional flow structure in an area known as the confluence hydrodynamic zone. In the confluence zone, substantial changes occur to the hydrodynamic and morphodynamic features which are of significant interest for researchers. The confluence of the Negro and Soli...

Environmental Hydraulics (EH) is the scientific study of environmental water flows and their related transport and transformation processes in natural water systems. This review provides some remarks about the historical development of EH throughout three different paradigms or ages, namely, the Public Health Age, the Water Quality Age, and finally...

Some basic characteristics of a classic hydraulic jump flow over a pebbled rough bed, as well as on smooth bed as a reference, are presented in this experimental study. For the experiments, inflow Froude number Fr1 from 1.54 to 4.94 and of inflow Reynolds number Re1 from 42,000 to 230,000 were considered. Visual observations and measurements sugges...

Confluences act as critical nodes in a river network as they affect flow, sediment transport, water quality and ecological patterns. A complete knowledge about hydro‐morpho‐sedimentary processes at river confluences is still incompleted and it has been usually accepted that secondary flows are weak because of the significant role of form roughness...

A hydraulic jump is an abrupt transition between subcritical and supercritical flows which is associated with energy dissipation, air entrainment, spray, splashing, and surface waves. Both physical and numerical modeling were largely applied to study hydrodynamics, turbulence and air-entrainment in the hydraulic jump, while the literature about the...

Cage-based aquaculture has been growing rapidly in recent years. In some locations, cage-based aquaculture has resulted in the clustering of large quantities of cages in fish farms located in inland lakes or reservoirs and coastal embayments or fjords, significantly affecting flow and mass transport in the surrounding waters. Existing studies have...

Data of paper “Hydrodynamics, sediment transport and morphological features at the confluence between the Yangtze River and the Poyang Lake” (Water Resources Research)-VMT files for RB

Data of paper"Hydrodynamics, sediment transport and morphological features at the confluence between the Yangtze River and the Poyang Lake" (Water Resources Research)-Survey 2 velocity data-Part 1

Data of paper "Hydrodynamics, sediment transport and morphological features at the confluence between the Yangtze River and the Poyang Lake" (Water Resources Research)-Survey 2 velocity data-Part 2

Data of paper "Hydrodynamics, sediment transport and morphological features at the confluence between the Yangtze River and the Poyang Lake" (Water Resources Research)-Survey 1 velocity data Part 1